[PATCH 7/7 cifs] ntlm authentication and signing - Use kernel crypto apis to calculate hashes and smb signatures

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



From: Shirish Pargaonkar <shirishpargaonkar@xxxxxxxxx>


Use kernel crypto sync hash apis insetead of cifs crypto functions.
The calls typically corrospond one to one except that insead of
key init, setkey is used.

Use crypto apis to generate smb signagtures also.
Use hmac-md5 to genereate ntlmv2 hash, ntlmv2 response, and HMAC (CR1 of
ntlmv2 auth blob.
User crypto apis to genereate signature and to verify signature.
md5 hash is used to calculate signature.
Use secondary key to calculate signature in case of ntlmssp.

For ntlssp, session key used in signature is of size 16 bytes and
for ntlmssp auth type, smb connection sequence nubmer is kept 0x0
till a type 3 message in the negotiation is sent.


Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@xxxxxxxxx>
---
 fs/cifs/cifsencrypt.c |  258 +++++++++++++++++++++++++++++++++++--------------
 fs/cifs/cifsproto.h   |    3 +-
 fs/cifs/transport.c   |    6 +-
 3 files changed, 190 insertions(+), 77 deletions(-)

diff --git a/fs/cifs/cifsencrypt.c b/fs/cifs/cifsencrypt.c
index dcdbd10..ccf25d3 100644
--- a/fs/cifs/cifsencrypt.c
+++ b/fs/cifs/cifsencrypt.c
@@ -43,19 +43,40 @@ extern void SMBencrypt(unsigned char *passwd, const unsigned char *c8,
 		       unsigned char *p24);
 
 static int cifs_calculate_signature(const struct smb_hdr *cifs_pdu,
-				const struct session_key *key, char *signature)
+			struct TCP_Server_Info *server, char *signature)
 {
-	struct	MD5Context context;
+	int rc;
+	unsigned int len;
 
-	if ((cifs_pdu == NULL) || (signature == NULL) || (key == NULL))
+	if (cifs_pdu == NULL || server == NULL || signature == NULL)
 		return -EINVAL;
 
-	cifs_MD5_init(&context);
-	cifs_MD5_update(&context, (char *)&key->data, key->len);
-	cifs_MD5_update(&context, cifs_pdu->Protocol, cifs_pdu->smb_buf_length);
+	if (!server->secmech.sdescmd5) {
+		cERROR(1,
+			"cifs_calculate_signature: can't generate signature\n");
+		return -1;
+	}
 
-	cifs_MD5_final(signature, &context);
-	return 0;
+	rc = crypto_shash_init(&server->secmech.sdescmd5->shash);
+	if (rc) {
+		cERROR(1, "cifs_calculate_signature: oould not init md5\n");
+		return rc;
+	}
+
+	if (server->secType == RawNTLMSSP)
+		len = CIFS_NTLMV2_SESSKEY_SIZE;
+	else
+		len = server->session_key.len;
+
+	crypto_shash_update(&server->secmech.sdescmd5->shash,
+		(char *)&server->session_key.data, len);
+
+	crypto_shash_update(&server->secmech.sdescmd5->shash,
+			cifs_pdu->Protocol, cifs_pdu->smb_buf_length);
+
+	rc = crypto_shash_final(&server->secmech.sdescmd5->shash, signature);
+
+	return rc;
 }
 
 int cifs_sign_smb(struct smb_hdr *cifs_pdu, struct TCP_Server_Info *server,
@@ -71,6 +92,8 @@ int cifs_sign_smb(struct smb_hdr *cifs_pdu, struct TCP_Server_Info *server,
 		return rc;
 
 	spin_lock(&GlobalMid_Lock);
+	if (server->secType == RawNTLMSSP && !server->session_estab)
+		server->sequence_number = 0x0;
 	cifs_pdu->Signature.Sequence.SequenceNumber =
 			cpu_to_le32(server->sequence_number);
 	cifs_pdu->Signature.Sequence.Reserved = 0;
@@ -79,8 +102,7 @@ int cifs_sign_smb(struct smb_hdr *cifs_pdu, struct TCP_Server_Info *server,
 	server->sequence_number++;
 	spin_unlock(&GlobalMid_Lock);
 
