4.2 NNTP Client Does Not Successfully Authenticate to an NNTP Server
This section illustrates the NTLM Authentication: NNTP Extension with an example scenario in which an NNTP client attempts NTLM authentication to an NNTP server and the authentication fails.
Figure 5: NNTP client attempts authentication to an NNTP server and is unsuccessful
The client sends an NNTP_AUTH_NTLM_Initiation_Command to the server. This command is defined in [RFC2980] section 3.1.3.
AUTHINFO GENERIC NTLM
The server sends the NNTP_NTLM_Supported_Response message, indicating that it can perform NTLM authentication.
381 Protocol supported, proceed
The client sends an NNTP_AUTH_NTLM_Blob_Command message.
AUTHINFO GENERIC TlRMTVNTUAABAAAAt4II4gAAAAAAAAAAAAAAAAAAAAAFAs4OAAAADw==
The contents of the NTLM message after base64 decoding are:
0x00000000 4E 54 4C 4D 53 53 50 00 01 00 00 00 B7 82 08 E2 NTLMSSP.....7_.b 0x00000010 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 0x00000020 05 02 CE 0E 00 00 00 0F ..N.....
The server responds with an NNTP_AUTH_NTLM_Blob_Response message.
381 TlRMTVNTUAACAAAAFgAWADgAAAA1gori2zhKR64TNyYAAAAAAAAAAGwAbABOAAAABQLODgAAAA9FAFgA QwBIAC0AQwBMAEkALQA2ADYAAgAWAEUAWABDAEgALQBDAEwASQAtADYANgABABYARQBYAEMASAAtAEMATABJ AC0ANgA2AAQAFgBlAHgAYwBoAC0AYwBsAGkALQA2ADYAAwAWAGUAeABjAGgALQBjAGwAaQAtADYANgAAAAAA
The contents of the NTLM message after base64 decoding are:
0x00000000 4E 54 4C 4D 53 53 50 00 02 00 00 00 16 00 16 00 NTLMSSP......... 0x00000010 38 00 00 00 35 82 8A E2 DB 38 4A 47 AE 13 37 26 8...5_b[8JG..7& 0x00000020 00 00 00 00 00 00 00 00 6C 00 6C 00 4E 00 00 00 ........l.l.N... 0x00000030 05 02 CE 0E 00 00 00 0F 45 00 58 00 43 00 48 00 ..N.....E.X.C.H. 0x00000040 2D 00 43 00 4C 00 49 00 2D 00 36 00 36 00 02 00 -.C.L.I.-.6.6... 0x00000050 16 00 45 00 58 00 43 00 48 00 2D 00 43 00 4C 00 ..E.X.C.H.-.C.L. 0x00000060 49 00 2D 00 36 00 36 00 01 00 16 00 45 00 58 00 I.-.6.6.....E.X. 0x00000070 43 00 48 00 2D 00 43 00 4C 00 49 00 2D 00 36 00 C.H.-.C.L.I.-.6. 0x00000080 36 00 04 00 16 00 65 00 78 00 63 00 68 00 2D 00 6.....e.x.c.h.-. 0x00000090 63 00 6C 00 69 00 2D 00 36 00 36 00 03 00 16 00 c.l.i.-.6.6..... 0x000000A0 65 00 78 00 63 00 68 00 2D 00 63 00 6C 00 69 00 e.x.c.h.-.c.l.i. 0x000000B0 2D 00 36 00 36 00 00 00 00 00 -.6.6.....
The client then sends an NNTP_AUTH_NTLM_Blob_Command.
AUTHINFO GENERIC TlRMTVNTUAADAAAAGAAYAHwAAAAYABgAlAAAABYAFgBIAAAACAAIAF4AAAAWABYAZgA AABAAEACsAAAANYKI4gUCzg4AAAAPZQB4AGMAaAAtAGMAbABpAC0ANgA2AHQAZQBzAHQARQBYAEMASAAtAEM ATABJAC0ANgA2AMW6+RoX0OggAAAAAAAAAAAAAAAAAAAAAKk1BEO/AprMd3f0tLtXMesmW2RK2ixxUaCLI3c IssJY2B2gBX/KYho=
The contents of the NTLM message after base64 decoding are:
0x00000000 4E 54 4C 4D 53 53 50 00 03 00 00 00 18 00 18 00 NTLMSSP......... 0x00000010 7C 00 00 00 18 00 18 00 94 00 00 00 16 00 16 00 |......._....... 0x00000020 48 00 00 00 08 00 08 00 5E 00 00 00 16 00 16 00 H.......^....... 0x00000030 66 00 00 00 10 00 10 00 AC 00 00 00 35 82 88 E2 f.......,...5__b 0x00000040 05 02 CE 0E 00 00 00 0F 65 00 78 00 63 00 68 00 ..N.....e.x.c.h. 0x00000050 2D 00 63 00 6C 00 69 00 2D 00 36 00 36 00 74 00 -.c.l.i.-.6.6.t. 0x00000060 65 00 73 00 74 00 45 00 58 00 43 00 48 00 2D 00 e.s.t.E.X.C.H.-. 0x00000070 43 00 4C 00 49 00 2D 00 36 00 36 00 C5 BA F9 1A C.L.I.-.6.6.E:y. 0x00000080 17 D0 E8 20 00 00 00 00 00 00 00 00 00 00 00 00 .Ph ............ 0x00000090 00 00 00 00 A9 35 04 43 BF 02 9A CC 77 77 F4 B4 ....)5.C?._Lwwt4 0x000000A0 BB 57 31 EB 26 5B 64 4A DA 2C 71 51 A0 8B 23 77 ;W1k&[dJZ,qQ #w 0x000000B0 08 B2 C2 58 D8 1D A0 05 7F CA 62 1A .2BXX. .Jb.
The server sends an NNTP_AUTH_Fail_Response message.
502 Permission denied