LukeLeighton

lkcl@switchboard.net

PaulAshton

paul@argo.demon.co.uk

DuncanStansfield

duncans@sco.com

01 November 97(version 0.0.24) This document contains information to provide an NT workstation with login services, without the need for an NT server. It is the sgml version of http://mailhost.cb1.com/~lkcl/cifsntdomain.txt, controlled by Luke. It should be possible to select a domain instead of a workgroup (in the NT workstation's TCP/IP settings) and after the obligatory reboot, type in a username, password, select a domain and successfully log in. I would appreciate any feedback on your experiences with this process, and any comments, corrections and additions to this document. The packets described here can be easily derived from (and are probably better understood using) Netmon.exe. You will need to use the version of Netmon that matches your system, in order to correctly decode the NETLOGON, lsarpc and srvsvc Transact pipes. This document is derived from NT Service Pack 1 and its corresponding version of Netmon. It is intended that an annotated packet trace be produced, which will likely be more instructive than this document. Also needed, to fully implement NT Domain Login Services, is the document describing the cryptographic part of the NT authentication. This document is available from comp.protocols.smb; from the ntsecurity.net digest and from the samba digest, amongst other sources. A copy is available from: http://ntbugtraq.rc.on.ca/SCRIPTS/WA.EXE?A2=ind9708;L=ntbugtraq;O=A;P=2935 http://mailhost.cb1.com/~lkcl/crypt.html A c-code implementation, provided by Linus Nordberg of this protocol is available from: http://samba.org/cgi-bin/mfs/01/digest/1997/97aug/0391.html http://mailhost.cb1.com/~lkcl/crypt.txt Also used to provide debugging information is the Check Build version of NT workstation, and enabling full debugging in NETLOGON. This is achieved by setting the following REG_SZ registry key to 0x1ffffff: HKLM\SYSTEM\CurrentControlSet\Services\Netlogon\Parameters Incorrect direct editing of the registry can cause your machine to fail. Then again, so can incorrect implementation of this protocol. See "Liability:" above. Bear in mind that each packet over-the-wire will have its origin in an API call. Therefore, there are likely to be structures, enumerations and defines that are usefully documented elsewhere. This document is by no means complete or authoritative. Missing sections include, but are not limited to: Mappings of RIDs to usernames (and vice-versa). What a User ID is and what a Group ID is. The exact meaning/definition of various magic constants or enumerations. The reply error code and use of that error code when a workstation becomes a member of a domain (to be described later). Failure to return this error code will make the workstation report that it is already a member of the domain. the cryptographic side of the NetrServerPasswordSet command, which would allow the workstation to change its password. This password is used to generate the long-term session key. [It is possible to reject this command, and keep the default workstation password]. cket Traces from Netmonitor (Service Pack 1 and above) ul Ashton and Luke Leighton's other "NT Domain" doc. FS documentation - cifs6.txt FS documentation - cifsrap2.txt Paul Ashton: loads of work with Net Monitor; understanding the NT authentication system; reference implementation of the NT domain support on which this document is originally based. Duncan Stansfield: low-level analysis of MSRPC Pipes. Linus Nordberg: producing c-code from Paul's crypto spec. Windows Sourcer development team In the SMB Transact pipes, some "Structures", described here, appear to be 4-byte aligned with the SMB header, at their start. Exactly which "Structures" need aligning is not precisely known or documented. In the UDP NTLOGON Mailslots, some "Structures", described here, appear to be 2-byte aligned with the start of the mailslot, at their start. Domain SID is of the format S-revision-version-auth1-auth2...authN. e.g S-1-5-123-456-789-123-456. the 5 could be a sub-revision. any undocumented buffer pointers must be non-zero if the string buffer it refers to contains characters. exactly what value they should be is unknown. 