cifs: merge the hash calculation helpers

three practically identical copies...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

3 files changed, 67 insertions, 140 deletions

diff --git a/fs/cifs/cifsencrypt.c b/fs/cifs/cifsencrypt.c
index 4897dacf8944..6aeb8d4616a4 100644
--- a/fs/cifs/cifsencrypt.c
+++ b/fs/cifs/cifsencrypt.c
@@ -66,45 +66,15 @@ cifs_crypto_shash_md5_allocate(struct TCP_Server_Info *server)
         return 0;
 }
 
-/*
- * Calculate and return the CIFS signature based on the mac key and SMB PDU.
- * The 16 byte signature must be allocated by the caller. Note we only use the
- * 1st eight bytes and that the smb header signature field on input contains
- * the sequence number before this function is called. Also, this function
- * should be called with the server->srv_mutex held.
- */
-static int cifs_calc_signature(struct smb_rqst *rqst,
-                        struct TCP_Server_Info *server, char *signature)
+int __cifs_calc_signature(struct smb_rqst *rqst,
+                        struct TCP_Server_Info *server, char *signature,
+                        struct shash_desc *shash)
 {
         int i;
         int rc;
         struct kvec *iov = rqst->rq_iov;
         int n_vec = rqst->rq_nvec;
 
-        if (iov == NULL || signature == NULL || server == NULL)
-                return -EINVAL;
-
-        if (!server->secmech.sdescmd5) {
-                rc = cifs_crypto_shash_md5_allocate(server);
-                if (rc) {
-                        cifs_dbg(VFS, "%s: Can't alloc md5 crypto\n", __func__);
-                        return -1;
-                }
-        }
-
-        rc = crypto_shash_init(&server->secmech.sdescmd5->shash);
-        if (rc) {
-                cifs_dbg(VFS, "%s: Could not init md5\n", __func__);
-                return rc;
-        }
-
-        rc = crypto_shash_update(&server->secmech.sdescmd5->shash,
-                server->session_key.response, server->session_key.len);
-        if (rc) {
-                cifs_dbg(VFS, "%s: Could not update with response\n", __func__);
-                return rc;
-        }
-
         for (i = 0; i < n_vec; i++) {
                 if (iov[i].iov_len == 0)
                         continue;
@@ -117,12 +87,10 @@ static int cifs_calc_signature(struct smb_rqst *rqst,
                 if (i == 0) {
                         if (iov[0].iov_len <= 8) /* cmd field at offset 9 */
                                 break; /* nothing to sign or corrupt header */
-                        rc =
-                        crypto_shash_update(&server->secmech.sdescmd5->shash,
+                        rc = crypto_shash_update(shash,
                                 iov[i].iov_base + 4, iov[i].iov_len - 4);
                 } else {
-                        rc =
-                        crypto_shash_update(&server->secmech.sdescmd5->shash,
+                        rc = crypto_shash_update(shash,
                                 iov[i].iov_base, iov[i].iov_len);
                 }
                 if (rc) {
@@ -134,21 +102,64 @@ static int cifs_calc_signature(struct smb_rqst *rqst,
 
         /* now hash over the rq_pages array */
         for (i = 0; i < rqst->rq_npages; i++) {
-                struct kvec p_iov;
+                void *kaddr = kmap(rqst->rq_pages[i]);
+                size_t len = rqst->rq_pagesz;
+
+                if (i == rqst->rq_npages - 1)
+                        len = rqst->rq_tailsz;
+
+                crypto_shash_update(shash, kaddr, len);
 
-                cifs_rqst_page_to_kvec(rqst, i, &p_iov);
-                crypto_shash_update(&server->secmech.sdescmd5->shash,
-                                        p_iov.iov_base, p_iov.iov_len);
                 kunmap(rqst->rq_pages[i]);
         }
 
