Network Working Group G. Zorn Internet-Draft Microsoft Corporation Category: Informational September 1998 <draft-ietf-pppext-mschap-v2-00.txt> Microsoft PPP CHAP Extensions, Version 2 1. Status of this Memo This document is an Internet-Draft. Internet-Drafts are working docu- ments of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working doc- uments as Internet-Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as ``work in progress''. To learn the current status of any Internet-Draft, please check the ``1id-abstracts.txt'' listing contained in the Internet-Drafts Shadow Directories on ftp.ietf.org (US East Coast), nic.nordu.net (Europe), ftp.isi.edu (US West Coast), or munnari.oz.au (Pacific Rim). This memo provides information for the Internet community. This memo does not specify an Internet standard of any kind. The distribution of this memo is unlimited. It is filed as <draft-ietf-pppext-mschap- v2-00.txt> and expires March 23, 1999. Please send comments to the PPP Extensions Working Group mailing list (ietf-ppp@merit.edu) or to the author (glennz@microsoft.com). 2. Abstract The Point-to-Point Protocol (PPP) [1] provides a standard method for transporting multi-protocol datagrams over point-to-point links. PPP defines an extensible Link Control Protocol and a family of Network Con- trol Protocols (NCPs) for establishing and configuring different net- work-layer protocols. This document describes version two of Microsoft's PPP CHAP dialect (MS- CHAP-V2). MS-CHAP-V2 is similar to, but incompatible with, MS-CHAP ver- sion one (MS-CHAP-V1, described in [9]). In particular, certain proto- col fields have been deleted or reused but with different semantics. In addition, MS-CHAP-V2 features mutual authentication. The algorithms used in the generation of various MS-CHAP-V2 protocol Zorn [Page 1]
INTERNET-DRAFT MS-CHAP-V2 July 1998 fields are described in an appendix. 3. Introduction Where possible, MS-CHAP-V2 is consistent with both MS-CHAP-V1 and stan- dard CHAP. Briefly, the differences between MS-CHAP-V2 and MS-CHAP-V1 are: * MS-CHAP-V2 is enabled by negotiating CHAP Algorithm 0x81 in LCP option 3, Authentication Protocol. * MS-CHAP-V2 provides mutual authentication between peers by piggybacking a peer challenge on the Response packet and an authenticator reponse on the Success packet. * The calculation of the "Windows NT compatible challenge response" sub-field in the Response packet has been changed to include the peer challenge and the user name. * In MS-CHAP-V1, the "LAN Manager compatible challenge response" sub-field was always sent in the Response packet. This field has been replaced in MS-CHAP-V2 by the Peer-Challenge field. * The format of the Message field in the Failure packet has been changed. * The Change Password (version 1) and Change Password (version 2) packets are no longer supported. They have been replaced with a single Change-Password packet. 4. Specification of Requirements In this document, the key words "MAY", "MUST, "MUST NOT", "optional", "recommended", "SHOULD", and "SHOULD NOT" are to be interpreted as described in [2]. 5. LCP Configuration The LCP configuration for MS-CHAP-V2 is identical to that for standard CHAP, except that the Algorithm field has value 0x81, rather than the MD5 value 0x05. PPP implementations which do not support MS-CHAP-V2, but correctly implement LCP Config-Rej, should have no problem dealing with this non-standard option. Zorn [Page 2]