0x0000 0002 seems to do the trick to indicate that the buffer exists. a NULL buffer pointer indicates that the string buffer is of zero length. If the buffer pointer is NULL, then it is suspected that the structure it refers to is NOT put into (or taken out of) the SMB data stream. This is empirically derived from, for example, the LSA SAM Logon response packet, where if the buffer pointer is NULL, the user information is not inserted into the data stream. Exactly what happens with an array of buffer pointers is not known, although an educated guess can be made. an array of structures (a container) appears to have a count and a pointer. if the count is zero, the pointer is also zero. no further data is put into or taken out of the SMB data stream. if the count is non-zero, then the pointer is also non-zero. immediately following the pointer is the count again, followed by an array of container sub-structures. the count appears a third time after the last sub-structure. command number in the msrpc packet header MSRPC_Request: 0x00 MSRPC_Response: 0x02 MSRPC_Bind: 0x0B MSRPC_BindAck: 0x0C The meaning of these flags is undocumented FirstFrag: 0x01 LastFrag: 0x02 NotaFrag: 0x04 RecRespond: 0x08 NoMultiplex: 0x10 NotForIdemp: 0x20 NotforBcast: 0x40 NoUuid: 0x80 sizeof VOID* is 32 bits. sizeof char is 8 bits. UTIME is 32 bits, indicating time in seconds since 01jan1970. documented in cifs6.txt (section 3.5 page, page 30). NTTIME is 64 bits. documented in cifs6.txt (section 3.5 page, page 30). UINT32 num of sub-authorities in domain SID UINT8 SID revision number UINT8 num of sub-authorities in domain SID UINT8[6] 6 bytes for domain SID - Identifier Authority. UINT16[n_subauths] domain SID sub-authorities Note: the domain SID is documented elsewhere. STR (string) is a char[] : a null-terminated string of ascii characters. UINT16 length of unicode string UINT16 max length of unicode string UINT32 4 - undocumented. UNIHDR unicode string header VOID* undocumented buffer pointer UINT16[] null-terminated string of unicode characters. UINT32 length of unicode string UINT16[] null-terminated string of unicode characters. UINT8[] padding to get unicode string 4-byte aligned with the start of the SMB header. UINT32 max length of unicode string UINT32 0 - undocumented UINT32 length of unicode string UINT16[] string of uncode characters UINT32 0x18 - length (in bytes) including the length field. VOID* 0 - root directory (pointer) VOID* 0 - object name (pointer) UINT32 0 - attributes (undocumented) VOID* 0 - security descriptior (pointer) UINT32 0 - security quality of service char[20] policy handle UINT32 5 - SID type UINT32 0 - undocumented UNIHDR2 domain SID unicode string header UNISTR domain SID unicode string Note: there is a conflict between the unicode string header and the unicode string itself as to which to use to indicate string length. this will need to be resolved. Note: the SID type indicates, for example, an alias; a well-known group etc. this is documented somewhere. UINT32 5 - well-known SID. 1 - user SID (see ShowACLs) UINT32 5 - undocumented UINT32 domain RID UINT32 0 - domain index out of above reference domains Note: logon server name starts with two '\' characters and is upper case. Note: account name is the logon client name from the LSA Request Challenge, with a $ on the end of it, in upper case. VOID* undocumented buffer pointer UNISTR2 logon server unicode string UNISTR2 account name unicode string UINT16 sec_chan - security channel type UNISTR2 logon client machine unicode string Note: logon server name starts with two '\' characters and is upper case. VOID* undocumented buffer pointer UNISTR2 logon server unicode string VOID* undocumented buffer pointer UNISTR2 logon client machine unicode string char[8] credentials UTIME time stamp Note: whenever this structure appears in a request, you must take a copy of the client-calculated credentials received, because they will beused in subsequent credential checks. the presumed intention is to maintain an authenticated request/response trail. CLNT_SRV client and server names UINT8[] ???? padding, for 4-byte alignment with SMB header. VOID* pointer to client credentials. CREDS client-calculated credentials + client time Note: whenever this structure appears in a request, you must take a copy of the client-calculated credentials received, because they will be used in subsequent credential checks. the presumed intention