1 files changed, 146 insertions, 2 deletions

diff --git a/fs/cifs/smb2transport.c b/fs/cifs/smb2transport.c
index c802ecfa770e..87563ee58d30 100644
--- a/fs/cifs/smb2transport.c
+++ b/fs/cifs/smb2transport.c
@@ -117,10 +117,154 @@ smb2_calc_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server)
 }
 
 int
+generate_smb3signingkey(struct TCP_Server_Info *server)
+{
+        unsigned char zero = 0x0;
+        __u8 i[4] = {0, 0, 0, 1};
+        __u8 L[4] = {0, 0, 0, 128};
+        int rc = 0;
+        unsigned char prfhash[SMB2_HMACSHA256_SIZE];
+        unsigned char *hashptr = prfhash;
+
+        memset(prfhash, 0x0, SMB2_HMACSHA256_SIZE);
+        memset(server->smb3signingkey, 0x0, SMB3_SIGNKEY_SIZE);
+
+        rc = crypto_shash_setkey(server->secmech.hmacsha256,
+                server->session_key.response, SMB2_NTLMV2_SESSKEY_SIZE);
+        if (rc) {
+                cifs_dbg(VFS, "%s: Could not set with session key\n", __func__);
+                goto smb3signkey_ret;
+        }
+
+        rc = crypto_shash_init(&server->secmech.sdeschmacsha256->shash);
+        if (rc) {
+                cifs_dbg(VFS, "%s: Could not init sign hmac\n", __func__);
+                goto smb3signkey_ret;
+        }
+
+        rc = crypto_shash_update(&server->secmech.sdeschmacsha256->shash,
+                                i, 4);
+        if (rc) {
+                cifs_dbg(VFS, "%s: Could not update with n\n", __func__);
+                goto smb3signkey_ret;
+        }
+
+        rc = crypto_shash_update(&server->secmech.sdeschmacsha256->shash,
+                                "SMB2AESCMAC", 12);
+        if (rc) {
+                cifs_dbg(VFS, "%s: Could not update with label\n", __func__);
+                goto smb3signkey_ret;
+        }
+
+        rc = crypto_shash_update(&server->secmech.sdeschmacsha256->shash,
+                                &zero, 1);
+        if (rc) {
+                cifs_dbg(VFS, "%s: Could not update with zero\n", __func__);
+                goto smb3signkey_ret;
+        }
+
+        rc = crypto_shash_update(&server->secmech.sdeschmacsha256->shash,
+                                "SmbSign", 8);
+        if (rc) {
+                cifs_dbg(VFS, "%s: Could not update with context\n", __func__);
+                goto smb3signkey_ret;
+        }
+
+        rc = crypto_shash_update(&server->secmech.sdeschmacsha256->shash,
+                                L, 4);
+        if (rc) {
+                cifs_dbg(VFS, "%s: Could not update with L\n", __func__);
+                goto smb3signkey_ret;
+        }
+
+        rc = crypto_shash_final(&server->secmech.sdeschmacsha256->shash,
+                                hashptr);
+        if (rc) {
+                cifs_dbg(VFS, "%s: Could not generate sha256 hash\n", __func__);
+                goto smb3signkey_ret;
+        }
+
+        memcpy(server->smb3signingkey, hashptr, SMB3_SIGNKEY_SIZE);
+
+smb3signkey_ret:
+        return rc;
+}
+
+int
 smb3_calc_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server)
 {
-        cifs_dbg(FYI, "smb3 signatures not supported yet\n");
-        return -EOPNOTSUPP;
+        int i, rc;
+        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;
+
+        memset(smb3_signature, 0x0, SMB2_CMACAES_SIZE);
+        memset(smb2_pdu->Signature, 0x0, SMB2_SIGNATURE_SIZE);
+
+        rc = crypto_shash_setkey(server->secmech.cmacaes,
+                server->smb3signingkey, SMB2_CMACAES_SIZE);
+        if (rc) {
+                cifs_dbg(VFS, "%s: Could not set key for cmac aes\n", __func__);
+                return rc;
+        }
+
+        rc = crypto_shash_init(&server->secmech.sdesccmacaes->shash);
+        if (rc) {
+                cifs_dbg(VFS, "%s: Could not init cmac aes\n", __func__);
+                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");
+                        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);
+
+        return rc;
 }
 
 /* must be called with server->srv_mutex held */