Jeremy requested that I get my NTLMSSP patch into CVS. He didn't request

the schannel code, but I've included that anyway. :-)

This patch revives the client-side NTLMSSP support for RPC named pipes
in Samba, and cleans up the client and server schannel code.  The use of the
new code is enabled by the 'sign', 'seal' and 'schannel' commands in
rpcclient.

The aim was to prove that our separate NTLMSSP client library actually
implements NTLMSSP signing and sealing as per Microsoft's NTLMv1 implementation,
in the hope that knowing this will assist us in correctly implementing
NTLMSSP signing for SMB packets.  (Still not yet functional)

This patch replaces the NTLMSSP implementation in rpc_client/cli_pipe.c with
calls to libsmb/ntlmssp.c.  In the process, we have gained the ability to
use the more secure NT password, and the ability to sign-only, instead of
having to seal the pipe connection.  (Previously we were limited to sealing,
and could only use the LM-password derived key).

Our new client-side NTLMSSP code also needed alteration to cope with our
comparatively simple server-side implementation.  A future step is to replace
it with calls to the same NTLMSSP library.

Also included in this patch is the schannel 'sign only' patch I submitted to
the team earlier.  While not enabled (and not functional, at this stage) the
work in this patch makes the code paths *much* easier to follow.  I have also
included similar hooks in rpccleint to allow the use of schannel on *any* pipe.

rpcclient now defaults to not using schannel (or any other extra per-pipe
authenticiation) for any connection.  The 'schannel' command enables schannel
for all pipes until disabled.

This code is also much more secure than the previous code, as changes to our
cli_pipe routines ensure that the authentication footer cannot be removed
by an attacker, and more error states are correctly handled.

(The same needs to be done to our server)

Andrew Bartlett
(This used to be commit 5472ddc9eaf4e79c5b2e1c8ee8c7f190dc285f19)

1 files changed, 95 insertions, 12 deletions

diff --git a/source3/libsmb/ntlmssp.c b/source3/libsmb/ntlmssp.c
index 4dc9d42659..66dc6e08eb 100644
--- a/source3/libsmb/ntlmssp.c
+++ b/source3/libsmb/ntlmssp.c
@@ -409,6 +409,10 @@ static NTSTATUS ntlmssp_client_initial(struct ntlmssp_client_state *ntlmssp_stat
 		ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_UNICODE;
 	}
 	
+	if (ntlmssp_state->use_ntlmv2) {
+		ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_NTLM2;
+	}
+	
 	/* generate the ntlmssp negotiate packet */
 	msrpc_gen(next_request, "CddAA",
 		  "NTLMSSP",
@@ -435,7 +439,7 @@ static NTSTATUS ntlmssp_client_challenge(struct ntlmssp_client_state *ntlmssp_st
 	uint32 chal_flags, ntlmssp_command, unkn1, unkn2;
 	DATA_BLOB server_domain_blob;
 	DATA_BLOB challenge_blob;
-	DATA_BLOB struct_blob;
+	DATA_BLOB struct_blob = data_blob(NULL, 0);
 	char *server_domain;
 	const char *chal_parse_string;
 	const char *auth_gen_string;
@@ -443,28 +447,48 @@ static NTSTATUS ntlmssp_client_challenge(struct ntlmssp_client_state *ntlmssp_st
 	DATA_BLOB nt_response = data_blob(NULL, 0);
 	DATA_BLOB session_key = data_blob(NULL, 0);
 	uint8 datagram_sess_key[16];
+	size_t datagram_sess_key_len;
 
+#if 0 /* until we know what flag to tigger it on */
 	generate_random_buffer(datagram_sess_key, sizeof(datagram_sess_key), False);	
+	datagram_sess_key_len = sizeof(datagram_sess_key);
+#else
+	ZERO_STRUCT(datagram_sess_key);
+	datagram_sess_key_len = 0;
+#endif
 
 	if (!msrpc_parse(&reply, "CdBd",
 			 "NTLMSSP",
 			 &ntlmssp_command, 
 			 &server_domain_blob,
 			 &chal_flags)) {
-		DEBUG(0, ("Failed to parse the NTLMSSP Challenge\n"));
+		DEBUG(1, ("Failed to parse the NTLMSSP Challenge: (#1)\n"));
+		dump_data(2, reply.data, reply.length);
+
 		return NT_STATUS_INVALID_PARAMETER;
 	}
 	
 	data_blob_free(&server_domain_blob);
 