is to maintain an authenticated request/response trail. LOG_INFO logon account info CREDS client-calculated credentials + client time VOID* ptr_id_info_1 UNIHDR domain name unicode header UINT32 param control UINT64 logon ID UNIHDR user name unicode header UNIHDR workgroup name unicode header char[16] arc4 LM OWF Password char[16] arc4 NT OWF Password UNISTR2 domain name unicode string UNISTR2 user name unicode string UNISTR2 workstation name unicode string Note: presumably, the return credentials is supposedly for the server to verify that the credential chain hasn't been compromised. CLNT_INFO2 client identification/authentication info VOID* pointer to return credentials. CRED return credentials - ignored. UINT16 logon level UINT16 switch value switch (switch_value) case 1: { ID_INFO_1 id_info_1; } UINT32 group id UINT32 user attributes (only used by NT 3.1 and 3.51) VOID* undocumented buffer pointer. UINT32 num referenced domains? VOID* undocumented domain name buffer pointer. UINT32 32 - max number of entries UINT32 4 - num referenced domains? UNIHDR2 domain name unicode string header UNIHDR2[num_ref_doms-1] referenced domain unicode string headers UNISTR domain name unicode string DOM_SID[num_ref_doms] referenced domain SIDs UINT8[] ??? padding to get 4-byte alignment with start of SMB header UINT16 domain name string length * 2 UINT16 domain name string length * 2 VOID* undocumented domain name string buffer pointer VOID* undocumented domain SID string buffer pointer UNISTR2 domain name (unicode string) DOM_SID domain SID Note: it would be nice to know what the 16 byte user session key is for. NTTIME logon time NTTIME logoff time NTTIME kickoff time NTTIME password last set time NTTIME password can change time NTTIME password must change time UNIHDR username unicode string header UNIHDR user's full name unicode string header UNIHDR logon script unicode string header UNIHDR profile path unicode string header UNIHDR home directory unicode string header UNIHDR home directory drive unicode string header UINT16 logon count UINT16 bad password count UINT32 User ID UINT32 Group ID UINT32 num groups VOID* undocumented buffer pointer to groups. UINT32 user flags char[16] user session key UNIHDR logon server unicode string header UNIHDR logon domain unicode string header VOID* undocumented logon domain id pointer char[40] 40 undocumented padding bytes. future expansion? UINT32 0 - num_other_sids? VOID* NULL - undocumented pointer to other domain SIDs. UNISTR2 username unicode string UNISTR2 user's full name unicode string UNISTR2 logon script unicode string UNISTR2 profile path unicode string UNISTR2 home directory unicode string UNISTR2 home directory drive unicode string UINT32 num groups GID[num_groups] group info UNISTR2 logon server unicode string UNISTR2 logon domain unicode string DOM_SID domain SID DOM_SID[num_sids] other domain SIDs? Note: see cifsrap2.txt section5, page 10. 0 for shi1_type indicates a Disk. 1 for shi1_type indicates a Print Queue. 2 for shi1_type indicates a Device. 3 for shi1_type indicates an IPC pipe. 0x8000 0000 (top bit set in shi1_type) indicates a hidden share. VOID* shi1_netname - pointer to net name UINT32 shi1_type - type of share. 0 - undocumented. VOID* shi1_remark - pointer to comment. UNISTR2 shi1_netname - unicode string of net name UNISTR2 shi1_remark - unicode string of comment. share container with 0 entries: UINT32 0 - EntriesRead UINT32 0 - Buffer share container with > 0 entries: UINT32 EntriesRead UINT32 non-zero - Buffer UINT32 EntriesRead SH_INFO_1_PTR[EntriesRead] share entry pointers SH_INFO_1_STR[EntriesRead] share entry strings UINT8[] padding to get unicode string 4-byte aligned with start of the SMB header. UINT32 EntriesRead UINT32 0 - padding Note: see cifs6.txt section 6.4 - the fields described therein will be of assistance here. for example, the type listed below is the same as fServerType, which is described in 6.4.1. SV_TYPE_WORKSTATION 0x00000001 All workstations SV_TYPE_SERVER 0x00000002 All servers SV_TYPE_SQLSERVER 0x00000004 Any server running with SQL server SV_TYPE_DOMAIN_CTRL 0x00000008 Primary domain controller SV_TYPE_DOMAIN_BAKCTRL 0x00000010 Backup domain controller SV_TYPE_TIME_SOURCE 0x00000020 Server running the timesource service SV_TYPE_AFP 0x00000040 Apple File Protocol servers SV_TYPE_NOVELL 