[CIFS] Fix ntlmv2 auth with ntlmssp

Make ntlmv2 as an authentication mechanism within ntlmssp
instead of ntlmv1.
Parse type 2 response in ntlmssp negotiation to pluck
AV pairs and use them to calculate ntlmv2 response token.
Also, assign domain name from the sever response in type 2
packet of ntlmssp and use that (netbios) domain name in
calculation of response.

Enable cifs/smb signing using rc4 and md5.

Changed name of the structure mac_key to session_key to reflect
the type of key it holds.

Use kernel crypto_shash_* APIs instead of the equivalent cifs functions.

Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Steve French <sfrench@us.ibm.com>

1 files changed, 89 insertions, 29 deletions

diff --git a/fs/cifs/sess.c b/fs/cifs/sess.c
index 0a57cb7db5dd..41fc5328120d 100644
--- a/fs/cifs/sess.c
+++ b/fs/cifs/sess.c
@@ -383,6 +383,9 @@ static int decode_ascii_ssetup(char **pbcc_area, int bleft,
 static int decode_ntlmssp_challenge(char *bcc_ptr, int blob_len,
                                     struct cifsSesInfo *ses)
 {
+        unsigned int tioffset; /* challeng message target info area */
+        unsigned int tilen; /* challeng message target info area length  */
+
         CHALLENGE_MESSAGE *pblob = (CHALLENGE_MESSAGE *)bcc_ptr;
 
         if (blob_len < sizeof(CHALLENGE_MESSAGE)) {
@@ -405,6 +408,18 @@ static int decode_ntlmssp_challenge(char *bcc_ptr, int blob_len,
         /* BB spec says that if AvId field of MsvAvTimestamp is populated then
                 we must set the MIC field of the AUTHENTICATE_MESSAGE */
 
+        tioffset = cpu_to_le16(pblob->TargetInfoArray.BufferOffset);
+        tilen = cpu_to_le16(pblob->TargetInfoArray.Length);
+        ses->server->tilen = tilen;
+        if (tilen) {
+                ses->server->tiblob = kmalloc(tilen, GFP_KERNEL);
+                if (!ses->server->tiblob) {
+                        cERROR(1, "Challenge target info allocation failure");
+                        return -ENOMEM;
+                }
+                memcpy(ses->server->tiblob,  bcc_ptr + tioffset, tilen);
+        }
+
         return 0;
 }
 
@@ -451,10 +466,12 @@ static int build_ntlmssp_auth_blob(unsigned char *pbuffer,
                                    struct cifsSesInfo *ses,
                                    const struct nls_table *nls_cp, bool first)
 {
+        int rc;
+        unsigned int size;
         AUTHENTICATE_MESSAGE *sec_blob = (AUTHENTICATE_MESSAGE *)pbuffer;
         __u32 flags;
         unsigned char *tmp;
-        char ntlm_session_key[CIFS_SESS_KEY_SIZE];
+        struct ntlmv2_resp ntlmv2_response = {};
 
         memcpy(sec_blob->Signature, NTLMSSP_SIGNATURE, 8);
         sec_blob->MessageType = NtLmAuthenticate;
@@ -477,19 +494,25 @@ static int build_ntlmssp_auth_blob(unsigned char *pbuffer,
         sec_blob->LmChallengeResponse.Length = 0;
         sec_blob->LmChallengeResponse.MaximumLength = 0;
 
-        /* calculate session key,  BB what about adding similar ntlmv2 path? */
-        SMBNTencrypt(ses->password, ses->server->cryptKey, ntlm_session_key);
-        if (first)
-                cifs_calculate_mac_key(&ses->server->mac_signing_key,
-                                       ntlm_session_key, ses->password);
-
-        memcpy(tmp, ntlm_session_key, CIFS_SESS_KEY_SIZE);
         sec_blob->NtChallengeResponse.BufferOffset = cpu_to_le32(tmp - pbuffer);
-        sec_blob->NtChallengeResponse.Length = cpu_to_le16(CIFS_SESS_KEY_SIZE);
-        sec_blob->NtChallengeResponse.MaximumLength =
-                                cpu_to_le16(CIFS_SESS_KEY_SIZE);
+        rc = setup_ntlmv2_rsp(ses, (char *)&ntlmv2_response, nls_cp);
+        if (rc) {
+                cERROR(1, "error rc: %d during ntlmssp ntlmv2 setup", rc);
+                goto setup_ntlmv2_ret;
+        }
+        size =  sizeof(struct ntlmv2_resp);
+        memcpy(tmp, (char *)&ntlmv2_response, size);
+        tmp += size;
+        if (ses->server->tilen > 0) {
+                memcpy(tmp, ses->server->tiblob, ses->server->tilen);
+                tmp += ses->server->tilen;
+        } else
+                ses->server->tilen = 0;
 
