[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;