[CIFS] Fix ntlmv2 auth with ntlmssp

Make ntlmv2 as an authentication mechanism within ntlmssp
instead of ntlmv1.
Parse type 2 response in ntlmssp negotiation to pluck
AV pairs and use them to calculate ntlmv2 response token.
Also, assign domain name from the sever response in type 2
packet of ntlmssp and use that (netbios) domain name in
calculation of response.

Enable cifs/smb signing using rc4 and md5.

Changed name of the structure mac_key to session_key to reflect
the type of key it holds.

Use kernel crypto_shash_* APIs instead of the equivalent cifs functions.
Signed-off-by: Shirish Pargaonkar <shirishpargaonkar@gmail.com>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Steve French <sfrench@us.ibm.com>

fs/cifs/Kconfig

@@ -2,6 +2,8 @@ config CIFS
 	tristate "CIFS support (advanced network filesystem, SMBFS successor)"
 	depends on INET
 	select NLS
+	select CRYPTO_MD5
+	select CRYPTO_ARC4
 	help
 	  This is the client VFS module for the Common Internet File System
 	  (CIFS) protocol which is the successor to the Server Message Block

fs/cifs/asn1.c

@@ -597,13 +597,13 @@ decode_negTokenInit(unsigned char *security_blob, int length,
 				if (compare_oid(oid, oidlen, MSKRB5_OID,
 						MSKRB5_OID_LEN))
 					server->sec_mskerberos = true;
-				else if (compare_oid(oid, oidlen, KRB5U2U_OID,
+				if (compare_oid(oid, oidlen, KRB5U2U_OID,
 						     KRB5U2U_OID_LEN))
 					server->sec_kerberosu2u = true;
-				else if (compare_oid(oid, oidlen, KRB5_OID,
+				if (compare_oid(oid, oidlen, KRB5_OID,
 						     KRB5_OID_LEN))
 					server->sec_kerberos = true;
-				else if (compare_oid(oid, oidlen, NTLMSSP_OID,
+				if (compare_oid(oid, oidlen, NTLMSSP_OID,
 						     NTLMSSP_OID_LEN))
 					server->sec_ntlmssp = true;
 

fs/cifs/cifsglob.h

@@ -25,6 +25,9 @@
 #include <linux/workqueue.h>
 #include "cifs_fs_sb.h"
 #include "cifsacl.h"
+#include <crypto/internal/hash.h>
+#include <linux/scatterlist.h>
+
 /*
  * The sizes of various internal tables and strings
  */
@@ -97,7 +100,7 @@ enum protocolEnum {
 	/* Netbios frames protocol not supported at this time */
 };
 
-struct mac_key {
+struct session_key {
 	unsigned int len;
 	union {
 		char ntlm[CIFS_SESS_KEY_SIZE + 16];
@@ -120,6 +123,14 @@ struct cifs_cred {
 	struct cifs_ace *aces;
 };
 
+struct ntlmssp_auth {
+	__u32 client_flags;
+	__u32 server_flags;
+	unsigned char ciphertext[CIFS_CPHTXT_SIZE];
+	struct crypto_shash *hmacmd5;
+	struct crypto_shash *md5;
+};
+
 /*
  *****************************************************************
  * Except the CIFS PDUs themselves all the
@@ -182,11 +193,14 @@ struct TCP_Server_Info {
 	/* 16th byte of RFC1001 workstation name is always null */
 	char workstation_RFC1001_name[RFC1001_NAME_LEN_WITH_NULL];
 	__u32 sequence_number; /* needed for CIFS PDU signature */
-	struct mac_key mac_signing_key;
+	struct session_key session_key;
 	char ntlmv2_hash[16];
 	unsigned long lstrp; /* when we got last response from this server */
 	u16 dialect; /* dialect index that server chose */
 	/* extended security flavors that server supports */
+	unsigned int tilen; /* length of the target info blob */
+	unsigned char *tiblob; /* target info blob in challenge response */
+	struct ntlmssp_auth ntlmssp; /* various keys, ciphers, flags */
 	bool	sec_kerberos;		/* supports plain Kerberos */
 	bool	sec_mskerberos;		/* supports legacy MS Kerberos */
 	bool	sec_kerberosu2u;	/* supports U2U Kerberos */

fs/cifs/cifspdu.h

@@ -134,6 +134,12 @@
  * Size of the session key (crypto key encrypted with the password
  */
 #define CIFS_SESS_KEY_SIZE (24)
+#define CIFS_CLIENT_CHALLENGE_SIZE (8)
+#define CIFS_SERVER_CHALLENGE_SIZE (8)
+#define CIFS_HMAC_MD5_HASH_SIZE (16)
+#define CIFS_CPHTXT_SIZE (16)
+#define CIFS_NTLMV2_SESSKEY_SIZE (16)
+#define CIFS_NTHASH_SIZE (16)
 
