#include "smb2proto.h"
#include "cifs_debug.h"
#include "smb2status.h"
+#include "smb2glob.h"
+
+static int
+smb2_calc_signature2(const struct kvec *iov, int n_vec,
+ struct TCP_Server_Info *server)
+{
+ int i, rc;
+ unsigned char smb2_signature[SMB2_HMACSHA256_SIZE];
+ unsigned char *sigptr = smb2_signature;
+ struct smb2_hdr *smb2_pdu = (struct smb2_hdr *)iov[0].iov_base;
+
+ memset(smb2_signature, 0x0, SMB2_HMACSHA256_SIZE);
+ memset(smb2_pdu->Signature, 0x0, SMB2_SIGNATURE_SIZE);
+
+ rc = crypto_shash_setkey(server->secmech.hmacsha256,
+ server->session_key.response, SMB2_NTLMV2_SESSKEY_SIZE);
+ if (rc) {
+ cERROR(1, "%s: Could not update with response\n", __func__);
+ return rc;
+ }
+
+ rc = crypto_shash_init(&server->secmech.sdeschmacsha256->shash);
+ if (rc) {
+ cERROR(1, "%s: Could not init md5\n", __func__);
+ return rc;
+ }
+
+ for (i = 0; i < n_vec; i++) {
+ if (iov[i].iov_len == 0)
+ continue;
+ if (iov[i].iov_base == NULL) {
+ cERROR(1, "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.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) {
+ cERROR(1, "%s: Could not update with payload\n",
+ __func__);
+ return rc;
+ }
+ }
+
+ rc = crypto_shash_final(&server->secmech.sdeschmacsha256->shash,
+ sigptr);
+ if (rc)
+ cERROR(1, "%s: Could not generate sha256 hash\n", __func__);
+
+ memcpy(smb2_pdu->Signature, sigptr, SMB2_SIGNATURE_SIZE);
+
+ return rc;
+}
+
+/* must be called with server->srv_mutex held */
+static int
+smb2_sign_smb2(struct kvec *iov, int n_vec, struct TCP_Server_Info *server)
+{
+ int rc = 0;
+ struct smb2_hdr *smb2_pdu = iov[0].iov_base;
+
+ if (!(smb2_pdu->Flags & SMB2_FLAGS_SIGNED) ||
+ server->tcpStatus == CifsNeedNegotiate)
+ return rc;
+
+ if (!server->session_estab) {
+ strncpy(smb2_pdu->Signature, "BSRSPYL", 8);
+ return rc;
+ }
+
+ rc = smb2_calc_signature2(iov, n_vec, server);
+
+ return rc;
+}
+
+int
+smb2_verify_signature2(struct kvec *iov, unsigned int n_vec,
+ struct TCP_Server_Info *server)
+{
+ unsigned int rc;
+ char server_response_sig[16];
+ struct smb2_hdr *smb2_pdu = (struct smb2_hdr *)iov[0].iov_base;
+
+ if ((smb2_pdu->Command == SMB2_NEGOTIATE) ||
+ (smb2_pdu->Command == SMB2_OPLOCK_BREAK) ||
+ (!server->session_estab))
+ return 0;
+
+ /*
+ * BB what if signatures are supposed to be on for session but
+ * server does not send one? BB
+ */
+
+ /* Do not need to verify session setups with signature "BSRSPYL " */
+ if (memcmp(smb2_pdu->Signature, "BSRSPYL ", 8) == 0)
+ cFYI(1, "dummy signature received for smb command 0x%x",
+ smb2_pdu->Command);
+
+ /*
+ * Save off the origiginal signature so we can modify the smb and check
+ * our calculated signature against what the server sent.
+ */
+ memcpy(server_response_sig, smb2_pdu->Signature, SMB2_SIGNATURE_SIZE);
+
+ memset(smb2_pdu->Signature, 0, SMB2_SIGNATURE_SIZE);
+
+ mutex_lock(&server->srv_mutex);
+ rc = smb2_calc_signature2(iov, n_vec, server);
+ mutex_unlock(&server->srv_mutex);
+
+ if (rc)
+ return rc;
+
+ if (memcmp(server_response_sig, smb2_pdu->Signature,
+ SMB2_SIGNATURE_SIZE))
+ return -EACCES;
+ else
+ return 0;
+}
+
+static int
+smb2_verify_signature(struct smb2_hdr *smb2_pdu, struct TCP_Server_Info *server)
+{
+ struct kvec iov;
+
+ iov.iov_base = (char *)smb2_pdu;
+ iov.iov_len = get_rfc1002_length(smb2_pdu) + 4;
+ return smb2_verify_signature2(&iov, 1, server);
+}
/*
* Set message id for the request. Should be called after wait_for_free_request
dump_smb(mid->resp_buf, min_t(u32, 80, len));
/* convert the length into a more usable form */
- /* BB - uncomment with SMB2 signing implementation */
- /* if ((len > 24) &&
+ if ((len > 24) &&
(server->sec_mode & (SECMODE_SIGN_REQUIRED|SECMODE_SIGN_ENABLED))) {
- if (smb2_verify_signature(mid->resp_buf, server))
- cERROR(1, "Unexpected SMB signature");
- } */
+ int rc;
+
+ rc = smb2_verify_signature(mid->resp_buf, server);
+ if (rc)
+ cERROR(1, "SMB signature verification returned error = "
+ "%d", rc);
+ }
return map_smb2_to_linux_error(mid->resp_buf, log_error);
}
rc = smb2_get_mid_entry(ses, hdr, &mid);
if (rc)
return rc;
- /* rc = smb2_sign_smb2(iov, nvec, ses->server);
+ rc = smb2_sign_smb2(iov, nvec, ses->server);
if (rc)
- delete_mid(mid); */
+ cifs_delete_mid(mid);
*ret_mid = mid;
return rc;
}
if (mid == NULL)
return -ENOMEM;
- /* rc = smb2_sign_smb2(iov, nvec, server);
+ rc = smb2_sign_smb2(iov, nvec, server);
if (rc) {
DeleteMidQEntry(mid);
return rc;
- }*/
+ }
+
*ret_mid = mid;
return rc;
}
projects / cascardo / linux.git / blobdiff