This article seeks to describe the NTLM authentication protocol and related security support provider functionality at an intermediate to advanced level of detail, suitable as a reference for implementors. It is hoped that this document will evolve into a comprehensive description of NTLM; at this time there are omissions, both in the author's knowledge and in his documentation, and almost certainly inaccuracies. However, this document should at least be able to provide a solid foundation for further research. The information presented herein was used as the basis for the implementation of NTLM authentication in the open-source jCIFS library, available at http://jcifs.samba.org. This documentation is based on independent research by the author and analysis of functionality implemented in the Samba software suite.
NTLM is a suite of authentication and session security protocols used in various Microsoft network protocol implementations and supported by the NTLM Security Support Provider ("NTLMSSP"). Originally used for authentication and negotiation of secure DCE/RPC, NTLM is also used throughout Microsoft's systems as an integrated single sign-on mechanism. It is probably best recognized as part of the "Integrated Windows Authentication" stack for HTTP authentication; however, it is also used in Microsoft implementations of SMTP, POP3, IMAP (all part of Exchange), CIFS/SMB, Telnet, SIP, and possibly others.
The NTLM Security Support Provider provides authentication, integrity, and confidentiality services within the Window Security Support Provider Interface (SSPI) framework. SSPI specifies a core set of security functionality that is implemented by supporting providers; the NTLMSSP is such a provider. The SSPI specifies, and the NTLMSSP implements, the following core operations:
Authentication -- NTLM provides a challenge-response authentication mechanism, in which clients are able to prove their identities without sending a password to the server.
Signing -- The NTLMSSP provides a means of applying a digital "signature" to a message. This ensures that the signed message has not been modified (either accidentally or intentionally) and that that signing party has knowledge of a shared secret. NTLM implements a symmetric signature scheme (Message Authentication Code, or MAC); that is, a valid signature can only be generated and verified by parties that possess the common shared key.
Sealing -- The NTLMSSP implements a symmetric-key encryption mechanism, which provides message confidentiality. In the case of NTLM, sealing also implies signing (a signed message is not necessarily sealed, but all sealed messages are signed).
NTLM has been largely supplanted by Kerberos as the authentication protocol of choice for domain-based scenarios. However, Kerberos is a trusted-third-party scheme, and cannot be used in situations where no trusted third party exists; for example, member servers (servers that are not part of a domain), local accounts, and authentication to resources in an untrusted domain. In such scenarios, NTLM continues to be the primary authentication mechanism (and likely will be for a long time).
Before we start digging in any further, we will need to define a few terms used in the various protocols.
NTLM authentication is a challenge-response scheme, consisting of three messages, commonly referred to as Type 1 (negotiation), Type 2 (challenge) and Type 3 (authentication). It basically works like this:
The responses in the Type 3 message are the most critical piece, as they prove to the server that the client user has knowledge of the account password.
The process of authentication establishes a shared context between the two involved parties; this includes a shared session key, used for subsequent signing and sealing operations.
In this document, to avoid confusion (as much as possible, anyway) the following convention will be observed:
This should keep things fairly clear, except for the possibly awkward case of "NTLM2 Session Response" authentication (a variant of NTLMv1 authentication that is used in conjunction with NTLM2 session security). Hopefully by the time we get there this will all make much more sense.
For our purposes, a "short" is a little-endian, 16-bit unsigned value. For example, the decimal value "1234" represented as a short would be physically laid out as "0xd204" in hexadecimal.
A "long" is a little-endian, 32-bit unsigned value. The decimal value "1234" represented as a long in hexidecimal would be "0xd2040000".
A Unicode string is a string in which each character is represented as a 16-bit little-endian value (16-bit UCS-2 Transformation Format, little-endian byte order, with no Byte Order Mark and no null-terminator). The string "hello" in Unicode would be represented hexidecimally as "0x680065006c006c006f00".
An OEM string is a string in which each character is represented as an 8-bit value from the local machine's native character set (DOS codepage). There is no null-terminator. In NTLM messages, OEM strings are typically presented in uppercase. The string "HELLO" in OEM would be represented hexidecimally as "0x48454c4c4f".
A "security buffer" is a structure used to point to a buffer of binary data. It consists of:
So the security buffer "0xd204d204e1100000" would be read as:
Length: 0xd204 (1234 bytes)
Allocated Space: 0xd204 (1234 bytes)
Offset: 0xe1100000 (4321 bytes)
If you started at the first byte in the message, and skipped ahead 4321 bytes, you would be at the start of the data buffer. You would read 1234 bytes (which is the length of the buffer). Since the allocated space for the buffer is also 1234 bytes, you would then be at the end of the buffer.
Now we're ready to look at the physical layout of NTLM authentication message headers.
All messages start with the NTLMSSP signature, which is (aptly enough) the null-terminated ASCII string "NTLMSSP" (hexadecimal "0x4e544c4d53535000").
Next is a long containing the message type (1, 2, or 3). A Type 1 message, for example, has type "0x01000000" in hex.
This is followed by message-specific information, typically consisting of security buffers and the message flags.
The message flags are contained in a bitfield within the header. This is a long, in which each bit represents a specific flag. Most of these will make more sense later, but we'll go ahead and present them here to establish a frame of reference for the rest of the discussion. Flags marked as "unidentified" or "unknown" in the table below are outside the realm of the author's knowledge (which is not by any means absolute).
Flag | Name | Description |
---|---|---|
0x00000001 | Negotiate Unicode | Indicates that Unicode strings are supported for use in security buffer data. |
0x00000002 | Negotiate OEM | Indicates that OEM strings are supported for use in security buffer data. |
0x00000004 | Request Target | Requests that the server's authentication realm be included in the Type 2 message. |
0x00000008 | unknown | This flag's usage has not been identified. |
0x00000010 | Negotiate Sign | Specifies that authenticated communication between the client and server should carry a digital signature (message integrity). |
0x00000020 | Negotiate Seal | Specifies that authenticated communication between the client and server should be encrypted (message confidentiality). |
0x00000040 | Negotiate Datagram Style | Indicates that datagram authentication is being used. |
0x00000080 | Negotiate Lan Manager Key | Indicates that the Lan Manager Session Key should be used for signing and sealing authenticated communications. |
0x00000100 | Negotiate Netware | This flag's usage has not been identified. |
0x00000200 | Negotiate NTLM | Indicates that NTLM authentication is being used. |
0x00000400 | unknown | This flag's usage has not been identified. |
0x00000800 | Negotiate Anonymous | Sent by the client in the Type 3 message to indicate that an anonymous context has been established. This also affects the response fields (as detailed in the "Anonymous Response" section). |
0x00001000 | Negotiate Domain Supplied | Sent by the client in the Type 1 message to indicate that the name of the domain in which the client workstation has membership is included in the message. This is used by the server to determine whether the client is eligible for local authentication. |
0x00002000 | Negotiate Workstation Supplied | Sent by the client in the Type 1 message to indicate that the client workstation's name is included in the message. This is used by the server to determine whether the client is eligible for local authentication. |
0x00004000 | Negotiate Local Call | Sent by the server to indicate that the server and client are on the same machine. Implies that the client may use the established local credentials for authentication instead of calculating a response to the challenge. |
0x00008000 | Negotiate Always Sign | Indicates that authenticated communication between the client and server should be signed with a "dummy" signature. |
0x00010000 | Target Type Domain | Sent by the server in the Type 2 message to indicate that the target authentication realm is a domain. |
0x00020000 | Target Type Server | Sent by the server in the Type 2 message to indicate that the target authentication realm is a server. |
0x00040000 | Target Type Share | Sent by the server in the Type 2 message to indicate that the target authentication realm is a share. Presumably, this is for share-level authentication. Usage is unclear. |
0x00080000 | Negotiate NTLM2 Key | Indicates that the NTLM2 signing and sealing scheme should be used for protecting authenticated communications. Note that this refers to a particular session security scheme, and is not related to the use of NTLMv2 authentication. This flag can, however, have an effect on the response calculations (as detailed in the "NTLM2 Session Response" section). |
0x00100000 | Request Init Response | This flag's usage has not been identified. |
0x00200000 | Request Accept Response | This flag's usage has not been identified. |
0x00400000 | Request Non-NT Session Key | This flag's usage has not been identified. |
0x00800000 | Negotiate Target Info | Sent by the server in the Type 2 message to indicate that it is including a Target Information block in the message. The Target Information block is used in the calculation of the NTLMv2 response. |
0x01000000 | unknown | This flag's usage has not been identified. |
0x02000000 | unknown | This flag's usage has not been identified. |
0x04000000 | unknown | This flag's usage has not been identified. |
0x08000000 | unknown | This flag's usage has not been identified. |
0x10000000 | unknown | This flag's usage has not been identified. |
0x20000000 | Negotiate 128 | Indicates that 128-bit encryption is supported. |
0x40000000 | Negotiate Key Exchange | Indicates that the client will provide an encrypted master key in the "Session Key" field of the Type 3 message. |
0x80000000 | Negotiate 56 | Indicates that 56-bit encryption is supported. |
As an example, consider a message specifying:
Negotiate Unicode (0x00000001)
Request Target (0x00000004)
Negotiate NTLM (0x00000200)
Negotiate Always Sign (0x00008000)
Combining the above gives "0x00008205". This would be physically laid out as "0x05820000" (since it is represented in little-endian byte order).
Let's jump in and take a look at the Type 1 message:
Description | Content | |
---|---|---|
0 | NTLMSSP Signature | Null-terminated ASCII "NTLMSSP" (0x4e544c4d53535000) |
8 | NTLM Message Type | long (0x01000000) |
12 | Flags | long |
(16) | Supplied Domain (Optional) | security buffer |
(24) | Supplied Workstation (Optional) | security buffer |
(32) | OS Version Structure (Optional) | 8 bytes |
(32) (40) | start of data block (if required) |
The Type 1 message is sent from the client to the server to initiate NTLM authentication. Its primary purpose is to establish the "ground rules" for authentication by indicating supported options via the flags. Optionally, it can also provide the server with the client's workstation name and the domain in which the client workstation has membership; this information is used by the server to determine whether the client is eligible for local authentication.
Typically, the Type 1 message contains flags from the following set:
Negotiate Unicode (0x00000001) | The client sets this flag to indicate that it supports Unicode strings. |
Negotiate OEM (0x00000002) | This is set to indicate that the client supports OEM strings. |
Request Target (0x00000004) | This requests that the server send the authentication target with the Type 2 reply. |
Negotiate NTLM (0x00000200) | Indicates that NTLM authentication is supported. |
Negotiate Domain Supplied (0x00001000) | When set, the client will send with the message the name of the domain in which the workstation has membership. |
Negotiate Workstation Supplied (0x00002000) | Indicates that the client is sending its workstation name with the message. |
Negotiate Always Sign (0x00008000) | Indicates that communication between the client and server after authentication should carry a "dummy" signature. |
Negotiate NTLM2 Key (0x00080000) | Indicates that this client supports the NTLM2 signing and sealing scheme; if negotiated, this can also affect the response calculations. |
Negotiate 128 (0x20000000) | Indicates that this client supports strong (128-bit) encryption. |
Negotiate 56 (0x80000000) | Indicates that this client supports medium (56-bit) encryption. |
The supplied domain is a security buffer containing the domain in which the client workstation has membership. This is always in OEM format, even if Unicode is supported by the client.
The supplied workstation is a security buffer containing the client workstation's name. This, too, is in OEM rather than Unicode.
The OS Version structure was introduced in recent Windows updates; it identifies the host's operating system build level, and is formatted as follows:
Description | Content | |
---|---|---|
0 | Major Version Number | 1 byte |
1 | Minor Version Number | 1 byte |
2 | Build Number | short |
4 | Unknown | 0x0000000f |
The operating system build can be found by running "winver.exe"; it should give a string similar to:
Version 5.1 (Build 2600.xpsp_sp2_gdr.050301-1519 : Service Pack 2)
This yields an OS Version structure of "0x0501280a0000000f":
0x05 | (major version 5) |
0x01 | (minor version 1; Windows XP) |
0x280a | (build number 2600 in hexadecimal little-endian) |
0x0000000f | (unknown/reserved) |
Note that the OS Version structure and the supplied domain/workstation are optional fields. There are three versions of the Type 1 message that have been observed in the wild:
Version 1 -- The Supplied Domain and Workstation security buffers and OS Version structure are omitted completely. In this case the message ends after the flags field, and is a fixed-length 16-byte structure. This form is typically seen in older Win9x-based systems, and is roughly documented in the Open Group's ActiveX reference documentation (Section 11.2.2).
Version 2 -- The Supplied Domain and Workstation buffers are present, but the OS Version structure is not. The data block begins immediately after the security buffer headers, at offset 32. This form is seen in most out-of-box shipping versions of Windows.
Version 3 -- Both the Supplied Domain/Workstation buffers are present, as well as the OS Version structure. The data block begins after the OS Version structure, at offset 40. This form was introduced in a relatively recent Service Pack, and is seen on currently-patched versions of Windows 2000, Windows XP, and Windows 2003.
The "most-minimal" well-formed Type 1 message, therefore, would be:
4e544c4d535350000100000002020000
This is a "Version 1" Type 1 message containing only the NTLMSSP signature, the NTLM message type, and the minimal set of flags (Negotiate NTLM and Negotiate OEM).
Consider the following hexadecimal Type 1 Message:
4e544c4d53535000010000000732000006000600330000000b000b0028000000 050093080000000f574f524b53544154494f4e444f4d41494e
We break this up as follows:
0 | 0x4e544c4d53535000 | NTLMSSP Signature |
8 | 0x01000000 | Type 1 Indicator |
12 | 0x07320000 |
Flags:
Negotiate Unicode (0x00000001)
|
16 | 0x0600060033000000 |
Supplied Domain Security Buffer:
Length: 6 bytes (0x0600)
|
24 | 0x0b000b0028000000 |
Supplied Workstation Security Buffer:
Length: 11 bytes (0x0b00)
|
32 | 0x050093080000000f |
OS Version Structure:
Major Version: 5 (0x05)
|
40 | 0x574f524b53544154494f4e | Supplied Workstation Data ("WORKSTATION") |
51 | 0x444f4d41494e | Supplied Domain Data ("DOMAIN") |
Analyzing this information, we can see:
Note that the supplied workstation and domain are in OEM format. Additionally, the order in which the security buffer data blocks are laid out is unimportant; in the example, the workstation data is placed before the domain data.
After creating the Type 1 message, the client sends it to the server. The server analyzes the message, much as we have just done, and creates a reply. This brings us to our next topic, the Type 2 message.
Description | Content | |
---|---|---|
0 | NTLMSSP Signature | Null-terminated ASCII "NTLMSSP" (0x4e544c4d53535000) |
8 | NTLM Message Type | long (0x02000000) |
12 | Target Name | security buffer |
20 | Flags | long |
24 | Challenge | 8 bytes |
(32) | Context (optional) | 8 bytes (two consecutive longs) |
(40) | Target Information (optional) | security buffer |
(48) | OS Version Structure (Optional) | 8 bytes |
32 (48) (56) | start of data block |
The Type 2 message is sent by the server to the client in response to the client's Type 1 message. It serves to complete the negotiation of options with the client, and also provides a challenge to the client. It may optionally contain information about the authentication target.
Typical Type 2 message flags include:
Negotiate Unicode (0x00000001) | The server sets this flag to indicate that it will be using Unicode strings. This should only be set if the client indicates (in the Type 1 message) that it supports Unicode. Either this flag or Negotiate OEM should be set, but not both. |
Negotiate OEM (0x00000002) | This flag is set to indicate that the server will be using OEM strings. This should only be set if the client indicates (in the Type 1 message) that it will support OEM strings. Either this flag or Negotiate Unicode should be set, but not both. |
Request Target (0x00000004) | This flag is often set in the Type 2 message; while it has a well-defined meaning within the Type 1 message, its semantics here are unclear. |
Negotiate NTLM (0x00000200) | Indicates that NTLM authentication is supported. |
Negotiate Local Call (0x00004000) | The server sets this flag to inform the client that the server and client are on the same machine. The server provides a local security context handle with the message. |
Negotiate Always Sign (0x00008000) | Indicates that communication between the client and server after authentication should carry a "dummy" signature. |
Target Type Domain (0x00010000) | The server sets this flag to indicate that the authentication target is being sent with the message and represents a domain. |
Target Type Server (0x00020000) | The server sets this flag to indicate that the authentication target is being sent with the message and represents a server. |
Target Type Share (0x00040000) | The server apparently sets this flag to indicate that the authentication target is being sent with the message and represents a network share. This has not been confirmed. |
Negotiate NTLM2 Key (0x00080000) | Indicates that this server supports the NTLM2 signing and sealing scheme; if negotiated, this can also affect the client's response calculations. |
Negotiate Target Info (0x00800000) | The server sets this flag to indicate that a Target Information block is being sent with the message. |
Negotiate 128 (0x20000000) | Indicates that this server supports strong (128-bit) encryption. |
Negotiate 56 (0x80000000) | Indicates that this server supports medium (56-bit) encryption. |
The target name is a security buffer containing the name of the authentication target. This is typically sent in response to a client requesting the target (via the Request Target flag in the Type 1 message). This can contain a domain, server, or (apparently) a network share. The target type is indicated via the Target Type Domain, Target Type Server, and Target Type Share flags. The target name can be either Unicode or OEM, as indicated by the presence of the appropriate flag in the Type 2 message.
The challenge is an 8-byte block of random data. The client will use this to formulate a response.
The context field is typically populated when Negotiate Local Call is set. It contains an SSPI context handle, which allows the client to "short-circuit" authentication and effectively circumvent responding to the challenge. Physically, the context is two long values. This is covered in greater detail later, in the "Local Authentication" section.
The target information is a security buffer containing a Target Information block, which is used in calculating the NTLMv2 response (discussed later). This is composed of a sequence of subblocks, each consisting of:
Field | Content | Description | ||||||||
---|---|---|---|---|---|---|---|---|---|---|
Type | short |
Indicates the type of data in this subblock:
|
||||||||
Length | short | Length in bytes of this subblock's content field | ||||||||
Content | Unicode string | Content as indicated by the type field. Always sent in Unicode, even when OEM is indicated by the message flags. |
The sequence is terminated by a terminator subblock; this is a subblock of type "0", of zero length. Subblocks of type "5" have also been encountered, apparently containing the "parent" DNS domain for servers in subdomains; it may be that there are other as-yet-unidentified subblock types as well.
The OS Version structure was described previously.
As with the Type 1 message, there are a few versions of the Type 2 that have been observed:
Version 1 -- The Context, Target Information, and OS Version structure are all omitted. The data block (containing only the contents of the Target Name security buffer) begins at offset 32. This form is seen in older Win9x-based systems, and is roughly documented in the Open Group's ActiveX reference documentation (Section 11.2.3).
Version 2 -- The Context and Target Information fields are present, but the OS Version structure is not. The data block begins after the Target Information header, at offset 48. This form is seen in most out-of-box shipping versions of Windows.
Version 3 -- The Context, Target Information, and OS Version structure are all present. The data block begins after the OS Version structure, at offset 56. Again, the buffers may be empty (yielding a zero-length data block). This form was introduced in a relatively recent Service Pack, and is seen on currently-patched versions of Windows 2000, Windows XP, and Windows 2003.
A minimal Type 2 message would look something like this:
4e544c4d53535000020000000000000000000000020200000123456789abcdef
This message contains the NTLMSSP signature, the NTLM message type, an empty target name, minimal flags (Negotiate NTLM and Negotiate OEM), and the challenge.
Let's look at the following hexadecimal Type 2 Message:
4e544c4d53535000020000000c000c003000000001028100 0123456789abcdef0000000000000000620062003c000000 44004f004d00410049004e0002000c0044004f004d004100 49004e0001000c0053004500520056004500520004001400 64006f006d00610069006e002e0063006f006d0003002200 7300650072007600650072002e0064006f006d0061006900 6e002e0063006f006d0000000000
Breaking this into its constituent fields gives:
0 | 0x4e544c4d53535000 | NTLMSSP Signature | ||||||||||
8 | 0x02000000 | Type 2 Indicator | ||||||||||
12 | 0x0c000c0030000000 |
Target Name Security Buffer:
Length: 12 bytes (0x0c00)
|
||||||||||
20 | 0x01028100 |
Flags:
Negotiate Unicode (0x00000001)
|
||||||||||
24 | 0x0123456789abcdef | Challenge | ||||||||||
32 | 0x0000000000000000 | Context | ||||||||||
40 | 0x620062003c000000 |
Target Information Security Buffer:
Length: 98 bytes (0x6200)
|
||||||||||
48 |
0x44004f004d004100 49004e00 |
Target Name Data ("DOMAIN") | ||||||||||
60 |
0x02000c0044004f00 4d00410049004e00 01000c0053004500 5200560045005200 0400140064006f00 6d00610069006e00 2e0063006f006d00 0300220073006500 7200760065007200 2e0064006f006d00 610069006e002e00 63006f006d000000 0000 |
Target Information Data:
|
An analysis of this message shows:
Note that the target name is in Unicode format (as specified by the Negotiate Unicode flag).
After the server creates the Type 2 message, it is sent to the client. The response to the server's challenge is provided in the client's Type 3 message.
Description | Content | |
---|---|---|
0 | NTLMSSP Signature | Null-terminated ASCII "NTLMSSP" (0x4e544c4d53535000) |
8 | NTLM Message Type | long (0x03000000) |
12 | LM/LMv2 Response | security buffer |
20 | NTLM/NTLMv2 Response | security buffer |
28 | Target Name | security buffer |
36 | User Name | security buffer |
44 | Workstation Name | security buffer |
(52) | Session Key (optional) | security buffer |
(60) | Flags (optional) | long |
(64) | OS Version Structure (Optional) | 8 bytes |
52 (64) (72) | start of data block |
The Type 3 message is the final step in authentication. This message contains the client's responses to the Type 2 challenge, which demonstrate that the client has knowledge of the account password without sending the password directly. The Type 3 message also indicates the authentication target (domain or server name) and username of the authenticating account, as well as the client workstation name.
Note that the flags in the Type 3 message are optional; older clients include neither the session key nor the flags in the message. It has been determined experimentally that the Type 3 flags (when included) do not carry any additional semantics in connection-oriented authentication; they do not appear to have any discernable effect on either authentication or the establishment of session security. Clients sending flags typically mirror the established Type 2 settings fairly closely. It is possible that the flags are sent as a "reminder" of established options, to allow the server to avoid caching the negotiated settings. The Type 3 flags are relevant during datagram-style authentication, however.
The LM/LMv2 and NTLM/NTLMv2 responses are security buffers containing replies created from the user's password in response to the Type 2 challenge; the process for generating these responses is outlined in the next section.
The target name is a security buffer containing the authentication realm in which the authenticating account has membership (a domain name for domain accounts, or server name for local machine accounts). This is either Unicode or OEM, depending on the negotiated encoding.
The user name is a security buffer containing the authenticating account name. This is either Unicode or OEM, depending on the negotiated encoding.
The workstation name is a security buffer containing the client workstation's name. This is either Unicode or OEM, depending on the negotiated encoding.
The session key value is used by the session security mechanism during key exchange; this is discussed in more detail in the Session Security section.
When "Negotiate Local Call" has been established in the Type 2 message, the security buffers in the Type 3 message are typically all empty (zero length). The client "adopts" the SSPI context sent in the Type 2 message, effectively circumventing the need to calculate an appropriate response.
The OS Version structure is the same format described previously.
Again, there are a few variations of the Type 3 message:
Version 1 -- The Session Key, flags, and OS Version structure are omitted. The data block in this case starts after the Workstation Name security buffer header, at offset 52. This form is seen in older Win9x-based systems.
Version 2 -- The Session Key and flags are included, but the OS Version structure is not. In this case, the data block begins after the flags field, at offset 64. This form is seen in most out-of-box shipping versions of Windows, and is roughly documented in the Open Group's ActiveX reference documentation (Section 11.2.4).