INTERNET-DRAFT MS-CHAP-V2 July 1998 6. Challenge Packet The MS-CHAP-V2 Challenge packet is identical in format to the standard CHAP Challenge packet. MS-CHAP-V2 authenticators send an 16-octet challenge Value field. Peers need not duplicate Microsoft's algorithm for selecting the 16-octet value, but the standard guidelines on randomness [1,2,7] SHOULD be observed. Microsoft authenticators do not currently provide information in the Name field. This may change in the future. 7. Response Packet The MS-CHAP-V2 Response packet is identical in format to the standard CHAP Response packet. However, the Value field is sub-formatted differ- ently as follows: 24 octets: Peer-Challenge 24 octets: NT-Response 1 octet : Flags The Peer-Challenge field is a 16-octet random number. As the name implies, it is generated by the peer and is used in the calculation of the NT-Response field, below. Peers need not duplicate Microsoft's algorithm for selecting the 16-octet value, but the standard guidelines on randomness [1,2,7] SHOULD be observed. The NT-Response field is an encoded function of the password, the user name, the contents of the Peer-Challenge field and the received chal- lenge as output by the routine GenerateNTResponse() (see section A.1, below). The Windows NT password is a string of 0 to (theoretically) 256 case-sensitive Unicode [8] characters. Current versions of Windows NT limit passwords to 14 characters, mainly for compatibility reasons; this may change in the future. When computing the NT-Response field con- tents, only the user name is used, without any associated Windows NT domain name. This is true regardless of whether a Windows NT domain name is present in the Name field (see below). The Flag field is reserved for future use and MUST be zero. The Name field is a string of 0 to (theoretically) 256 case-sensitive ASCII characters which identifies the peer's user account name. The Windows NT domain name may prefix the user's account name (e.g. "BIGCO\johndoe" where "BIGCO" is a Windows NT domain containing the user account "johndoe"). If a domain is not provided, the backslash should Zorn [Page 3]
INTERNET-DRAFT MS-CHAP-V2 July 1998 also be omitted, (e.g. "johndoe"). 8. Success Packet The Success packet is identical in format to the standard CHAP Success packet. However, the Message field contains a 42-octet authenticator response string of the form "S=<auth_string>" where <auth_string> is a 20 octet number encoded in ASCII as 40 hexadec- imal digits. The hexadecimal digits A-F (if present) MUST be uppercase. This number is derived from the challenge from the Challenge packet, the Peer-Challenge and NT-Response fields from the Response packet, and the peer password as output by the routine GenerateAuthenticatorResponse() (see section A.6, below). The authenticating peer MUST verify the authenticator response when a Success packet is received. The method for verifying the authenticator is described in section A.7, below. If the authenticator response is either missing or incorrect, the peer MUST end the session. 9. Failure Packet The Failure packet is identical in format to the standard CHAP Failure packet. There is, however, formatted text stored in the Message field which, contrary to the standard CHAP rules, does affect the operation of the protocol. The Message field format is: "E=eeeeeeeeee R=r C=cccccccccccccccccccccccccccccccc V=vvvvvvvvvv" where The "eeeeeeeeee" is the ASCII representation of a decimal error code (need not be 10 digits) corresponding to one of those listed below, though implementations should deal with codes not on this list gracefully. 646 ERROR_RESTRICTED_LOGON_HOURS 647 ERROR_ACCT_DISABLED 648 ERROR_PASSWD_EXPIRED 649 ERROR_NO_DIALIN_PERMISSION 691 ERROR_AUTHENTICATION_FAILURE 709 ERROR_CHANGING_PASSWORD The "r" is an ASCII flag set to '1' if a retry is allowed, and '0' if not. When the authenticator sets this flag to '1' it disables Zorn [Page 4]