-        rc = crypto_shash_final(&server->secmech.sdescmd5->shash, signature);
+        rc = crypto_shash_final(shash, signature);
         if (rc)
-                cifs_dbg(VFS, "%s: Could not generate md5 hash\n", __func__);
+                cifs_dbg(VFS, "%s: Could not generate hash\n", __func__);
 
         return rc;
 }
 
+/*
+ * Calculate and return the CIFS signature based on the mac key and SMB PDU.
+ * The 16 byte signature must be allocated by the caller. Note we only use the
+ * 1st eight bytes and that the smb header signature field on input contains
+ * the sequence number before this function is called. Also, this function
+ * should be called with the server->srv_mutex held.
+ */
+static int cifs_calc_signature(struct smb_rqst *rqst,
+                        struct TCP_Server_Info *server, char *signature)
+{
+        int rc;
+
+        if (!rqst->rq_iov || !signature || !server)
+                return -EINVAL;
+
+        if (!server->secmech.sdescmd5) {
+                rc = cifs_crypto_shash_md5_allocate(server);
+                if (rc) {
+                        cifs_dbg(VFS, "%s: Can't alloc md5 crypto\n", __func__);
+                        return -1;
+                }
+        }
+
+        rc = crypto_shash_init(&server->secmech.sdescmd5->shash);
+        if (rc) {
+                cifs_dbg(VFS, "%s: Could not init md5\n", __func__);
+                return rc;
+        }
+
+        rc = crypto_shash_update(&server->secmech.sdescmd5->shash,
+                server->session_key.response, server->session_key.len);
+        if (rc) {
+                cifs_dbg(VFS, "%s: Could not update with response\n", __func__);
+                return rc;
+        }
+
+        return __cifs_calc_signature(rqst, server, signature,
+                                     &server->secmech.sdescmd5->shash);
+}
+
 /* must be called with server->srv_mutex held */
 int cifs_sign_rqst(struct smb_rqst *rqst, struct TCP_Server_Info *server,
                    __u32 *pexpected_response_sequence_number)
diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h
index eed7ff50faf0..d9b4f444fdf9 100644
--- a/fs/cifs/cifsproto.h
+++ b/fs/cifs/cifsproto.h
@@ -512,4 +512,7 @@ int cifs_create_mf_symlink(unsigned int xid, struct cifs_tcon *tcon,
                            struct cifs_sb_info *cifs_sb,
                            const unsigned char *path, char *pbuf,
                            unsigned int *pbytes_written);
+int __cifs_calc_signature(struct smb_rqst *rqst,
+                        struct TCP_Server_Info *server, char *signature,
+                        struct shash_desc *shash);
 #endif                  /* _CIFSPROTO_H */
diff --git a/fs/cifs/smb2transport.c b/fs/cifs/smb2transport.c
index 8732a43b1008..bc9a7b634643 100644
--- a/fs/cifs/smb2transport.c
+++ b/fs/cifs/smb2transport.c
@@ -135,11 +135,10 @@ smb2_find_smb_ses(struct smb2_hdr *smb2hdr, struct TCP_Server_Info *server)
 int
 smb2_calc_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server)
 {
-        int i, rc;
+        int rc;
         unsigned char smb2_signature[SMB2_HMACSHA256_SIZE];
         unsigned char *sigptr = smb2_signature;
         struct kvec *iov = rqst->rq_iov;
-        int n_vec = rqst->rq_nvec;
         struct smb2_hdr *smb2_pdu = (struct smb2_hdr *)iov[0].iov_base;
         struct cifs_ses *ses;
 
@@ -171,53 +170,11 @@ smb2_calc_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server)
                 return rc;
         }
 