Version 3 -- The Session Key, flags, and OS Version structure are all present. The data block begins after the OS Version structure, at offset 72. This form was introduced in a relatively recent Service Pack, and is seen on currently-patched versions of Windows 2000, Windows XP, and Windows 2003.
Format | Type 3 Field Content | Notes |
---|---|---|
DOMAIN\user |
User Name = "user" Target Name = "DOMAIN" |
This is the "normal" format; the User Name field contains the Windows user name, and the Target Name contains the NT-style NetBIOS domain or server name. |
domain.com\user |
User Name = "user" Target Name = "domain.com" |
Here, the Target Name field in the Type 3 message is populated with the DNS domain/realm name (or fully-qualified DNS host name in the case of local machine accounts). |
user@DOMAIN |
User Name = "user@DOMAIN" Target Name is empty |
In this case, the Target Name field is empty (zero-length), and the User Name field uses the Kerberos-style "user@realm" format; however, the NetBIOS domain name is used instead of the DNS domain. It has been observed that this format is not supported for local machine accounts; additionally, this form does not appear to be supported under NTLMv2/LMv2 authentication. |
user@domain.com |
User Name = "user@domain.com" Target Name is empty |
Here, the Target Name field in the Type 3 message is empty; the User Name field contains the Kerberos-style "user@realm" format, with the DNS domain. This form does not appear to be supported for local machine accounts. |
The client creates one or more responses to the Type 2 challenge, and sends these to the server in the Type 3 message. There are six types of responses:
The responses serve as an indirect proof of knowledge of the password. The password is used by the client to derive the LM and/or NTLM hash (discussed in the next section); these values are in turn used to calculate an appropriate response to the challenge. The domain controller (or server for local machine accounts) stores the LM and NTLM hashes for the password; when the response is received from the client, these stored values are used to calculate the appropriate response values which are compared to those sent by the client. A match yields a successful authentication of the user.
Note that unlike Unix password hashes, the LM and NTLM hash are password-equivalents in the context of the response calculations; they must be protected, as they can be used to authenticate users across the network even without knowledge of the actual password itself.
The LM response is sent by most clients. This scheme is older than the NTLM response, and less secure. While newer clients support the NTLM response, they typically send both responses for compatibility with legacy servers; hence, the security flaws present in the LM response are still exhibited in many clients supporting the NTLM response.
The LM response is calculated as follows (see Appendix D for a sample implementation in Java):
In the event that the user's password is longer than 15 characters, the host or domain controller will not store the LM hash for the user; the LM response cannot be used to authenticate the user in this case. A response is still generated and placed in the LM Response field, using a 16-byte null value (0x00000000000000000000000000000000) as the LM hash in the calculation. This value is ignored by the target.
The response calculation process is best illustrated with a detailed example. Consider a user with the password "SecREt01", responding to the Type 2 challenge "0x0123456789abcdef".
01010011 01000101 01000011 01010010 01000101 01010100 00110000
A non-parity-adjusted DES key for this value would be:
01010010 10100010 01010000 01101010 00100100 00101010 01010000 01100000
(the parity bits are shown in red above). This is "0x52a2506a242a5060" in hexadecimal. Applying odd-parity to ensure that the total number of set bits in each octet is odd gives:
01010010 10100010 01010001 01101011 00100101 00101010 01010001 01100001
This is the first DES key ("0x52a2516b252a5161" in hex). We then apply the same process to our second 7-byte value, "0x31000000000000", represented in binary as:
00110001 00000000 00000000 00000000 00000000 00000000 00000000
Creating a non-parity-adjusted DES key gives:
00110000 10000000 00000000 00000000 00000000 00000000 00000000 00000000
("0x3080000000000000" in hexadecimal). Adjusting the parity bits gives:
00110001 10000000 00000001 00000001 00000001 00000001 00000001 00000001
This is our second DES key, "0x3180010101010101" in hexadecimal. Note that if our particular DES implementation does not enforce parity (many do not), the parity-adjustment steps can be skipped; the non-parity-adjusted values would then be used as the DES keys. In any case, the parity bits will not affect the encryption process.
11111111 00110111 01010000 10111100 11000010 10110010 00100100
Gives us the parity-adjusted DES key:
11111110 10011011 11010101 00010110 11001101 00010101 11001000 01001001
("0xfe9bd516cd15c849" in hexadecimal). The second value:
00010010 11000010 00100110 01011011 00100011 01110011 01001110
Results in the key:
00010011 01100001 10001001 11001011 10110011 00011010 11001101 10011101
("0x136189cbb31acd9d"). Finally, the third value:
00001101 10101100 00000000 00000000 00000000 00000000 00000000
Gives us:
00001101 11010110 00000001 00000001 00000001 00000001 00000001 00000001
This is the third DES key ("0x0dd6010101010101").
0xc337cd5cbd44fc9782a667af6d427c6de67c20c2d3e77c56
There are several weaknesses in this algorithm which make it susceptible to attack. While these are covered in detail in the Hertel text, the most prominent problems are:
The NTLM response is sent by newer clients. This scheme addresses some of the flaws in the LM response; however, it is still considered fairly weak. Additionally, the NTLM response is nearly always sent in conjunction with the LM response. The weaknesses in that algorithm can be exploited to obtain the case-insensitive password, and trial-and-error used to find the case-sensitive password employed by the NTLM response.
The NTLM response is calculated as follows (see Appendix D for a sample Java implementation):
Note that only the calculation of the hash value differs from the LM scheme; the response calculation is the same. To illustrate this process, we will apply it to our previous example (a user with the password "SecREt01", responding to the Type 2 challenge "0x0123456789abcdef").
11001101 00000110 11001010 01111100 01111110 00010000 11001001
Results in the parity-adjusted key:
11001101 10000011 10110011 01001111 11000111 11110001 01000011 10010010
("0xcd83b34fc7f14392" in hexadecimal). The second value:
10011011 00011101 00110011 10110111 01001000 01011010 00101110
Gives the key:
10011011 10001111 01001100 01110110 01110101 01000011 01101000 01011101
("0x9b8f4c767543685d"). Our third value:
11011000 00001000 00000000 00000000 00000000 00000000 00000000
Yields our third key:
11011001 00000100 00000001 00000001 00000001 00000001 00000001 00000001
("0xd904010101010101" in hexadecimal).
0x25a98c1c31e81847466b29b2df4680f39958fb8c213a9cc6
NTLM version 2 ("NTLMv2") was concocted to address the security issues present in NTLM. When NTLMv2 is enabled, the NTLM response is replaced with the NTLMv2 response, and the LM response is replaced with the LMv2 response (which we will discuss next).
The NTLMv2 response is calculated as follows (see Appendix D for a sample implementation in Java):
Description | Content | |
---|---|---|
0 | Blob Signature | 0x01010000 |
4 | Reserved | long (0x00000000) |
8 | Timestamp | Little-endian, 64-bit signed value representing the number of tenths of a microsecond since January 1, 1601. |
16 | Client Nonce | 8 bytes |
24 | Unknown | 4 bytes |
28 | Target Information | Target Information block (from the Type 2 message). |
(variable) | Unknown | 4 bytes |
Let's look at an example. Since we need a bit more information to calculate the NTLMv2 response, we will use the following values from the examples presented previously:
Target: | DOMAIN |
Username: | user |
Password: | SecREt01 |
Challenge: | 0x0123456789abcdef |
Target Information: |
0x02000c0044004f00 4d00410049004e00 01000c0053004500 5200560045005200 0400140064006f00 6d00610069006e00 2e0063006f006d00 0300220073006500 7200760065007200 2e0064006f006d00 610069006e002e00 63006f006d000000 0000 |
We also need to generate an 8-byte random "client nonce"; we will use the not-so-random "0xffffff0011223344". Constructing the rest of the blob is easy; we just concatenate:
0x01010000 | (the blob signature) |
0x00000000 | (reserved value) |
0x0090d336b734c301 | (our timestamp) |
0xffffff0011223344 | (a random client nonce) |
0x00000000 | (unknown, but zero will work) |
0x02000c0044004f00 4d00410049004e00 01000c0053004500 5200560045005200 0400140064006f00 6d00610069006e00 2e0063006f006d00 0300220073006500 7200760065007200 2e0064006f006d00 610069006e002e00 63006f006d000000 0000 |
(our target information block) |
0x00000000 | (unknown, but zero will work) |
0x0123456789abcdef0101000000000000 0090d336b734c301ffffff0011223344 0000000002000c0044004f004d004100 49004e0001000c005300450052005600 450052000400140064006f006d006100 69006e002e0063006f006d0003002200 7300650072007600650072002e006400 6f006d00610069006e002e0063006f00 6d000000000000000000
Applying HMAC-MD5 to this value using the NTLMv2 hash from step 2 as the key gives us the 16-byte value "0xcbabbca713eb795d04c97abc01ee4983".
0xcbabbca713eb795d04c97abc01ee4983 01010000000000000090d336b734c301 ffffff00112233440000000002000c00 44004f004d00410049004e0001000c00 53004500520056004500520004001400 64006f006d00610069006e002e006300 6f006d00030022007300650072007600 650072002e0064006f006d0061006900 6e002e0063006f006d00000000000000 0000
The LMv2 response is used to provide pass-through authentication compatibility with older servers. It is quite possible that the server with which the client is communicating will not actually perform the authentication; rather, it will pass the responses through to a domain controller for verification. Older servers pass only the LM response, and expect it to be exactly 24 bytes. The LMv2 response was designed to allow such servers to operate properly; it is effectively a "miniature" NTLMv2 response, obtained as follows (see Appendix D for a sample Java implementation):
We will illustrate this process with a brief example using our tried-and-true sample values:
Target: | DOMAIN |
Username: | user |
Password: | SecREt01 |
Challenge: | 0x0123456789abcdef |
0x0123456789abcdefffffff0011223344
Applying HMAC-MD5 to this value using the NTLMv2 hash from step 2 as the key gives us the 16-byte value "0xd6e6152ea25d03b7c6ba6629c2d6aaf0".
0xd6e6152ea25d03b7c6ba6629c2d6aaf0ffffff0011223344
The NTLM2 session response can be employed in conjunction with NTLM2 session security (it is made available with the "Negotiate NTLM2 Key" flag). This is used to provide enhanced protection against precomputed dictionary attacks (particularly Rainbow Table-based attacks) in environments which do not support full NTLMv2 authentication.
The NTLM2 session response replaces both the LM and NTLM response fields as follows (see Appendix D for a sample implementation in Java):
To demonstrate this with our previous example values (a user with the password "SecREt01", responding to the Type 2 challenge "0x0123456789abcdef"):
0xffffff001122334400000000000000000000000000000000
This value is placed in the LM response field of the Type 3 message.
0x10d550832d12b2ccb79d5ad1f4eed3df82aca4c3681dd455
which is placed in the NTLM response field of the Type 3 message.
The Anonymous Response is seen when the client is establishing an anonymous context, rather than a true user-based context. This is typically seen when a "placeholder" is needed for operations that do not require an authenticated user. Anonymous connections are not the same as the Windows "Guest" user (the latter is an actual user account, while anonymous connections are associated with no account at all).
In an anonymous Type 3 message, the client indicates the "Negotiate Anonymous" flag; the NTLM response field is empty (zero-length); and the LM response field contains a single null byte ("0x00").
Now that we're familiar with the Type 3 responses, we are ready to examine a Type 3 Message:
4e544c4d5353500003000000180018006a00000018001800 820000000c000c0040000000080008004c00000016001600 54000000000000009a0000000102000044004f004d004100 49004e00750073006500720057004f0052004b0053005400 4100540049004f004e00c337cd5cbd44fc9782a667af6d42 7c6de67c20c2d3e77c5625a98c1c31e81847466b29b2df46 80f39958fb8c213a9cc6
This message is decomposed as:
0 | 0x4e544c4d53535000 | NTLMSSP Signature |
8 | 0x03000000 | Type 3 Indicator |
12 | 0x180018006a000000 |
LM Response Security Buffer:
Length: 24 bytes (0x1800)
|
20 | 0x1800180082000000 |
NTLM Response Security Buffer:
Length: 24 bytes (0x1800)
|
28 | 0x0c000c0040000000 |
Target Name Security Buffer:
Length: 12 bytes (0x0c00)
|
36 | 0x080008004c000000 |
User Name Security Buffer:
Length: 8 bytes (0x0800)
|
44 | 0x1600160054000000 |
Workstation Name Security Buffer:
Length: 22 bytes (0x1600)
|
52 | 0x000000009a000000 |
Session Key Security Buffer:
Length: 0 bytes (0x0000)
|
60 | 0x01020000 |
Flags:
Negotiate Unicode (0x00000001)
|
64 |
0x44004f004d004100 49004e00 |
Target Name Data ("DOMAIN") |
76 | 0x7500730065007200 | User Name Data ("user") |
84 |
0x57004f0052004b00 5300540041005400 49004f004e00 |
Workstation Name Data ("WORKSTATION") |
106 |
0xc337cd5cbd44fc97 82a667af6d427c6d e67c20c2d3e77c56 |
LM Response Data |
130 |
0x25a98c1c31e81847 466b29b2df4680f3 9958fb8c213a9cc6 |
NTLM Response Data |
Analysis of this reveals:
Upon receipt of the Type 3 message, the server calculates the LM and NTLM responses and compares them to the values provided by the client; if they match, the user is successfully authenticated.
NTLM version 2 consists of three new response algorithms (NTLMv2, LMv2, and the NTLM2 session response, discussed previously) and a new signing and sealing scheme (NTLM2 session security). NTLM2 session security is negotiated via the "Negotiate NTLM2 Key" flag; NTLMv2 authentication, however, is enabled through a modification to the registry. Further, the registry setting on the client and domain controller must be compatible in order for authentication to be successful (although it is possible for NTLMv2 authentication to pass through an older server to an NTLMv2 domain controller). The result of the configuration and planning required to deploy NTLMv2 is that many hosts just use the default setting (NTLMv1), and NTLMv2 authentication is underutilized.
Instructions for enabling NTLM version 2 are detailed in Microsoft Knowledge Base Article 239869; briefly, a modification is made to the registry value:
HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\LSA\LMCompatibilityLevel
(LMCompatibility on Win9x-based systems). This is a REG_DWORD entry, and can be set to one of the following values:
Level | Sent by Client | Accepted by Server |
---|---|---|
0 |
LM
NTLM |
LM
NTLM LMv2 NTLMv2 |
1 |
LM
NTLM |
LM
NTLM LMv2 NTLMv2 |
2 | NTLM |
LM
NTLM LMv2 NTLMv2 |
3 |
LMv2
NTLMv2 |
LM
NTLM LMv2 NTLMv2 |
4 |
LMv2
NTLMv2 |
NTLM
LMv2 NTLMv2 |
5 |
LMv2
NTLMv2 |
LMv2
NTLMv2 |
In all levels, NTLM2 session security is supported and negotiated when available (most available documentation indicates that NTLM2 session security is only enabled on levels 1 and above, but it is seen in practice with Level 0 as well). By default, only the LM response is supported on Windows 95 and Windows 98 platforms; installing the Directory Services client makes NTLMv2 available on these hosts as well (and enables the LMCompatibility setting, although only levels 0 and 3 are available).
In Level 2, clients send the NTLM response twice (in both the LM and NTLM response fields). At Level 3 and higher, the LMv2 and NTLMv2 responses replace the LM and NTLM responses, respectively.
When NTLM2 session security has been negotiated (indicated by the "Negotiate NTLM2 Key" flag), the NTLM2 session response can be used in Levels 0, 1, and 2 as a replacement for the weaker LM and NTLM responses. This offers heightened protection over NTLMv1 against server-based precomputed dictionary attacks; the client's response to a given challenge is made variable by adding a random client nonce to the calculation.
The NTLM2 session response is interesting in that it can be negotiated between a client and server that support the newer schemes, even in the presence of an older domain controller that does not. In a typical scenario, the server in an authentication transaction does not actually possess the user's password hash; that is instead held at the domain controller. When a machine is joined to an NT-style domain, it establishes an encrypted, mutually-authenticated channel to the domain controller (colloquially deemed the "NetLogon pipe"). When a client authenticates to the server using the "vanilla" NTLMv1 handshake, the following transactions occur in the background:
In the case of the NTLM2 Session Response, it is possible that a client and server have been upgraded to allow the newer protocol, but the domain controller has not. To allow for this contingency, the handshake described above is modified slightly as follows:
Essentially, this allows upgraded clients and servers to use the NTLM2 Session Response in networks where the domain controller has not yet been upgraded to NTLMv2 (or where the network administrator has not yet configured the LMCompatibilityLevel registry setting to use NTLMv2).
Related to the LMCompatibilityLevel setting are the NtlmMinClientSec and NtlmMinServerSec settings; these specify minimum requirements for NTLM contexts established by the NTLMSSP. Both are REG_WORD entries, and are bitfields specifying a combination of the following NTLM flags:
At this point, we will start to look at how NTLM fits into the "big picture".
Windows provides a security framework known as SSPI - the Security Support Provider interface. This is the Microsoft equivalent of the GSS-API (Generic Security Service Application Program Interface, RFC 2743), and allows for a very high-level, mechanism-independent means of applying authentication, integrity, and confidentiality primitives. SSPI supports several underlying providers; one of these is the NTLMSSP (NTLM Security Support Provider), which provides the NTLM authentication mechanism we have been discussing thus far. SSPI supplies a flexible API for handling opaque, provider-specific authentication tokens; the NTLM Type 1, Type 2, and Type 3 messages are such tokens, specific to and processed by the NTLMSSP. The API provided by SSPI abstracts away almost all the details of NTLM. The application developer doesn't even have to be aware that NTLM is being used, and another authentication mechanism (such as Kerberos) can be swapped in with little or no changes at the application level.
We aren't going to delve too deeply into the SSPI framework, but this is a good point to look at the SSPI authentication handshake as applied to NTLM:
We have alluded to the local authentication sequence at various points in our discussion; having a basic understanding of SSPI, we can look at this scenario in more detail.
Local authentication is negotiated through a series of decisions made by the client and server, based on the information in the NTLM messages. It works as follows:
Datagram-style authentication is used to negotiate NTLM over a connectionless transport. While much of the semantics around the messages remain unchanged, there are a few significant differences:
During "normal" (connection-oriented) authentication, all options are negotiated in the first transaction between the client and the server, during the exchange of the Type 1 and Type 2 messages. The negotiated settings are "remembered" by the server and applied to the client's Type 3 message. Although most clients send the agreed-upon flags with the Type 3 message, they are not used in connection authentication.
In datagram authentication, however, the game changes a bit; to alleviate the server's need to track the negotiated options (which becomes more difficult without a persistent connection), the Type 1 message is removed completely. The server generates a Type 2 message containing all supported flags (as well as the challenge, of course). The client then decides which options it will support, and replies with a Type 3 message containing the responses to the challenge and the set of selected flags. The SSPI handshake sequence for datagram authentication is as follows:
When used with SSPI, there is apparently no means of producing a datagram-style Type 1 message. It is interesting to note, however, that we can "induce" datagram semantics at a lower level by subtly manipulating the NTLMSSP tokens to produce our own datagram Type 1 token.
This can be achieved by setting the "Negotiate Datagram Style" flag on the Type 1 message produced by the first InitializeSecurityContext call in a connection-oriented SSPI handshake before passing the token to the server. When the modified Type 1 message is passed into the AcceptSecurityContext function, the server will adopt datagram semantics (even though ASC_REQ_DATAGRAM was not specified). This will produce a Type 2 message with the "Negotiate Datagram Style" flag set, but otherwise identical to the connection-oriented message that would normally have been generated; that is, the Type 1 flags sent by the client are considered during the construction of the Type 2 message, rather than simply offering all supported options.
The client can then call InitializeSecurityContext with this Type 2 token. Note that the client is still in connection-oriented mode; the Type 3 message produced will ignore the "Negotiate Datagram Style" flag applied to the Type 2 message. The server, however, is enforcing datagram semantics, and will now require the Type 3 flags to be set appropriately. Adding the "Negotiate Datagram Style" flag to the Type 3 message manually before sending it to the server allows the server to successfully call AcceptSecurityContext with the modified token.
This results in successful authentication; the "doctored" Type 1 message effectively switches the server into datagram-style authentication, in which the Type 3 flags are observed and enforced. There is no known practical use for this, but it does demonstrate some of the interesting and unexpected behavior that can be observed by strategically manipulating the NTLM messages.
In addition to the SSPI authentication services, message integrity and confidentiality functionality is provided. This is also implemented by the NTLM Security Support Provider. "Signing" is performed by the SSPI MakeSignature function, which applies a Message Authentication Code (MAC) to a message. This can be verified by the recipient, and provides a strong assurance that the message was not modified in transit. The signature is generated using a secret key, known to the sender and receiver; the MAC can only be verified by a party possessing the key (which in turn provides assurance that the signature was created by the sender). "Sealing" is performed by the SSPI EncryptMessage function. This applies encryption to a message to prevent it from being viewed by a third party in transit; the NTLMSSP uses a variety of symmetric encryption mechanisms (the same key is used to decrypt as to encrypt).
The keys used in signing and sealing are established as a by-product of the NTLM authentication process; in addition to verifying a client's identity, the authentication handshake establishes a context between the client and server which includes the key(s) needed to sign and seal messages between the parties. We will discuss the derivation of these keys, and the mechanisms used for signing and sealing by the NTLMSSP.
There are numerous key schemes employed during signing and sealing; we will start with an overview of the different types of keys and core session security concepts.
This is the basic key type employed in session security. There are many variants:
Used when only the LM response is provided (i.e., with Win9x clients). The LM User Session Key is derived as follows:
As with the LM hash itself, this key only changes in response to a change of password by the user. Note also that only the first 7 password characters have input to the key (see the process for computing the LM Response; the LM User Session Key is the first half of the LM hash). Additionally, the keyspace is actually much smaller, as the LM hash itself is based on the uppercase password. All of these factors combined render the LM User Session Key very weak against attack.
This variant is used when the client sends the NTLM response. The calculation of the key is fairly straightforward:
The NTLM User Session Key is much improved over the LM User Session Key. The password space is larger (it is case-sensitive, rather than converting the password to uppercase); additionally, all password characters have input in the key generation. However, it is still only changed when the user changes his or her password; this makes offline attacks much easier.
Used when the LMv2 response is sent (but not the NTLMv2 response). Deriving this key is a bit more complicated, but not terribly complex:
The LMv2 User Session Key offers several improvements over the NTLMv1-based keys. It is derived from the NTLMv2 hash (itself derived from the NTLM hash), which is specific to the username and domain/server; additionally, both the server challenge and client nonce provide input to the key calculation. The key calculation can also be stated simply as the HMAC-MD5 digest of the first 16 bytes of the LMv2 response (using the NTLMv2 hash as the key).
Used when the NTLMv2 response is sent. Calculation of this key is very similar to the LMv2 User Session Key:
The NTLMv2 User Session Key is quite similar cryptographically to the LMv2 User Session Key. It can be stated as the HMAC-MD5 digest of the first 16 bytes of the NTLMv2 response (using the NTLMv2 hash as the key).
Used when NTLMv1 authentication is employed with NTLM2 session security. This key is derived from the NTLM2 session response information as follows:
The NTLM2 Session Response User Session Key is notable in that it is calculated between the client and server, rather than at the domain controller. The domain controller derives the NTLM User Session Key and supplies it to the server, as before; if NTLM2 session security has been negotiated with the client, the server then takes the HMAC-MD5 digest of the session nonce using the NTLM User Session Key as the MAC key.
The Null User Session Key is employed when Anonymous authentication is performed. This one is simple; it's just 16 null bytes ("0x00000000000000000000000000000000").