-        tmp += CIFS_SESS_KEY_SIZE;
+        sec_blob->NtChallengeResponse.Length = cpu_to_le16(size +
+                                ses->server->tilen);
+        sec_blob->NtChallengeResponse.MaximumLength =
+                cpu_to_le16(size + ses->server->tilen);
 
         if (ses->domainName == NULL) {
                 sec_blob->DomainName.BufferOffset = cpu_to_le32(tmp - pbuffer);
@@ -501,7 +524,6 @@ static int build_ntlmssp_auth_blob(unsigned char *pbuffer,
                 len = cifs_strtoUCS((__le16 *)tmp, ses->domainName,
                                     MAX_USERNAME_SIZE, nls_cp);
                 len *= 2; /* unicode is 2 bytes each */
-                len += 2; /* trailing null */
                 sec_blob->DomainName.BufferOffset = cpu_to_le32(tmp - pbuffer);
                 sec_blob->DomainName.Length = cpu_to_le16(len);
                 sec_blob->DomainName.MaximumLength = cpu_to_le16(len);
@@ -518,7 +540,6 @@ static int build_ntlmssp_auth_blob(unsigned char *pbuffer,
                 len = cifs_strtoUCS((__le16 *)tmp, ses->userName,
                                     MAX_USERNAME_SIZE, nls_cp);
                 len *= 2; /* unicode is 2 bytes each */
-                len += 2; /* trailing null */
                 sec_blob->UserName.BufferOffset = cpu_to_le32(tmp - pbuffer);
                 sec_blob->UserName.Length = cpu_to_le16(len);
                 sec_blob->UserName.MaximumLength = cpu_to_le16(len);
@@ -530,9 +551,26 @@ static int build_ntlmssp_auth_blob(unsigned char *pbuffer,
         sec_blob->WorkstationName.MaximumLength = 0;
         tmp += 2;
 
-        sec_blob->SessionKey.BufferOffset = cpu_to_le32(tmp - pbuffer);
-        sec_blob->SessionKey.Length = 0;
-        sec_blob->SessionKey.MaximumLength = 0;
+        if ((ses->server->ntlmssp.server_flags & NTLMSSP_NEGOTIATE_KEY_XCH) &&
+                        !calc_seckey(ses->server)) {
+                memcpy(tmp, ses->server->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 =
+                        cpu_to_le16(CIFS_CPHTXT_SIZE);
+                tmp += CIFS_CPHTXT_SIZE;
+        } else {
+                sec_blob->SessionKey.BufferOffset = cpu_to_le32(tmp - pbuffer);
+                sec_blob->SessionKey.Length = 0;
+                sec_blob->SessionKey.MaximumLength = 0;
+        }
+
+        ses->server->sequence_number = 0;
+
+setup_ntlmv2_ret:
+        if (ses->server->tilen > 0)
+                kfree(ses->server->tiblob);
+
         return tmp - pbuffer;
 }
 
@@ -546,15 +584,14 @@ static void setup_ntlmssp_neg_req(SESSION_SETUP_ANDX *pSMB,
         return;
 }
 
-static int setup_ntlmssp_auth_req(SESSION_SETUP_ANDX *pSMB,
+static int setup_ntlmssp_auth_req(char *ntlmsspblob,
                                   struct cifsSesInfo *ses,
                                   const struct nls_table *nls, bool first_time)
 {
         int bloblen;
 
-        bloblen = build_ntlmssp_auth_blob(&pSMB->req.SecurityBlob[0], ses, nls,
+        bloblen = build_ntlmssp_auth_blob(ntlmsspblob, ses, nls,
                                           first_time);
-        pSMB->req.SecurityBlobLength = cpu_to_le16(bloblen);
 
         return bloblen;
 }
@@ -580,6 +617,7 @@ CIFS_SessSetup(unsigned int xid, struct cifsSesInfo *ses,
         struct key *spnego_key = NULL;
         __le32 phase = NtLmNegotiate; /* NTLMSSP, if needed, is multistage */
         bool first_time;
+        char *ntlmsspblob;
 
         if (ses == NULL)
                 return -EINVAL;
@@ -690,7 +728,7 @@ ssetup_ntlmssp_authenticate:
 
                 if (first_time) /* should this be moved into common code
                                   with similar ntlmv2 path? */
-                        cifs_calculate_mac_key(&ses->server->mac_signing_key,
+                        cifs_calculate_session_key(&ses->server->session_key,
                                 ntlm_session_key, ses->password);
                 /* copy session key */
 