 /*
  * Maximum user name length
@@ -663,7 +669,6 @@ struct ntlmv2_resp {
 	__le64  time;
 	__u64  client_chal; /* random */
 	__u32  reserved2;
-	struct ntlmssp2_name names[2];
 	/* array of name entries could follow ending in minimum 4 byte struct */
 } __attribute__((packed));
 

fs/cifs/cifsproto.h

@@ -361,15 +361,15 @@ 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 mac_key *mac_key,
+				 struct TCP_Server_Info *server,
 				__u32 expected_sequence_number);
-extern int cifs_calculate_mac_key(struct mac_key *key, const char *rn,
+extern int cifs_calculate_session_key(struct session_key *key, const char *rn,
 				 const char *pass);
-extern int CalcNTLMv2_partial_mac_key(struct cifsSesInfo *,
-			const struct nls_table *);
-extern void CalcNTLMv2_response(const struct cifsSesInfo *, char *);
-extern void setup_ntlmv2_rsp(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 *);
+extern void cifs_crypto_shash_release(struct TCP_Server_Info *);
+extern int calc_seckey(struct TCP_Server_Info *);
 #ifdef CONFIG_CIFS_WEAK_PW_HASH
 extern void calc_lanman_hash(const char *password, const char *cryptkey,
 				bool encrypt, char *lnm_session_key);

fs/cifs/cifssmb.c

@@ -604,11 +604,14 @@ CIFSSMBNegotiate(unsigned int xid, struct cifsSesInfo *ses)
 			else
 				rc = -EINVAL;
 
-			if (server->sec_kerberos || server->sec_mskerberos)
-				server->secType = Kerberos;
-			else if (server->sec_ntlmssp)
-				server->secType = RawNTLMSSP;
-			else
+			if (server->secType == Kerberos) {
+				if (!server->sec_kerberos &&
+						!server->sec_mskerberos)
+					rc = -EOPNOTSUPP;
+			} else if (server->secType == RawNTLMSSP) {
+				if (!server->sec_ntlmssp)
+					rc = -EOPNOTSUPP;
+			} else
 				rc = -EOPNOTSUPP;
 		}
 	} else

fs/cifs/connect.c

@@ -1707,6 +1707,7 @@ cifs_put_smb_ses(struct cifsSesInfo *ses)
 		CIFSSMBLogoff(xid, ses);
 		_FreeXid(xid);
 	}
+	cifs_crypto_shash_release(server);
 	sesInfoFree(ses);
 	cifs_put_tcp_session(server);
 }
@@ -1786,13 +1787,23 @@ cifs_get_smb_ses(struct TCP_Server_Info *server, struct smb_vol *volume_info)
 	ses->linux_uid = volume_info->linux_uid;
 	ses->overrideSecFlg = volume_info->secFlg;
 
+	rc = cifs_crypto_shash_allocate(server);
+	if (rc) {
+		cERROR(1, "could not setup hash structures rc %d", rc);
+		goto get_ses_fail;
+	}
+	server->tilen = 0;
+	server->tiblob = NULL;
+
 	mutex_lock(&ses->session_mutex);
 	rc = cifs_negotiate_protocol(xid, ses);
 	if (!rc)
 		rc = cifs_setup_session(xid, ses, volume_info->local_nls);
 	mutex_unlock(&ses->session_mutex);
-	if (rc)
+	if (rc) {
+		cifs_crypto_shash_release(ses->server);
 		goto get_ses_fail;
+	}
 
 	/* success, put it on the list */
 	write_lock(&cifs_tcp_ses_lock);

fs/cifs/ntlmssp.h

@@ -61,6 +61,19 @@
 #define NTLMSSP_NEGOTIATE_KEY_XCH   0x40000000
 #define NTLMSSP_NEGOTIATE_56        0x80000000
 