The Lan Manager Session Key is an alternative to the User Session Keys, used to derive keys in NTLM1 signing and sealing when the "Negotiate Lan Manager Key" NTLM flag is set. Calculation of the Lan Manager Session Key is as follows:
Note that the Lan Manager Session Key is based on the LM response (rather than simply the LM hash), which means that it will change in response to a different server challenge. This is an advantage over the LM and NTLM User Session Keys, which are based solely on the password hash; the Lan Manager Session Key changes for each authentication operation, while the LM/NTLM User Session Keys remain the same until the user changes his or her password. For this reason, the Lan Manager Session Key is a much stronger scheme than the LM User Session Key (both have a similar key strength, but the Lan Manager Session Key prevents against replay attacks). The NTLM User Session Key has a full 128-bit keyspace, but like the LM User Session Key does not vary on each authentication.
When the "Negotiate Key Exchange" flag is negotiated, the client and server will agree upon a "secondary" key, used instead of the session key for signing and sealing. This done as follows:
Additionally, the key exchange process subtly changes the signing protocol in NTLM2 session security (discussed in a subsequent section).
The key used for signing and sealing is "weakened" in accordance with cryptographic export restrictions. The key strength is determined by the "Negotiate 128" and "Negotiate 56" flags. The strength of the final key used is the maximum strength supported by both the client and server; if neither flag is set, the default key length of 40 bits is used. NTLM1 signing and sealing supports 40-bit and 56-bit keys; NTLM2 session security supports 40-bit, 56-bit, and unweakened 128-bit keys.
NTLM1 is the "original" NTLMSSP signing and sealing scheme, used when the "Negotiate NTLM2 Key" flag is not negotiated. Key derivation in this scheme is driven by the following NTLM flags:
Negotiate Lan Manager Key | When set, the Lan Manager Session Key is used as the basis for the signing and sealing keys (rather than the User Session Key). If not established, the User Session Key will be used for key derivation. |
Negotiate 56 | Indicates support for 56-bit keys. If not negotiated, 40-bit keys will be used. This is only applicable in combination with "Negotiate Lan Manager Key"; User Session Keys are not weakened under NTLM1 (as they are already weak). |
Negotiate Key Exchange | Indicates that key exchange will be performed to negotiate a secondary key for signing and sealing. |
Deriving NTLM1 keys is essentially a three-step process:
The first step is negotiation of the 128-bit "master key" from which the final signing and sealing key will be derived. This is driven by the "Negotiate Lan Manager Key" NTLM flag; if set, the Lan Manager Session Key will be used as the master key. Otherwise, the appropriate User Session Key is employed.
As an example, consider our example user with the password "SecREt01". If the "Negotiate Lan Manager" key is not set, and an NTLM response was provided in the Type 3 message, the NTLM User Session Key will be selected as the master key. This is calculated by taking the MD4 digest of the NTLM hash (which is itself the MD4 hash of the Unicode password):
0x3f373ea8e4af954f14faa506f8eebdc4
If the "Negotiate Key Exchange" flag is set, the client will populate the "Session Key" field in the Type 3 message with a new master key, RC4-encrypted with the previously selected master key. The server will decrypt this value to receive the new master key.
For example, assume that the client selects the random master key "0xf0f0aabb00112233445566778899aabb". The client will encrypt this value using RC4 with the previously negotiated master key ("0x3f373ea8e4af954f14faa506f8eebdc4") to obtain the value:
0x1d3355eb71c82850a9a2d65c2952e6f3
This is sent to the server in the "Session Key" field of the Type 3 message. The server RC4-decrypts this value using the old master key to recover the new master key selected by the client ("0xf0f0aabb00112233445566778899aabb").
Finally, the key is weakened to comply with export restrictions. NTLM1 supports 40-bit and 56-bit keys. If the "Negotiate 56" NTLM flag is set, the 128-bit master key will be weakened to 56-bits; otherwise, it will be weakened to 40-bits. Note that key weakening is only employed under NTLM1 when the Lan Manager Session Key is used ("Negotiate Lan Manager Key" is set). The LM and NTLM User Session Keys are based on the password hashes, rather than the responses; a given password will always result in the same User Session Key under NTLM1. Weakening was apparently not deemed necessary, since the User Session Key can be easily recovered given a user's password hash.
The process for key weakening under NTLM1 is as follows:
Using the master key "0x0102030405060708090a0b0c0d0e0f00" as an example, the 40-bit key used for signing and sealing would be "0x0102030405e538b0". If 56-bit keys are negotiated, the final key would be "0x01020304050607a0".
Once the key has been negotiated it can be used to produce digital signatures, providing message integrity. Support for signing is indicated by the presence of the "Negotiate Sign" NTLM flag.
NTLM1 signing (as done by the SSPI MakeSignature function) is performed as follows:
As an example, assume that we are signing the message "jCIFS" (hexadecimal "0x6a43494653") using the 40-bit key from the previous example:
0x0100000078010900397420fe0e5a0f89
The next message signed would receive the sequence number 1; also, note again that the RC4 keystream initialized with the first signing is not reset for subsequent signatures.
In addition to message integrity, message confidentiality is provided via sealing. The "Negotiate Seal" NTLM flag indicates support for sealing. Under SSPI with the NTLM provider, sealing is always performed in combination with signing (sealing a message simultaneously generates a signature); the same RC4 keystream is used for both signing and sealing.
NTLM1 sealing (as done by the SSPI EncryptMessage function) is performed as follows:
As an example, consider the sealing of the message "jCIFS" ("0x6a43494653") using the 40-bit key "0x0102030405e538b0":
0x0100000078010900fa3e828bcc8affc3
A hexadecimal dump of the entire sealed structure would be:
0x86fc55abca0100000078010900fa3e828bcc8affc3
NTLM2 is a newer signing and sealing scheme, used when the "Negotiate NTLM2 Key" flag has been established. Key derivation in this scheme is driven by the following NTLM flags:
Negotiate NTLM2 Key | Indicates support for NTLM2 session security. |
Negotiate 56 | Indicates support for 56-bit keys. If neither this flag nor "Negotiate 128" are specified, 40-bit keys will be used. |
Negotiate 128 | Indicates support for 128-bit keys. If neither this flag nor "Negotiate 56" are specified, 40-bit keys will be used. |
Negotiate Key Exchange | Indicates that key exchange will be performed to negotiate a secondary base key for signing and sealing. |
Key derivation in NTLM2 is a four-step process:
The User Session Key is always used as the base master key in NTLM2 signing and sealing. When NTLMv2 authentication is used, either the LMv2 or NTLMv2 User Session Key will be employed as the master key. When NTLMv1 authentication is used with NTLM2 session security, the NTLM2 Session Response User Session Key is used as the master key. Note that the User Session Keys used in NTLM2 are significantly stronger than either their NTLM1 counterparts or the Lan Manager Session Key, as they incorporate both the server challenge and client nonce.
Key exchange is performed as previously discussed for NTLM1. The client selects a secondary master key, RC4-encrypts it with the base master key, and sends the ciphertext value to the server in the Type 3 "Session Key" field. This is indicated by the presence of the "Negotiate Key Exchange" flag.
Key weakening in NTLM2 is performed simply by truncating the master key (or secondary master key, if key exchange is performed) to the appropriate length; for example, the master key "0xf0f0aabb00112233445566778899aabb" would be weakened to 40 bits as "0xf0f0aabb00", and 56 bits as "0xf0f0aabb001122". Note that 128-bit keys are supported under NTLM2; in this case, the master key is used directly in the generation of subkeys (with no weakening performed).
The master key is only weakened under NTLM2 when generating the sealing subkeys; the full 128-bit master key is always used in the generation of signing keys.
Under NTLM2, up to four subkeys are established; the master key is never actually used to sign or seal messages. The subkeys are generated as follows:
session key to client-to-server signing key magic constant
In hexadecimal, this constant is:
0x73657373696f6e206b657920746f2063 6c69656e742d746f2d73657276657220 7369676e696e67206b6579206d616769 6320636f6e7374616e7400
The line breaks in the above are for display purposes only. The MD5 message-digest algorithm is applied to this, resulting in a 16-byte value. This is the Client Signing Key, used by the client to create signatures for messages.
session key to server-to-client signing key magic constant
In hexadecimal, this constant is:
0x73657373696f6e206b657920746f2073 65727665722d746f2d636c69656e7420 7369676e696e67206b6579206d616769 6320636f6e7374616e7400
The MD5 digest of this is taken, resulting in the 16-byte Server Signing Key. This is used by the server to create signatures for messages.
session key to client-to-server sealing key magic constant
In hexadecimal, this constant is:
0x73657373696f6e206b657920746f2063 6c69656e742d746f2d73657276657220 7365616c696e67206b6579206d616769 6320636f6e7374616e7400
The MD5 digest is taken to obtain the 16-byte Client Sealing Key. This is used by the client to encrypt messages.
session key to server-to-client sealing key magic constant
In hexadecimal, this constant is:
0x73657373696f6e206b657920746f2073 65727665722d746f2d636c69656e7420 7365616c696e67206b6579206d616769 6320636f6e7374616e7400
The MD5 digest algorithm is applied, yielding the 16-byte Server Sealing Key. This key is used by the server to encrypt messages.
Signing support is again indicated by the "Negotiate Sign" NTLM flag. Signing by the client is done using the Client Signing Key; the server signs messages using the Server Signing Key. Signing keys are generated from the unweakened master key (as discussed previously).
NTLM2 signing (as done by the SSPI MakeSignature function) is performed as follows:
As an example, assume that we are signing the message "jCIFS" (hexadecimal "0x6a43494653") on the client, using the master key "0x0102030405060708090a0b0c0d0e0f00". This is concatenated with the client-to-server signing constant, and MD5 is applied to yield the Client Signing Key ("0xf7f97a82ec390f9c903dac4f6aceb132") and Client Sealing Key ("0x2785f595293f3e2813439d73a223810d"); these are used as follows to sign the message:
0x000000006a43494653
HMAC-MD5 is applied using the Client Signing Key ("0xf7f97a82ec390f9c903dac4f6aceb132"). This results in the 16-byte value "0x0a003602317a759a720dc9c7a2a95257".
0x01000000e37f97f2544f4d7e00000000
The "Negotiate Seal" NTLM flag again indicates support for message confidentiality in NTLM2. NTLM2 sealing (as done by the SSPI EncryptMessage function) is performed as follows:
As an example, assume that we are sealing the message "jCIFS" (hexadecimal "0x6a43494653") on the client, using the master key "0x0102030405060708090a0b0c0d0e0f00". As in our previous example, we generate the Client Signing Key ("0xf7f97a82ec390f9c903dac4f6aceb132") using the unweakened master key. We also need to generate the Client Sealing Key; we will assume that 40-bit weakening has been negotiated. We concatenate the weakened master key ("0x0102030405") with the client-to-server sealing constant, and MD5 is applied to yield the Client Sealing Key ("0x6f0d99535033951cbe499cd1914fe9ee"). The following procedure is used to seal the message:
0x000000006a43494653
HMAC-MD5 is applied using the Client Signing Key ("0xf7f97a82ec390f9c903dac4f6aceb132"). This results in the 16-byte value "0x0a003602317a759a720dc9c7a2a95257".
0x01000000884b14809e53bfe700000000
A hexadecimal dump of the entire sealed structure would be:
0xcf0eb0a93901000000884b14809e53bfe700000000
There are a couple of other session security topics which don't really fit anywhere else:
This is used when a datagram context has been established (indicated by the datagram authentication handshake and the presence of the "Negotiate Datagram Style" flag). The semantics regarding datagram session security are a bit different; signing can begin on the client immediately after the first call to the SSPI InitializeSecurityContext function (i.e., before any communication to the server). This implies a prearranged signing and sealing scheme (as signatures can be created before any options are negotiated with the server). Datagram session security is based on 40-bit Lan Manager Session Key NTLM1 with key exchange (although there may be some means of predetermining a stronger scheme through the registry).
The sequence number is not incremented in datagram mode; it is fixed at zero, and each signature reflects this. Also, the RC4 keystream is reset for each signing or sealing operation. This is significant, in that messages are potentially susceptible to known plaintext attacks.
This is used if the SSPI context was initialized without specifying support for message integrity. If the "Negotiate Always Sign" NTLM flag is established, calls to MakeSignature will succeed, returning the constant "signature":
0x01000000000000000000000000000000
Calls to EncryptMessage succeed normally (including the "real" signature in the security trailer buffer). If "Negotiate Always Sign" is not negotiated, both signing and sealing will fail.
Note that due to the highly dynamic and transient nature of the Web, these may or may not be available.
Microsoft has established the proprietary "NTLM" authentication scheme for HTTP to provide integrated authentication to IIS web servers. This authentication mechanism allows clients to access resources using their Windows credentials, and is typically used within corporate environments to provide single sign-on functionality to intranet sites. Historically, NTLM authentication was only supported by Internet Explorer; recently, however, support has been added to various other user agents.
The NTLM HTTP authentication mechanism works as follows:
GET /index.html HTTP/1.1
HTTP/1.1 401 Unauthorized WWW-Authenticate: NTLM Connection: close
Note that Internet Explorer will only select NTLM if it is the first mechanism offered; this is at odds with RFC 2616, which states that the client must select the strongest supported authentication scheme.
GET /index.html HTTP/1.1 Authorization: NTLM TlRMTVNTUAABAAAABzIAAAYABgArAAAACwALACAAAABXT1 JLU1RBVElPTkRPTUFJTg==
HTTP/1.1 401 Unauthorized WWW-Authenticate: NTLM TlRMTVNTUAACAAAADAAMADAAAAABAoEAASNFZ4mrze8 AAAAAAAAAAGIAYgA8AAAARABPAE0AQQBJAE4AAgAMAEQATwBNAEEASQBOAAEADABTA EUAUgBWAEUAUgAEABQAZABvAG0AYQBpAG4ALgBjAG8AbQADACIAcwBlAHIAdgBlAHI ALgBkAG8AbQBhAGkAbgAuAGMAbwBtAAAAAAA=
GET /index.html HTTP/1.1 Authorization: NTLM TlRMTVNTUAADAAAAGAAYAGoAAAAYABgAggAAAAwADABAAA AACAAIAEwAAAAWABYAVAAAAAAAAACaAAAAAQIAAEQATwBNAEEASQBOAHUAcwBlAHIA VwBPAFIASwBTAFQAQQBUAEkATwBOAMM3zVy9RPyXgqZnr21CfG3mfCDC0+d8ViWpjB wx6BhHRmspst9GgPOZWPuMITqcxg==
HTTP/1.1 200 OK
This scheme differs from most "normal" HTTP authentication mechanisms, in that subsequent requests over the authenticated connection are not themselves authenticated; NTLM is connection-oriented, rather than request-oriented. So a second request for "/index.html" would not carry any authentication information, and the server would request none. If the server detects that the connection to the client has been dropped, a request for "/index.html" would result in the server reinitiating the NTLM handshake.
A notable exception to the above is the client's behavior when submitting a POST request (typically employed when the client is sending form data to the server). If the client determines that the server is not the local host, the client will initiate reauthentication for POST requests over the active connection. The client will first submit an empty POST request with a Type 1 message in the "Authorization" header; the server responds with the Type 2 message (in the "WWW-Authenticate" header as shown above). The client then resubmits the POST with the Type 3 message, sending the form data with the request.
The NTLM HTTP mechanism can also be used for HTTP proxy authentication. The process is similar, except:
With Windows 2000, Microsoft introduced the "Negotiate" HTTP authentication mechanism. While primarily aimed at providing a means of authenticating the user against Active Directory via Kerberos, it is backward-compatible with the NTLM scheme. When the Negotiate mechanism is used in "legacy" mode, the headers passed between the client and server are identical, except "Negotiate" (rather than "NTLM") is indicated as the mechanism name.
Microsoft's Exchange server provides an NTLM authentication mechanism for the POP3 protocol. This is a proprietary extension used with the POP3 AUTH command as documented in RFC 1734. On the client side, this mechanism is supported by Outlook and Outlook Express, and is called "Secure Password Authentication".
The POP3 NTLM authentication handshake occurs during the POP3 "authorization" state, and works as follows:
AUTH
+OK The operation completed successfully. NTLM .
AUTH NTLM
+ OK
TlRMTVNTUAABAAAABzIAAAYABgArAAAACwALACAAAABXT1JLU1RBVElPTkRPTUFJTg==
+ TlRMTVNTUAACAAAADAAMADAAAAABAoEAASNFZ4mrze8AAAAAAAAAAGIAYgA8AAAA RABPAE0AQQBJAE4AAgAMAEQATwBNAEEASQBOAAEADABTAEUAUgBWAEUAUgAEABQAZA BvAG0AYQBpAG4ALgBjAG8AbQADACIAcwBlAHIAdgBlAHIALgBkAG8AbQBhAGkAbgAu AGMAbwBtAAAAAAA=
TlRMTVNTUAADAAAAGAAYAGoAAAAYABgAggAAAAwADABAAAAACAAIAEwAAAAWABYAVA AAAAAAAACaAAAAAQIAAEQATwBNAEEASQBOAHUAcwBlAHIAVwBPAFIASwBTAFQAQQBU AEkATwBOAMM3zVy9RPyXgqZnr21CfG3mfCDC0+d8ViWpjBwx6BhHRmspst9GgPOZWP uMITqcxg==
+OK User successfully logged on
After successful authentication has occurred, the POP3 session enters the "transaction" state, allowing messages to be retrieved by the client.
Exchange provides an IMAP authentication mechanism similar in form to the POP3 mechanism previously discussed. IMAP authentication is documented in RFC 1730; the NTLM mechanism is a proprietary extension provided by Exchange and supported by the Outlook client family.
The handshake sequence is similar to the POP3 mechanism:
0000 CAPABILITY
* CAPABILITY IMAP4 IMAP4rev1 IDLE LITERAL+ AUTH=NTLM 0000 OK CAPABILITY completed.
0001 AUTHENTICATE NTLM
+
TlRMTVNTUAABAAAABzIAAAYABgArAAAACwALACAAAABXT1JLU1RBVElPTkRPTUFJTg==
+ TlRMTVNTUAACAAAADAAMADAAAAABAoEAASNFZ4mrze8AAAAAAAAAAGIAYgA8AAAA RABPAE0AQQBJAE4AAgAMAEQATwBNAEEASQBOAAEADABTAEUAUgBWAEUAUgAEABQAZA BvAG0AYQBpAG4ALgBjAG8AbQADACIAcwBlAHIAdgBlAHIALgBkAG8AbQBhAGkAbgAu AGMAbwBtAAAAAAA=
TlRMTVNTUAADAAAAGAAYAGoAAAAYABgAggAAAAwADABAAAAACAAIAEwAAAAWABYAVA AAAAAAAACaAAAAAQIAAEQATwBNAEEASQBOAHUAcwBlAHIAVwBPAFIASwBTAFQAQQBU AEkATwBOAMM3zVy9RPyXgqZnr21CfG3mfCDC0+d8ViWpjBwx6BhHRmspst9GgPOZWP uMITqcxg==
0001 OK AUTHENTICATE NTLM completed.
In addition to the NTLM authentication mechanisms provided for POP3 and IMAP, Exchange provides similar functionality for the SMTP protocol. This allows NTLM authentication of users sending outgoing mail messages. This is a proprietary extension used with the SMTP AUTH command (documented in RFC 2554).
The SMTP NTLM authentication handshake operates as follows:
EHLO client.example.com
250-server.example.com Hello [10.10.2.20] 250-HELP 250-AUTH LOGIN NTLM 250-AUTH=LOGIN NTLM 250 SIZE 10240000
AUTH NTLM TlRMTVNTUAABAAAABzIAAAYABgArAAAACwALACAAAABXT1JLU1RBVElPTkRPTUFJTg==
According to RFC 2554, the client may opt not to send the initial response parameter (instead merely sending "AUTH NTLM" and waiting for an empty server challenge before replying with the Type 1 message). However, this did not appear to work properly when tested against Exchange.
334 TlRMTVNTUAACAAAADAAMADAAAAABAoEAASNFZ4mrze8AAAAAAAAAAGIAYgA8AAAA RABPAE0AQQBJAE4AAgAMAEQATwBNAEEASQBOAAEADABTAEUAUgBWAEUAUgAEABQAZA BvAG0AYQBpAG4ALgBjAG8AbQADACIAcwBlAHIAdgBlAHIALgBkAG8AbQBhAGkAbgAu AGMAbwBtAAAAAAA=
TlRMTVNTUAADAAAAGAAYAGoAAAAYABgAggAAAAwADABAAAAACAAIAEwAAAAWABYAVA AAAAAAAACaAAAAAQIAAEQATwBNAEEASQBOAHUAcwBlAHIAVwBPAFIASwBTAFQAQQBU AEkATwBOAMM3zVy9RPyXgqZnr21CfG3mfCDC0+d8ViWpjBwx6BhHRmspst9GgPOZWP uMITqcxg==
235 NTLM authentication successful.
After authenticating, the client is able to send messages normally.
This section contains detailed analysis and decomposition of various authentication and signing/sealing operations. This is by no means a comprehensive catalog of possible scenarios, but does include some of the more interesting variants. These were produced by calling the InitializeSecurityContext and AcceptSecurityContext SSPI functions between two peers, and applying subtle manipulations to the resulting NTLM messages. After the context was established, the ExportSecurityContext function was called to dump the contents of the context to a file, for use in subsequent offline analysis. Additionally, the MakeSignature and EncryptMessage functions were used to perform signing and sealing, respectively.
Demonstration of NTLMv1 authentication with NTLM User Session Key NTLM1 signing and sealing (without key exchange).