-	rc = cifs_calculate_signature(cifs_pdu, &server->session_key,
-				      smb_signature);
+	rc = cifs_calculate_signature(cifs_pdu, server, smb_signature);
 	if (rc)
 		memset(cifs_pdu->Signature.SecuritySignature, 0, 8);
 	else
@@ -90,21 +112,39 @@ int cifs_sign_smb(struct smb_hdr *cifs_pdu, struct TCP_Server_Info *server,
 }
 
 static int cifs_calc_signature2(const struct kvec *iov, int n_vec,
-				const struct session_key *key, char *signature)
+			struct TCP_Server_Info *server, char *signature)
 {
-	struct  MD5Context context;
 	int i;
+	int rc;
+	unsigned int len;
 
-	if ((iov == NULL) || (signature == NULL) || (key == NULL))
+	if (iov == NULL || server == NULL || signature == NULL)
 		return -EINVAL;
 
-	cifs_MD5_init(&context);
-	cifs_MD5_update(&context, (char *)&key->data, key->len);
+	if (!server->secmech.sdescmd5) {
+		cERROR(1, "cifs_calc_signature2: can't generate signature\n");
+		return -1;
+	}
+
+	rc = crypto_shash_init(&server->secmech.sdescmd5->shash);
+	if (rc) {
+		cERROR(1, "cifs_calc_signature2: oould not init md5\n");
+		return rc;
+	}
+
+	if (server->secType == RawNTLMSSP)
+		len = CIFS_NTLMV2_SESSKEY_SIZE;
+	else
+		len = server->session_key.len;
+
+	crypto_shash_update(&server->secmech.sdescmd5->shash,
+		(char *)&server->session_key.data, len);
+
 	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");
+			cERROR(1, "cifs_calc_signature2: null iovec entry");
 			return -EIO;
 		}
 		/* The first entry includes a length field (which does not get
@@ -112,18 +152,18 @@ static int cifs_calc_signature2(const struct kvec *iov, int n_vec,
 		if (i == 0) {
 			if (iov[0].iov_len <= 8) /* cmd field at offset 9 */
 				break; /* nothing to sign or corrupt header */
-			cifs_MD5_update(&context, iov[0].iov_base+4,
-				  iov[0].iov_len-4);
+			crypto_shash_update(&server->secmech.sdescmd5->shash,
+				iov[i].iov_base + 4, iov[i].iov_len - 4);
 		} else
-			cifs_MD5_update(&context, iov[i].iov_base, iov[i].iov_len);
+			crypto_shash_update(&server->secmech.sdescmd5->shash,
+				iov[i].iov_base, iov[i].iov_len);
 	}
 
-	cifs_MD5_final(signature, &context);
+	rc = crypto_shash_final(&server->secmech.sdescmd5->shash, signature);
 
-	return 0;
+	return rc;
 }
 
-
 int cifs_sign_smb2(struct kvec *iov, int n_vec, struct TCP_Server_Info *server,
 		   __u32 *pexpected_response_sequence_number)
 {
@@ -138,6 +178,8 @@ int cifs_sign_smb2(struct kvec *iov, int n_vec, struct TCP_Server_Info *server,
 		return rc;
 
 	spin_lock(&GlobalMid_Lock);
+	if (server->secType == RawNTLMSSP && !server->session_estab)
+		server->sequence_number = 0x0;
 	cifs_pdu->Signature.Sequence.SequenceNumber =
 				cpu_to_le32(server->sequence_number);
 	cifs_pdu->Signature.Sequence.Reserved = 0;
@@ -146,8 +188,7 @@ int cifs_sign_smb2(struct kvec *iov, int n_vec, struct TCP_Server_Info *server,
 	server->sequence_number++;
 	spin_unlock(&GlobalMid_Lock);
 
-	rc = cifs_calc_signature2(iov, n_vec, &server->session_key,
-				      smb_signature);
+	rc = cifs_calc_signature2(iov, n_vec, server, smb_signature);
 	if (rc)
 		memset(cifs_pdu->Signature.SecuritySignature, 0, 8);
 	else
@@ -157,14 +198,14 @@ int cifs_sign_smb2(struct kvec *iov, int n_vec, struct TCP_Server_Info *server,
 }
 
 int cifs_verify_signature(struct smb_hdr *cifs_pdu,
-			  const struct session_key *session_key,
+			  struct TCP_Server_Info *server,
 			  __u32 expected_sequence_number)
 {
-	unsigned int rc;
+	int rc;
 	char server_response_sig[8];
 	char what_we_think_sig_should_be[20];
 
-	if (cifs_pdu == NULL || session_key == NULL)
+	if (cifs_pdu == NULL || server == NULL)
 		return -EINVAL;
 
 	if (cifs_pdu->Command == SMB_COM_NEGOTIATE)
@@ -193,7 +234,7 @@ int cifs_verify_signature(struct smb_hdr *cifs_pdu,
 					cpu_to_le32(expected_sequence_number);
 	cifs_pdu->Signature.Sequence.Reserved = 0;
 
