diff options
Diffstat (limited to 'fs/cifs/smb2transport.c')
| -rw-r--r-- | fs/cifs/smb2transport.c | 151 |
1 files changed, 147 insertions, 4 deletions
diff --git a/fs/cifs/smb2transport.c b/fs/cifs/smb2transport.c index 01f0ac800780..09b4fbaadeb6 100644 --- a/fs/cifs/smb2transport.c +++ b/fs/cifs/smb2transport.c @@ -116,11 +116,155 @@ smb2_calc_signature(struct smb_rqst *rqst, struct TCP_Server_Info *server) return rc; } +void +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; +} + 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 */ @@ -275,8 +419,7 @@ smb2_check_receive(struct mid_q_entry *mid, struct TCP_Server_Info *server, dump_smb(mid->resp_buf, min_t(u32, 80, len)); /* convert the length into a more usable form */ - if ((len > 24) && - (server->sec_mode & (SECMODE_SIGN_REQUIRED|SECMODE_SIGN_ENABLED))) { + if (len > 24 && server->sign) { int rc; rc = smb2_verify_signature(&rqst, server); |