LMCompatibilityLevel set to 0 (LM/NTLM). AcquireCredentialsHandle called with domain "TESTNT", user "test", password "test1234". -------------------------------------------------------------------------------- InitializeSecurityContext called with ISC_REQ_INTEGRITY and ISC_REQ_CONFIDENTIALITY. Following flags were masked off of resulting Type 1 message: Negotiate Lan Manager Key (0x00000080) Negotiate NTLM2 Key (0x00080000) Negotiate 128 (0x20000000) Negotiate Key Exchange (0x40000000) Negotiate 56 (0x80000000) 4e544c4d53535000010000003782000000000000000000000000000000000000 4e544c4d53535000 "NTLMSSP" 01000000 Type 1 message 37820000 Flags Negotiate Unicode (0x00000001) Negotiate OEM (0x00000002) Request Target (0x00000004) Negotiate Sign (0x00000010) Negotiate Seal (0x00000020) Negotiate NTLM (0x00000200) Negotiate Always Sign (0x00008000) 0000000000000000 Supplied Domain header (empty, supplied credentials) 0000000000000000 Supplied Workstation header (empty, supplied credentials) -------------------------------------------------------------------------------- AcceptSecurityContext called with ASC_REQ_INTEGRITY and ASC_REQ_CONFIDENTIALITY. Produces Type 2 message: 4e544c4d53535000020000000c000c003000000035828100b019d38bad875c9d 0000000000000000460046003c00000054004500530054004e00540002000c00 54004500530054004e00540001000c004d0045004d0042004500520003001e00 6d0065006d006200650072002e0074006500730074002e0063006f006d000000 0000 4e544c4d53535000 "NTLMSSP" 02000000 Type 2 message 0c000c0030000000 Target Name header (length 12, offset 48) 35828100 Flags Negotiate Unicode (0x00000001) Request Target (0x00000004) Negotiate Sign (0x00000010) Negotiate Seal (0x00000020) Negotiate NTLM (0x00000200) Negotiate Always Sign (0x00008000) Target Type Domain (0x00010000) Negotiate Target Info (0x00800000) b019d38bad875c9d Challenge 0000000000000000 Context 460046003c000000 Target Information header (length 70, length 60) 54004500530054004e005400 Target Name ("TESTNT") Target Information block: 02000c00 NetBIOS Domain Name (length 12) 54004500530054004e005400 "TESTNT" 01000c00 NetBIOS Server Name (length 12) 4d0045004d00420045005200 "MEMBER" 03001e00 DNS Server Name (length 30) 6d0065006d006200650072002e0074006500730074002e0063006f006d00 "member.test.com" 00000000 Target Information Terminator -------------------------------------------------------------------------------- InitializeSecurityContext called. Produces a Type 3 message: 4e544c4d5353500003000000180018006000000018001800780000000c000c00 40000000080008004c0000000c000c0054000000000000009000000035828000 54004500530054004e00540074006500730074004d0045004d00420045005200 1879f60127f8a877022132ec221bcbf3ca016a9f76095606e6285df3287c5d19 4f84df1a94817c7282d09754b6f9e02a 4e544c4d53535000 "NTLMSSP" 03000000 Type 3 message 1800180060000000 LM/LMv2 Response header (length 24, offset 96) 1800180078000000 NTLM/NTLMv2 Response header (length 24, offset 120) 0c000c0040000000 Domain Name header (length 12, offset 64) 080008004c000000 User Name header (length 8, offset 76) 0c000c0054000000 Workstation Name header (length 12, offset 84) 0000000090000000 Session Key header (empty) 35828000 Flags Negotiate Unicode (0x00000001) Request Target (0x00000004) Negotiate Sign (0x00000010) Negotiate Seal (0x00000020) Negotiate NTLM (0x00000200) Negotiate Always Sign (0x00008000) Negotiate Target Info (0x00800000) 54004500530054004e005400 Domain Name ("TESTNT") 7400650073007400 User Name ("test") 4d0045004d00420045005200 Workstation Name ("MEMBER") 1879f60127f8a877022132ec221bcbf3ca016a9f76095606 LM/LMv2 Response e6285df3287c5d194f84df1a94817c7282d09754b6f9e02a NTLM/NTLMv2 Response -------------------------------------------------------------------------------- AcceptSecurityContext called to complete the server-side context. Server Context Export: 40a42e7840a42e7800000000000000000000000000000000 08ee0b00 server context handle dwUpper 35828101 flags 0000000000000000e8290900e8290900682a0900682a09000000000000000000 d002000000000000000000000000000000000000000000000200000000000000 ffffffffffffff7f20010000 ae33a32dca8c9821844f740d5b3f4d6c outbound signing key ae33a32dca8c9821844f740d5b3f4d6c inbound verifying key ae33a32dca8c9821844f740d5b3f4d6c outbound encrypting key ae33a32dca8c9821844f740d5b3f4d6c inbound decrypting key 000000000000000000000000 ae3787b72ff94884680d3e5658c064df9d9e5d8f0655f22a002ebc7e9f944e29 08cf90e0057f622d31a92b7d0ca6f586d5d36e24af70cdbe52ea49d067aa4ffa e85a5cb1a41e3241a288f8de8a4c8909593cc698b657750af014b26f13778eee 855310d716f61ce5c795a0a3bbac358bb02611c954a54b2791d6e297f1fd8c6d 18fffc190b9c69b80122f7c8fb036146c2b581443960fe239b967b17e33de15b 73e445401f1db3a8c5ad51f48d665e38796b8263b9ca363f763aef71d1ec12d8 a76cb46a333b0fddab7850ba3493dcd4077299d22515eb5f300221e9e79a80d9 1a1b4d2865e6ccc3470eda7c4ace04bfbddbedc1cb207483f343c4a1422c7a92 00000000000000000000000000000000 ae3787b72ff94884680d3e5658c064df9d9e5d8f0655f22a002ebc7e9f944e29 08cf90e0057f622d31a92b7d0ca6f586d5d36e24af70cdbe52ea49d067aa4ffa e85a5cb1a41e3241a288f8de8a4c8909593cc698b657750af014b26f13778eee 855310d716f61ce5c795a0a3bbac358bb02611c954a54b2791d6e297f1fd8c6d 18fffc190b9c69b80122f7c8fb036146c2b581443960fe239b967b17e33de15b 73e445401f1db3a8c5ad51f48d665e38796b8263b9ca363f763aef71d1ec12d8 a76cb46a333b0fddab7850ba3493dcd4077299d22515eb5f300221e9e79a80d9 1a1b4d2865e6ccc3470eda7c4ace04bfbddbedc1cb207483f343c4a1422c7a92 0000000000000000 54004500530054004e0054005c007400650073007400 "TESTNT\test" ntlmHash = md4(password) = 0x3b1b47e42e0463276e3ded6cef349f93 NTLMUserSessionKey = md4(ntlmHash) = 0xae33a32dca8c9821844f740d5b3f4d6c Key is *not* weakened (NTLM1 only weakens Lan Manager Session Keys). Called MakeSignature on the server-side context for message "0x0102030405060708". Yields signature: 0100000090010700087de41e039ae5c5 CRC32(0x0102030405060708) = 0xc588ca3f Sequence number is 0. 0x00000000 + crc32 + seqnum = 0x00000000c588ca3f00000000 RC4(key, 0x00000000c588ca3f00000000) = 0x20961389087de41e039ae5c5 version num + first 4 bytes overwritten with counter value (0x90010700 here): 0100000090010700087de41e039ae5c5 = signature -------------------------------------------------------------------------------- Called EncryptMessage twice on the server-side context for message "0x0102030405060708". Yields encrypted messages: 3ec555aea59eb55001000000a0030700f64393466a9317f7 1caf3c9a114ca2f4010000008803070095c1958123ecafce same RC4 cipher is used from previous signing operation (i.e., not reset): RC4(0x0102030405060708) = sealed message = 0x3ec555aea59eb550 trailer buffer gets signature; again uses same RC4 cipher (sequence number is now 1 because of previous signing): RC4(0x00000000c588ca3f01000000) = 0x8e8adf2bf64393466a9317f7 version num + first 4 bytes overwritten w/counter (0xa0030700): 01000000a0030700f64393466a9317f7 = trailer signature second message is same: RC4(0x0102030405060708) = sealed message = 0x1caf3c9a114ca2f4 trailer buffer signature with sequence 2: RC4(0x00000000c588ca3f02000000) = 0xf23fc1e495c1958123ecafce version num + first 4 bytes overwritten w/counter (0x88030700) 010000008803070095c1958123ecafce = trailer signature
Demonstration of NTLMv1 authentication with LM User Session Key NTLM1 signing and sealing (without key exchange). NTLM response is manually removed from the Type 3 message to force the server-side context to use the LM User Session Key.
LMCompatibilityLevel set to 0 (LM/NTLM). AcquireCredentialsHandle called with domain "TESTNT", user "test", password "test1234". -------------------------------------------------------------------------------- InitializeSecurityContext called with ISC_REQ_INTEGRITY and ISC_REQ_CONFIDENTIALITY. Following flags were masked off of resulting Type 1 message: Negotiate Lan Manager Key (0x00000080) Negotiate NTLM2 Key (0x00080000) Negotiate 128 (0x20000000) Negotiate Key Exchange (0x40000000) Negotiate 56 (0x80000000) 4e544c4d53535000010000003782000000000000000000000000000000000000 4e544c4d53535000 "NTLMSSP" 01000000 Type 1 message 37820000 Flags Negotiate Unicode (0x00000001) Negotiate OEM (0x00000002) Request Target (0x00000004) Negotiate Sign (0x00000010) Negotiate Seal (0x00000020) Negotiate NTLM (0x00000200) Negotiate Always Sign (0x00008000) 0000000000000000 Supplied Domain header (empty, supplied credentials) 0000000000000000 Supplied Workstation header (empty, supplied credentials) -------------------------------------------------------------------------------- AcceptSecurityContext called with ASC_REQ_INTEGRITY and ASC_REQ_CONFIDENTIALITY. Produces Type 2 message: 4e544c4d53535000020000000c000c0030000000358281006da297169f7aa9c2 0000000000000000460046003c00000054004500530054004e00540002000c00 54004500530054004e00540001000c004d0045004d0042004500520003001e00 6d0065006d006200650072002e0074006500730074002e0063006f006d000000 0000 4e544c4d53535000 "NTLMSSP" 02000000 Type 2 message 0c000c0030000000 Target Name header (length 12, offset 48) 35828100 Flags Negotiate Unicode (0x00000001) Request Target (0x00000004) Negotiate Sign (0x00000010) Negotiate Seal (0x00000020) Negotiate NTLM (0x00000200) Negotiate Always Sign (0x00008000) Target Type Domain (0x00010000) Negotiate Target Info (0x00800000) 6da297169f7aa9c2 Challenge 0000000000000000 Context 460046003c000000 Target Information header (length 70, offset 60) 54004500530054004e005400 Target Name ("TESTNT") Target Information block: 02000c00 NetBIOS Domain Name (length 12) 54004500530054004e005400 "TESTNT" 01000c00 NetBIOS Server Name (length 12) 4d0045004d00420045005200 "MEMBER" 03001e00 DNS Server Name (length 30) 6d0065006d006200650072002e0074006500730074002e0063006f006d00 "member.test.com" 00000000 Target Information Terminator -------------------------------------------------------------------------------- InitializeSecurityContext called. Produces a Type 3 message; NTLM response is removed to force usage of the LM User Session Key: 4e544c4d5353500003000000180018004000000000000000000000000c000c00 5800000008000800640000000c000c006c000000000000000000000035828000 2e17884ea16177e2b751d53b5cc756c3cd57cdfd6e3bf8b95400450053005400 4e00540074006500730074004d0045004d00420045005200 4e544c4d53535000 "NTLMSSP" 03000000 Type 3 message 1800180040000000 LM/LMv2 Response (length 24, offset 64) 0000000000000000 NTLM/NTLMv2 Response (empty, removed) 0c000c0058000000 Domain Name header (length 12, offset 88) 0800080064000000 User Name header (length 8, offset 100) 0c000c006c000000 Workstation Name header (length 12, offset 108) 0000000000000000 Session Key header (empty) 35828000 Flags Negotiate Unicode (0x00000001) Request Target (0x00000004) Negotiate Sign (0x00000010) Negotiate Seal (0x00000020) Negotiate NTLM (0x00000200) Negotiate Always Sign (0x00008000) Negotiate Target Info (0x00800000) 2e17884ea16177e2b751d53b5cc756c3cd57cdfd6e3bf8b9 LM/LMv2 Response 54004500530054004e005400 Domain Name ("TESTNT") 7400650073007400 User Name ("test") 4d0045004d00420045005200 Workstation Name ("MEMBER") -------------------------------------------------------------------------------- AcceptSecurityContext called to complete the server-side context. Server Context Export: 40a42e7840a42e7800000000000000000000000000000000 08ee0b00 server context handle dwUpper 35828101 flags 0000000000000000f8290900f8290900782a0900782a09000000000000000000 d002000000000000000000000000000000000000000000000200000000000000 ffffffffffffff7f28010000 624aac413795cdc10000000000000000 outbound signing key 624aac413795cdc10000000000000000 inbound verifying key 624aac413795cdc10000000000000000 outbound encrypting key 624aac413795cdc10000000000000000 inbound decrypting key 000000000000000000000000 59ad15f0da768c3d17b6c57d41885c21d530a998e4140743f86c0a45067994a3 4a91002db96aae962b0b7abe77feaf1651ccaa249ae754563ab8abe6c9869ddc 1d1052e3328a6f2564b0f7408eeb6b57e9d268dd73198b5bf3c75a995e1fbffa bcdf851a958fc2ea49a8d839fc5dd755fb44c4a258600523ed7ea1ee38351bca 29b72f37d075b567a5d4123ee20de5a09b63ffd633183bfd660ef5780ceccb28 6e97c8e0e84e48c16d7b114cbaa622b4c62708655f1e20c32cf2bb7fb136f672 accf84027c3101d1902eb2932ab3e13f4271826209343c1c61269cd3f4509253 80cd47f946f1efc00313cedb4fa49e879fbd04a7748969d970830f4b8dde814d 00000000000000000000000000000000 59ad15f0da768c3d17b6c57d41885c21d530a998e4140743f86c0a45067994a3 4a91002db96aae962b0b7abe77feaf1651ccaa249ae754563ab8abe6c9869ddc 1d1052e3328a6f2564b0f7408eeb6b57e9d268dd73198b5bf3c75a995e1fbffa bcdf851a958fc2ea49a8d839fc5dd755fb44c4a258600523ed7ea1ee38351bca 29b72f37d075b567a5d4123ee20de5a09b63ffd633183bfd660ef5780ceccb28 6e97c8e0e84e48c16d7b114cbaa622b4c62708655f1e20c32cf2bb7fb136f672 accf84027c3101d1902eb2932ab3e13f4271826209343c1c61269cd3f4509253 80cd47f946f1efc00313cedb4fa49e879fbd04a7748969d970830f4b8dde814d 0000000000000000 54004500530054004e0054005c007400650073007400 "TESTNT\test" lmHash = lmEncrypt(password, "KGS!@#$%") = 0x624aac413795cdc1ff17365faf1ffe89 LMUserSessionKey = trunc(lmHash) = 0x624aac413795cdc10000000000000000 Key is *not* weakened (NTLM1 only weakens Lan Manager Session Keys). Called MakeSignature on the server-side context for message "0x0102030405060708". Yields signature: 0100000090010700cacc888006466cb5 CRC32(0x0102030405060708) = 0xc588ca3f Sequence number is 0. 0x00000000 + crc32 + seqnum = 0x00000000c588ca3f00000000 RC4(key, 0x00000000c588ca3f00000000) = 0xdd0e70b1cacc888006466cb5 version num + first 4 bytes overwritten with counter value (0x90010700 here): 0100000090010700cacc888006466cb5 = signature -------------------------------------------------------------------------------- Called EncryptMessage twice on the server-side context for message "0x0102030405060708". Yields encrypted messages: 48793abbf0145ddb01000000a0030700e286c6021ffc3742 09613b9790f7d40e0100000088030700fb8e614d1cf2284c same RC4 cipher is used from previous signing operation (i.e., not reset): RC4(0x0102030405060708) = sealed message = 0x48793abbf0145ddb trailer buffer gets signature; again uses same RC4 cipher (sequence number is now 1 because of previous signing): RC4(0x00000000c588ca3f01000000) = 0x623bc698e286c6021ffc3742 version num + first 4 bytes overwritten w/counter (0xa0030700): 01000000a0030700e286c6021ffc3742 = trailer signature second message is same: RC4(0x0102030405060708) = sealed message = 0x09613b9790f7d40e trailer buffer signature with sequence 2: RC4(0x00000000c588ca3f02000000) = 0x85433470fb8e614d1cf2284c version num + first 4 bytes overwritten w/counter (0x88030700) 0100000088030700fb8e614d1cf2284c = trailer signature
Demonstration of NTLMv1 authentication with 56-bit Lan Manager Session Key NTLM1 signing and sealing (without key exchange).
LMCompatibilityLevel set to 0 (LM/NTLM). AcquireCredentialsHandle called with domain "TESTNT", user "test", password "test1234". -------------------------------------------------------------------------------- InitializeSecurityContext called with ISC_REQ_INTEGRITY and ISC_REQ_CONFIDENTIALITY. Following flags were masked off of resulting Type 1 message: Negotiate NTLM2 Key (0x00080000) Negotiate 128 (0x20000000) Negotiate Key Exchange (0x40000000) 4e544c4d5353500001000000b782008000000000000000000000000000000000 4e544c4d53535000 "NTLMSSP" 01000000 Type 1 message b7820080 Flags Negotiate Unicode (0x00000001) Negotiate OEM (0x00000002) Request Target (0x00000004) Negotiate Sign (0x00000010) Negotiate Seal (0x00000020) Negotiate Lan Manager Key (0x00000080) Negotiate NTLM (0x00000200) Negotiate Always Sign (0x00008000) Negotiate 56 (0x80000000) 0000000000000000 Supplied Domain header (empty, supplied credentials) 0000000000000000 Supplied Workstation header (empty, supplied credentials) -------------------------------------------------------------------------------- AcceptSecurityContext called with ASC_REQ_INTEGRITY and ASC_REQ_CONFIDENTIALITY. Produces Type 2 message: 4e544c4d53535000020000000c000c0030000000b5828180c77c1fcdb77ad042 0000000000000000460046003c00000054004500530054004e00540002000c00 54004500530054004e00540001000c004d0045004d0042004500520003001e00 6d0065006d006200650072002e0074006500730074002e0063006f006d000000 0000 4e544c4d53535000 "NTLMSSP" 02000000 Type 2 message 0c000c0030000000 Target Name header (length 12, offset 48) b5828180 Flags Negotiate Unicode (0x00000001) Request Target (0x00000004) Negotiate Sign (0x00000010) Negotiate Seal (0x00000020) Negotiate Lan Manager Key (0x00000080) Negotiate NTLM (0x00000200) Negotiate Always Sign (0x00008000) Target Type Domain (0x00010000) Negotiate Target Info (0x00800000) Negotiate 56 (0x80000000) c77c1fcdb77ad042 Challenge 0000000000000000 Context 460046003c000000 Target Information header (length 70, offset 60) 54004500530054004e005400 Target Name ("TESTNT") Target Information block: 02000c00 NetBIOS Domain Name (length 12) 54004500530054004e005400 "TESTNT" 01000c00 NetBIOS Server Name (length 12) 4d0045004d00420045005200 "MEMBER" 03001e00 DNS Server Name (length 30) 6d0065006d006200650072002e0074006500730074002e0063006f006d00 "member.test.com" 00000000 Target Information Terminator -------------------------------------------------------------------------------- InitializeSecurityContext called. Produces a Type 3 message: 4e544c4d5353500003000000180018006000000018001800780000000c000c00 40000000080008004c0000000c000c00540000000000000090000000b5828080 54004500530054004e00540074006500730074004d0045004d00420045005200 2e1580af209c1579bbd95a0c9568e2a7455764064cd8ff8c75791b1820178018 c9d00365a5dedfaa455ef8c3b3ad1c1c 4e544c4d53535000 "NTLMSSP" 03000000 Type 3 message 1800180060000000 LM/LMv2 Response header (length 24, offset 96) 1800180078000000 NTLM/NTLMv2 Response header (length 24, offset 120) 0c000c0040000000 Domain Name header (length 12, offset 64) 080008004c000000 User Name header (length 8, offset 76) 0c000c0054000000 Workstation Name header (length 12, offset 84) 0000000090000000 Session Key header (empty) b5828080 Flags Negotiate Unicode (0x00000001) Request Target (0x00000004) Negotiate Sign (0x00000010) Negotiate Seal (0x00000020) Negotiate Lan Manager Key (0x00000080) Negotiate NTLM (0x00000200) Negotiate Always Sign (0x00008000) Negotiate Target Info (0x00800000) Negotiate 56 (0x80000000) 54004500530054004e005400 Domain Name ("TESTNT") 7400650073007400 User Name ("test") 4d0045004d00420045005200 Workstation Name ("MEMBER") 2e1580af209c1579bbd95a0c9568e2a7455764064cd8ff8c LM/LMv2 Response 75791b1820178018c9d00365a5dedfaa455ef8c3b3ad1c1c NTLM/NTLMv2 Response -------------------------------------------------------------------------------- AcceptSecurityContext called to complete the server-side context. Server Context Export: 40a42e7840a42e7800000000000000000000000000000000 08ee0b00 server context handle dwUpper b5828181 flags, also has an unknown flag set 0000000000000000e8290900e8290900682a0900682a09000000000000000000 d002000000000000000000000000000000000000000000000200000000000000 ffffffffffffff7f20010000 f41c7848bec59daa4cfe52156645f77b f41c7848bec59daa4cfe52156645f77b f41c7848bec59daa4cfe52156645f77b f41c7848bec59daa4cfe52156645f77b 000000000000000000000000 f41115be030662aca4a022504869d30421ae431964da92b42af589ea8a4e5f5e 4c140ab6b342bacb3405ce25e787e5176f30108229c538b5db44e86b1367ad86 573b5294818d6e5174f683c10ecf2ec7a27831dd1efbeeb2fe7302e48b402061 af07bf45d5bcfacc36b81c3e3d6018128e79a54b93998097ab66b798720bbd47 d96a6890d2c2f0ffcdc985a9955ae09fc36c54f17f71d0287d8fdea34df35688 6dc6bb1dc823241a7e7ac4edefa10d7c26d18c77639675d40ce37bebf75cd62c ecfd84769a3fb15ba82d2f53d74f32fca7e6aa0f279bb02b41084ae1f8dff2e9 e2399c003aa6b95d5833ca1b37dc65593c914916099e7001551f9dd8c04635f9 00000000000000000000000000000000 f41115be030662aca4a022504869d30421ae431964da92b42af589ea8a4e5f5e 4c140ab6b342bacb3405ce25e787e5176f30108229c538b5db44e86b1367ad86 573b5294818d6e5174f683c10ecf2ec7a27831dd1efbeeb2fe7302e48b402061 af07bf45d5bcfacc36b81c3e3d6018128e79a54b93998097ab66b798720bbd47 d96a6890d2c2f0ffcdc985a9955ae09fc36c54f17f71d0287d8fdea34df35688 6dc6bb1dc823241a7e7ac4edefa10d7c26d18c77639675d40ce37bebf75cd62c ecfd84769a3fb15ba82d2f53d74f32fca7e6aa0f279bb02b41084ae1f8dff2e9 e2399c003aa6b95d5833ca1b37dc65593c914916099e7001551f9dd8c04635f9 0000000000000000 54004500530054004e0054005c007400650073007400 "TESTNT\test" lmHash = lmEncrypt(password, "KGS!@#$%") = 0x624aac413795cdc1ff17365faf1ffe89 trunc(lmHash + pad) = 0x624aac413795cdc1bdbdbdbdbdbd lmResponse[0-7] = 0x2e1580af209c1579 LanManagerSessionKey = lmEncrypt(0x624aac413795cdc1bdbdbdbdbdbd, 0x2e1580af209c1579) = 0xf41c7848bec59daa4cfe52156645f77b Key is weakened to 56-bit w/0xa0 = 0xf41c7848bec59da0 Called MakeSignature on the server-side context for message "0x0102030405060708". Yields signature: 0100000090010700598d18d8150514cc CRC32(0x0102030405060708) = 0xc588ca3f Sequence number is 0. 0x00000000 + crc32 + seqnum = 0x00000000c588ca3f00000000 RC4(key, 0x00000000c588ca3f00000000) = 0x2cfc55af598d18d8150514cc version num + first 4 bytes overwritten with counter value (0x90010700 here): 0100000090010700598d18d8150514cc = signature -------------------------------------------------------------------------------- Called EncryptMessage twice on the server-side context for message "0x0102030405060708". Yields encrypted messages: 357f77b267a494c101000000a0030700fb2ce7d1bfd23a0a 4db804533e6ffc2301000000880307003736d2b43c149c48 same RC4 cipher is used from previous signing operation (i.e., not reset): RC4(0x0102030405060708) = sealed message = 0x357f77b267a494c1 trailer buffer gets signature; again uses same RC4 cipher (sequence number is now 1 because of previous signing): RC4(0x00000000c588ca3f01000000) = 0x757b9976fb2ce7d1bfd23a0a version num + first 4 bytes overwritten w/counter (0xa0030700): 01000000a0030700fb2ce7d1bfd23a0a = trailer signature second message is same: RC4(0x0102030405060708) = sealed message = 0x4db804533e6ffc23 trailer buffer signature with sequence 2: RC4(0x00000000c588ca3f02000000) = 0x5eb9ab2f3736d2b43c149c48 version num + first 4 bytes overwritten w/counter (0x88030700) 01000000880307003736d2b43c149c48 = trailer signature
Demonstration of NTLMv1 authentication with 40-bit Lan Manager Session Key NTLM1 signing and sealing (without key exchange).