-        for (i = 0; i < n_vec; i++) {
-                if (iov[i].iov_len == 0)
-                        continue;
-                if (iov[i].iov_base == NULL) {
-                        cifs_dbg(VFS, "null iovec entry\n");
-                        return -EIO;
-                }
-                /*
-                 * The first entry includes a length field (which does not get
-                 * signed that occupies the first 4 bytes before the header).
-                 */
-                if (i == 0) {
-                        if (iov[0].iov_len <= 8) /* cmd field at offset 9 */
-                                break; /* nothing to sign or corrupt header */
-                        rc =
-                        crypto_shash_update(
-                                &server->secmech.sdeschmacsha256->shash,
-                                iov[i].iov_base + 4, iov[i].iov_len - 4);
-                } else {
-                        rc =
-                        crypto_shash_update(
-                                &server->secmech.sdeschmacsha256->shash,
-                                iov[i].iov_base, iov[i].iov_len);
-                }
-                if (rc) {
-                        cifs_dbg(VFS, "%s: Could not update with payload\n",
-                                 __func__);
-                        return rc;
-                }
-        }
-
-        /* now hash over the rq_pages array */
-        for (i = 0; i < rqst->rq_npages; i++) {
-                struct kvec p_iov;
-
-                cifs_rqst_page_to_kvec(rqst, i, &p_iov);
-                crypto_shash_update(&server->secmech.sdeschmacsha256->shash,
-                                        p_iov.iov_base, p_iov.iov_len);
-                kunmap(rqst->rq_pages[i]);
-        }
-
-        rc = crypto_shash_final(&server->secmech.sdeschmacsha256->shash,
-                                sigptr);
-        if (rc)
-                cifs_dbg(VFS, "%s: Could not generate sha256 hash\n", __func__);
+        rc = __cifs_calc_signature(rqst, server, sigptr,
+                &server->secmech.sdeschmacsha256->shash);
 
-        memcpy(smb2_pdu->Signature, sigptr, SMB2_SIGNATURE_SIZE);
+        if (!rc)
+                memcpy(smb2_pdu->Signature, sigptr, SMB2_SIGNATURE_SIZE);
 
         return rc;
 }
@@ -395,12 +352,10 @@ generate_smb311signingkey(struct cifs_ses *ses)
 int
 smb3_calc_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server)
 {
-        int i;
         int rc = 0;
         unsigned char smb3_signature[SMB2_CMACAES_SIZE];
         unsigned char *sigptr = smb3_signature;
         struct kvec *iov = rqst->rq_iov;
-        int n_vec = rqst->rq_nvec;
         struct smb2_hdr *smb2_pdu = (struct smb2_hdr *)iov[0].iov_base;
         struct cifs_ses *ses;
 
@@ -431,54 +386,12 @@ smb3_calc_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server)
                 cifs_dbg(VFS, "%s: Could not init cmac aes\n", __func__);
                 return rc;
         }
+        
+        rc = __cifs_calc_signature(rqst, server, sigptr,
+                                   &server->secmech.sdesccmacaes->shash);
 
-        for (i = 0; i < n_vec; i++) {
-                if (iov[i].iov_len == 0)
-                        continue;
-                if (iov[i].iov_base == NULL) {
-                        cifs_dbg(VFS, "null iovec entry");
-                        return -EIO;
-                }
-                /*
-                 * The first entry includes a length field (which does not get
-                 * signed that occupies the first 4 bytes before the header).
-                 */
-                if (i == 0) {
-                        if (iov[0].iov_len <= 8) /* cmd field at offset 9 */
-                                break; /* nothing to sign or corrupt header */
-                        rc =
-                        crypto_shash_update(
-                                &server->secmech.sdesccmacaes->shash,
-                                iov[i].iov_base + 4, iov[i].iov_len - 4);
-                } else {
-                        rc =
-                        crypto_shash_update(
-                                &server->secmech.sdesccmacaes->shash,
-                                iov[i].iov_base, iov[i].iov_len);
-                }
-                if (rc) {
-                        cifs_dbg(VFS, "%s: Couldn't update cmac aes with payload\n",
-                                                        __func__);
-                        return rc;
-                }
-        }
-
-        /* now hash over the rq_pages array */
-        for (i = 0; i < rqst->rq_npages; i++) {
-                struct kvec p_iov;
-
-                cifs_rqst_page_to_kvec(rqst, i, &p_iov);
-                crypto_shash_update(&server->secmech.sdesccmacaes->shash,
-                                        p_iov.iov_base, p_iov.iov_len);
-                kunmap(rqst->rq_pages[i]);
-        }
-
-        rc = crypto_shash_final(&server->secmech.sdesccmacaes->shash,
-                                                sigptr);
-        if (rc)
-                cifs_dbg(VFS, "%s: Could not generate cmac aes\n", __func__);
-
-        memcpy(smb2_pdu->Signature, sigptr, SMB2_SIGNATURE_SIZE);
+        if (!rc)
+                memcpy(smb2_pdu->Signature, sigptr, SMB2_SIGNATURE_SIZE);
 
         return rc;
 }