0x00000080 Novell servers SV_TYPE_DOMAIN_MEMBER 0x00000100 Domain Member SV_TYPE_PRINTQ_SERVER 0x00000200 Server sharing print queue SV_TYPE_DIALIN_SERVER 0x00000400 Server running dialin service. SV_TYPE_XENIX_SERVER 0x00000800 Xenix server SV_TYPE_NT 0x00001000 NT server SV_TYPE_WFW 0x00002000 Server running Windows for SV_TYPE_SERVER_NT 0x00008000 Windows NT non DC server SV_TYPE_POTENTIAL_BROWSER 0x00010000 Server that can run the browser service SV_TYPE_BACKUP_BROWSER 0x00020000 Backup browser server SV_TYPE_MASTER_BROWSER 0x00040000 Master browser server SV_TYPE_DOMAIN_MASTER 0x00080000 Domain Master Browser server SV_TYPE_LOCAL_LIST_ONLY 0x40000000 Enumerate only entries marked "local" SV_TYPE_DOMAIN_ENUM 0x80000000 Enumerate Domains. The pszServer and pszDomain parameters must be NULL. UINT32 500 - platform_id VOID* pointer to name UINT32 5 - major version UINT32 4 - minor version UINT32 type (SV_TYPE_... bit field) VOID* pointer to comment UNISTR2 sv101_name - unicode string of server name UNISTR2 sv_101_comment - unicode string of server comment. UINT8[] padding to get unicode string 4-byte aligned with start of the SMB header. For details on the SMB Transact Named Pipe, see cifs6.txt The MSRPC is conducted over an SMB Transact Pipe with a name of \PIPE\. You must first obtain a 16 bit file handle, by sending a SMBopenX with the pipe name \PIPE\srvsvc for example. You can then perform an SMB Trans, and must carry out an SMBclose on the file handle once you are finished. Trans Requests must be sent with two setup UINT16s, no UINT16 params (none known about), and UINT8 data parameters sufficient to contain the MSRPC header, and MSRPC data. The first UINT16 setup parameter must be either 0x0026 to indicate an RPC, or 0x0001 to indicate Set Named Pipe Handle state. The second UINT16 parameter must be the file handle for the pipe, obtained above. The Data section for an API Command of 0x0026 (RPC pipe) in the Trans Request is the RPC Header, followed by the RPC Data. The Data section for an API Command of 0x0001 (Set Named Pipe Handle state) is two bytes. The only value seen for these two bytes is 0x00 0x43. MSRPC Responses are sent as response data inside standard SMB Trans responses, with the MSRPC Header, MSRPC Data and MSRPC tail. It is suspected that the Trans Requests will need to be at least 2-byte aligned (probably 4-byte). This is standard practice for SMBs. It is also independent of the observed 4-byte alignments with the start of the MSRPC header, including the 4-byte alignment between the MSRPC header and the MSRPC data. First, an SMBtconX connection is made to the IPC$ share. The connection must be made using encrypted passwords, not clear-text. Then, an SMBopenX is made on the pipe. Then, a Set Named Pipe Handle State must be sent, after which the pipe is ready to accept API commands. Lastly, and SMBclose is sent. To be resolved: lkcl/01nov97 there appear to be two additional bytes after the null-terminated \PIPE\ name for the RPC pipe. Values seen so far are listed below: initial SMBopenX request: RPC API command 0x26 params: "\\PIPE\\lsarpc" 0x65 0x63; 0x72 0x70; 0x44 0x65; "\\PIPE\\srvsvc" 0x73 0x76; 0x4E 0x00; 0x5C 0x43; [section to be rewritten, following receipt of work by Duncan Stansfield] Interesting note: if you set packed data representation to 0x0100 0000 then all 4-byte and 2-byte word ordering is turned around! The start of each of the NTLSA and NETLOGON named pipes begins with: offsetVariable typeVariable data 00UINT85 - RPC major version 01UINT80 - RPC minor version 02UINT82 - RPC response packet 03UINT83 - (FirstFrag bit-wise or with LastFrag) 04UINT320x1000 0000 - packed data representation 08UINT16fragment length - data size (bytes) inc header and tail. 0AUINT160 - authentication length 0CUINT32call identifier. matches 12th UINT32 of incoming RPC data. 10UINT32allocation hint - data size (bytes) minus header and tail. 14UINT160 - presentation context identifier 16UINT80 - cancel count 17UINT8in replies: 0 - reserved; in requests: opnum - see #defines. 