LMCompatibilityLevel set to 0 (LM/NTLM). AcquireCredentialsHandle called with domain "TESTNT", user "test", password "test1234". -------------------------------------------------------------------------------- InitializeSecurityContext called with ISC_REQ_INTEGRITY and ISC_REQ_CONFIDENTIALITY. Following flags were masked off of resulting Type 1 message: Negotiate NTLM2 Key (0x00080000) Negotiate 128 (0x20000000) Negotiate Key Exchange (0x40000000) Negotiate 56 (0x80000000) 4e544c4d5353500001000000b782000000000000000000000000000000000000 4e544c4d53535000 "NTLMSSP" 01000000 Type 1 message b7820000 Flags Negotiate Unicode (0x00000001) Negotiate OEM (0x00000002) Request Target (0x00000004) Negotiate Sign (0x00000010) Negotiate Seal (0x00000020) Negotiate Lan Manager Key (0x00000080) Negotiate NTLM (0x00000200) Negotiate Always Sign (0x00008000) 0000000000000000 Supplied Domain header (empty, supplied credentials) 0000000000000000 Supplied Workstation header (empty, supplied credentials) -------------------------------------------------------------------------------- AcceptSecurityContext called with ASC_REQ_INTEGRITY and ASC_REQ_CONFIDENTIALITY. Produces Type 2 message: 4e544c4d53535000020000000c000c0030000000b58281007116b94341ee4e70 0000000000000000460046003c00000054004500530054004e00540002000c00 54004500530054004e00540001000c004d0045004d0042004500520003001e00 6d0065006d006200650072002e0074006500730074002e0063006f006d000000 0000 4e544c4d53535000 "NTLMSSP" 02000000 Type 2 message 0c000c0030000000 Target Name header (length 12, offset 48) b5828100 Flags Negotiate Unicode (0x00000001) Request Target (0x00000004) Negotiate Sign (0x00000010) Negotiate Seal (0x00000020) Negotiate Lan Manager Key (0x00000080) Negotiate NTLM (0x00000200) Negotiate Always Sign (0x00008000) Target Type Domain (0x00010000) Negotiate Target Info (0x00800000) 7116b94341ee4e70 Challenge 0000000000000000 Context 460046003c000000 Target Information header (length 70, offset 60) 54004500530054004e005400 Target Name ("TESTNT") Target Information block: 02000c00 NetBIOS Domain Name (length 12) 54004500530054004e005400 "TESTNT" 01000c00 NetBIOS Server Name (length 12) 4d0045004d00420045005200 "MEMBER" 03001e00 DNS Server Name (length 30) 6d0065006d006200650072002e0074006500730074002e0063006f006d00 "member.test.com" 00000000 Target Information Terminator -------------------------------------------------------------------------------- InitializeSecurityContext called. Produces a Type 3 message: 4e544c4d5353500003000000180018006000000018001800780000000c000c00 40000000080008004c0000000c000c00540000000000000090000000b5828000 54004500530054004e00540074006500730074004d0045004d00420045005200 66271e46d60b246d25fcc3340235841057c2821f490d073304c6e94c5624abad 6c922d8e64b6c86d43138f8f0d94fc3f 4e544c4d53535000 "NTLMSSP" 03000000 Type 3 message 1800180060000000 LM/LMv2 Response header (length 24, offset 96) 1800180078000000 NTLM/NTLMv2 Response header (length 24, offset 120) 0c000c0040000000 Domain Name header (length 12, offset 64) 080008004c000000 User Name header (length 8, offset 76) 0c000c0054000000 Workstation Name header (length 12, offset 84) 0000000090000000 Session Key header (empty) b5828000 Flags Negotiate Unicode (0x00000001) Request Target (0x00000004) Negotiate Sign (0x00000010) Negotiate Seal (0x00000020) Negotiate Lan Manager Key (0x00000080) Negotiate NTLM (0x00000200) Negotiate Always Sign (0x00008000) Negotiate Target Info (0x00800000) 54004500530054004e005400 Domain Name ("TESTNT") 7400650073007400 User Name ("test") 4d0045004d00420045005200 Workstation Name ("MEMBER") 66271e46d60b246d25fcc3340235841057c2821f490d0733 LM/LMv2 Response 04c6e94c5624abad6c922d8e64b6c86d43138f8f0d94fc3f NTLM/NTLMv2 Response -------------------------------------------------------------------------------- AcceptSecurityContext called to complete the server-side context. Server Context Export: 40a42e7840a42e7800000000000000000000000000000000 08ee0b00 server context handle dwUpper b5828101 flags 0000000000000000182e0900182e0900982e0900982e09000000000000000000 d002000000000000000000000000000000000000000000000200000000000000 ffffffffffffff7f20010000 b98a3a22c81e31f99e7eca1e123c04d1 outbound signing key b98a3a22c81e31f99e7eca1e123c04d1 inbound verifying key b98a3a22c81e31f99e7eca1e123c04d1 outbound encrypting key b98a3a22c81e31f99e7eca1e123c04d1 inbound decrypting key 000000000000000000000000 b94480a5718a4f50e1a4e815e91021e0a9a387263fbbd69d6e3b03a2027c0e56 1c47582cab375deacb92462f4db09bb32965670de5dc573e7bf20a901fb68ecd 6d697800a1ced9de7a9a79091b5318b104c827bf7791ad3448c606c5e4bca6eb 7da0949e28ec137596fd5cbaeedb08af52898845a75a95e78d63c36bfe054af0 703df1432aef32f3b2d8594e9961b5251d33f9ae8b2b8fc46a2ef520140fc1d1 d3f785428493a8ff3af8cad216da734c556fdfb4384bb8acf4687672367f1a23 835fc20bcfc05bd0fadd31edfb98b78c823cc9cc629faa1924e3d4300c8681bd 7411e6e235be49396601419cd7541251f6605ed51e6cfcc7407e97176407222d 00000000000000000000000000000000 b94480a5718a4f50e1a4e815e91021e0a9a387263fbbd69d6e3b03a2027c0e56 1c47582cab375deacb92462f4db09bb32965670de5dc573e7bf20a901fb68ecd 6d697800a1ced9de7a9a79091b5318b104c827bf7791ad3448c606c5e4bca6eb 7da0949e28ec137596fd5cbaeedb08af52898845a75a95e78d63c36bfe054af0 703df1432aef32f3b2d8594e9961b5251d33f9ae8b2b8fc46a2ef520140fc1d1 d3f785428493a8ff3af8cad216da734c556fdfb4384bb8acf4687672367f1a23 835fc20bcfc05bd0fadd31edfb98b78c823cc9cc629faa1924e3d4300c8681bd 7411e6e235be49396601419cd7541251f6605ed51e6cfcc7407e97176407222d 0000000000000000 54004500530054004e0054005c007400650073007400 "TESTNT\test" lmHash = lmEncrypt(password, "KGS!@#$%") = 0x624aac413795cdc1ff17365faf1ffe89 trunc(lmHash + pad) = 0x624aac413795cdc1bdbdbdbdbdbd lmResponse[0-7] = 0x66271e46d60b246d LanManagerSessionKey = lmEncrypt(0x624aac413795cdc1bdbdbdbdbdbd, 0x66271e46d60b246d) = 0xb98a3a22c81e31f99e7eca1e123c04d1 Key is weakened to 40-bit w/0xe538b0 = 0xb98a3a22c8e538b0 Called MakeSignature on the server-side context for message "0x0102030405060708". Yields signature: 01000000ffffff001a7599e9ad0ad460 CRC32(0x0102030405060708) = 0xc588ca3f Sequence number is 0. 0x00000000 + crc32 + seqnum = 0x00000000c588ca3f00000000 RC4(key, 0x00000000c588ca3f00000000) = 0xbeb185ce1a7599e9ad0ad460 version num + first 4 bytes overwritten with counter value (0xffffff00 here): 01000000ffffff001a7599e9ad0ad460 = signature -------------------------------------------------------------------------------- Called EncryptMessage twice on the server-side context for message "0x0102030405060708". Yields encrypted messages: 075c81a318754894010000006003070033df86be9d65813d da731ecef152bd750100000048030700a61d753437944ee5 same RC4 cipher is used from previous signing operation (i.e., not reset): RC4(0x0102030405060708) = sealed message = 0x075c81a318754894 trailer buffer gets signature; again uses same RC4 cipher (sequence number is now 1 because of previous signing): RC4(0x00000000c588ca3f01000000) = 0x0004c5b033df86be9d65813d version num + first 4 bytes overwritten w/counter (0x60030700): 010000006003070033df86be9d65813d = trailer signature second message is same: RC4(0x0102030405060708) = sealed message = 0xda731ecef152bd75 trailer buffer signature with sequence 2: RC4(0x00000000c588ca3f02000000) = 0xf012a98ca61d753437944ee5 version num + first 4 bytes overwritten w/counter (0x48030700) 0100000048030700a61d753437944ee5 = trailer signature
Demonstration of datagram-style authentication with default options (defaults to 40-bit Lan Manager Session Key NTLM1 with key exchange when used with NTLMv1).
LMCompatibilityLevel set to 0 (LM/NTLM). AcquireCredentialsHandle called with domain "TESTNT", user "test", password "test1234". -------------------------------------------------------------------------------- InitializeSecurityContext called with: ISC_REQ_INTEGRITY | ISC_REQ_CONFIDENTIALITY | ISC_REG_DATAGRAM Produces no token (datagram-style). Client context can be used for signing and sealing immediately. -------------------------------------------------------------------------------- AcceptSecurityContext called with: ASC_REQ_INTEGRITY | ASC_REQ_CONFIDENTIALITY | ASC_REG_DATAGRAM Produces a Type 2 message: 4e544c4d53535000020000000000000030000000f38298e0ada5839570b5cb99 00000000000000000000000030000000 4e544c4d53535000 "NTLMSSP" 02000000 Type 2 message 0000000030000000 Target Name header (empty) f38298e0 Flags Negotiate Unicode (0x00000001) Negotiate OEM (0x00000002) Negotiate Sign (0x00000010) Negotiate Seal (0x00000020) Negotiate Datagram Style (0x00000040) Negotiate Lan Manager Key (0x00000080) Negotiate NTLM (0x00000200) Negotiate Always Sign (0x00008000) Negotiate NTLM2 Key (0x00080000) Request Init Response (0x00100000) Negotiate Target Info (0x00800000) Negotiate 128 (0x20000000) Negotiate Key Exchange (0x40000000) Negotiate 56 (0x80000000) ada5839570b5cb99 Challenge 0000000000000000 Context 0000000030000000 Target Information header (empty) -------------------------------------------------------------------------------- InitializeSecurityContext called. Produces a Type 3 message: 4e544c4d5353500003000000180018006000000018001800780000000c000c00 40000000080008004c0000000c000c00540000001000100090000000f5828040 54004500530054004e00540074006500730074004d0045004d00420045005200 e8cff653006525da77c6bef2fed79bc6d7d839f598ead91a4e37300050075eeb aa5915480c3620b8ee6fa869cdf16e7c9227ebee8b19a312664fa4ed44bd3377 4e544c4d53535000 "NTLMSSP" 03000000 Type 3 message 1800180060000000 LM/LMv2 Response header (length 24, offset 96) 1800180078000000 NTLM/NTLMv2 Response header (length 24, offset 120) 0c000c0040000000 Domain Name header (length 12, offset 64) 080008004c000000 User Name header (length 8, offset 76) 0c000c0054000000 Workstation Name header (length 12, offset 84) 1000100090000000 Session Key header (length 16, offset 144) f5828040 Flags Negotiate Unicode (0x00000001) Request Target (0x00000004) Negotiate Sign (0x00000010) Negotiate Seal (0x00000020) Negotiate Datagram Style (0x00000040) Negotiate Lan Manager Key (0x00000080) Negotiate NTLM (0x00000200) Negotiate Always Sign (0x00008000) Negotiate Target Info (0x00800000) Negotiate Key Exchange (0x40000000) 54004500530054004e005400 Domain Name ("TESTNT") 7400650073007400 User Name ("test") 4d0045004d00420045005200 Workstation Name ("MEMBER") e8cff653006525da77c6bef2fed79bc6d7d839f598ead91a LM/LMv2 Response 4e37300050075eebaa5915480c3620b8ee6fa869cdf16e7c NTLM/NTLMv2 Response 9227ebee8b19a312664fa4ed44bd3377 Session Key -------------------------------------------------------------------------------- AcceptSecurityContext called to complete the server-side context. Server Context Export: 40a42e7840a42e7800000000000000000000000000000000 08ee0b00 server context handle dwUpper f5828041 flags 000000000000000080740a0080740a0000750a0000750a000000000000000000 d002000000000000000000000000000000000000000000000200000000000000 ffffffffffffff7f20010000 d56070a4c355c2d91693d8f3406d4d82 outbound signing key d56070a4c355c2d91693d8f3406d4d82 inbound verifying key d56070a4c355c2d91693d8f3406d4d82 outbound encrypting key d56070a4c355c2d91693d8f3406d4d82 inbound decrypting key 000000000000000000000000 05f9b27f16db3ea4563b296433256b1076cdd372908ac60367f37d5e495c11ab 378f70d165ea3d633ca5f819e2f45a3906328b8993718c7726d78145042099a7 b0dde1c831986f661ef6bc9dc7de558d80ed447e4cdf749b02b346c4227915cc 09cb75c9430fa3ba53c018fa78b7daff9f62b9efd2a92a60845fe5e0278692dc e983be951f24b6a2ec592194bd352c0cb596fd7ae747fba0a1c5340861b85dc1 91f1aad9fc14e801858251d687a61dbbb157303fd0bf73e4ce526a9c0d0ec250 d454cf2e38ad4dac6c42f0b41223079ef21b7ba83a0a7c5b2debca404f1300e6 d58e582b692f68eee31a88c3ae4a17fe4b484e419a1c280b6e36afd8f56d97f7 00000000000000000000000000000000 05f9b27f16db3ea4563b296433256b1076cdd372908ac60367f37d5e495c11ab 378f70d165ea3d633ca5f819e2f45a3906328b8993718c7726d78145042099a7 b0dde1c831986f661ef6bc9dc7de558d80ed447e4cdf749b02b346c4227915cc 09cb75c9430fa3ba53c018fa78b7daff9f62b9efd2a92a60845fe5e0278692dc e983be951f24b6a2ec592194bd352c0cb596fd7ae747fba0a1c5340861b85dc1 91f1aad9fc14e801858251d687a61dbbb157303fd0bf73e4ce526a9c0d0ec250 d454cf2e38ad4dac6c42f0b41223079ef21b7ba83a0a7c5b2debca404f1300e6 d58e582b692f68eee31a88c3ae4a17fe4b484e419a1c280b6e36afd8f56d97f7 0000000000000000 54004500530054004e0054005c007400650073007400 "TESTNT\test" lmHash = lmEncrypt(password, "KGS!@#$%") = 0x624aac413795cdc1ff17365faf1ffe89 trunc(lmHash + pad) = 0x624aac413795cdc1bdbdbdbdbdbd lmResponse[0-7] = 0xe8cff653006525da LanManagerSessionKey = lmEncrypt(0x624aac413795cdc1bdbdbdbdbdbd, 0xe8cff653006525da) = 0x97dba8c110cd6b7976c02c203c6be07a Key exchange performed: type3Key (from Type 3) = 0x9227ebee8b19a312664fa4ed44bd3377 key = RC4(LanManagerSessionKey, type3Key) = 0xd56070a4c355c2d91693d8f3406d4d82 Key is weakened to 40-bit w/0xe538b0 = 0xd56070a4c3e538b0 Called MakeSignature on the server-side context for message "0x0102030405060708". Yields signature: 010000009801070012c00705ba25a7ec CRC32(0x0102030405060708) = 0xc588ca3f Sequence number is 0. 0x00000000 + crc32 + seqnum = 0x00000000c588ca3f00000000 RC4(key, 0x00000000c588ca3f00000000) = 0x39ec604d12c00705ba25a7ec version num + first 4 bytes overwritten with counter value (0x98010700 here): 010000009801070012c00705ba25a7ec = signature -------------------------------------------------------------------------------- Called EncryptMessage twice on the server-side context for message "0x0102030405060708". Yields encrypted messages: 38ee6349d24eca32010000008803070012c00705ba25a7ec 38ee6349d24eca32010000007003070012c00705ba25a7ec RC4 cipher is reset after each signing/sealing operation in datagram-style: RC4(key, 0x0102030405060708) = sealed message = 0x38ee6349d24eca32 trailer buffer gets signature; RC4 cipher is reset and sequence number is *not* incremented in datagram-style: RC4(key, 0x00000000c588ca3f00000000) = 0x39ec604d12c00705ba25a7ec version num + first 4 bytes overwritten w/counter (0x88030700): 010000008803070012c00705ba25a7ec = trailer signature second message is same: RC4(key, 0x00000000c588ca3f00000000) = 0x39ec604d12c00705ba25a7ec version num + first 4 bytes overwritten w/counter (0x70030700): 010000007003070012c00705ba25a7ec = trailer signature
Demonstration of "dummy" signing and sealing. Context is *not* initialized with support for integrity or confidentiality. "Negotiate Always Sign" is negotiated, which allows the context to be used in dummy signing and sealing.
LMCompatibilityLevel set to 0 (LM/NTLM). AcquireCredentialsHandle called with domain "TESTNT", user "test", password "test1234". -------------------------------------------------------------------------------- InitializeSecurityContext called with default options. Produces Type 1 message: 4e544c4d5353500001000000078200a000000000000000000000000000000000 4e544c4d53535000 "NTLMSSP" 01000000 Type 1 message 078200a0 Flags Negotiate Unicode (0x00000001) Negotiate OEM (0x00000002) Request Target (0x00000004) Negotiate NTLM (0x00000200) Negotiate Always Sign (0x00008000) Negotiate 128 (0x20000000) Negotiate 56 (0x80000000) 0000000000000000 Supplied Domain header (empty, supplied credentials) 0000000000000000 Supplied Workstation header (empty, supplied credentials) -------------------------------------------------------------------------------- AcceptSecurityContext called with default options. Produces Type 2 message: 4e544c4d53535000020000000c000c0030000000058281a0eacf7d5a2a6fa7d4 0000000000000000460046003c00000054004500530054004e00540002000c00 54004500530054004e00540001000c004d0045004d0042004500520003001e00 6d0065006d006200650072002e0074006500730074002e0063006f006d000000 0000 4e544c4d53535000 "NTLMSSP" 02000000 Type 2 message 0c000c0030000000 Target Name header (length 12, offset 48) 058281a0 Flags Negotiate Unicode (0x00000001) Request Target (0x00000004) Negotiate NTLM (0x00000200) Negotiate Always Sign (0x00008000) Target Type Domain (0x00010000) Negotiate Target Info (0x00800000) Negotiate 128 (0x20000000) Negotiate 56 (0x80000000) eacf7d5a2a6fa7d4 Challenge 0000000000000000 Context 460046003c000000 Target Information header (length 70, offset 60) 54004500530054004e005400 Target Name ("TESTNT") Target Information block: 02000c00 NetBIOS Domain Name (length 12) 54004500530054004e005400 "TESTNT" 01000c00 NetBIOS Server Name (length 12) 4d0045004d00420045005200 "MEMBER" 03001e00 DNS Server Name (length 30) 6d0065006d006200650072002e0074006500730074002e0063006f006d00 "member.test.com" 00000000 Target Information Terminator -------------------------------------------------------------------------------- InitializeSecurityContext called. Produces a Type 3 message: 4e544c4d53535000 "NTLMSSP" 03000000 Type 3 message 1800180060000000 LM/LMv2 Response header (length 24, offset 96) 1800180078000000 NTLM/NTLMv2 Response header (length 24, offset 120) 0c000c0040000000 Domain Name header (length 12, offset 64) 080008004c000000 User Name header (length 8, offset 76) 0c000c0054000000 Workstation Name header (length 12, offset 84) 0000000090000000 Session Key header (empty) 058280a0 Flags Negotiate Unicode (0x00000001) Request Target (0x00000004) Negotiate NTLM (0x00000200) Negotiate Always Sign (0x00008000) Negotiate Target Info (0x00800000) Negotiate 128 (0x20000000) Negotiate 56 (0x80000000) 54004500530054004e005400 Domain Name ("TESTNT") 7400650073007400 User Name ("test") 4d0045004d00420045005200 Workstation Name ("MEMBER") 6c454794b50321a067fdf78e92ee5085a5b0a23057e9125b LM/LMv2 Response d2025bc5d6c201af7472550a677ca9904245a16ebb542a8e NTLM/NTLMv2 Response -------------------------------------------------------------------------------- AcceptSecurityContext called to complete the server-side context. Server Context Export: 40a42e7840a42e7800000000000000000000000000000000 08ee0b00 server context handle dwUpper 058281a1 flags 000000000000000028f5080028f50800a8f50800a8f508000000000000000000 d002000000000000000000000000000000000000000000000200000000000000 ffffffffffffff7f20010000 ae33a32dca8c9821844f740d5b3f4d6c outbound signing key ae33a32dca8c9821844f740d5b3f4d6c inbound verifying key ae33a32dca8c9821844f740d5b3f4d6c outbound encrypting key ae33a32dca8c9821844f740d5b3f4d6c inbound decrypting key 000000000000000000000000 ae3787b72ff94884680d3e5658c064df9d9e5d8f0655f22a002ebc7e9f944e29 08cf90e0057f622d31a92b7d0ca6f586d5d36e24af70cdbe52ea49d067aa4ffa e85a5cb1a41e3241a288f8de8a4c8909593cc698b657750af014b26f13778eee 855310d716f61ce5c795a0a3bbac358bb02611c954a54b2791d6e297f1fd8c6d 18fffc190b9c69b80122f7c8fb036146c2b581443960fe239b967b17e33de15b 73e445401f1db3a8c5ad51f48d665e38796b8263b9ca363f763aef71d1ec12d8 a76cb46a333b0fddab7850ba3493dcd4077299d22515eb5f300221e9e79a80d9 1a1b4d2865e6ccc3470eda7c4ace04bfbddbedc1cb207483f343c4a1422c7a92 00000000000000000000000000000000 ae3787b72ff94884680d3e5658c064df9d9e5d8f0655f22a002ebc7e9f944e29 08cf90e0057f622d31a92b7d0ca6f586d5d36e24af70cdbe52ea49d067aa4ffa e85a5cb1a41e3241a288f8de8a4c8909593cc698b657750af014b26f13778eee 855310d716f61ce5c795a0a3bbac358bb02611c954a54b2791d6e297f1fd8c6d 18fffc190b9c69b80122f7c8fb036146c2b581443960fe239b967b17e33de15b 73e445401f1db3a8c5ad51f48d665e38796b8263b9ca363f763aef71d1ec12d8 a76cb46a333b0fddab7850ba3493dcd4077299d22515eb5f300221e9e79a80d9 1a1b4d2865e6ccc3470eda7c4ace04bfbddbedc1cb207483f343c4a1422c7a92 0000000000000000 54004500530054004e0054005c007400650073007400 "TESTNT\test" ntlmHash = md4(password) = 0x3b1b47e42e0463276e3ded6cef349f93 NTLMUserSessionKey = md4(ntlmHash) = 0xae33a32dca8c9821844f740d5b3f4d6c Key is *not* weakened (NTLM1 only weakens Lan Manager Session Keys). Called MakeSignature on the server-side context for message "0x0102030405060708". Yields signature: 01000000000000000000000000000000 ("dummy" signature) -------------------------------------------------------------------------------- Called EncryptMessage twice on the server-side context for message "0x0102030405060708". Yields encrypted messages: 2194108dc8f329290100000048020700fa4f9c95a098b258 8f88dc2f36cd5e710100000030020700d825f5a1154aa5fc RC4(key, 0x0102030405060708) = sealed message = 0x2194108dc8f32929 trailer buffer gets signature; uses same RC4 cipher as sealing (sequence number is 0, previous dummy signing doesn't count): RC4(0x00000000c588ca3f00000000) = 0x039ae5c5fa4f9c95a098b258 version num + first 4 bytes overwritten w/counter (0x48020700): 0100000048020700fa4f9c95a098b258 = trailer signature second message is same: RC4(0x0102030405060708) = sealed message = 0x8f88dc2f36cd5e71 trailer buffer signature with sequence 1 (previous trailer signature incremented it): RC4(0x00000000c588ca3f01000000) = 0x6b9317f7d825f5a1154aa5fc version num + first 4 bytes overwritten w/counter (0x30020700) 0100000030020700d825f5a1154aa5fc = trailer signature
Demonstration of NTLMv1 authentication with 128-bit NTLM2 Session Response User Session Key NTLM2 signing and sealing, with key exchange enabled.