INTERNET-DRAFT MS-CHAP-V2 July 1998 short timeouts, expecting the peer to prompt the user for new cre- dentials and resubmit the response. The "cccccccccccccccccccccccccccccccc" is the ASCII representation of a hexadecimal challenge value. This field MUST be exactly 32 octets long and MUST be present. The "vvvvvvvvvv" is the ASCII representation of a decimal version code (need not be 10 digits) indicating the password changing pro- tocol version supported on the server. For MS-CHAP-V2, this value SHOULD always be 3. Implementations should accept but ignore additional text they do not recognize. 10. Change-Password Packet The Change-Password packet does not appear in either standard CHAP or MS-CHAP-V1. It allows the peer to change the password on the account specified in the preceding Response packet. The Change-Password packet should be sent only if the authenticator reports ERROR_PASSWD_EXPIRED (E=648) in the Message field of the Failure packet. This packet type is supported by recent versions of Windows NT 4.0, Win- dows 95 and Windows 98. It is not supported by Windows NT 3.5, Windows NT 3.51, or early versions of Windows NT 4.0, Windows 95 and Windows 98. The format of this packet is as follows: 1 octet : Code 1 octet : Identifier 2 octets : Length 516 octets : Encrypted-Password 16 octets : Encrypted-Hash 24 octets : Peer-Challenge 24 octets : NT-Response 2-octet : Flags Code 7 Identifier The Identifier field is one octet and aids in matching requests and replies. The value is the Identifier of the received Failure packet to which this packet responds plus 1. Length Zorn [Page 5]
INTERNET-DRAFT MS-CHAP-V2 July 1998 586 Encrypted-Password This field contains the PWBLOCK form of the new Windows NT pass- word encrypted with the old Windows NT password hash, as output by the NewPasswordEncryptedWithOldNtPasswordHash() routine (see sec- tion A.8, below). Encrypted-Hash This field contains the old Windows NT password hash encrypted with the new Windows NT password hash, as output by the OldNtPass- wordHashEncryptedWithNewNtPasswordHash() routine (see section A.11, below). Peer-Challenge A 16-octet random quantity, as described in the Response packet description. NT-Response The NT-Response field (as described in the Response packet description), but calculated on the new password and the challenge received in the Failure packet. Flags This field is two octets in length. It is a bit field of option flags where 0 is the least significant bit of the 16-bit quantity. The format of this field is illustrated in the following diagram: 1 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Bits 0-15 Reserved, always clear (0). 11. Security Considerations As an implementation detail, the authenticator SHOULD limit the number of password retries allowed to make brute-force password guessing attacks more difficult. Zorn [Page 6]
INTERNET-DRAFT MS-CHAP-V2 July 1998 12. References [1] Simpson, W., "The Point-to-Point Protocol (PPP)", STD 51, RFC 1661, July 1994 [2] Simpson, W., "PPP Challenge Handshake Authentication Protocol (CHAP)", RFC 1994, August 1996 [3] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, March 1997 [4] "Data Encryption Standard (DES)", Federal Information Processing Standard Publication 46-2, National Institute of Standards and Technology, December 1993 [5] Rivest, R., "MD4 Message Digest Algorithm", RFC 1320, April 1992. [6] RC4 is a proprietary encryption algorithm available under license from RSA Data Security Inc. For licensing information, contact: RSA Data Security, Inc. 100 Marine Parkway Redwood City, CA 94065-1031 [7] Eastlake, D., et. al., "Randomness Recomnendations for Security", RFC 1750, December 1994 [8] "The Unicode Standard, Version 2.0", The Unicode Consortium, Addi- son-Wesley, 1996. ISBN 0-201-48345-9. [9] Zorn, G. and Cobb, S., "Microsoft PPP CHAP Extensions", draft-ietf- pppext-mschap-00.txt (work in progress), March 1998 [10] "DES Modes of Operation", Federal Information Processing Standards Publication 81, National Institute of Standards and Technology, December 1980 [11] "Secure Hash Standard", Federal Information Processing Standards Publication 180-1, National Institute of Standards and Technology, April 1995 13. Acknowledgements Thanks (in no particular order) to Bruce Johnson (bjohn- son@microsoft.com), Tony Bell (tonybe@microsoft.com), Paul Leach (paulle@microsoft.com, Terence Spies (terences@microsoft.com), Dan Simon (dansimon@microsoft.com), Narendra Gidwani (nareng@microsoft.com), Gur- deep Singh Pall (gurdeep@microsoft.com), Jody Terrill Zorn [Page 7]