18......start of data (goes on for allocation_hint bytes) UINT8 versionmaj reply same as request (0x05) UINT8 versionmin reply same as request (0x00) UINT8 type one of the MSRPC_Type enums UINT8 flags reply same as request (0x00 for Bind, 0x03 for Request) UINT32 representation reply same as request (0x00000010) UINT16 fraglength the length of the data section of the SMB trans packet UINT16 authlength UINT32 callid call identifier. (e.g. 0x00149594) * stub USE TvPacket the remainder of the packet depending on the "type" the interfaces are numbered. as yet I haven't seen more than one interface used on the same pipe name srvsvc abstract (0x4B324FC8, 0x01D31670, 0x475A7812, 0x88E16EBF, 0x00000003) transfer (0x8A885D04, 0x11C91CEB, 0x0008E89F, 0x6048102B, 0x00000002) UINT8 byte[16] 16 bytes of number UINT32 version the interface number the remainder of the packet after the header if "type" was Bind in the response header, "type" should be BindAck UINT16 maxtsize maximum transmission fragment size (0x1630) UINT16 maxrsize max receive fragment size (0x1630) UINT32 assocgid associated group id (0x0) UINT32 numelements the number of elements (0x1) UINT16 contextid presentation context identifier (0x0) UINT8 numsyntaxes the number of syntaxes (has always been 1?)(0x1) UINT8[] 4-byte alignment padding, against SMB header * abstractint USE RPC_Iface num and vers. of interface client is using * transferint USE RPC_Iface num and vers. of interface to use for replies UINT16 length length of the string including null terminator * port USE string the string above in single byte, null terminated form the response to place after the header in the reply packet UINT16 maxtsize same as request UINT16 maxrsize same as request UINT32 assocgid zero * secondaddr USE RPC_Address the address string, as described earlier UINT8[] 4-byte alignment padding, against SMB header UINT8 numresults the number of results (0x01) UINT8[] 4-byte alignment padding, against SMB header UINT16 result result (0x00 = accept) UINT16 reason reason (0x00 = no reason specified) * transfersyntax USE RPC_Iface the transfer syntax from the request the remainder of the packet after the header for every other other request UINT32 allochint the size of the stub data in bytes UINT16 prescontext presentation context identifier (0x0) UINT16 opnum operation number (0x15) * stub USE TvPacket a packet dependent on the pipe name (probably the interface) and the op number) UINT32 allochint # size of the stub data in bytes UINT16 prescontext # presentation context identifier (same as request) UINT8 cancelcount # cancel count? (0x0) UINT8 reserved # 0 - one byte padding * stub USE TvPacket # the remainder of the reply The end of each of the NTLSA and NETLOGON named pipes ends with: ...... end of data UINT32 return code RPC Binds are the process of associating an RPC pipe (e.g \PIPE\lsarpc) with a "transfer syntax" (see RPC_Iface structure). The purpose for doing this is unknown. Note: The RPC_ResBind SMB Transact request is sent with two uint16 setup parameters. The first is 0x0026; the second is the file handle returned by the SMBopenX Transact response. Note: The RPC_ResBind members maxtsize, maxrsize and assocgid are the same in the response as the same members in the RPC_ReqBind. The RPC_ResBind member transfersyntax is the same in the response as the Note: The RPC_ResBind response member secondaddr contains the name of what is presumed to be the service behind the RPC pipe. The mapping identified so far is: initial SMBopenX request: RPC_ResBind response: "\\PIPE\\srvsvc" "\\PIPE\\ntsvcs" "\\PIPE\\samr" "\\PIPE\\lsass" "\\PIPE\\lsarpc" "\\PIPE\\lsass" "\\PIPE\\wkssvc" "\\PIPE\\wksvcs" "\\PIPE\\NETLOGON" "\\PIPE\\NETLOGON" Note: The RPC_Packet fraglength member in both the Bind Request and Bind Acknowledgment must contain the length of the entire RPC data, including the RPC_Packet header. Request: RPC_Packet RPC_ReqBind Response: RPC_Packet RPC_ResBind The sequence of actions taken on this pipe are: Establish a connection to the IPC$ share (SMBtconX). use encrypted passwords. Open an RPC Pipe with the name "\\PIPE\\lsarpc". Store the file handle. Using the file handle, send a Set Named Pipe Handle state to 0x4300. Send an LSA Open Policy request. Store the Policy Handle. Using the Policy Handle, send LSA Query Info Policy requests, etc. Using the Policy Handle, send an LSA Close. Close the IPC$ share. Defines for this pipe, identifying the query are: LSA Open Policy: 0x2c LSA Query Info Policy: 0x07 LSA Enumerate Trusted Domains: 0x0d LSA Open Secret: 0xff LSA Lookup SIDs: 0xfe LSA Lookup Names: 0xfd LSA Close: 