LMCompatibilityLevel set to 0 (LM/NTLM). AcquireCredentialsHandle called with domain "TESTNT", user "test", password "test1234". -------------------------------------------------------------------------------- InitializeSecurityContext called with ISC_REQ_INTEGRITY and ISC_REQ_CONFIDENTIALITY. 4e544c4d5353500001000000b78208e000000000000000000000000000000000 4e544c4d53535000 "NTLMSSP" 01000000 Type 1 message b78208e0 Flags Negotiate Unicode (0x00000001) Negotiate OEM (0x00000002) Request Target (0x00000004) Negotiate Sign (0x00000010) Negotiate Seal (0x00000020) Negotiate Lan Manager Key (0x00000080) Negotiate NTLM (0x00000200) Negotiate Always Sign (0x00008000) Negotiate NTLM2 Key (0x00080000) Negotiate 128 (0x20000000) Negotiate Key Exchange (0x40000000) Negotiate 56 (0x80000000) 0000000000000000 Supplied Domain header (empty, supplied credentials) 0000000000000000 Supplied Workstation header (empty, supplied credentials) -------------------------------------------------------------------------------- AcceptSecurityContext called with ASC_REQ_INTEGRITY and ASC_REQ_CONFIDENTIALITY. Produces Type 2 message: 4e544c4d53535000020000000c000c0030000000358289e0677f1c557a5ee96c 0000000000000000460046003c00000054004500530054004e00540002000c00 54004500530054004e00540001000c004d0045004d0042004500520003001e00 6d0065006d006200650072002e0074006500730074002e0063006f006d000000 0000 4e544c4d53535000 "NTLMSSP" 02000000 Type 2 message 0c000c0030000000 Target Name header (length 12, offset 48) 358289e0 Flags Negotiate Unicode (0x00000001) Request Target (0x00000004) Negotiate Sign (0x00000010) Negotiate Seal (0x00000020) Negotiate NTLM (0x00000200) Negotiate Always Sign (0x00008000) Target Type Domain (0x00010000) Negotiate NTLM2 Key (0x00080000) Negotiate Target Info (0x00800000) Negotiate 128 (0x20000000) Negotiate Key Exchange (0x40000000) Negotiate 56 (0x80000000) 677f1c557a5ee96c Challenge 0000000000000000 Context 460046003c000000 Target Information header (length 70, offset 60) 54004500530054004e005400 Target Name ("TESTNT") Target Information block: 02000c00 NetBIOS Domain Name (length 12) 54004500530054004e005400 "TESTNT" 01000c00 NetBIOS Server Name (length 12) 4d0045004d00420045005200 "MEMBER" 03001e00 DNS Server Name (length 30) 6d0065006d006200650072002e0074006500730074002e0063006f006d00 "member.test.com" 00000000 Target Information Terminator -------------------------------------------------------------------------------- InitializeSecurityContext called. Produces a Type 3 message: 4e544c4d5353500003000000180018006000000018001800780000000c000c00 40000000080008004c0000000c000c00540000001000100090000000358288e0 54004500530054004e00540074006500730074004d0045004d00420045005200 404d1b6f6915258000000000000000000000000000000000ea8cc49f24da157f 13436637f77693d8b992d619e584c7ee727a5240822ec7af4e9100c43e6fee7f 4e544c4d53535000 "NTLMSSP" 03000000 Type 3 message 1800180060000000 LM/LMv2 Response header (length 24, offset 96) 1800180078000000 NTLM/NTLMv2 Response header (length 24, offset 120) 0c000c0040000000 Domain Name header (length 12, offset 64) 080008004c000000 User Name header (length 8, offset 76) 0c000c0054000000 Workstation Name header (length 12, offset 84) 1000100090000000 Session Key header (length 16, offset 144) 358288e0 Flags Negotiate Unicode (0x00000001) Request Target (0x00000004) Negotiate Sign (0x00000010) Negotiate Seal (0x00000020) Negotiate NTLM (0x00000200) Negotiate Always Sign (0x00008000) Negotiate NTLM2 Key (0x00080000) Negotiate Target Info (0x00800000) Negotiate 128 (0x20000000) Negotiate Key Exchange (0x40000000) Negotiate 56 (0x80000000) 54004500530054004e005400 Domain Name ("TESTNT") 7400650073007400 User Name ("test") 4d0045004d00420045005200 Workstation Name ("MEMBER") 404d1b6f6915258000000000000000000000000000000000 LM/LMv2 Response ea8cc49f24da157f13436637f77693d8b992d619e584c7ee NTLM/NTLMv2 Response 727a5240822ec7af4e9100c43e6fee7f Session Key -------------------------------------------------------------------------------- AcceptSecurityContext called to complete the server-side context. Server Context Export: 48a42e7848a42e7800000000000000000000000000000000 70f10b00 server context handle dwUpper 358289e1 flags 0000000000000000382e09003c2e0900b82e0900c82f09000000000000000000 d002000000000000000000000000000000000000000000000200000000000000 ffffffffffffff7f20010000 6c713b60e6571035c9396ece1e456395 outbound signing key e775c02a63d159ec64185f6d7d993344 inbound verifying key e9b0f8e2cbf7b453b8389e8d2d7bb4ba outbound encrypting key cc0fc51f360b7da837cde6cb417fd735 inbound decrypting key 000000000000000000000000 e932727927bbfe589b599a99d212bf23479fa99e7d8953bd6764862e690a6fac b5f935ba02df8a75e415ddf7d30fc9a89778a2b7d4f0cc0c032b8757b4312663 8c0b39136536b8af1c3a774fc890cf30fbd16b18059c5eec7b3b3782efe06628 216aeda7e83fcb1446344bdeeb1ef5914ad894333d96ea51fdfc8311ad175b52 254ed93ce58bff50d0c78561aeb36ef8952c205acef3cad506085d5c700080ab c6d77c22b1c22fb9c32a73a0481d100e298e929dc0e1a671ee1f8d4438a5c476 f22d847ec1196ce6094d5f3edc4201b28f6d43aaf4cdf1e362d6fa98a19307b0 55f640e7544c457424bc04c5dadb41160d7f88beb656a41be21a607a688149a3 00000000000000000000000000000000 cc094487604571968040c0ac1fe2da492938751932bc4139040def8c27635807 ad4e68b5ab6c6a65897f8f2df24f02164cc35466d0111d81f026a23d6d7221fd 34c9cb885e52b10ec88e532ec57a8ba5a6eb3f769446b62ab8a3840548220cd8 ff3b9bb2b731e1e64a50ae08917dc28d869215cf5a677920a801a493c143ec97 1efb576bd717b0303ea9be9fdb9a5dd55b1b8a77aaf42f9ccea183ea6eb36428 f7984bf9d39e9524a7eedd00cae5425533d9bded0b51ded2e43769c7c41a7bc6 af595ff1e33612e8614ddfe9f523785673a085fcd1d67ed4356f5ccd9ddc9003 0a4799bb2b70e71418823cfa06e0f62cbffe133a7cb4baf8101cf325620fb974 0000000000000000 54004500530054004e0054005c007400650073007400 "TESTNT\test" ntlmHash = md4(password) = 0x3b1b47e42e0463276e3ded6cef349f93 NTLMUserSessionKey = md4(ntlmHash) = 0xae33a32dca8c9821844f740d5b3f4d6c challenge (from Type 2) = 0x677f1c557a5ee96c nonce (from Type 3) = 0x404d1b6f69152580 NTLM2SessionResponseUserSessionKey = HMAC(NTLMUserSessionKey, challenge + nonce) = 0x0d4b30a8750b73ab2dab39e889455fcd Key exchange performed: type3Key (from Type 3) = 0x727a5240822ec7af4e9100c43e6fee7f key = RC4(NTLM2SessionResponseUserSessionKey, type3Key) = 0x5764dc0a93b1292fa898c29524c30a54 We are using server context: serverSigningConstant = "session key to server-to-client signing key magic constant" = 0x73657373696f6e206b657920746f207365727665722d746f2d636c69656e74 207369676e696e67206b6579206d6167696320636f6e7374616e7400 serverSealingConstant = "session key to server-to-client sealing key magic constant" = 0x73657373696f6e206b657920746f207365727665722d746f2d636c69656e74 207365616c696e67206b6579206d6167696320636f6e7374616e7400 signingKey = MD5(key + serverSigningConstant) = 0x6c713b60e6571035c9396ece1e456395 User Session Key is not weakened (128-bit negotiated). sealingKey = MD5(key + serverSealingConstant) = 0xe9b0f8e2cbf7b453b8389e8d2d7bb4ba Called MakeSignature on the server-side context for message "0x0102030405060708". Yields signature: 0100000069de1aff9cbee43100000000 Sequence number is 0. seqnum + message = 0x000000000102030405060708 HMAC(signingKey, 0x000000000102030405060708) = 0x9d642651faec52f2164297dcaaa1ff6e sig = RC4(sealingKey, first 8 bytes) = 0x69de1aff9cbee431 version num + sig + seqnum: 0100000069de1aff9cbee43100000000 = signature -------------------------------------------------------------------------------- Called EncryptMessage twice on the server-side context for message "0x0102030405060708". Yields encrypted messages: 5b4cbbd3b2d8e8a401000000272c6dee5b236fe201000000 29535954c1e00fb9010000002922b8fcada4cda202000000 Uses RC4 cipher from previous signing operation (key exchange encrypts signature with sealing key as well). RC4(0x0102030405060708) = sealed message = 0x5b4cbbd3b2d8e8a4 trailer buffer gets signature (sequence number is now 1 because of previous signing, same RC4 cipher used for this signature too): HMAC(signingKey, 0x010000000102030405060708) = 0x1b7fc502e4cc73b6d85360d7ee052800 sig = RC4(first 8 bytes) = 0x272c6dee5b236fe2 version num + sig + seqnum: 01000000272c6dee5b236fe201000000 = trailer signature second message is same, using RC4 cipher from previous operations: RC4(0x0102030405060708) = sealed message = 0x29535954c1e00fb9 trailer buffer signature with sequence 2: HMAC(signingKey, 0x020000000102030405060708) = 0x3e46a45716671a6e0d056636f77db4bb sig = RC4(first 8 bytes) = 0x2922b8fcada4cda2 version num + sig + seqnum: 010000002922b8fcada4cda202000000 = trailer signature
Demonstration of NTLMv1 authentication with 40-bit NTLM2 Session Response User Session Key NTLM2 signing and sealing (without key exchange).
LMCompatibilityLevel set to 0 (LM/NTLM). AcquireCredentialsHandle called with domain "TESTNT", user "test", password "test1234". -------------------------------------------------------------------------------- InitializeSecurityContext called with ISC_REQ_INTEGRITY and ISC_REQ_CONFIDENTIALITY. Following flags were masked off of resulting Type 1 message: Negotiate 128 (0x20000000) Negotiate Key Exchange (0x40000000) Negotiate 56 (0x80000000) 4e544c4d5353500001000000b782080000000000000000000000000000000000 4e544c4d53535000 "NTLMSSP" 01000000 Type 1 message b7820800 Flags Negotiate Unicode (0x00000001) Negotiate OEM (0x00000002) Request Target (0x00000004) Negotiate Sign (0x00000010) Negotiate Seal (0x00000020) Negotiate Lan Manager Key (0x00000080) Negotiate NTLM (0x00000200) Negotiate Always Sign (0x00008000) Negotiate NTLM2 Key (0x00080000) 0000000000000000 Supplied Domain (empty, supplied credentials) 0000000000000000 Supplied Workstation (empty, supplied credentials) -------------------------------------------------------------------------------- AcceptSecurityContext called with ASC_REQ_INTEGRITY and ASC_REQ_CONFIDENTIALITY. Produces Type 2 message: 4e544c4d53535000020000000c000c003000000035828900919013ccde5c4d16 0000000000000000460046003c00000054004500530054004e00540002000c00 54004500530054004e00540001000c004d0045004d0042004500520003001e00 6d0065006d006200650072002e0074006500730074002e0063006f006d000000 0000 4e544c4d53535000 "NTLMSSP" 02000000 Type 2 message 0c000c0030000000 Target Name header (length 12, offset 48) 35828900 Flags Negotiate Unicode (0x00000001) Request Target (0x00000004) Negotiate Sign (0x00000010) Negotiate Seal (0x00000020) Negotiate NTLM (0x00000200) Negotiate Always Sign (0x00008000) Target Type Domain (0x00010000) Negotiate NTLM2 Key (0x00080000) Negotiate Target Info (0x00800000) 919013ccde5c4d16 Challenge 0000000000000000 Context 460046003c000000 Target Information header (length 70, offset 60) 54004500530054004e005400 Target Name ("TESTNT") Target Information block: 02000c00 NetBIOS Domain Name (length 12) 54004500530054004e005400 "TESTNT" 01000c00 NetBIOS Server Name (length 12) 4d0045004d00420045005200 "MEMBER" 03001e00 DNS Server Name (length 30) 6d0065006d006200650072002e0074006500730074002e0063006f006d00 "member.test.com" 00000000 Target Information Terminator -------------------------------------------------------------------------------- InitializeSecurityContext called. Produces a Type 3 message: 4e544c4d5353500003000000180018006000000018001800780000000c000c00 40000000080008004c0000000c000c0054000000000000009000000035828800 54004500530054004e00540074006500730074004d0045004d00420045005200 02a668799b43b02600000000000000000000000000000000191c91d68a26a933 82ec89178c1e496d8f2f63a1c7dc0b54 4e544c4d53535000 "NTLMSSP" 03000000 Type 3 message 1800180060000000 LM/LMv2 Response header (length 24, offset 96) 1800180078000000 NTLM/NTLMv2 Response header (length 24, offset 120) 0c000c0040000000 Domain Name header (length 12, offset 64) 080008004c000000 User Name header (length 8, offset 76) 0c000c0054000000 Workstation Name header (length 12, offset 84) 0000000090000000 Session Key header (empty) 35828800 Flags Negotiate Unicode (0x00000001) Request Target (0x00000004) Negotiate Sign (0x00000010) Negotiate Seal (0x00000020) Negotiate NTLM (0x00000200) Negotiate Always Sign (0x00008000) Negotiate NTLM2 Key (0x00080000) Negotiate Target Info (0x00800000) 54004500530054004e005400 Domain Name ("TESTNT") 7400650073007400 User Name ("test") 4d0045004d00420045005200 Workstation Name ("MEMBER") 02a668799b43b02600000000000000000000000000000000 LM/LMv2 Response 191c91d68a26a93382ec89178c1e496d8f2f63a1c7dc0b54 NTLM/NTLMv2 Response -------------------------------------------------------------------------------- AcceptSecurityContext called to complete the server-side context. Server Context Export: 40a42e7840a42e7800000000000000000000000000000000 08ee0b00 server context handle dwUpper 35828901 flags 0000000000000000f8290900fc290900782a0900882b09000000000000000000 d002000000000000000000000000000000000000000000000200000000000000 ffffffffffffff7f20010000 605b738984f36aea7d2ccc5678670f2c outbound signing key 94d75dd6591eb8569d8480b5c9c25136 inbound verifying key e4c55ca209611e9e007009731b7103d5 outbound encrypting key 738e75e9b0df0ac9139839abf5cc8354 inbound decrypting key 000000000000000000000000 37aa90adbac5442beb5c77f553b782d01859687c2e421e524e2fbc4ad5ff0555 43657a283af2366b3f3cafa80372a3a781b123dd6f2c22e45e0c57d23bd78399 f64935c94bbf9112156a67a2dc843e1a7069f8ec30f99388fa61c4cf4c3d3824 b046df9c31fc0a0150d6638ca17fb651c79db25d07efbea5dea02580fe406211 ea9b1341b41f76e366857d5afbe92adb6ee2940bfd6c4fe12995b5acc05fbb73 a98bbd33b906ae14a4da00cb0dcc1b75f0edc2792d9e60cef1c192741d8a1039 8d7b479a97b30e20f4217ef39fe6c30948199604c8f79856d1ee4dd9e589648e 26ca86c67802e78f5b34e8a617d3ab5408582745cdd416711c32e06d87b80fd8 00000000000000000000000000000000 eb024b64187446dcf798db69a299356807ba78fec2b642e6cd77a097a80bb9a5 38e7548a935d923dbd22e1b7d80127fc1cc9fad61e404eac033f6bab10e57923 878f729e84500ce97139d5cb8c11c7b21741e2325f56a34aad757a804f34ed19 a747bf05af9b912f94ffea700dd43a8806d73eb4458bd97e1a375c6d9633f3c6 49092dc8635a9a589ce35221c5dda1f926ef1f6a5bc03bb1ce65e089149d2baa 28b3cab59f448655306c25133629bc812c57be592a1b0e1204537bcf00d176b0 3c0faecce8f6c4dfd0674cfbd27d95fdf1da318e8d8582bbec7f16f0c162eea6 0a8324f26660151d2eb851736edea9e4f86f08a45e4dc3d37c48f54390f46120 0000000000000000 54004500530054004e0054005c007400650073007400 "TESTNT\test" ntlmHash = md4(password) = 0x3b1b47e42e0463276e3ded6cef349f93 NTLMUserSessionKey = md4(ntlmHash) = 0xae33a32dca8c9821844f740d5b3f4d6c challenge (from Type 2) = 0x919013ccde5c4d16 nonce (from Type 3) = 0x02a668799b43b026 NTLM2SessionResponseUserSessionKey = HMAC(NTLMUserSessionKey, challenge + nonce) = 0x6b60097a8f9dbbff2d23f5b15377ca28 We are using server context: serverSigningConstant = "session key to server-to-client signing key magic constant" = 0x73657373696f6e206b657920746f207365727665722d746f2d636c69656e74 207369676e696e67206b6579206d6167696320636f6e7374616e7400 serverSealingConstant = "session key to server-to-client sealing key magic constant" = 0x73657373696f6e206b657920746f207365727665722d746f2d636c69656e74 207365616c696e67206b6579206d6167696320636f6e7374616e7400 signingKey = MD5(key + serverSigningConstant) = 0x605b738984f36aea7d2ccc5678670f2c User Session Key is weakened to 40-bit for sealing by truncating = 0x6b60097a8f sealingKey = MD5(weakenedKey + serverSealingConstant) = 0xe4c55ca209611e9e007009731b7103d5 Called MakeSignature on the server-side context for message "0x0102030405060708". Yields signature: 01000000d1e2d811145d81ec00000000 Sequence number is 0. seqnum + message = 0x000000000102030405060708 HMAC(signingKey, 0x000000000102030405060708) = 0xd1e2d811145d81ecf5f8723312c75e3c version num + first 8 bytes + seqnum: 01000000d1e2d811145d81ec00000000 = signature -------------------------------------------------------------------------------- Called EncryptMessage twice on the server-side context for message "0x0102030405060708". Yields encrypted messages: ab8d38bb0cad7dd601000000eed64de8afb80c8001000000 b011cc07a7f6127b01000000644a8509d73ac48c02000000 RC4(sealingKey, 0x0102030405060708) = sealed message = 0xab8d38bb0cad7dd6 trailer buffer gets signature (sequence number is now 1 because of previous signing): HMAC(signingKey, 0x010000000102030405060708) = 0xeed64de8afb80c801ea5ddd1d98cbdc8 version num + first 8 bytes + seqnum: 01000000eed64de8afb80c8001000000 = trailer signature second message is same, using RC4 cipher from previous sealing operation: RC4(0x0102030405060708) = sealed message = 0xb011cc07a7f6127b trailer buffer signature with sequence 2: HMAC(signingKey, 0x020000000102030405060708) = 0x644a8509d73ac48c8f5a7f7f65bc8381 version num + first 8 bytes + seqnum: 01000000644a8509d73ac48c02000000 = trailer signature
Demonstration of NTLMv2 authentication with NTLMv2 User Session Key NTLM1 signing and sealing (without key exchange).