-	rc = cifs_calculate_signature(cifs_pdu, session_key,
+	rc = cifs_calculate_signature(cifs_pdu, server,
 		what_we_think_sig_should_be);
 
 	if (rc)
@@ -403,38 +444,52 @@ static int calc_ntlmv2_hash(struct cifsSesInfo *ses,
 {
 	int rc = 0;
 	int len;
-	char nt_hash[16];
-	struct HMACMD5Context *pctxt;
+	char nt_hash[CIFS_NTHASH_SIZE];
 	wchar_t *user;
 	wchar_t *domain;
+	wchar_t *server;
 
-	pctxt = kmalloc(sizeof(struct HMACMD5Context), GFP_KERNEL);
-
-	if (pctxt == NULL)
-		return -ENOMEM;
+	if (!ses->server->secmech.sdeschmacmd5) {
+		cERROR(1, "calc_ntlmv2_hash: can't generate ntlmv2 hash\n");
+		return -1;
+	}
 
 	/* calculate md4 hash of password */
 	E_md4hash(ses->password, nt_hash);
 
-	/* convert Domainname to unicode and uppercase */
-	hmac_md5_init_limK_to_64(nt_hash, 16, pctxt);
+	crypto_shash_setkey(ses->server->secmech.hmacmd5, nt_hash,
+				CIFS_NTHASH_SIZE);
+
+	rc = crypto_shash_init(&ses->server->secmech.sdeschmacmd5->shash);
+	if (rc) {
+		cERROR(1, "calc_ntlmv2_hash: could not init hmacmd5\n");
+		return rc;
+	}
 
 	/* convert ses->userName to unicode and uppercase */
 	len = strlen(ses->userName);
 	user = kmalloc(2 + (len * 2), GFP_KERNEL);
-	if (user == NULL)
+	if (user == NULL) {
+		cERROR(1, "calc_ntlmv2_hash: user mem alloc failure\n");
+		rc = -ENOMEM;
 		goto calc_exit_2;
+	}
 	len = cifs_strtoUCS((__le16 *)user, ses->userName, len, nls_cp);
 	UniStrupr(user);
-	hmac_md5_update((char *)user, 2*len, pctxt);
+
+	crypto_shash_update(&ses->server->secmech.sdeschmacmd5->shash,
+				(char *)user, 2 * len);
 
 	/* convert ses->domainName to unicode and uppercase */
 	if (ses->domainName) {
 		len = strlen(ses->domainName);
 
 		domain = kmalloc(2 + (len * 2), GFP_KERNEL);
-		if (domain == NULL)
+		if (domain == NULL) {
+			cERROR(1, "calc_ntlmv2_hash: domain mem alloc failure");
+			rc = -ENOMEM;
 			goto calc_exit_1;
+		}
 		len = cifs_strtoUCS((__le16 *)domain, ses->domainName, len,
 					nls_cp);
 		/* the following line was removed since it didn't work well
@@ -442,18 +497,73 @@ static int calc_ntlmv2_hash(struct cifsSesInfo *ses,
 		   Maybe converting the domain name earlier makes sense */
 		/* UniStrupr(domain); */
 
-		hmac_md5_update((char *)domain, 2*len, pctxt);
+		crypto_shash_update(&ses->server->secmech.sdeschmacmd5->shash,
+					(char *)domain, 2 * len);
 
