diff options
Diffstat (limited to 'fs/cifs/sess.c')
| -rw-r--r-- | fs/cifs/sess.c | 54 |
1 files changed, 36 insertions, 18 deletions
diff --git a/fs/cifs/sess.c b/fs/cifs/sess.c index af63548eaf26..035dc3e245dc 100644 --- a/fs/cifs/sess.c +++ b/fs/cifs/sess.c @@ -590,8 +590,8 @@ int decode_ntlmssp_challenge(char *bcc_ptr, int blob_len, { unsigned int tioffset; /* challenge message target info area */ unsigned int tilen; /* challenge message target info area length */ - CHALLENGE_MESSAGE *pblob = (CHALLENGE_MESSAGE *)bcc_ptr; + __u32 server_flags; if (blob_len < sizeof(CHALLENGE_MESSAGE)) { cifs_dbg(VFS, "challenge blob len %d too small\n", blob_len); @@ -609,12 +609,37 @@ int decode_ntlmssp_challenge(char *bcc_ptr, int blob_len, return -EINVAL; } + server_flags = le32_to_cpu(pblob->NegotiateFlags); + cifs_dbg(FYI, "%s: negotiate=0x%08x challenge=0x%08x\n", __func__, + ses->ntlmssp->client_flags, server_flags); + + if ((ses->ntlmssp->client_flags & (NTLMSSP_NEGOTIATE_SEAL | NTLMSSP_NEGOTIATE_SIGN)) && + (!(server_flags & NTLMSSP_NEGOTIATE_56) && !(server_flags & NTLMSSP_NEGOTIATE_128))) { + cifs_dbg(VFS, "%s: requested signing/encryption but server did not return either 56-bit or 128-bit session key size\n", + __func__); + return -EINVAL; + } + if (!(server_flags & NTLMSSP_NEGOTIATE_NTLM) && !(server_flags & NTLMSSP_NEGOTIATE_EXTENDED_SEC)) { + cifs_dbg(VFS, "%s: server does not seem to support either NTLMv1 or NTLMv2\n", __func__); + return -EINVAL; + } + if (ses->server->sign && !(server_flags & NTLMSSP_NEGOTIATE_SIGN)) { + cifs_dbg(VFS, "%s: forced packet signing but server does not seem to support it\n", + __func__); + return -EOPNOTSUPP; + } + if ((ses->ntlmssp->client_flags & NTLMSSP_NEGOTIATE_KEY_XCH) && + !(server_flags & NTLMSSP_NEGOTIATE_KEY_XCH)) + pr_warn_once("%s: authentication has been weakened as server does not support key exchange\n", + __func__); + + ses->ntlmssp->server_flags = server_flags; + memcpy(ses->ntlmssp->cryptkey, pblob->Challenge, CIFS_CRYPTO_KEY_SIZE); - /* BB we could decode pblob->NegotiateFlags; some may be useful */ /* In particular we can examine sign flags */ /* BB spec says that if AvId field of MsvAvTimestamp is populated then we must set the MIC field of the AUTHENTICATE_MESSAGE */ - ses->ntlmssp->server_flags = le32_to_cpu(pblob->NegotiateFlags); + tioffset = le32_to_cpu(pblob->TargetInfoArray.BufferOffset); tilen = le16_to_cpu(pblob->TargetInfoArray.Length); if (tioffset > blob_len || tioffset + tilen > blob_len) { @@ -721,13 +746,13 @@ int build_ntlmssp_negotiate_blob(unsigned char **pbuffer, flags = NTLMSSP_NEGOTIATE_56 | NTLMSSP_REQUEST_TARGET | NTLMSSP_NEGOTIATE_128 | NTLMSSP_NEGOTIATE_UNICODE | NTLMSSP_NEGOTIATE_NTLM | NTLMSSP_NEGOTIATE_EXTENDED_SEC | - NTLMSSP_NEGOTIATE_SEAL; - if (server->sign) - flags |= NTLMSSP_NEGOTIATE_SIGN; + NTLMSSP_NEGOTIATE_ALWAYS_SIGN | NTLMSSP_NEGOTIATE_SEAL | + NTLMSSP_NEGOTIATE_SIGN; if (!server->session_estab || ses->ntlmssp->sesskey_per_smbsess) flags |= NTLMSSP_NEGOTIATE_KEY_XCH; tmp = *pbuffer + sizeof(NEGOTIATE_MESSAGE); + ses->ntlmssp->client_flags = flags; sec_blob->NegotiateFlags = cpu_to_le32(flags); /* these fields should be null in negotiate phase MS-NLMP 3.1.5.1.1 */ @@ -779,15 +804,8 @@ int build_ntlmssp_auth_blob(unsigned char **pbuffer, memcpy(sec_blob->Signature, NTLMSSP_SIGNATURE, 8); sec_blob->MessageType = NtLmAuthenticate; - flags = NTLMSSP_NEGOTIATE_56 | - NTLMSSP_REQUEST_TARGET | NTLMSSP_NEGOTIATE_TARGET_INFO | - NTLMSSP_NEGOTIATE_128 | NTLMSSP_NEGOTIATE_UNICODE | - NTLMSSP_NEGOTIATE_NTLM | NTLMSSP_NEGOTIATE_EXTENDED_SEC | - NTLMSSP_NEGOTIATE_SEAL | NTLMSSP_NEGOTIATE_WORKSTATION_SUPPLIED; - if (ses->server->sign) - flags |= NTLMSSP_NEGOTIATE_SIGN; - if (!ses->server->session_estab || ses->ntlmssp->sesskey_per_smbsess) - flags |= NTLMSSP_NEGOTIATE_KEY_XCH; + flags = ses->ntlmssp->server_flags | NTLMSSP_REQUEST_TARGET | + NTLMSSP_NEGOTIATE_TARGET_INFO | NTLMSSP_NEGOTIATE_WORKSTATION_SUPPLIED; tmp = *pbuffer + sizeof(AUTHENTICATE_MESSAGE); sec_blob->NegotiateFlags = cpu_to_le32(flags); @@ -834,9 +852,9 @@ int build_ntlmssp_auth_blob(unsigned char **pbuffer, *pbuffer, &tmp, nls_cp); - if (((ses->ntlmssp->server_flags & NTLMSSP_NEGOTIATE_KEY_XCH) || - (ses->ntlmssp->server_flags & NTLMSSP_NEGOTIATE_EXTENDED_SEC)) - && !calc_seckey(ses)) { + if ((ses->ntlmssp->server_flags & NTLMSSP_NEGOTIATE_KEY_XCH) && + (!ses->server->session_estab || ses->ntlmssp->sesskey_per_smbsess) && + !calc_seckey(ses)) { memcpy(tmp, ses->ntlmssp->ciphertext, CIFS_CPHTXT_SIZE); sec_blob->SessionKey.BufferOffset = cpu_to_le32(tmp - *pbuffer); sec_blob->SessionKey.Length = cpu_to_le16(CIFS_CPHTXT_SIZE); |