+/* Define AV Pair Field IDs */
+#define NTLMSSP_AV_EOL			0
+#define NTLMSSP_AV_NB_COMPUTER_NAME	1
+#define NTLMSSP_AV_NB_DOMAIN_NAME	2
+#define NTLMSSP_AV_DNS_COMPUTER_NAME	3
+#define NTLMSSP_AV_DNS_DOMAIN_NAME	4
+#define NTLMSSP_AV_DNS_TREE_NAME	5
+#define NTLMSSP_AV_FLAGS		6
+#define NTLMSSP_AV_TIMESTAMP		7
+#define NTLMSSP_AV_RESTRICTION		8
+#define NTLMSSP_AV_TARGET_NAME		9
+#define NTLMSSP_AV_CHANNEL_BINDINGS	10
+
 /* Although typedefs are not commonly used for structure definitions */
 /* in the Linux kernel, in this particular case they are useful      */
 /* to more closely match the standards document for NTLMSSP from     */

fs/cifs/sess.c

@@ -383,6 +383,9 @@ static int decode_ascii_ssetup(char **pbcc_area, int bleft,
 static int decode_ntlmssp_challenge(char *bcc_ptr, int blob_len,
 				    struct cifsSesInfo *ses)
 {
+	unsigned int tioffset; /* challeng message target info area */
+	unsigned int tilen; /* challeng message target info area length  */
+
 	CHALLENGE_MESSAGE *pblob = (CHALLENGE_MESSAGE *)bcc_ptr;
 
 	if (blob_len < sizeof(CHALLENGE_MESSAGE)) {
@@ -405,6 +408,18 @@ static int decode_ntlmssp_challenge(char *bcc_ptr, int blob_len,
 	/* BB spec says that if AvId field of MsvAvTimestamp is populated then
 		we must set the MIC field of the AUTHENTICATE_MESSAGE */
 
+	tioffset = cpu_to_le16(pblob->TargetInfoArray.BufferOffset);
+	tilen = cpu_to_le16(pblob->TargetInfoArray.Length);
+	ses->server->tilen = tilen;
+	if (tilen) {
+		ses->server->tiblob = kmalloc(tilen, GFP_KERNEL);
+		if (!ses->server->tiblob) {
+			cERROR(1, "Challenge target info allocation failure");
+			return -ENOMEM;
+		}
+		memcpy(ses->server->tiblob,  bcc_ptr + tioffset, tilen);
+	}
+
 	return 0;
 }
 
@@ -451,10 +466,12 @@ static int build_ntlmssp_auth_blob(unsigned char *pbuffer,
 				   struct cifsSesInfo *ses,
 				   const struct nls_table *nls_cp, bool first)
 {
+	int rc;
+	unsigned int size;
 	AUTHENTICATE_MESSAGE *sec_blob = (AUTHENTICATE_MESSAGE *)pbuffer;
 	__u32 flags;
 	unsigned char *tmp;
-	char ntlm_session_key[CIFS_SESS_KEY_SIZE];
+	struct ntlmv2_resp ntlmv2_response = {};
 
 	memcpy(sec_blob->Signature, NTLMSSP_SIGNATURE, 8);
 	sec_blob->MessageType = NtLmAuthenticate;
@@ -477,19 +494,25 @@ static int build_ntlmssp_auth_blob(unsigned char *pbuffer,
 	sec_blob->LmChallengeResponse.Length = 0;
 	sec_blob->LmChallengeResponse.MaximumLength = 0;
 
-	/* calculate session key,  BB what about adding similar ntlmv2 path? */
-	SMBNTencrypt(ses->password, ses->server->cryptKey, ntlm_session_key);
-	if (first)
-		cifs_calculate_mac_key(&ses->server->mac_signing_key,
-				       ntlm_session_key, ses->password);
-
-	memcpy(tmp, ntlm_session_key, CIFS_SESS_KEY_SIZE);
 	sec_blob->NtChallengeResponse.BufferOffset = cpu_to_le32(tmp - pbuffer);
-	sec_blob->NtChallengeResponse.Length = cpu_to_le16(CIFS_SESS_KEY_SIZE);
-	sec_blob->NtChallengeResponse.MaximumLength =
-				cpu_to_le16(CIFS_SESS_KEY_SIZE);
+	rc = setup_ntlmv2_rsp(ses, (char *)&ntlmv2_response, nls_cp);
+	if (rc) {
+		cERROR(1, "error rc: %d during ntlmssp ntlmv2 setup", rc);
+		goto setup_ntlmv2_ret;
+	}
+	size =  sizeof(struct ntlmv2_resp);
+	memcpy(tmp, (char *)&ntlmv2_response, size);
+	tmp += size;
+	if (ses->server->tilen > 0) {
+		memcpy(tmp, ses->server->tiblob, ses->server->tilen);
+		tmp += ses->server->tilen;
+	} else
+		ses->server->tilen = 0;
 