 		kfree(domain);
+	} else if (ses->serverName) {
+		len = strlen(ses->serverName);
+
+		server = kmalloc(2 + (len * 2), GFP_KERNEL);
+		if (server == NULL) {
+			cERROR(1, "calc_ntlmv2_hash: server mem alloc failure");
+			rc = -ENOMEM;
+			goto calc_exit_1;
+		}
+		len = cifs_strtoUCS((__le16 *)server, ses->serverName, len,
+						nls_cp);
+		/* the following line was removed since it didn't work well
+		   with lower cased domain name that passed as an option.
+		   Maybe converting the domain name earlier makes sense */
+		/* UniStrupr(domain); */
+
+		crypto_shash_update(&ses->server->secmech.sdeschmacmd5->shash,
+					(char *)server, 2 * len);
+
+		kfree(server);
 	}
+
+	rc = crypto_shash_final(&ses->server->secmech.sdeschmacmd5->shash,
+					ses->ntlmv2_hash);
+
 calc_exit_1:
 	kfree(user);
 calc_exit_2:
-	/* BB FIXME what about bytes 24 through 40 of the signing key?
-	   compare with the NTLM example */
-	hmac_md5_final(ses->ntlmv2_hash, pctxt);
+	return rc;
+}
+
+static int
+CalcNTLMv2_response(const struct cifsSesInfo *ses, char *v2_session_response)
+{
+	int rc;
+
+	if (!ses->server->secmech.sdeschmacmd5) {
+		cERROR(1, "calc_ntlmv2_hash: can't generate ntlmv2 hash\n");
+		return -1;
+	}
+
+	crypto_shash_setkey(ses->server->secmech.hmacmd5,
+				ses->ntlmv2_hash, CIFS_HMAC_MD5_HASH_SIZE);
+
+	rc = crypto_shash_init(&ses->server->secmech.sdeschmacmd5->shash);
+	if (rc) {
+		cERROR(1, "CalcNTLMv2_response: could not init hmacmd5");
+		return rc;
+	}
+
+	memcpy(v2_session_response + CIFS_SERVER_CHALLENGE_SIZE,
+		ses->cryptKey, CIFS_SERVER_CHALLENGE_SIZE);
+	crypto_shash_update(&ses->server->secmech.sdeschmacmd5->shash,
+		v2_session_response + CIFS_SERVER_CHALLENGE_SIZE,
+		sizeof(struct ntlmv2_resp) - CIFS_SERVER_CHALLENGE_SIZE);
+
+	if (ses->tilen)
+		crypto_shash_update(&ses->server->secmech.sdeschmacmd5->shash,
+				ses->auth_key.data.ntlmv2.tiblob, ses->tilen);
+
+	rc = crypto_shash_final(&ses->server->secmech.sdeschmacmd5->shash,
+				v2_session_response);
 
-	kfree(pctxt);
 	return rc;
 }
 
@@ -463,7 +573,6 @@ setup_ntlmv2_rsp(struct cifsSesInfo *ses, char *resp_buf,
 {
 	int rc;
 	struct ntlmv2_resp *buf = (struct ntlmv2_resp *)resp_buf;
-	struct HMACMD5Context context;
 
 	buf->blob_signature = cpu_to_le32(0x00000101);
 	buf->reserved = 0;
@@ -493,16 +602,39 @@ setup_ntlmv2_rsp(struct cifsSesInfo *ses, char *resp_buf,
 		cERROR(1, "could not get v2 hash rc %d", rc);
 		goto setup_ntlmv2_rsp_ret;
 	}
-	CalcNTLMv2_response(ses, resp_buf);
 
-	/* now calculate the session key for NTLMv2 */
-	hmac_md5_init_limK_to_64(ses->ntlmv2_hash, 16, &context);
-	hmac_md5_update(resp_buf, 16, &context);
-	hmac_md5_final(ses->auth_key.data.ntlmv2.key, &context);
+	rc = CalcNTLMv2_response(ses, resp_buf);
+	if (rc) {
+		cERROR(1, "could not get v2 hash rc %d", rc);
+		goto setup_ntlmv2_rsp_ret;
+	}
+
+	if (!ses->server->secmech.sdeschmacmd5) {
+		cERROR(1, "calc_ntlmv2_hash: can't generate ntlmv2 hash\n");
+		rc = -1;
+		goto setup_ntlmv2_rsp_ret;
+	}
+
+	/* Now we are calculating ntlmv2 session key */
+	crypto_shash_setkey(ses->server->secmech.hmacmd5,
+			ses->ntlmv2_hash, CIFS_HMAC_MD5_HASH_SIZE);
+
+	rc = crypto_shash_init(&ses->server->secmech.sdeschmacmd5->shash);
+	if (rc) {
+		cERROR(1, "setup_ntlmv2_rsp: could not init hmacmd5\n");
+		goto setup_ntlmv2_rsp_ret;
+	}
+
+	crypto_shash_update(&ses->server->secmech.sdeschmacmd5->shash,
+					resp_buf, CIFS_HMAC_MD5_HASH_SIZE);
+
+	rc = crypto_shash_final(&ses->server->secmech.sdeschmacmd5->shash,
+			ses->auth_key.data.ntlmv2.key);
 
 	memcpy(&ses->auth_key.data.ntlmv2.resp, resp_buf,
-	       sizeof(struct ntlmv2_resp));
-	ses->auth_key.len = 16 + sizeof(struct ntlmv2_resp);
+			sizeof(struct ntlmv2_resp));
+	ses->auth_key.len = CIFS_NTLMV2_SESSKEY_SIZE +
+			sizeof(struct ntlmv2_resp);
 	if (ses->tilen)
 		ses->auth_key.len += ses->tilen;
 