INTERNET-DRAFT MS-CHAP-V2 July 1998 (jodyt@extendsys.com) and Joe Davies (josephd@microsoft.com) for useful suggestions and feedback. 14. Chair's Address The PPP Extensions Working Group can be contacted via the current chair: Karl Fox Ascend Communications 3518 Riverside Drive Suite 101 Columbus, OH 43221 Phone: +1 614 326 6841 Email: karl@ascend.com 15. Author's Address Questions about this memo can also be directed to: Glen Zorn Microsoft Corporation One Microsoft Way Redmond, Washington 98052 Phone: +1 425 703 1559 FAX: +1 425 936 7329 EMail: glennz@microsoft.com 16. Expiration Date This memo is filed as <draft-ietf-pppext-mschap-v2-00.txt> and expires on March 23, 1999. Appendix A - Pseudocode The routines mentioned in the text are described in pseudocode below. A.1 GenerateNTResponse() GenerateNTResponse( IN 16-octet AuthenticatorChallenge, IN 16-octet PeerChallenge, Zorn [Page 8]
INTERNET-DRAFT MS-CHAP-V2 July 1998 IN 0-to-256-char UserName, IN 0-to-256-unicode-char Password, OUT 24-octet Response ) { 8-octet Challenge 16-octet PasswordHash ChallengeHash( PeerChallenge, AuthenticatorChallenge, UserName, giving Challenge) NtPasswordHash( Password, giving PasswordHash ) ChallengeResponse( Challenge, PasswordHash, giving Response ) } A.2 ChallengeHash() ChallengeHash( IN 16-octet PeerChallenge, IN 16-octet AuthenticatorChallenge, IN 0-to-256-char UserName, OUT 8-octet Challenge { /* * SHAInit(), SHAUpdate() and SHAFinal() functions are an * implementation of Secure Hash Algorithm (SHA-1) [11]. These are * available in public domain or can be licensed from * RSA Data Security, Inc. */ SHAInit(Context) SHAUpdate(Context, PeerChallenge, 16) SHAUpdate(Context, AuthenticatorChallenge, 16) /* * Only the user name (as presented by the peer and * excluding any prepended domain name) * is used as input to SHAUpdate(). */ SHAUpdate(Context, UserName, strlen(Username)) SHAFinal(Context, Digest) memcpy(Challenge, Digest, 8) } A.3 NtPasswordHash() Zorn [Page 9]
INTERNET-DRAFT MS-CHAP-V2 July 1998 NtPasswordHash( IN 0-to-256-unicode-char Password, OUT 16-octet PasswordHash ) { /* * Use the MD4 algorithm [5] to irreversibly hash Password * into PasswordHash. Only the password is hashed without * including any terminating 0. */ } A.4 ChallengeResponse() ChallengeResponse( IN 8-octet Challenge, IN 16-octet PasswordHash, OUT 24-octet Response ) { Set ZPasswordHash to PasswordHash zero-padded to 21 octets DesEncrypt( Challenge, 1st 7-octets of ZPasswordHash, giving 1st 8-octets of Response ) DesEncrypt( Challenge, 2nd 7-octets of ZPasswordHash, giving 2nd 8-octets of Response ) DesEncrypt( Challenge, 3rd 7-octets of ZPasswordHash, giving 3rd 8-octets of Response ) } A.5 DesEncrypt() DesEncrypt( IN 8-octet Clear, IN 7-octet Key, OUT 8-octet Cypher ) { /* * Use the DES encryption algorithm [4] in ECB mode [10] * to encrypt Clear into Cypher such that Cypher can * only be decrypted back to Clear by providing Key. * Note that the DES algorithm takes as input a 64-bit * stream where the 8th, 16th, 24th, etc. bits are Zorn [Page 10]
