cifs: Cleanup and thus reduce smb session structure and fields used during authentication

Removed following fields from smb session structure
 cryptkey, ntlmv2_hash, tilen, tiblob
and ntlmssp_auth structure is allocated dynamically only if the auth mech
in NTLMSSP.

response field within a session_key structure is used to initially store the
target info (either plucked from type 2 challenge packet in case of NTLMSSP
or fabricated in case of NTLMv2 without extended security) and then to store
Message Authentication Key (mak) (session key + client response).

Server challenge or cryptkey needed during a NTLMSSP authentication
is now part of ntlmssp_auth structure which gets allocated and freed
once authenticaiton process is done.

Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>

1 files changed, 18 insertions, 11 deletions

diff --git a/fs/cifs/sess.c b/fs/cifs/sess.c
index f74c5a88dd4c..7b01d3f6eed6 100644
--- a/fs/cifs/sess.c
+++ b/fs/cifs/sess.c
@@ -399,23 +399,22 @@ static int decode_ntlmssp_challenge(char *bcc_ptr, int blob_len,
                 return -EINVAL;
         }
 
-        memcpy(ses->cryptkey, pblob->Challenge, CIFS_CRYPTO_KEY_SIZE);
+        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);
+        ses->ntlmssp->server_flags = le32_to_cpu(pblob->NegotiateFlags);
         tioffset = cpu_to_le16(pblob->TargetInfoArray.BufferOffset);
         tilen = cpu_to_le16(pblob->TargetInfoArray.Length);
-        ses->tilen = tilen;
-        if (ses->tilen) {
-                ses->tiblob = kmalloc(tilen, GFP_KERNEL);
-                if (!ses->tiblob) {
+        if (tilen) {
+                ses->auth_key.response = kmalloc(tilen, GFP_KERNEL);
+                if (!ses->auth_key.response) {
                         cERROR(1, "Challenge target info allocation failure");
-                        ses->tilen = 0;
                         return -ENOMEM;
                 }
-                memcpy(ses->tiblob,  bcc_ptr + tioffset, ses->tilen);
+                memcpy(ses->auth_key.response, bcc_ptr + tioffset, tilen);
+                ses->auth_key.len = tilen;
         }
 
         return 0;
@@ -545,9 +544,9 @@ static int build_ntlmssp_auth_blob(unsigned char *pbuffer,
         sec_blob->WorkstationName.MaximumLength = 0;
         tmp += 2;
 
-        if ((ses->ntlmssp.server_flags & NTLMSSP_NEGOTIATE_KEY_XCH) &&
+        if ((ses->ntlmssp->server_flags & NTLMSSP_NEGOTIATE_KEY_XCH) &&
                         !calc_seckey(ses)) {
-                memcpy(tmp, ses->ntlmssp.ciphertext, CIFS_CPHTXT_SIZE);
+                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);
                 sec_blob->SessionKey.MaximumLength =
@@ -601,8 +600,16 @@ CIFS_SessSetup(unsigned int xid, struct cifsSesInfo *ses,
                 return -EINVAL;
 
         type = ses->server->secType;
-
         cFYI(1, "sess setup type %d", type);
+        if (type == RawNTLMSSP) {
+                /* if memory allocation is successful, caller of this function
+                 * frees it.
+                 */
+                ses->ntlmssp = kmalloc(sizeof(struct ntlmssp_auth), GFP_KERNEL);
+                if (!ses->ntlmssp)
+                        return -ENOMEM;
+        }
+
 ssetup_ntlmssp_authenticate:
         if (phase == NtLmChallenge)
                 phase = NtLmAuthenticate; /* if ntlmssp, now final phase */