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Diffstat (limited to 'fs/cifs/sess.c')
-rw-r--r--fs/cifs/sess.c54
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);