INTERNET-DRAFT MS-CHAP-V2 July 1998 * parity bits ignored by the encrypting algorithm. * Unless you write your own DES to accept 56-bit input * without parity, you will need to insert the parity bits * yourself. */ } A.6 GenerateAuthenticatorResponse() GenerateAuthenticatorResponse( IN 0-to-256-unicode-char Password, IN 24-octet NT-Response, IN 16-octet PeerChallenge, IN 16-octet AuthenticatorChallenge, IN 0-to-256-unicode-char UserName, OUT 42-octet AuthenticatorResponse ) { 16-octet PasswordHash 16-octet PasswordHashHash 8-octet Challenge /* * "Magic" constants used in response generation */ Magic1[39] = {0x4D, 0x61, 0x67, 0x69, 0x63, 0x20, 0x73, 0x65, 0x72, 0x76, 0x65, 0x72, 0x20, 0x74, 0x6F, 0x20, 0x63, 0x6C, 0x69, 0x65, 0x6E, 0x74, 0x20, 0x73, 0x69, 0x67, 0x6E, 0x69, 0x6E, 0x67, 0x20, 0x63, 0x6F, 0x6E, 0x73, 0x74, 0x61, 0x6E, 0x74}; Magic2[41] = {0x50, 0x61, 0x64, 0x20, 0x74, 0x6F, 0x20, 0x6D, 0x61, 0x6B, 0x65, 0x20, 0x69, 0x74, 0x20, 0x64, 0x6F, 0x20, 0x6D, 0x6F, 0x72, 0x65, 0x20, 0x74, 0x68, 0x61, 0x6E, 0x20, 0x6F, 0x6E, 0x65, 0x20, 0x69, 0x74, 0x65, 0x72, 0x61, 0x74, 0x69, 0x6F, 0x6E}; /* * Hash the password with MD4 */ NtPasswordHash( Password, giving PasswordHash ) /* * Now hash the hash */ Zorn [Page 11]
INTERNET-DRAFT MS-CHAP-V2 July 1998 HashNtPasswordHash( PasswordHash, giving PasswordHashHash) SHAInit(Context) SHAUpdate(Context, PasswordHashHash, 16) SHAUpdate(Context, NTResponse, 24) SHAUpdate(Context, Magic1, 45) SHAFinal(Context, Digest) ChallengeHash( PeerChallenge, AuthenticatorChallenge, UserName, giving Challenge) SHAInit(Context) SHAUpdate(Context, Digest, 20) SHAUpdate(Context, Challenge, 8) SHAUpdate(Context, Magic2, 48) SHAFinal(Context, Digest) /* * Encode the value of 'Digest' as "S=" followed by * 40 ASCII hexadecimal digits and return it in * AuthenticatorResponse. * For example, * "S=0123456789ABCDEF0123456789ABCDEF01234567" */ } A.7 CheckAuthenticatorResponse() CheckAuthenticatorResponse( IN 0-to-256-unicode-char Password, IN 24-octet NtResponse, IN 16-octet PeerChallenge, IN 16-octet AuthenticatorChallenge, IN 0-to-256-unicode-char UserName, IN 42-octet ReceivedResponse OUT Boolean ResponseOK ) { 20-octet MyResponse set ResponseOK = FALSE GenerateAuthenticatorResponse( Password, NtResponse, PeerChallenge, AuthenticatorChallenge, UserName, giving MyResponse) if (MyResponse = ReceivedResponse) then set ResponseOK = TRUE Zorn [Page 12]
INTERNET-DRAFT MS-CHAP-V2 July 1998 return ResponseOK } A.8 NewPasswordEncryptedWithOldNtPasswordHash() datatype-PWBLOCK { 256-unicode-char Password 4-octets PasswordLength } NewPasswordEncryptedWithOldNtPasswordHash( IN 0-to-256-unicode-char NewPassword, IN 0-to-256-unicode-char OldPassword, OUT datatype-PWBLOCK EncryptedPwBlock ) { NtPasswordHash( OldPassword, giving PasswordHash ) EncryptPwBlockWithPasswordHash( NewPassword, PasswordHash, giving EncryptedPwBlock ) } A.9 EncryptPwBlockWithPasswordHash() EncryptPwBlockWithPasswordHash( IN 0-to-256-unicode-char Password, IN 16-octet PasswordHash, OUT datatype-PWBLOCK PwBlock ) { Fill ClearPwBlock with random octet values PwSize = lstrlenW( Password ) * sizeof( unicode-char ) PwOffset = sizeof( ClearPwBlock.Password ) - PwSize Move PwSize octets to (ClearPwBlock.Password + PwOffset ) from Password ClearPwBlock.PasswordLength = PwSize Rc4Encrypt( ClearPwBlock, sizeof( ClearPwBlock ), PasswordHash, sizeof( PasswordHash ), giving PwBlock ) } A.10 Rc4Encrypt() Zorn [Page 13]
INTERNET-DRAFT MS-CHAP-V2 July 1998 Rc4Encrypt( IN x-octet Clear, IN integer ClearLength, IN y-octet Key, IN integer KeyLength, OUT x-octet Cypher ) { /* * Use the RC4 encryption algorithm [6] to encrypt Clear of * length ClearLength octets into a Cypher of the same length * such that the Cypher can only be decrypted back to Clear * by providing a Key of length KeyLength octets. */ } A.11 OldNtPasswordHashEncryptedWithNewNtPasswordHash() OldNtPasswordHashEncryptedWithNewNtPasswordHash( IN 0-to-256-unicode-char NewPassword, IN 0-to-256-unicode-char OldPassword, OUT 16-octet EncryptedPasswordHash ) { NtPasswordHash( OldPassword, giving OldPasswordHash ) NtPasswordHash( NewPassword, giving NewPasswordHash ) NtPasswordHashEncryptedWithBlock( OldPasswordHash, NewPasswordHash, giving EncryptedPasswordHash ) } A.12 NtPasswordHashEncryptedWithBlock() NtPasswordHashEncryptedWithBlock( IN 16-octet PasswordHash, IN 16-octet Block, OUT 16-octet Cypher ) { DesEncrypt( 1st 8-octets PasswordHash, 1st 7-octets Block, giving 1st 8-octets Cypher ) DesEncrypt( 2nd 8-octets PasswordHash, 2nd 7-octets Block, giving 2nd 8-octets Cypher ) } Appendix B - Examples Zorn [Page 14]