@@ -514,25 +646,6 @@ setup_ntlmv2_rsp_ret:
 	return rc;
 }
 
-void CalcNTLMv2_response(const struct cifsSesInfo *ses,
-			 char *v2_session_response)
-{
-	struct HMACMD5Context context;
-	/* rest of v2 struct already generated */
-	memcpy(v2_session_response + 8, ses->cryptKey, 8);
-	hmac_md5_init_limK_to_64(ses->ntlmv2_hash, 16, &context);
-
-	hmac_md5_update(v2_session_response+8,
-			sizeof(struct ntlmv2_resp) - 8, &context);
-
-	if (ses->tilen)
-		hmac_md5_update(ses->auth_key.data.ntlmv2.tiblob, ses->tilen,
-					&context);
-
-	hmac_md5_final(v2_session_response, &context);
-/*	cifs_dump_mem("v2_sess_rsp: ", v2_session_response, 32); */
-}
-
 int
 calc_seckey(struct cifsSesInfo *ses)
 {
@@ -566,7 +679,8 @@ calc_seckey(struct cifsSesInfo *ses)
 	}
 
 	/* make secondary_key/nonce as session key */
-	memcpy(&ses->auth_key.data, sec_key, CIFS_NTLMV2_SESSKEY_SIZE);
+	memcpy(ses->auth_key.data.ntlmv2.key, sec_key,
+			CIFS_NTLMV2_SESSKEY_SIZE);
 
 	crypto_free_blkcipher(tfm_arc4);
 
diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h
index 98945c7..0332b5a 100644
--- a/fs/cifs/cifsproto.h
+++ b/fs/cifs/cifsproto.h
@@ -363,11 +363,10 @@ extern int cifs_sign_smb(struct smb_hdr *, struct TCP_Server_Info *, __u32 *);
 extern int cifs_sign_smb2(struct kvec *iov, int n_vec, struct TCP_Server_Info *,
 			  __u32 *);
 extern int cifs_verify_signature(struct smb_hdr *,
-				 const struct session_key *session_key,
+				 struct TCP_Server_Info *server,
 				__u32 expected_sequence_number);
 extern int cifs_calculate_session_key(struct session_key *key, const char *rn,
 				 const char *pass);
-extern void CalcNTLMv2_response(const struct cifsSesInfo *, char *);
 extern int setup_ntlmv2_rsp(struct cifsSesInfo *, char *,
 			     const struct nls_table *);
 extern int cifs_crypto_shash_allocate(struct TCP_Server_Info *);
diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c
index a66c91e..e0588cd 100644
--- a/fs/cifs/transport.c
+++ b/fs/cifs/transport.c
@@ -543,7 +543,7 @@ SendReceive2(const unsigned int xid, struct cifsSesInfo *ses,
 		    (ses->server->secMode & (SECMODE_SIGN_REQUIRED |
 					     SECMODE_SIGN_ENABLED))) {
 			rc = cifs_verify_signature(midQ->resp_buf,
-						&ses->server->session_key,
+						ses->server,
 						midQ->sequence_number+1);
 			if (rc) {
 				cERROR(1, "Unexpected SMB signature");
@@ -731,7 +731,7 @@ SendReceive(const unsigned int xid, struct cifsSesInfo *ses,
 		    (ses->server->secMode & (SECMODE_SIGN_REQUIRED |
 					     SECMODE_SIGN_ENABLED))) {
 			rc = cifs_verify_signature(out_buf,
-						&ses->server->session_key,
+						ses->server,
 						midQ->sequence_number+1);
 			if (rc) {
 				cERROR(1, "Unexpected SMB signature");
@@ -981,7 +981,7 @@ SendReceiveBlockingLock(const unsigned int xid, struct cifsTconInfo *tcon,
 	    (ses->server->secMode & (SECMODE_SIGN_REQUIRED |
 				     SECMODE_SIGN_ENABLED))) {
 		rc = cifs_verify_signature(out_buf,
-					   &ses->server->session_key,
+					   ses->server,
 					   midQ->sequence_number+1);
 		if (rc) {
 			cERROR(1, "Unexpected SMB signature");
-- 
1.6.0.2

--
To unsubscribe from this list: send the line "unsubscribe linux-cifs" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html


[Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]

  Powered by Linux