0x00 Note: The policy handle can be anything you like. VOID* buffer pointer UNISTR2 server name - unicode string starting with two '\'s OBJ_ATTR object attributes UINT32 1 - desired access POL_HND LSA policy handle return 0 - indicates success Note: The info class in response must be the same as that in the request. POL_HND LSA policy handle UINT16 info class (also a policy handle?) VOID* undocumented buffer pointer UINT16 info class (same as info class in request). switch (info class) case 3: case 5: { DOM_INFO domain info, levels 3 and 5 (are the same). } return 0 - indicates success no extra data UINT32 0 - enumeration context UINT32 0 - entries read UINT32 0 - trust information return 0x8000 001a - "no trusted domains" success code no extra data UINT32 0 - undocumented UINT32 0 - undocumented UINT32 0 - undocumented UINT32 0 - undocumented UINT32 0 - undocumented return 0x0C00 0034 - "no such secret" success code POL_HND policy handle to be closed POL_HND 0s - closed policy handle (all zeros) return 0 - indicates success Note: num_entries in response must be same as num_entries in request. POL_HND LSA policy handle UINT32 num_entries VOID* undocumented domain SID buffer pointer VOID* undocumented domain name buffer pointer VOID*[num_entries] undocumented domain SID pointers to be looked up. DOM_SID[num_entries] domain SIDs to be looked up. char[16] completely undocumented 16 bytes. DOM_REF domain reference response UINT32 num_entries (listed above) VOID* undocumented buffer pointer UINT32 num_entries (listed above) DOM_SID2[num_entries] domain SIDs (from Request, listed above). UINT32 num_entries (listed above) return 0 - indicates success Note: num_entries in response must be same as num_entries in request. POL_HND LSA policy handle UINT32 num_entries UINT32 num_entries VOID* undocumented domain SID buffer pointer VOID* undocumented domain name buffer pointer NAME[num_entries] names to be looked up. char[] undocumented bytes - falsely translated SID structure? DOM_REF domain reference response UINT32 num_entries (listed above) VOID* undocumented buffer pointer UINT32 num_entries (listed above) DOM_RID[num_entries] domain SIDs (from Request, listed above). UINT32 num_entries (listed above) return 0 - indicates success The sequence of actions taken on this pipe are: tablish a connection to the IPC$ share (SMBtconX). use encrypted passwords. en an RPC Pipe with the name "\\PIPE\\NETLOGON". Store the file handle. ing the file handle, send a Set Named Pipe Handle state to 0x4300. eate Client Challenge. Send LSA Request Challenge. Store Server Challenge. lculate Session Key. Send an LSA Auth 2 Challenge. Store Auth2 Challenge. lc/Verify Client Creds. Send LSA Srv PW Set. Calc/Verify Server Creds. lc/Verify Client Creds. Send LSA SAM Logon . Calc/Verify Server Creds. lc/Verify Client Creds. Send LSA SAM Logoff. Calc/Verify Server Creds. ose the IPC$ share. Defines for this pipe, identifying the query are LSA Request Challenge: 0x04 LSA Server Password Set: 0x06 LSA SAM Logon: 0x02 LSA SAM Logoff: 0x03 LSA Auth 2: 0x0f LSA Logon Control: 0x0e Note: logon server name starts with two '\' characters and is upper case. Note: logon client is the machine, not the user. Note: the initial LanManager password hash, against which the challenge is issued, is the machine name itself (lower case). there will becalls issued (LSA Server Password Set) which will change this, later. refusing these calls allows you to always deal with the same password (i.e the LM# of the machine name in lower case). VOID* undocumented buffer pointer UNISTR2 logon server unicode string UNISTR2 logon client unicode string char[8] client challenge char[8] server challenge return 0 - indicates success Note: in between request and response, calculate the client credentials, and check them against the client-calculated credentials (this process uses the previously received client credentials). Note: neg_flags in the response is the same as that in the request. Note: you must take a copy of the client-calculated credentials received here, because they will be used in subsequent authentication packets. LOG_INFO client identification info char[8] client-calculated credentials UINT8[] padding to 4-byte align with start of SMB header. UINT32 neg_flags - negotiated flags (usual value is 0x0000 01ff) char[8] server