LMCompatibilityLevel set to 3 (LMv2/NTLMv2). AcquireCredentialsHandle called with domain "TESTNT", user "test", password "test1234". -------------------------------------------------------------------------------- InitializeSecurityContext called with ISC_REQ_INTEGRITY and ISC_REQ_CONFIDENTIALITY. Following flags were masked off of resulting Type 1 message: Negotiate Lan Manager Key (0x00000080) Negotiate NTLM2 Key (0x00080000) Negotiate 128 (0x20000000) Negotiate Key Exchange (0x40000000) Negotiate 56 (0x80000000) 4e544c4d53535000010000003782000000000000000000000000000000000000 4e544c4d53535000 "NTLMSSP" 01000000 Type 1 message 37820000 Flags Negotiate Unicode (0x00000001) Negotiate OEM (0x00000002) Request Target (0x00000004) Negotiate Sign (0x00000010) Negotiate Seal (0x00000020) Negotiate NTLM (0x00000200) Negotiate Always Sign (0x00008000) 0000000000000000 Supplied Domain header (empty, supplied credentials) 0000000000000000 Supplied Workstation header (empty, supplied credentials) -------------------------------------------------------------------------------- AcceptSecurityContext called with ASC_REQ_INTEGRITY and ASC_REQ_CONFIDENTIALITY. Produces Type 2 message: 4e544c4d53535000020000000c000c0030000000358281000033b02d17275b77 0000000000000000460046003c00000054004500530054004e00540002000c00 54004500530054004e00540001000c004d0045004d0042004500520003001e00 6d0065006d006200650072002e0074006500730074002e0063006f006d000000 0000 4e544c4d53535000 "NTLMSSP" 02000000 Type 2 message 0c000c0030000000 Target Name header (length 12, offset 48) 35828100 Flags Negotiate Unicode (0x00000001) Request Target (0x00000004) Negotiate Sign (0x00000010) Negotiate Seal (0x00000020) Negotiate NTLM (0x00000200) Negotiate Always Sign (0x00008000) Target Type Domain (0x00010000) Negotiate Target Info (0x00800000) 0033b02d17275b77 Challenge 0000000000000000 Context 460046003c000000 Target Information header (length 70, offset 60) 54004500530054004e005400 Target Name ("TESTNT") Target Information block: 02000c00 NetBIOS Domain Name (length 12) 54004500530054004e005400 "TESTNT" 01000c00 NetBIOS Server Name (length 12) 4d0045004d00420045005200 "MEMBER" 03001e00 DNS Server Name (length 30) 6d0065006d006200650072002e0074006500730074002e0063006f006d00 "member.test.com" 00000000 Target Information Terminator -------------------------------------------------------------------------------- InitializeSecurityContext called. Produces a Type 3 message: 4e544c4d5353500003000000180018006000000076007600780000000c000c00 40000000080008004c0000000c000c005400000000000000ee00000035828000 54004500530054004e00540074006500730074004d0045004d00420045005200 5d55a02b60a40526ac9a1e4d15fa45a0f2e6329726c598e8f77c67dad00b9321 6242b197fe6addfa0101000000000000502db638677bc301f2e6329726c598e8 0000000002000c0054004500530054004e00540001000c004d0045004d004200 4500520003001e006d0065006d006200650072002e0074006500730074002e00 63006f006d000000000000000000 4e544c4d53535000 "NTLMSSP" 03000000 Type 3 message 1800180060000000 LM/LMv2 Response header (length 24, offset 96) 7600760078000000 NTLM/NTLMv2 Response header (length 118, offset 120) 0c000c0040000000 Domain Name header (length 12, offset 64) 080008004c000000 User Name header (length 8, offset 76) 0c000c0054000000 Workstation Name header (length 12, offset 84) 00000000ee000000 Session Key header (empty) 35828000 Flags Negotiate Unicode (0x00000001) Request Target (0x00000004) Negotiate Sign (0x00000010) Negotiate Seal (0x00000020) Negotiate NTLM (0x00000200) Negotiate Always Sign (0x00008000) Negotiate Target Info (0x00800000) 54004500530054004e005400 Domain Name ("TESTNT") 7400650073007400 User Name ("test") 4d0045004d00420045005200 Workstation Name ("MEMBER") 5d55a02b60a40526ac9a1e4d15fa45a0f2e6329726c598e8 LM/LMv2 Response NTLM/NTLMv2 Response: f77c67dad00b93216242b197fe6addfa0101000000000000502db638677bc301 f2e6329726c598e80000000002000c0054004500530054004e00540001000c00 4d0045004d0042004500520003001e006d0065006d006200650072002e007400 6500730074002e0063006f006d000000000000000000 -------------------------------------------------------------------------------- AcceptSecurityContext called to complete the server-side context. Server Context Export: 40a42e7840a42e7800000000000000000000000000000000 08ee0b00 server context handle dwUpper 35828101 flags, also has an unknown flag set 0000000000000000782e0900782e0900f82e0900f82e09000000000000000000 d002000000000000000000000000000000000000000000000200000000000000 ffffffffffffff7f20010000 1c4c7aaa7403acf01b1fa565bc950810 outbound signing key 1c4c7aaa7403acf01b1fa565bc950810 inbound verifying key 1c4c7aaa7403acf01b1fa565bc950810 outbound encrypting key 1c4c7aaa7403acf01b1fa565bc950810 inbound decrypting key 000000000000000000000000 783ee50c1d1209b1cb2ea115e7899fbe9547b2b03c1ef14c20d102e0a7282a00 d4919756821af4ff388a5333c51835fc482c71a5f6bdea3745e2dc6124dd3241 c9a9849d267ebc3d7608554962235fb568d6874699cd141fb7395b801b796650 ca0edaee65d2304afe707504067aefb38669eda3547f7c5d946ecf3aadbf437d 6f4288e1d9a6935e63ae7ba467afaac1ccc3529a1c36d7b49cf2e407779e2985 3173db8d814e9b405cc00d01d5d016a022b6c62be96b90c2f792ecce4dc4f36c f58b2d74980a6dde17d3d8f8e63b0b7264342f600fab05580344bae88ffa5ab9 27df19f96a51bba8f083eb3f10ac218cfdc8fb8ea2255711c74b4f5913e3b896 00000000000000000000000000000000 783ee50c1d1209b1cb2ea115e7899fbe9547b2b03c1ef14c20d102e0a7282a00 d4919756821af4ff388a5333c51835fc482c71a5f6bdea3745e2dc6124dd3241 c9a9849d267ebc3d7608554962235fb568d6874699cd141fb7395b801b796650 ca0edaee65d2304afe707504067aefb38669eda3547f7c5d946ecf3aadbf437d 6f4288e1d9a6935e63ae7ba467afaac1ccc3529a1c36d7b49cf2e407779e2985 3173db8d814e9b405cc00d01d5d016a022b6c62be96b90c2f792ecce4dc4f36c f58b2d74980a6dde17d3d8f8e63b0b7264342f600fab05580344bae88ffa5ab9 27df19f96a51bba8f083eb3f10ac218cfdc8fb8ea2255711c74b4f5913e3b896 0000000000000000 54004500530054004e0054005c007400650073007400 "TESTNT\test" ntlmHash = md4(password) = 0x3b1b47e42e0463276e3ded6cef349f93 ntlmv2Hash = hmac(ntlmHash, "TESTTESTNT") = 0xc4ea95cb148df11bf9d7c3611ad6d722 challenge (from Type 2) = 0x0033b02d17275b77 blob (from Type 3) = 0x0101000000000000502db638677bc301f2e632972 6c598e80000000002000c0054004500530054004e00540001000c004d0045004 d0042004500520003001e006d0065006d006200650072002e007400650073007 4002e0063006f006d000000000000000000 NTLMv2UserSessionKey = HMAC(ntlmv2Hash(HMAC(ntlmv2Hash, challenge + blob))) = 0x1c4c7aaa7403acf01b1fa565bc950810 Key is *not* weakened (NTLM1 only weakens Lan Manager Session Keys). Called MakeSignature on the server-side context for message "0x0102030405060708". Yields signature: 01000000ffffff0051cefea77f098ee3 CRC32(0x0102030405060708) = 0xc588ca3f Sequence number is 0. 0x00000000 + crc32 + seqnum = 0x00000000c588ca3f00000000 RC4(key, 0x00000000c588ca3f00000000) = 0x8661cb7d51cefea77f098ee3 version num + first 4 bytes overwritten with counter value (0xffffff00 here): 01000000ffffff0051cefea77f098ee3 = signature -------------------------------------------------------------------------------- Called EncryptMessage twice on the server-side context for message "0x0102030405060708". Yields encrypted messages: f483b904264d83060100000098010700bd9719c0b34f5362 022cc2127f9e206e01000000800307001855ec8494231273 same RC4 cipher is used from previous signing operation (i.e., not reset): RC4(0x0102030405060708) = sealed message = 0xf483b904264d8306 trailer buffer gets signature; again uses same RC4 cipher (sequence number is now 1 because of previous signing): RC4(0x00000000c588ca3f01000000) = 0x2246e9cbbd9719c0b34f5362 version num + first 4 bytes overwritten w/counter (0x98010700): 0100000098010700bd9719c0b34f5362 = trailer signature second message is same: RC4(0x0102030405060708) = sealed message = 0x022cc2127f9e206e trailer buffer signature with sequence 2: RC4(0x00000000c588ca3f02000000) = 0x6fde4d031855ec8494231273 version num + first 4 bytes overwritten w/counter (0x80030700) 01000000800307001855ec8494231273 = trailer signature
Demonstration of NTLMv2 authentication with 56-bit NTLMv2 User Session Key NTLM2 signing and sealing (without key exchange).
LMCompatibilityLevel set to 3 (LMv2/NTLMv2). AcquireCredentialsHandle called with domain "TESTNT", user "test", password "test1234". -------------------------------------------------------------------------------- InitializeSecurityContext called with ISC_REQ_INTEGRITY and ISC_REQ_CONFIDENTIALITY. Following flags were masked off of resulting Type 1 message: Negotiate 128 (0x20000000) Negotiate Key Exchange (0x40000000) 4e544c4d5353500001000000b782088000000000000000000000000000000000 4e544c4d53535000 "NTLMSSP" 01000000 Type 1 message b7820880 Flags Negotiate Unicode (0x00000001) Negotiate OEM (0x00000002) Request Target (0x00000004) Negotiate Sign (0x00000010) Negotiate Seal (0x00000020) Negotiate Lan Manager Key (0x00000080) Negotiate NTLM (0x00000200) Negotiate Always Sign (0x00008000) Negotiate NTLM2 Key (0x00080000) Negotiate 56 (0x80000000) 0000000000000000 Supplied Domain header (empty, supplied credentials) 0000000000000000 Supplied Workstation header (empty, supplied credentials) -------------------------------------------------------------------------------- AcceptSecurityContext called with ASC_REQ_INTEGRITY and ASC_REQ_CONFIDENTIALITY. Produces Type 2 message: 4e544c4d53535000020000000c000c003000000035828980514246973ea892c1 0000000000000000460046003c00000054004500530054004e00540002000c00 54004500530054004e00540001000c004d0045004d0042004500520003001e00 6d0065006d006200650072002e0074006500730074002e0063006f006d000000 0000 4e544c4d53535000 "NTLMSSP" 02000000 Type 2 message 0c000c0030000000 Target Name header (length 12, offset 48) 35828980 Flags Negotiate Unicode (0x00000001) Request Target (0x00000004) Negotiate Sign (0x00000010) Negotiate Seal (0x00000020) Negotiate NTLM (0x00000200) Negotiate Always Sign (0x00008000) Target Type Domain (0x00010000) Negotiate NTLM2 Key (0x00080000) Negotiate Target Info (0x00800000) Negotiate 56 (0x80000000) 514246973ea892c1 Challenge 0000000000000000 Context 460046003c000000 Target Information header (length 70, offset 60) 54004500530054004e005400 Target Name ("TESTNT") Target Information block: 02000c00 NetBIOS Domain Name (length 12) 54004500530054004e005400 "TESTNT" 01000c00 NetBIOS Server Name (length 12) 4d0045004d00420045005200 "MEMBER" 03001e00 DNS Server Name (length 30) 6d0065006d006200650072002e0074006500730074002e0063006f006d00 "member.test.com" 00000000 Target Information Terminator -------------------------------------------------------------------------------- InitializeSecurityContext called. Produces a Type 3 message: 4e544c4d5353500003000000180018006000000076007600780000000c000c00 40000000080008004c0000000c000c005400000000000000ee00000035828880 54004500530054004e00540074006500730074004d0045004d00420045005200 bf2e015119f6bdb3f6fdb768aa12d478f5ce3d2401c8f6e9caa4da8f25d5e840 974ed8976d3ada46010100000000000030fa7e3c677bc301f5ce3d2401c8f6e9 0000000002000c0054004500530054004e00540001000c004d0045004d004200 4500520003001e006d0065006d006200650072002e0074006500730074002e00 63006f006d000000000000000000 4e544c4d53535000 "NTLMSSP" 03000000 Type 3 message 1800180060000000 LM/LMv2 Response header (length 24, offset 96) 7600760078000000 NTLM/NTLMv2 Response header (length 118, offset 120) 0c000c0040000000 Domain Name header (length 12, offset 64) 080008004c000000 User Name header (length 8, offset 76) 0c000c0054000000 Workstation Name header (length 12, offset 84) 00000000ee000000 Session Key header (empty) 35828880 Flags Negotiate Unicode (0x00000001) Request Target (0x00000004) Negotiate Sign (0x00000010) Negotiate Seal (0x00000020) Negotiate NTLM (0x00000200) Negotiate Always Sign (0x00008000) Negotiate NTLM2 Key (0x00080000) Negotiate Target Info (0x00800000) Negotiate 56 (0x80000000) 54004500530054004e005400 Domain Name ("TESTNT") 7400650073007400 User Name ("test") 4d0045004d00420045005200 Workstation Name ("MEMBER") bf2e015119f6bdb3f6fdb768aa12d478f5ce3d2401c8f6e9 LM/LMv2 Response NTLM/NTLMv2 Response: caa4da8f25d5e840974ed8976d3ada46010100000000000030fa7e3c677bc301 f5ce3d2401c8f6e90000000002000c0054004500530054004e00540001000c00 4d0045004d0042004500520003001e006d0065006d006200650072002e007400 6500730074002e0063006f006d000000000000000000 -------------------------------------------------------------------------------- AcceptSecurityContext called to complete the server-side context. Server Context Export: 40a42e7840a42e7800000000000000000000000000000000 08ee0b00 server context handle dwUpper 35828981 flags 0000000000000000282e09002c2e0900a82e0900b82f09000000000000000000 d002000000000000000000000000000000000000000000000200000000000000 ffffffffffffff7f20010000 f7301e5d23f1d578c51ec0728b67453e outbound signing key 06403212f9e8c05ce1739938c200eca5 inbound verifying key 3d6483dce52cd6c4d7553545e607d92d outbound encrypting key ccc6efbcea980c0ac685753a4c9bbe0c inbound decrypting key 000000000000000000000000 3a6d27764b2010cdeda24d421b961cb92835eac0ecd6bf50375d308219362975 443ce13be9d2621d1283dc484f3e6ae66c4e8851f12632c3c1d9d5808763770b 9b61ebf7b7152252da1ff484b611732e3dcca15e9567939ce48bac450c7d46df 14ff026557a49db4dbe54cde538c21c6d0a59a24d87a06498dd74340bc4a13ab 6f851aa070a7587f9fa86b560d16d4e3b22d97b33147eefccbc87c6e3479f53f bab898af09865aa3692f5b330a99f600c2b118cec766fec903a6551ecfe0e225 e77bae642ad3c5fa0fbb0e5caac4bd9e07ef2b602c1754f2908eb501be5991fd 41ad688add8f392308f3f974f881783872b07ee8fb7104055fa99289d1f0ca94 00000000000000000000000000000000 21a58f9635cee06b4f94512adc8125717aa7a877750d646503e17073b1e5c1a6 d874c3a2b0499f905bebef1a3f5f8bee8e8ce69c4b87c900bf2f41ea72167f91 1dfc82a959862708575caf3a0a7bbbd7f337ba5ab6fae7c69734e9a1e367a44e cfc5292ed9da1f5e0f2d01a0ae0214b58a1eb8619b524c7dbe47d41bc83bb346 0983d533dd40ab76c742ca45c0e4c2cbf5e8f6f7f222b76658a31c795005193e f17812d0c4247e806e4afddb10cc68d6b90c2807b20e9860549318621130ac06 bc15e2f8232b9aec20fb95decd89d2f43d0b69bdd3136f382644888d533284b4 92feedaa7c9df9393c55316cffd1489ead172cdf43995636636a85f05d6d044d 0000000000000000 54004500530054004e0054005c007400650073007400 "TESTNT\test" ntlmHash = md4(password) = 0x3b1b47e42e0463276e3ded6cef349f93 ntlmv2Hash = hmac(ntlmHash, "TESTTESTNT") = 0xc4ea95cb148df11bf9d7c3611ad6d722 challenge (from Type 2) = 0x514246973ea892c1 blob (from Type 3) = 0x010100000000000030fa7e3c677bc301f5ce3d240 1c8f6e90000000002000c0054004500530054004e00540001000c004d0045004 d0042004500520003001e006d0065006d006200650072002e007400650073007 4002e0063006f006d000000000000000000 NTLMv2UserSessionKey = HMAC(ntlmv2Hash(HMAC(ntlmv2Hash, challenge + blob))) = 0x62ff13231f566f5dadf7391e183b5f39 We are using server context: serverSigningConstant = "session key to server-to-client signing key magic constant" = 0x73657373696f6e206b657920746f207365727665722d746f2d636c69656e74 207369676e696e67206b6579206d6167696320636f6e7374616e7400 serverSealingConstant = "session key to server-to-client sealing key magic constant" = 0x73657373696f6e206b657920746f207365727665722d746f2d636c69656e74 207365616c696e67206b6579206d6167696320636f6e7374616e7400 signingKey = MD5(key + serverSigningConstant) = 0xf7301e5d23f1d578c51ec0728b67453e User Session Key is weakened to 56-bit for sealing by truncating = 0x62ff13231f566f sealingKey = MD5(weakenedKey + serverSealingConstant) = 0x3d6483dce52cd6c4d7553545e607d92d Called MakeSignature on the server-side context for message "0x0102030405060708". Yields signature: 01000000fa317a333d8f510c00000000 Sequence number is 0. seqnum + message = 0x000000000102030405060708 HMAC(signingKey, 0x000000000102030405060708) = 0xfa317a333d8f510cccab257d9f2193c4 version num + first 8 bytes + seqnum: 01000000fa317a333d8f510c00000000 = signature -------------------------------------------------------------------------------- Called EncryptMessage twice on the server-side context for message "0x0102030405060708". Yields encrypted messages: a8e6671c79cf265701000000673773407fb60b4201000000 2fe89f6c6ea06d4b01000000244e0bcbce6ec16c02000000 RC4(sealingKey, 0x0102030405060708) = sealed message = 0xa8e6671c79cf2657 trailer buffer gets signature (sequence number is now 1 because of previous signing): HMAC(signingKey, 0x010000000102030405060708) = 0x673773407fb60b428f70358ca67720ba version num + first 8 bytes + seqnum: 01000000673773407fb60b4201000000 = trailer signature second message is same, using RC4 cipher from previous sealing operation: RC4(0x0102030405060708) = sealed message = 0x2fe89f6c6ea06d4b trailer buffer signature with sequence 2: HMAC(signingKey, 0x020000000102030405060708) = 0x244e0bcbce6ec16ce3493f55854bcc5c version num + first 8 bytes + seqnum: 01000000244e0bcbce6ec16c02000000 = trailer signature
Demonstration of anonymous authentication with signing and sealing.
LMCompatibilityLevel set to 0 (LM/NTLM). AcquireCredentialsHandle called with empty string ("") for domain, user, and password. -------------------------------------------------------------------------------- InitializeSecurityContext called with ISC_REQ_INTEGRITY and ISC_REQ_CONFIDENTIALITY. Produces Type 1 message: 4e544c4d5353500001000000b78208e000000000000000000000000000000000 4e544c4d53535000 "NTLMSSP" 01000000 Type 1 message b78208e0 Flags Negotiate Unicode (0x00000001) Negotiate OEM (0x00000002) Request Target (0x00000004) Negotiate Sign (0x00000010) Negotiate Seal (0x00000020) Negotiate Lan Manager Key (0x00000080) Negotiate NTLM (0x00000200) Negotiate Always Sign (0x00008000) Negotiate NTLM2 Key (0x00080000) Negotiate 128 (0x20000000) Negotiate Key Exchange (0x40000000) Negotiate 56 (0x80000000) 0000000000000000 Supplied Domain header (empty, supplied credentials) 0000000000000000 Supplied Workstation header (empty, supplied credentials) -------------------------------------------------------------------------------- AcceptSecurityContext called with ASC_REQ_INTEGRITY and ASC_REQ_CONFIDENTIALITY. Produces Type 2 message: 4e544c4d53535000020000000c000c0030000000358289e05bce6f12f47ddbdf 0000000000000000460046003c00000054004500530054004e00540002000c00 54004500530054004e00540001000c004d0045004d0042004500520003001e00 6d0065006d006200650072002e0074006500730074002e0063006f006d000000 0000 4e544c4d53535000 "NTLMSSP" 02000000 Type 2 message 0c000c0030000000 Target Name header (length 12, offset 48) 358289e0 Flags Negotiate Unicode (0x00000001) Request Target (0x00000004) Negotiate Sign (0x00000010) Negotiate Seal (0x00000020) Negotiate NTLM (0x00000200) Negotiate Always Sign (0x00008000) Target Type Domain (0x00010000) Negotiate NTLM2 Key (0x00080000) Negotiate Target Info (0x00800000) Negotiate 128 (0x20000000) Negotiate Key Exchange (0x40000000) Negotiate 56 (0x80000000) 5bce6f12f47ddbdf Challenge 0000000000000000 Context 460046003c000000 Target Information header (length 70, offset 60) 54004500530054004e005400 Target Name ("TESTNT") Target Information block: 02000c00 NetBIOS Domain Name (length 12) 54004500530054004e005400 "TESTNT" 01000c00 NetBIOS Server Name (length 12) 4d0045004d00420045005200 "MEMBER" 03001e00 DNS Server Name (length 30) 6d0065006d006200650072002e0074006500730074002e0063006f006d00 "member.test.com" 00000000 Target Information Terminator -------------------------------------------------------------------------------- InitializeSecurityContext called. Produces a Type 3 message: 4e544c4d5353500003000000010001004c000000000000004d00000000000000 4000000000000000400000000c000c0040000000100010004d000000358a88e0 4d0045004d0042004500520000c1442e6cca8c010e77138430aa35738e 4e544c4d53535000 "NTLMSSP" 03000000 Type 3 message 010001004c000000 LM/LMv2 Response header (length 1, offset 76) 000000004d000000 NTLM/NTLMv2 Response header (empty) 0000000040000000 Domain Name header (empty) 0000000040000000 User Name header (empty) 0c000c0040000000 Workstation Name header (length 12, offset 64) 100010004d000000 Session Key header (length 16, offset 77) 358a88e0 Flags Negotiate Unicode (0x00000001) Request Target (0x00000004) Negotiate Sign (0x00000010) Negotiate Seal (0x00000020) Negotiate NTLM (0x00000200) Negotiate Anonymous (0x00000800) Negotiate Always Sign (0x00008000) Negotiate NTLM2 Key (0x00080000) Negotiate Target Info (0x00800000) Negotiate 128 (0x20000000) Negotiate Key Exchange (0x40000000) Negotiate 56 (0x80000000) 4d0045004d00420045005200 Workstation Name ("MEMBER") 00 LM/LMv2 Response c1442e6cca8c010e77138430aa35738e Session Key -------------------------------------------------------------------------------- AcceptSecurityContext called to complete the server-side context. Server Context Export (on Win2k, appears to vary by OS): 40a42e7840a42e7800000000000000000000000000000000 08ee0b00 server context handle dwUpper 358a89e1 flags 0000000000000000e8290900ec290900682a0900782b09000000000000000000 0000000000000000000000000000000000000000000000000200000000000000 ffffffffffffff7f00000000 9128c3e5df618a48a83b44cfd92d58fe outbound signing key 594757aaa803afd943de25e087e3f9f1 inbound verifying key fc52e8bf1605ab57e89c6d6b4ffa92f6 outbound encrypting key 96465577ba181d141711572e5e15fe5d inbound decrypting key 000000000000000000000000 53a979fb1564d02ea0c33a32b0a1b2015f261b6ee6207804aa4f88fc57826b61 5a9fe8764931f9903efea3e1d258cddda292d6da10b536287a9859ff212d6781 f51a0eb439afc1f30cf0a75d4b54145c5bf4e7036a95c573dc0a3b479dcbbb09 6c4c698b1fc22acc8eeb8f7183ea99182274d1e4dfe5bf8d13382941f6ca25b7 7084a56216c906ad7da891fa42082b9b170733b65ef23437a4fd667e5686c6de 87240080ec89d3d4bc194e759aaebde302d55550f83f1d0b46303545c71eb3b1 3c2f6f7b9eb8ab6d1c4011f12c51baf77fcec00fd7e07248e2604485be238aef 77b91265ac5227ee944ded8cd868634a973dc4db439c0dc8a696937ccfd9e905 00000000000000000000000000000000 09dd12ae4213ac358896e19a9d26cfc8957750b5f557bae5f3ef98d891a4059f f25ed0195d141aea3d62e31fd7a9aa1e07fd83cb4d3f7401825b7e66a14b28cd 52d6e8a2049036756dfcb929d220d5463499ca3368a071634c0c9cd10dcc4ef9 11d30f108a45648979477f0641c2b485f6adc0a8922be91dde847c93278040a6 b886c6605ac132fe731c589467a76131c9498db13beb2f9baf2c59e06f6c6af0 bbc4b00e6bce78da2de602e797f103b2b6bf4f1b388c0816dfbde2258bd9a3b7 157b5600c55ffaf79e3ac78e48ee55308737ff43817d515cf83e6e70c317bcec 2aed21442e24d465a56923be0b53f4fb8fb3e454ab18760a7adc2239723c4adb 0000000000000000 Anonymous User Session Key = 0x00000000000000000000000000000000 Key exchange performed: type3Key (from Type 3) = 0xc1442e6cca8c010e77138430aa35738e key = RC4(AnonymousUserSessionKey, type3Key) = 0x1f5ca72d69bb5c34fd159a57fd5be1e3 We are using server context: serverSigningConstant = "session key to server-to-client signing key magic constant" = 0x73657373696f6e206b657920746f207365727665722d746f2d636c69656e74 207369676e696e67206b6579206d6167696320636f6e7374616e7400 serverSealingConstant = "session key to server-to-client sealing key magic constant" = 0x73657373696f6e206b657920746f207365727665722d746f2d636c69656e74 207365616c696e67206b6579206d6167696320636f6e7374616e7400 signingKey = MD5(key + serverSigningConstant) = 0x9128c3e5df618a48a83b44cfd92d58fe sealingKey = MD5(key + serverSealingConstant) = 0xfc52e8bf1605ab57e89c6d6b4ffa92f6 Called MakeSignature on the server-side context for message "0x0102030405060708". Yields signature: 01000000ae0cbe0dd0b2110300000000 Sequence number is 0. seqnum + message = 0x000000000102030405060708 HMAC(signingKey, 0x000000000102030405060708) = 0xc14074817421530195b4532d61a4e625 sig = RC4(sealingKey, first 8 bytes) = 0xae0cbe0dd0b21103 version num + sig + seqnum: 01000000ae0cbe0dd0b2110300000000 = signature -------------------------------------------------------------------------------- Called EncryptMessage twice on the server-side context for message "0x0102030405060708". Yields encrypted messages: fb2e1d6ff8a3569a01000000cc2c5bf59319e7ca01000000 1e2216588e5a7d9801000000e9a3066b8fab0bf102000000 Uses RC4 cipher from previous signing operation (key exchange encrypts signature with sealing key as well). RC4(0x0102030405060708) = sealed message = 0xfb2e1d6ff8a3569a trailer buffer gets signature (sequence number is now 1 because of previous signing, same RC4 cipher used for this signature too): HMAC(signingKey, 0x010000000102030405060708) = 0x25141e76f441b10622cfaf0e61450663 sig = RC4(first 8 bytes) = 0xcc2c5bf59319e7ca version num + sig + seqnum: 01000000cc2c5bf59319e7ca01000000 = trailer signature second message is same, using RC4 cipher from previous operations: RC4(0x0102030405060708) = sealed message = 0x1e2216588e5a7d98 trailer buffer signature with sequence 2: HMAC(signingKey, 0x020000000102030405060708) = 0x7efa2ba18ed911696a0f4d571b05a244 sig = RC4(first 8 bytes) = 0xe9a3066b8fab0bf1 version num + sig + seqnum: 01000000e9a3066b8fab0bf102000000 = trailer signature
Demonstration of local authentication with signing and sealing. It is assumed that the User Session Key derivation and Key Exchange processes are performed normally offline within the established local context (in the absence of the required information being provided over-the-wire).
