cifs: merge the hash calculation helpers

BugLink: http://bugs.launchpad.net/bugs/1670508
three practically identical copies...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
(cherry picked from commit 16c568efff82e4a6a75d2bd86576e648fad8a7fe)
Signed-off-by: Joseph Salisbury <joseph.salisbury@canonical.com>

diff --git a/fs/cifs/cifsencrypt.c b/fs/cifs/cifsencrypt.c
index 4acbc390a7d6b40d3cc9a6ae839ae068493a5bcc..84103f40fcd204073a882fca7305b6025f7bc772 100644 (file)
--- a/fs/cifs/cifsencrypt.c
+++ b/fs/cifs/cifsencrypt.c
@@ -65,45 +65,15 @@ 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;
@@ -116,12 +86,10 @@ 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) {
@@ -133,21 +101,64 @@ 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 0080e94a5b80d2129d2aa674c973aff779801689..a34ca342f448f21bfdd22f1ea8bd64138469894b 100644 (file)
--- a/fs/cifs/cifsproto.h
+++ b/fs/cifs/cifsproto.h
@@ -515,4 +515,7 @@ 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 8732a43b10084bf787a8410498e3ec51c69ea93c..bc9a7b63464347ad4036f41a60fc2a2fdc1bfe6e 100644 (file)
--- 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;
 }