credentials. UINT32 neg_flags - same as neg_flags in request. return 0 - indicates success. failure value unknown. Note: the new password is suspected to be a DES encryption using the old password to generate the key. Note: in between request and response, calculate the client credentials, and check them against the client-calculated credentials (this process uses the previously received client credentials). Note: the server credentials are constructed from the client-calculated credentials and the client time + 1 second. Note: you must take a copy of the client-calculated credentials received here, because they will be used in subsequent authentication packets. CLNT_INFO client identification/authentication info char[] new password - undocumented. CREDS server credentials. server time stamp appears to be ignored. return 0 - indicates success; 0xC000 006a indicates failure Note: valid_user is True iff the username and password hash are valid for the requested domain. SAM_INFO sam_id structure VOID* undocumented buffer pointer CREDS server credentials. server time stamp appears to be ignored. if (valid_user) { UINT16 3 - switch value indicating USER_INFO structure. VOID* non-zero - pointer to USER_INFO structure USER_INFO user logon information UINT32 1 - Authoritative response; 0 - Non-Auth? return 0 - indicates success } else { UINT16 0 - switch value. value to indicate no user presumed. VOID* 0x0000 0000 - indicates no USER_INFO structure. UINT32 1 - Authoritative response; 0 - Non-Auth? return 0xC000 0064 - NT_STATUS_NO_SUCH_USER. } Note: presumably, the SAM_INFO structure is validated, and a (currently undocumented) error code returned if the Logoff is invalid. SAM_INFO sam_id structure VOID* undocumented buffer pointer CREDS server credentials. server time stamp appears to be ignored. return 0 - indicates success. undocumented failure indication. Note: mailslots will contain a response mailslot, to which the response should be sent. the target NetBIOS name is REQUEST_NAME<20>, where REQUEST_NAME is the name of the machine that sent the request. Note: NTversion, LMNTtoken, LM20token in response are the same as those given in the request. UINT16 0x0007 - Query for PDC STR machine name STR response mailslot UINT8[] padding to 2-byte align with start of mailslot. UNISTR machine name UINT32 NTversion UINT16 LMNTtoken UINT16 LM20token UINT16 0x000A - Respose to Query for PDC STR machine name (in uppercase) UINT8[] padding to 2-byte align with start of mailslot. UNISTR machine name UNISTR domain name UINT32 NTversion (same as received in request) UINT16 LMNTtoken (same as received in request) UINT16 LM20token (same as received in request) Note: machine name in response is preceded by two '\' characters. Note: NTversion, LMNTtoken, LM20token in response are the same as those given in the request. Note: user name in the response is presumably the same as that in the request. UINT16 0x0012 - SAM Logon UINT16 request count UNISTR machine name UNISTR user name STR response mailslot UINT32 alloweable account UINT32 domain SID size char[sid_size] domain SID, of sid_size bytes. UINT8[] ???? padding to 4? 2? -byte align with start of mailslot. UINT32 NTversion UINT16 LMNTtoken UINT16 LM20token UINT16 0x0013 - Response to SAM Logon UNISTR machine name UNISTR user name - workstation trust account UNISTR domain name UINT32 NTversion UINT16 LMNTtoken UINT16 LM20token Defines for this pipe, identifying the query are: Net Share Enum 0x0f Net Server Get Info 0x15 Note: share level and switch value in the response are presumably the same as those in the request. Note: cifsrap2.txt (section 5) may be of limited assistance here. VOID* pointer (to server name?) UNISTR2 server name UINT8[] padding to get unicode string 4-byte aligned with the start of the SMB header. UINT32 share level UINT32 switch value VOID* pointer to SHARE_INFO_1_CTR SHARE_INFO_1_CTR share info with 0 entries UINT32 preferred maximum length (0xffff ffff) UINT32 share level UINT32 switch value VOID* pointer to SHARE_INFO_1_CTR SHARE_INFO_1_CTR share info (only added if share info ptr is non-zero) return 0 - indicates success Note: level is the same value as in the request. UNISTR2 server name UINT32 switch level UINT32 switch level VOID* pointer to SERVER_INFO_101 SERVER_INFO_101 server info (only added if server info ptr is