-	tmp += CIFS_SESS_KEY_SIZE;
+	sec_blob->NtChallengeResponse.Length = cpu_to_le16(size +
+				ses->server->tilen);
+	sec_blob->NtChallengeResponse.MaximumLength =
+		cpu_to_le16(size + ses->server->tilen);
 
 	if (ses->domainName == NULL) {
 		sec_blob->DomainName.BufferOffset = cpu_to_le32(tmp - pbuffer);
@@ -501,7 +524,6 @@ static int build_ntlmssp_auth_blob(unsigned char *pbuffer,
 		len = cifs_strtoUCS((__le16 *)tmp, ses->domainName,
 				    MAX_USERNAME_SIZE, nls_cp);
 		len *= 2; /* unicode is 2 bytes each */
-		len += 2; /* trailing null */
 		sec_blob->DomainName.BufferOffset = cpu_to_le32(tmp - pbuffer);
 		sec_blob->DomainName.Length = cpu_to_le16(len);
 		sec_blob->DomainName.MaximumLength = cpu_to_le16(len);
@@ -518,7 +540,6 @@ static int build_ntlmssp_auth_blob(unsigned char *pbuffer,
 		len = cifs_strtoUCS((__le16 *)tmp, ses->userName,
 				    MAX_USERNAME_SIZE, nls_cp);
 		len *= 2; /* unicode is 2 bytes each */
-		len += 2; /* trailing null */
 		sec_blob->UserName.BufferOffset = cpu_to_le32(tmp - pbuffer);
 		sec_blob->UserName.Length = cpu_to_le16(len);
 		sec_blob->UserName.MaximumLength = cpu_to_le16(len);
@@ -530,9 +551,26 @@ static int build_ntlmssp_auth_blob(unsigned char *pbuffer,
 	sec_blob->WorkstationName.MaximumLength = 0;
 	tmp += 2;
 
-	sec_blob->SessionKey.BufferOffset = cpu_to_le32(tmp - pbuffer);
-	sec_blob->SessionKey.Length = 0;
-	sec_blob->SessionKey.MaximumLength = 0;
+	if ((ses->server->ntlmssp.server_flags & NTLMSSP_NEGOTIATE_KEY_XCH) &&
+			!calc_seckey(ses->server)) {
+		memcpy(tmp, ses->server->ntlmssp.ciphertext, CIFS_CPHTXT_SIZE);
+		sec_blob->SessionKey.BufferOffset = cpu_to_le32(tmp - pbuffer);
+		sec_blob->SessionKey.Length = cpu_to_le16(CIFS_CPHTXT_SIZE);
+		sec_blob->SessionKey.MaximumLength =
+			cpu_to_le16(CIFS_CPHTXT_SIZE);
+		tmp += CIFS_CPHTXT_SIZE;
+	} else {
+		sec_blob->SessionKey.BufferOffset = cpu_to_le32(tmp - pbuffer);
+		sec_blob->SessionKey.Length = 0;
+		sec_blob->SessionKey.MaximumLength = 0;
+	}
+
+	ses->server->sequence_number = 0;
+
+setup_ntlmv2_ret:
+	if (ses->server->tilen > 0)
+		kfree(ses->server->tiblob);
+
 	return tmp - pbuffer;
 }
 
@@ -546,15 +584,14 @@ static void setup_ntlmssp_neg_req(SESSION_SETUP_ANDX *pSMB,
 	return;
 }
 
-static int setup_ntlmssp_auth_req(SESSION_SETUP_ANDX *pSMB,
+static int setup_ntlmssp_auth_req(char *ntlmsspblob,
 				  struct cifsSesInfo *ses,
 				  const struct nls_table *nls, bool first_time)
 {
 	int bloblen;
 
-	bloblen = build_ntlmssp_auth_blob(&pSMB->req.SecurityBlob[0], ses, nls,
+	bloblen = build_ntlmssp_auth_blob(ntlmsspblob, ses, nls,
 					  first_time);
-	pSMB->req.SecurityBlobLength = cpu_to_le16(bloblen);
 
 	return bloblen;
 }
@@ -580,6 +617,7 @@ CIFS_SessSetup(unsigned int xid, struct cifsSesInfo *ses,
 	struct key *spnego_key = NULL;
 	__le32 phase = NtLmNegotiate; /* NTLMSSP, if needed, is multistage */
 	bool first_time;
+	char *ntlmsspblob;
 
 	if (ses == NULL)
 		return -EINVAL;
@@ -690,7 +728,7 @@ CIFS_SessSetup(unsigned int xid, struct cifsSesInfo *ses,
 
 		if (first_time) /* should this be moved into common code
 				  with similar ntlmv2 path? */
-			cifs_calculate_mac_key(&ses->server->mac_signing_key,
+			cifs_calculate_session_key(&ses->server->session_key,
 				ntlm_session_key, ses->password);
 		/* copy session key */
 