LMCompatibilityLevel set to 0 (LM/NTLM). AcquireCredentialsHandle called with NULL identity (using default credentials handle for authenticated local user). -------------------------------------------------------------------------------- InitializeSecurityContext called with ISC_REQ_INTEGRITY and ISC_REQ_CONFIDENTIALITY. Produces Type 1 message: 4e544c4d5353500001000000b7b208e006000600260000000600060020000000 4d454d424552544553544e54 4e544c4d53535000 "NTLMSSP" 01000000 Type 1 message b7b208e0 Flags Negotiate Unicode (0x00000001) Negotiate OEM (0x00000002) Request Target (0x00000004) Negotiate Sign (0x00000010) Negotiate Seal (0x00000020) Negotiate Lan Manager Key (0x00000080) Negotiate NTLM (0x00000200) Negotiate Domain Supplied (0x00001000) Negotiate Workstation Supplied (0x00002000) Negotiate Always Sign (0x00008000) Negotiate NTLM2 Key (0x00080000) Negotiate 128 (0x20000000) Negotiate Key Exchange (0x40000000) Negotiate 56 (0x80000000) 0600060026000000 Supplied Domain header (length 6, offset 38) 0600060020000000 Supplied Workstation header (length 6, offset 32) 4d454d424552 Supplied Workstation ("MEMBER") 544553544e54 Supplied Domain ("TESTNT") -------------------------------------------------------------------------------- AcceptSecurityContext called with ASC_REQ_INTEGRITY and ASC_REQ_CONFIDENTIALITY. Produces Type 2 message: 4e544c4d53535000020000000c000c003000000035c289e0d7ef496afa055352 08ee0b0000000000460046003c00000054004500530054004e00540002000c00 54004500530054004e00540001000c004d0045004d0042004500520003001e00 6d0065006d006200650072002e0074006500730074002e0063006f006d000000 0000 4e544c4d53535000 "NTLMSSP" 02000000 Type 2 message 0c000c0030000000 Target Name header (length 12, offset 48) 35c289e0 Flags Negotiate Unicode (0x00000001) Request Target (0x00000004) Negotiate Sign (0x00000010) Negotiate Seal (0x00000020) Negotiate NTLM (0x00000200) Negotiate Local Call (0x00004000) Negotiate Always Sign (0x00008000) Target Type Domain (0x00010000) Negotiate NTLM2 Key (0x00080000) Negotiate Target Info (0x00800000) Negotiate 128 (0x20000000) Negotiate Key Exchange (0x40000000) Negotiate 56 (0x80000000) d7ef496afa055352 Challenge 08ee0b0000000000 Context (equal to server context handle's dwUpper field) 460046003c000000 Target Information header (length 70, offset 60) 54004500530054004e005400 Target Name ("TESTNT") Target Information block: 02000c00 NetBIOS Domain Name (length 12) 54004500530054004e005400 "TESTNT" 01000c00 NetBIOS Server Name (length 12) 4d0045004d00420045005200 "MEMBER" 03001e00 DNS Server Name (length 30) 6d0065006d006200650072002e0074006500730074002e0063006f006d00 "member.test.com" 00000000 Target Information Terminator -------------------------------------------------------------------------------- InitializeSecurityContext called. Produces a Type 3 message: 4e544c4d53535000030000000000000040000000000000004000000000000000 4000000000000000400000000000000040000000000000004000000035c288e0 4e544c4d53535000 "NTLMSSP" 03000000 Type 3 message 0000000040000000 LM/LMv2 Response header (empty, local authentication) 0000000040000000 NTLM/NTLMv2 Response header (empty, local authentication) 0000000040000000 Domain Name header (empty, local authentication) 0000000040000000 User Name header (empty, local authentication) 0000000040000000 Workstation Name header (empty, local authentication) 0000000040000000 Session Key header (empty) 35c288e0 Flags Negotiate Unicode (0x00000001) Request Target (0x00000004) Negotiate Sign (0x00000010) Negotiate Seal (0x00000020) Negotiate NTLM (0x00000200) Negotiate Local Call (0x00004000) Negotiate Always Sign (0x00008000) Negotiate NTLM2 Key (0x00080000) Negotiate Target Info (0x00800000) Negotiate 128 (0x20000000) Negotiate Key Exchange (0x40000000) Negotiate 56 (0x80000000) -------------------------------------------------------------------------------- AcceptSecurityContext called to complete the server-side context. Server Context Export: 40a42e7840a42e7800000000000000000000000000000000 08ee0b00 server context handle dwUpper 35c289e1 flags 0000000000000000182e09001c2e0900982e0900a82f09000000000000000000 d002000000000000000000000000000000000000000000000200000000000000 ffffffffffffff7f00000000 65836771d7bf52df502634e521b3154b outbound signing key 9ed7ce6558f0f26db1fbf5163d7b24f9 inbound verifying key f56d6b81749b7adaf3467f37bc36224e outbound encrypting key 65adf5ede40e84e7338d681e6cbc38ff inbound decrypting key 000000000000000000000000 7263d05c01f686ab2717e06f35c91b7a10fd0f5289ced6b6c423a213e6256a4d 3d128d30290899cbb502412f2d77ae1d4e55cf3fa6df5a785ded4aa3504c5484 155396d88345ff065beab3b738956e07f2b0ad36b8a80ba9f49305753e14e540 3428b4ccd3641ad18b037e9b67be3c1e70a17d816520565e744bd587bfc5b27f 8558099048ec800af1a5bbef92cdd2afe8c3042e510026f3bac7579ec8db5fbd eb24bc43a742fc6111def922666dfe9d4791e9c60ef0d431d98cc259e2162b7c 49c0da1c2af5ee8e4f440c9a60ca4668391f3b213288f7a46be1c19f198a9c79 699737aadcfb829476f8d7b17be42c73338f71a0fa986c0dac18b9e3e73add62 00000000000000000000000000000000 651771fae2f5fc6da8973bd149126e92212b2f896101d23c568e40b325a383bd 42ec2752b295e5d09e36c899a94fffb8e053ac1c5c72d4de7c66b14b8d862977 bf5f47cfb76a81201f829098a067df7b78dc51630d8f790e0985316cb459e7d5 7f466b6f5a13948b38434ac54c7ee9ab340a6926d75d2aa523d81d0bc23ae4cc aa1a419fc303cd88f6a4be04e100bb32e6cbf4feae9ab04808d9a111f937fb76 50104dc1c696b6c0740528f193f87d14cedd3f442e15d324454e64c7733e0f9c ea0c163de8f3c92d1eebed33ba30f7f2350757d6b98abccafd7568229d1bef7a 5519da065e709be3ad2c8418dbb5f002a2eea68c395891c454af62806087a75b 0000000000000000 54004500530054004e0054005c007400650073007400 "TESTNT\test" User Session Key = ???? Key exchange performed somehow? Shows up in signatures. We are using server context: serverSigningConstant = "session key to server-to-client signing key magic constant" = 0x73657373696f6e206b657920746f207365727665722d746f2d636c69656e74 207369676e696e67206b6579206d6167696320636f6e7374616e7400 serverSealingConstant = "session key to server-to-client sealing key magic constant" = 0x73657373696f6e206b657920746f207365727665722d746f2d636c69656e74 207365616c696e67206b6579206d6167696320636f6e7374616e7400 signingKey = MD5(key + serverSigningConstant) = 0x65836771d7bf52df502634e521b3154b (from context export) sealingKey = MD5(key + serverSealingConstant) = 0xf56d6b81749b7adaf3467f37bc36224e (from context export) Called MakeSignature on the server-side context for message "0x0102030405060708". Yields signature: 01000000adc70c8bd4834ae800000000 Sequence number is 0. seqnum + message = 0x000000000102030405060708 HMAC(signingKey, 0x000000000102030405060708) = 0xb0bd637382da53f4ad3edf2c5a2c9592 sig = RC4(sealingKey, first 8 bytes) = 0xadc70c8bd4834ae8 version num + sig + seqnum: 01000000adc70c8bd4834ae800000000 = signature -------------------------------------------------------------------------------- Called EncryptMessage twice on the server-side context for message "0x0102030405060708". Yields encrypted messages: 9c89720008251ab601000000d4af70567f5ab1df01000000 a8950e40b10e9af501000000c5447ccf7102d98c02000000 Uses RC4 cipher from previous signing operation (key exchange encrypts signature with sealing key as well). RC4(0x0102030405060708) = sealed message = 0x9c89720008251ab6 trailer buffer gets signature (sequence number is now 1 because of previous signing, same RC4 cipher used for this signature too): HMAC(signingKey, 0x010000000102030405060708) = 0xcd1d04a1962b7d82e6ffd7c37871bf15 sig = RC4(first 8 bytes) = 0xd4af70567f5ab1df version num + sig + seqnum: 01000000d4af70567f5ab1df01000000 = trailer signature second message is same, using RC4 cipher from previous operations: RC4(0x0102030405060708) = sealed message = 0xa8950e40b10e9af5 trailer buffer signature with sequence 2: HMAC(signingKey, 0x020000000102030405060708) = 0x3011549106db10de5694f567749cb9eb sig = RC4(first 8 bytes) = 0xc5447ccf7102d98c version num + sig + seqnum: 01000000c5447ccf7102d98c02000000 = trailer signature
Listed below is an annotated sample implementation of the various Type 3 response calculations in Java. This example requires a JCE provider implementing the MD4 message-digest algorithm; the author recommends GNU Crypto, available at http://www.gnu.org/software/gnu-crypto/.
import java.security.Key; import java.security.MessageDigest; import javax.crypto.Cipher; import javax.crypto.spec.SecretKeySpec; /** * Calculates the various Type 3 responses. */ public class Responses { /** * Calculates the LM Response for the given challenge, using the specified * password. * * @param password The user's password. * @param challenge The Type 2 challenge from the server. * * @return The LM Response. */ public static byte[] getLMResponse(String password, byte[] challenge) throws Exception { byte[] lmHash = lmHash(password); return lmResponse(lmHash, challenge); } /** * Calculates the NTLM Response for the given challenge, using the * specified password. * * @param password The user's password. * @param challenge The Type 2 challenge from the server. * * @return The NTLM Response. */ public static byte[] getNTLMResponse(String password, byte[] challenge) throws Exception { byte[] ntlmHash = ntlmHash(password); return lmResponse(ntlmHash, challenge); } /** * Calculates the NTLMv2 Response for the given challenge, using the * specified authentication target, username, password, target information * block, and client nonce. * * @param target The authentication target (i.e., domain). * @param user The username. * @param password The user's password. * @param targetInformation The target information block from the Type 2 * message. * @param challenge The Type 2 challenge from the server. * @param clientNonce The random 8-byte client nonce. * * @return The NTLMv2 Response. */ public static byte[] getNTLMv2Response(String target, String user, String password, byte[] targetInformation, byte[] challenge, byte[] clientNonce) throws Exception { byte[] ntlmv2Hash = ntlmv2Hash(target, user, password); byte[] blob = createBlob(targetInformation, clientNonce); return lmv2Response(ntlmv2Hash, blob, challenge); } /** * Calculates the LMv2 Response for the given challenge, using the * specified authentication target, username, password, and client * challenge. * * @param target The authentication target (i.e., domain). * @param user The username. * @param password The user's password. * @param challenge The Type 2 challenge from the server. * @param clientNonce The random 8-byte client nonce. * * @return The LMv2 Response. */ public static byte[] getLMv2Response(String target, String user, String password, byte[] challenge, byte[] clientNonce) throws Exception { byte[] ntlmv2Hash = ntlmv2Hash(target, user, password); return lmv2Response(ntlmv2Hash, clientNonce, challenge); } /** * Calculates the NTLM2 Session Response for the given challenge, using the * specified password and client nonce. * * @param password The user's password. * @param challenge The Type 2 challenge from the server. * @param clientNonce The random 8-byte client nonce. * * @return The NTLM2 Session Response. This is placed in the NTLM * response field of the Type 3 message; the LM response field contains * the client nonce, null-padded to 24 bytes. */ public static byte[] getNTLM2SessionResponse(String password, byte[] challenge, byte[] clientNonce) throws Exception { byte[] ntlmHash = ntlmHash(password); MessageDigest md5 = MessageDigest.getInstance("MD5"); md5.update(challenge); md5.update(clientNonce); byte[] sessionHash = new byte[8]; System.arraycopy(md5.digest(), 0, sessionHash, 0, 8); return lmResponse(ntlmHash, sessionHash); } /** * Creates the LM Hash of the user's password. * * @param password The password. * * @return The LM Hash of the given password, used in the calculation * of the LM Response. */ private static byte[] lmHash(String password) throws Exception { byte[] oemPassword = password.toUpperCase().getBytes("US-ASCII"); int length = Math.min(oemPassword.length, 14); byte[] keyBytes = new byte[14]; System.arraycopy(oemPassword, 0, keyBytes, 0, length); Key lowKey = createDESKey(keyBytes, 0); Key highKey = createDESKey(keyBytes, 7); byte[] magicConstant = "KGS!@#$%".getBytes("US-ASCII"); Cipher des = Cipher.getInstance("DES/ECB/NoPadding"); des.init(Cipher.ENCRYPT_MODE, lowKey); byte[] lowHash = des.doFinal(magicConstant); des.init(Cipher.ENCRYPT_MODE, highKey); byte[] highHash = des.doFinal(magicConstant); byte[] lmHash = new byte[16]; System.arraycopy(lowHash, 0, lmHash, 0, 8); System.arraycopy(highHash, 0, lmHash, 8, 8); return lmHash; } /** * Creates the NTLM Hash of the user's password. * * @param password The password. * * @return The NTLM Hash of the given password, used in the calculation * of the NTLM Response and the NTLMv2 and LMv2 Hashes. */ private static byte[] ntlmHash(String password) throws Exception { byte[] unicodePassword = password.getBytes("UnicodeLittleUnmarked"); MessageDigest md4 = MessageDigest.getInstance("MD4"); return md4.digest(unicodePassword); } /** * Creates the NTLMv2 Hash of the user's password. * * @param target The authentication target (i.e., domain). * @param user The username. * @param password The password. * * @return The NTLMv2 Hash, used in the calculation of the NTLMv2 * and LMv2 Responses. */ private static byte[] ntlmv2Hash(String target, String user, String password) throws Exception { byte[] ntlmHash = ntlmHash(password); String identity = user.toUpperCase() + target; return hmacMD5(identity.getBytes("UnicodeLittleUnmarked"), ntlmHash); } /** * Creates the LM Response from the given hash and Type 2 challenge. * * @param hash The LM or NTLM Hash. * @param challenge The server challenge from the Type 2 message. * * @return The response (either LM or NTLM, depending on the provided * hash). */ private static byte[] lmResponse(byte[] hash, byte[] challenge) throws Exception { byte[] keyBytes = new byte[21]; System.arraycopy(hash, 0, keyBytes, 0, 16); Key lowKey = createDESKey(keyBytes, 0); Key middleKey = createDESKey(keyBytes, 7); Key highKey = createDESKey(keyBytes, 14); Cipher des = Cipher.getInstance("DES/ECB/NoPadding"); des.init(Cipher.ENCRYPT_MODE, lowKey); byte[] lowResponse = des.doFinal(challenge); des.init(Cipher.ENCRYPT_MODE, middleKey); byte[] middleResponse = des.doFinal(challenge); des.init(Cipher.ENCRYPT_MODE, highKey); byte[] highResponse = des.doFinal(challenge); byte[] lmResponse = new byte[24]; System.arraycopy(lowResponse, 0, lmResponse, 0, 8); System.arraycopy(middleResponse, 0, lmResponse, 8, 8); System.arraycopy(highResponse, 0, lmResponse, 16, 8); return lmResponse; } /** * Creates the LMv2 Response from the given hash, client data, and * Type 2 challenge. * * @param hash The NTLMv2 Hash. * @param clientData The client data (blob or client nonce). * @param challenge The server challenge from the Type 2 message. * * @return The response (either NTLMv2 or LMv2, depending on the * client data). */ private static byte[] lmv2Response(byte[] hash, byte[] clientData, byte[] challenge) throws Exception { byte[] data = new byte[challenge.length + clientData.length]; System.arraycopy(challenge, 0, data, 0, challenge.length); System.arraycopy(clientData, 0, data, challenge.length, clientData.length); byte[] mac = hmacMD5(data, hash); byte[] lmv2Response = new byte[mac.length + clientData.length]; System.arraycopy(mac, 0, lmv2Response, 0, mac.length); System.arraycopy(clientData, 0, lmv2Response, mac.length, clientData.length); return lmv2Response; } /** * Creates the NTLMv2 blob from the given target information block and * client nonce. * * @param targetInformation The target information block from the Type 2 * message. * @param clientNonce The random 8-byte client nonce. * * @return The blob, used in the calculation of the NTLMv2 Response. */ private static byte[] createBlob(byte[] targetInformation, byte[] clientNonce) { byte[] blobSignature = new byte[] { (byte) 0x01, (byte) 0x01, (byte) 0x00, (byte) 0x00 }; byte[] reserved = new byte[] { (byte) 0x00, (byte) 0x00, (byte) 0x00, (byte) 0x00 }; byte[] unknown1 = new byte[] { (byte) 0x00, (byte) 0x00, (byte) 0x00, (byte) 0x00 }; byte[] unknown2 = new byte[] { (byte) 0x00, (byte) 0x00, (byte) 0x00, (byte) 0x00 }; long time = System.currentTimeMillis(); time += 11644473600000l; // milliseconds from January 1, 1601 -> epoch. time *= 10000; // tenths of a microsecond. // convert to little-endian byte array. byte[] timestamp = new byte[8]; for (int i = 0; i < 8; i++) { timestamp[i] = (byte) time; time >>>= 8; } byte[] blob = new byte[blobSignature.length + reserved.length + timestamp.length + clientNonce.length + unknown1.length + targetInformation.length + unknown2.length]; int offset = 0; System.arraycopy(blobSignature, 0, blob, offset, blobSignature.length); offset += blobSignature.length; System.arraycopy(reserved, 0, blob, offset, reserved.length); offset += reserved.length; System.arraycopy(timestamp, 0, blob, offset, timestamp.length); offset += timestamp.length; System.arraycopy(clientNonce, 0, blob, offset, clientNonce.length); offset += clientNonce.length; System.arraycopy(unknown1, 0, blob, offset, unknown1.length); offset += unknown1.length; System.arraycopy(targetInformation, 0, blob, offset, targetInformation.length); offset += targetInformation.length; System.arraycopy(unknown2, 0, blob, offset, unknown2.length); return blob; } /** * Calculates the HMAC-MD5 hash of the given data using the specified * hashing key. * * @param data The data for which the hash will be calculated. * @param key The hashing key. * * @return The HMAC-MD5 hash of the given data. */ private static byte[] hmacMD5(byte[] data, byte[] key) throws Exception { byte[] ipad = new byte[64]; byte[] opad = new byte[64]; for (int i = 0; i < 64; i++) { ipad[i] = (byte) 0x36; opad[i] = (byte) 0x5c; } for (int i = key.length - 1; i >= 0; i--) { ipad[i] ^= key[i]; opad[i] ^= key[i]; } byte[] content = new byte[data.length + 64]; System.arraycopy(ipad, 0, content, 0, 64); System.arraycopy(data, 0, content, 64, data.length); MessageDigest md5 = MessageDigest.getInstance("MD5"); data = md5.digest(content); content = new byte[data.length + 64]; System.arraycopy(opad, 0, content, 0, 64); System.arraycopy(data, 0, content, 64, data.length); return md5.digest(content); } /** * Creates a DES encryption key from the given key material. * * @param bytes A byte array containing the DES key material. * @param offset The offset in the given byte array at which * the 7-byte key material starts. * * @return A DES encryption key created from the key material * starting at the specified offset in the given byte array. */ private static Key createDESKey(byte[] bytes, int offset) { byte[] keyBytes = new byte[7]; System.arraycopy(bytes, offset, keyBytes, 0, 7); byte[] material = new byte[8]; material[0] = keyBytes[0]; material[1] = (byte) (keyBytes[0] << 7 | (keyBytes[1] & 0xff) >>> 1); material[2] = (byte) (keyBytes[1] << 6 | (keyBytes[2] & 0xff) >>> 2); material[3] = (byte) (keyBytes[2] << 5 | (keyBytes[3] & 0xff) >>> 3); material[4] = (byte) (keyBytes[3] << 4 | (keyBytes[4] & 0xff) >>> 4); material[5] = (byte) (keyBytes[4] << 3 | (keyBytes[5] & 0xff) >>> 5); material[6] = (byte) (keyBytes[5] << 2 | (keyBytes[6] & 0xff) >>> 6); material[7] = (byte) (keyBytes[6] << 1); oddParity(material); return new SecretKeySpec(material, "DES"); } /** * Applies odd parity to the given byte array. * * @param bytes The data whose parity bits are to be adjusted for * odd parity. */ private static void oddParity(byte[] bytes) { for (int i = 0; i < bytes.length; i++) { byte b = bytes[i]; boolean needsParity = (((b >>> 7) ^ (b >>> 6) ^ (b >>> 5) ^ (b >>> 4) ^ (b >>> 3) ^ (b >>> 2) ^ (b >>> 1)) & 0x01) == 0; if (needsParity) { bytes[i] |= (byte) 0x01; } else { bytes[i] &= (byte) 0xfe; } } } }
Copyright © 2003, 2006 Eric Glass
Permission to use, copy, modify, and distribute this document for any purpose and without any fee is hereby granted, provided that the above copyright notice and this list of conditions appear in all copies.
The most current version of this document may be obtained from http://davenport.sourceforge.net/ntlm.html. The author may be contacted vie e-mail at eric.glass at gmail.com.