non-zero) return 0 - indicates success Add(A1,A2) Intel byte ordered addition of corresponding 4 byte words in arrays A1 and A2 E(K,D) DES ECB encryption of 8 byte data D using 7 byte key K lmowf() Lan man hash ntowf() NT hash PW md4(machine_password) == md4(lsadump $machine.acc) == pwdump(machine$) (initially) == md4(lmowf(unicode(machine))) ARC4(K,Lk,D,Ld) ARC4 encryption of data D of length Ld with key K of length Lk v[m..n(,l)] subset of v from bytes m to n, optionally padded with zeroes to length l Cred(K,D) E(K[7..7,7],E(K[0..6],D)) computes a credential Time() 4 byte current time Cc,Cs 8 byte client and server challenges Rc,Rs: 8 byte client and server credentials C->S ReqChal,Cc S->C Cs C & S compute session key Ks = E(PW[9..15],E(PW[0..6],Add(Cc,Cs))) C: Rc = Cred(Ks,Cc) C->S Authenticate,Rc S: Rs = Cred(Ks,Cs), assert(Rc == Cred(Ks,Cc)) S->C Rs C: assert(Rs == Cred(Ks,Cs)) On joining the domain the client will optionally attempt to change its password and the domain controller may refuse to update it depending on registry settings. This will also occur weekly afterwards. C: Tc = Time(), Rc' = Cred(Ks,Rc+Tc) C->S ServerPasswordSet,Rc',Tc,arc4(Ks[0..7,16],lmowf(randompassword()) C: Rc = Cred(Ks,Rc+Tc+1) S: assert(Rc' == Cred(Ks,Rc+Tc)), Ts = Time() S: Rs' = Cred(Ks,Rs+Tc+1) S->C Rs',Ts C: assert(Rs' == Cred(Ks,Rs+Tc+1)) S: Rs = Rs' User: U with password P wishes to login to the domain (incidental data such as workstation and domain omitted) C: Tc = Time(), Rc' = Cred(Ks,Rc+Tc) C->S NetLogonSamLogon,Rc',Tc,U,arc4(Ks[0..7,16],16,ntowf(P),16), arc4(Ks[0..7,16],16,lmowf(P),16) S: assert(Rc' == Cred(Ks,Rc+Tc)) assert(passwords match those in SAM) S: Ts = Time() S->C Cred(Ks,Cred(Ks,Rc+Tc+1)),userinfo(logon script,UID,SIDs,etc) C: assert(Rs == Cred(Ks,Cred(Rc+Tc+1)) C: Rc = Cred(Ks,Rc+Tc+1) On first joining the domain the session key could be computed by anyone listening in on the network as the machine password has a well known value. Until the machine is rebooted it will use this session key to encrypt NT and LM one way functions of passwords which are password equivalents. Any user who logs in before the machine has been rebooted a second time will have their password equivalent exposed. Of course the new machine password is exposed at this time anyway. None of the returned user info such as logon script, profile path and SIDs *appear* to be protected by anything other than the TCP checksum. The server time stamps appear to be ignored. The client sends a ReturnAuthenticator in the SamLogon request which I can't find a use for. However its time is used as the timestamp returned by the server. The password OWFs should NOT be sent over the network reversibly encrypted. They should be sent using ARC4(Ks,md4(owf)) with the server computing the same function using the owf values in the SAM. SIDs and RIDs are well documented elsewhere. A SID is an NT Security ID (see DOM_SID structure). They are of the form: revision-NN-SubAuth1-SubAuth2-SubAuth3... revision-0xNNNNNNNNNNNN-SubAuth1-SubAuth2-SubAuth3... currently, the SID revision is 1. The Sub-Authorities are known as Relative IDs (RIDs). Null SID S-1-0-0 World S-1-1-0 Local S-1-2-0 Creator Owner ID S-1-3-0 Creator Group ID S-1-3-1 Creator Owner Server ID S-1-3-2 Creator Group Server ID S-1-3-3 (Non-unique IDs) S-1-4 NT Authority S-1-5 Dialup S-1-5-1 Network S-1-5-2 Batch S-1-5-3 Interactive S-1-5-4 Service S-1-5-6 AnonymousLogon(aka null logon session) S-1-5-7 Proxy S-1-5-8 ServerLogon(aka domain controller account) S-1-5-8 (Logon IDs) S-1-5-5-X-Y (NT non-unique IDs) S-1-5-0x15-... (Built-in domain) s-1-5-0x20 A RID is a sub-authority value, as part of either a SID, or in the case of Group RIDs, part of the DOM_GID structure, in the USER_INFO_1 structure, in the LSA SAM Logon response. Groupname ???? RID DOMAIN_USER_RID_ADMIN0x000001F4 DOMAIN_USER_RID_GUEST0x000001F5 Groupname ???? RID DOMAIN_GROUP_RID_ADMINS0x00000200 DOMAIN_GROUP_RID_USERS0x00000201 DOMAIN_GROUP_RID_GUESTS0x00000202 Groupname ???? RID DOMAIN_ALIAS_RID_ADMINS0x00000220 DOMAIN_ALIAS_RID_USERS0x00000221 DOMAIN_ALIAS_RID_GUESTS0x00000222 DOMAIN_ALIAS_RID_POWER_USERS0x00000223 DOMAIN_ALIAS_RID_ACCOUNT_OPS0x00000224 DOMAIN_ALIAS_RID_SYSTEM_OPS0x00000225 DOMAIN_ALIAS_RID_PRINT_OPS0x00000226 DOMAIN_ALIAS_RID_BACKUP_OPS0x00000227 DOMAIN_ALIAS_RID_REPLICATOR0x00000228