@@ -729,12 +767,21 @@ CIFS_SessSetup(unsigned int xid, struct cifsSesInfo *ses,
 			cpu_to_le16(sizeof(struct ntlmv2_resp));
 
 		/* calculate session key */
-		setup_ntlmv2_rsp(ses, v2_sess_key, nls_cp);
+		rc = setup_ntlmv2_rsp(ses, v2_sess_key, nls_cp);
+		if (rc) {
+			kfree(v2_sess_key);
+			goto ssetup_exit;
+		}
 		/* FIXME: calculate MAC key */
 		memcpy(bcc_ptr, (char *)v2_sess_key,
 		       sizeof(struct ntlmv2_resp));
 		bcc_ptr += sizeof(struct ntlmv2_resp);
 		kfree(v2_sess_key);
+		if (ses->server->tilen > 0) {
+			memcpy(bcc_ptr, ses->server->tiblob,
+				ses->server->tilen);
+			bcc_ptr += ses->server->tilen;
+		}
 		if (ses->capabilities & CAP_UNICODE) {
 			if (iov[0].iov_len % 2) {
 				*bcc_ptr = 0;
@@ -765,15 +812,15 @@ CIFS_SessSetup(unsigned int xid, struct cifsSesInfo *ses,
 		}
 		/* bail out if key is too long */
 		if (msg->sesskey_len >
-		    sizeof(ses->server->mac_signing_key.data.krb5)) {
+		    sizeof(ses->server->session_key.data.krb5)) {
 			cERROR(1, "Kerberos signing key too long (%u bytes)",
 				msg->sesskey_len);
 			rc = -EOVERFLOW;
 			goto ssetup_exit;
 		}
 		if (first_time) {
-			ses->server->mac_signing_key.len = msg->sesskey_len;
-			memcpy(ses->server->mac_signing_key.data.krb5,
+			ses->server->session_key.len = msg->sesskey_len;
+			memcpy(ses->server->session_key.data.krb5,
 				msg->data, msg->sesskey_len);
 		}
 		pSMB->req.hdr.Flags2 |= SMBFLG2_EXT_SEC;
@@ -815,12 +862,26 @@ CIFS_SessSetup(unsigned int xid, struct cifsSesInfo *ses,
 			if (phase == NtLmNegotiate) {
 				setup_ntlmssp_neg_req(pSMB, ses);
 				iov[1].iov_len = sizeof(NEGOTIATE_MESSAGE);
+				iov[1].iov_base = &pSMB->req.SecurityBlob[0];
 			} else if (phase == NtLmAuthenticate) {
 				int blob_len;
-				blob_len = setup_ntlmssp_auth_req(pSMB, ses,
-								  nls_cp,
-								  first_time);
+				ntlmsspblob = kmalloc(5 *
+					sizeof(struct _AUTHENTICATE_MESSAGE),
+					GFP_KERNEL);
+				if (!ntlmsspblob) {
+					cERROR(1, "Can't allocate NTLMSSP");
+					rc = -ENOMEM;
+					goto ssetup_exit;
+				}
+
+				blob_len = setup_ntlmssp_auth_req(ntlmsspblob,
+								ses,
+								nls_cp,
+								first_time);
 				iov[1].iov_len = blob_len;
+				iov[1].iov_base = ntlmsspblob;
+				pSMB->req.SecurityBlobLength =
+					cpu_to_le16(blob_len);
 				/* Make sure that we tell the server that we
 				   are using the uid that it just gave us back
 				   on the response (challenge) */
@@ -830,7 +891,6 @@ CIFS_SessSetup(unsigned int xid, struct cifsSesInfo *ses,
 				rc = -ENOSYS;
 				goto ssetup_exit;
 			}
-			iov[1].iov_base = &pSMB->req.SecurityBlob[0];
 			/* unicode strings must be word aligned */
 			if ((iov[0].iov_len + iov[1].iov_len) % 2) {
 				*bcc_ptr = 0;

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->mac_signing_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->mac_signing_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->mac_signing_key,
+					   ses->server,
 					   midQ->sequence_number+1);
 		if (rc) {
 			cERROR(1, "Unexpected SMB signature");