INTERNET-DRAFT MS-CHAP-V2 July 1998 B.1 Negotiation Examples Here are some examples of typical negotiations. The peer is on the left and the authenticator is on the right. The packet sequence ID is incremented on each authentication retry Response and on the change password response. All cases where the packet sequence ID is updated are noted below. Response retry is never allowed after Change Password. Change Password may occur after Response retry. B.1.1 Successful authentication <- Challenge Response -> <- Success B.1.2 Failed authentication with no retry allowed <- Challenge Response -> <- Failure (E=691 R=0) B.1.3 Successful authentication after retry <- Challenge Response -> <- Failure (E=691 R=1), disable short timeout Response (++ID) to challenge in failure message -> <- Success B.1.4 Failed hack attack with 3 attempts allowed <- Challenge Response -> <- Failure (E=691 R=1), disable short timeout Response (++ID) to challenge in Failure message -> <- Failure (E=691 R=1), disable short timeout Response (++ID) to challenge in Failure message -> <- Failure (E=691 R=0) B.1.5 Successful authentication with password change Zorn [Page 15]
INTERNET-DRAFT MS-CHAP-V2 July 1998 <- Challenge Response -> <- Failure (E=648 R=0 V=3), disable short timeout ChangePassword (++ID) to challenge in Failure message -> <- Success B.1.6 Successful authentication with retry and password change <- Challenge Response -> <- Failure (E=691 R=1), disable short timeout Response (++ID) to first challenge+23 -> <- Failure (E=648 R=0 V=2), disable short timeout ChangePassword (++ID) to first challenge+23 -> <- Success B.2 Hash Example Intermediate values for user name "User" and password "clientPass". All numeric values are hexadecimal. 0-to-256-char UserName: 55 73 65 72 0-to-256-unicode-char Password: 63 00 6C 00 69 00 65 00 6E 00 74 00 50 00 61 00 73 00 73 00 16-octet AuthenticatorChallenge: 5B 5D 7C 7D 7B 3F 2F 3E 3C 2C 60 21 32 26 26 28 16-octet PeerChallenge: 21 40 23 24 25 5E 26 2A 28 29 5F 2B 3A 33 7C 7E 8-octet Challenge: D0 2E 43 86 BC E9 12 26 16-octet PasswordHash: 44 EB BA 8D 53 12 B8 D6 11 47 44 11 F5 69 89 AE 24 octet NT-Response: 82 30 9E CD 8D 70 8B 5E A0 8F AA 39 81 CD 83 54 42 33 11 4A 3D 85 D6 DF 16-octet PasswordHashHash: 41 C0 0C 58 4B D2 D9 1C 40 17 A2 A1 2F A5 9F 3F 42-octet AuthenticatorResponse: Zorn [Page 16]
INTERNET-DRAFT MS-CHAP-V2 July 1998 "S=407A5589115FD0D6209F510FE9C04566932CDA56" B.3 Example of DES Key Generation DES uses 56-bit keys, expanded to 64 bits by the insertion of parity bits. After the parity of the key has been fixed, every eighth bit is a parity bit and the number of bits that are set (1) in each octet is odd; i.e., odd parity. Note that many DES engines do not check parity, how- ever, simply stripping the parity bits. The following example illus- trates the values resulting from the use of the password "MyPw" to gen- erate a pair of DES keys (e.g., for use in the NtPasswordHashEncrypted- WithBlock() described in Appendix A.12). 0-to-256-unicode-char Password: 4D 79 50 77 16-octet PasswordHash: FC 15 6A F7 ED CD 6C 0E DD E3 33 7D 42 7F 4E AC First "raw" DES key (initial 7 octets of password hash): FC 15 6A F7 ED CD 6C First parity-corrected DES key (eight octets): FD 0B 5B 5E 7F 6E 34 D9 Second "raw" DES key (second 7 octets of password hash) 0E DD E3 33 7D 42 7F Second parity-corrected DES key (eight octets): 0E 6E 79 67 37 EA 08 FE Zorn [Page 17]