@@ -729,12 +767,21 @@ ssetup_ntlmssp_authenticate:
                         cpu_to_le16(sizeof(struct ntlmv2_resp));
 
                 /* calculate session key */
-                setup_ntlmv2_rsp(ses, v2_sess_key, nls_cp);
+                rc = setup_ntlmv2_rsp(ses, v2_sess_key, nls_cp);
+                if (rc) {
+                        kfree(v2_sess_key);
+                        goto ssetup_exit;
+                }
                 /* FIXME: calculate MAC key */
                 memcpy(bcc_ptr, (char *)v2_sess_key,
                        sizeof(struct ntlmv2_resp));
                 bcc_ptr += sizeof(struct ntlmv2_resp);
                 kfree(v2_sess_key);
+                if (ses->server->tilen > 0) {
+                        memcpy(bcc_ptr, ses->server->tiblob,
+                                ses->server->tilen);
+                        bcc_ptr += ses->server->tilen;
+                }
                 if (ses->capabilities & CAP_UNICODE) {
                         if (iov[0].iov_len % 2) {
                                 *bcc_ptr = 0;
@@ -765,15 +812,15 @@ ssetup_ntlmssp_authenticate:
                 }
                 /* bail out if key is too long */
                 if (msg->sesskey_len >
-                    sizeof(ses->server->mac_signing_key.data.krb5)) {
+                    sizeof(ses->server->session_key.data.krb5)) {
                         cERROR(1, "Kerberos signing key too long (%u bytes)",
                                 msg->sesskey_len);
                         rc = -EOVERFLOW;
                         goto ssetup_exit;
                 }
                 if (first_time) {
-                        ses->server->mac_signing_key.len = msg->sesskey_len;
-                        memcpy(ses->server->mac_signing_key.data.krb5,
+                        ses->server->session_key.len = msg->sesskey_len;
+                        memcpy(ses->server->session_key.data.krb5,
                                 msg->data, msg->sesskey_len);
                 }
                 pSMB->req.hdr.Flags2 |= SMBFLG2_EXT_SEC;
@@ -815,12 +862,26 @@ ssetup_ntlmssp_authenticate:
                         if (phase == NtLmNegotiate) {
                                 setup_ntlmssp_neg_req(pSMB, ses);
                                 iov[1].iov_len = sizeof(NEGOTIATE_MESSAGE);
+                                iov[1].iov_base = &pSMB->req.SecurityBlob[0];
                         } else if (phase == NtLmAuthenticate) {
                                 int blob_len;
-                                blob_len = setup_ntlmssp_auth_req(pSMB, ses,
-                                                                  nls_cp,
-                                                                  first_time);
+                                ntlmsspblob = kmalloc(5 *
+                                        sizeof(struct _AUTHENTICATE_MESSAGE),
+                                        GFP_KERNEL);
+                                if (!ntlmsspblob) {
+                                        cERROR(1, "Can't allocate NTLMSSP");
+                                        rc = -ENOMEM;
+                                        goto ssetup_exit;
+                                }
+
+                                blob_len = setup_ntlmssp_auth_req(ntlmsspblob,
+                                                                ses,
+                                                                nls_cp,
+                                                                first_time);
                                 iov[1].iov_len = blob_len;
+                                iov[1].iov_base = ntlmsspblob;
+                                pSMB->req.SecurityBlobLength =
+                                        cpu_to_le16(blob_len);
                                 /* Make sure that we tell the server that we
                                    are using the uid that it just gave us back
                                    on the response (challenge) */
@@ -830,7 +891,6 @@ ssetup_ntlmssp_authenticate:
                                 rc = -ENOSYS;
                                 goto ssetup_exit;
                         }
-                        iov[1].iov_base = &pSMB->req.SecurityBlob[0];
                         /* unicode strings must be word aligned */
                         if ((iov[0].iov_len + iov[1].iov_len) % 2) {
                                 *bcc_ptr = 0;