+	DEBUG(3, ("Got challenge flags:\n"));
+	debug_ntlmssp_flags(chal_flags);
+
 	if (chal_flags & NTLMSSP_NEGOTIATE_UNICODE) {
-		chal_parse_string = "CdUdbddB";
+		if (chal_flags & NTLMSSP_CHAL_TARGET_INFO) {
+			chal_parse_string = "CdUdbddB";
+		} else {
+			chal_parse_string = "CdUdbdd";
+		}
 		auth_gen_string = "CdBBUUUBd";
 		ntlmssp_state->unicode = True;
 		ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_UNICODE;
 		ntlmssp_state->neg_flags &= ~NTLMSSP_NEGOTIATE_OEM;
 	} else if (chal_flags & NTLMSSP_NEGOTIATE_OEM) {
-		chal_parse_string = "CdAdbddB";
+		if (chal_flags & NTLMSSP_CHAL_TARGET_INFO) {
+			chal_parse_string = "CdAdbddB";
+		} else {
+			chal_parse_string = "CdAdbdd";
+		}
 		auth_gen_string = "CdBBAAABd";
 		ntlmssp_state->unicode = False;
 		ntlmssp_state->neg_flags &= ~NTLMSSP_NEGOTIATE_UNICODE;
@@ -473,6 +497,25 @@ static NTSTATUS ntlmssp_client_challenge(struct ntlmssp_client_state *ntlmssp_st
 		return NT_STATUS_INVALID_PARAMETER;
 	}
 
+	if (chal_flags & NTLMSSP_NEGOTIATE_LM_KEY && lp_client_lanman_auth()) {
+		/* server forcing us to use LM */
+		ntlmssp_state->neg_flags |= NTLMSSP_NEGOTIATE_LM_KEY;
+		ntlmssp_state->use_ntlmv2 = False;
+	} else {
+		ntlmssp_state->neg_flags &= ~NTLMSSP_NEGOTIATE_LM_KEY;
+	}
+
+	if (!(chal_flags & NTLMSSP_NEGOTIATE_NTLM2)) {
+		ntlmssp_state->neg_flags &= ~NTLMSSP_NEGOTIATE_NTLM2;
+	}
+
+	if (!(chal_flags & NTLMSSP_NEGOTIATE_128)) {
+		ntlmssp_state->neg_flags &= ~NTLMSSP_NEGOTIATE_128;
+	}
+
+	DEBUG(3, ("NTLMSSP: Set final flags:\n"));
+	debug_ntlmssp_flags(ntlmssp_state->neg_flags);
+
 	if (!msrpc_parse(&reply, chal_parse_string,
 			 "NTLMSSP",
 			 &ntlmssp_command, 
@@ -481,7 +524,8 @@ static NTSTATUS ntlmssp_client_challenge(struct ntlmssp_client_state *ntlmssp_st
 			 &challenge_blob, 8,
 			 &unkn1, &unkn2,
 			 &struct_blob)) {
-		DEBUG(0, ("Failed to parse the NTLMSSP Challenge\n"));
+		DEBUG(1, ("Failed to parse the NTLMSSP Challenge: (#2)\n"));
+		dump_data(2, reply.data, reply.length);
 		return NT_STATUS_INVALID_PARAMETER;
 	}
 
@@ -493,6 +537,11 @@ static NTSTATUS ntlmssp_client_challenge(struct ntlmssp_client_state *ntlmssp_st
 
 	if (ntlmssp_state->use_ntlmv2) {
 
+		if (!struct_blob.length) {
+			/* be lazy, match win2k - we can't do NTLMv2 without it */
+			return NT_STATUS_INVALID_PARAMETER;
+		}
+
 		/* TODO: if the remote server is standalone, then we should replace 'domain'
 		   with the server name as supplied above */
 		
@@ -506,10 +555,12 @@ static NTSTATUS ntlmssp_client_challenge(struct ntlmssp_client_state *ntlmssp_st
 			return NT_STATUS_NO_MEMORY;
 		}
 	} else {
+		uchar lm_hash[16];
 		uchar nt_hash[16];
+		E_deshash(ntlmssp_state->password, lm_hash);
 		E_md4hash(ntlmssp_state->password, nt_hash);
 		
-		/* non encrypted password supplied. Ignore ntpass. */
+		/* lanman auth is insecure, it may be disabled */
 		if (lp_client_lanman_auth()) {
 			lm_response = data_blob(NULL, 24);
 			SMBencrypt(ntlmssp_state->password,challenge_blob.data,
@@ -519,8 +570,15 @@ static NTSTATUS ntlmssp_client_challenge(struct ntlmssp_client_state *ntlmssp_st
 		nt_response = data_blob(NULL, 24);
 		SMBNTencrypt(ntlmssp_state->password,challenge_blob.data,
 			     nt_response.data);
+
 		session_key = data_blob(NULL, 16);
-		SMBsesskeygen_ntv1(nt_hash, NULL, session_key.data);
+		if ((ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_LM_KEY) 
+		      && lp_client_lanman_auth()) {
+			SMBsesskeygen_lmv1(lm_hash, lm_response.data, 
+					   session_key.data);
+		} else {
+			SMBsesskeygen_ntv1(nt_hash, NULL, session_key.data);
+		}
 	}
 	data_blob_free(&struct_blob);
 
@@ -533,7 +591,7 @@ static NTSTATUS ntlmssp_client_challenge(struct ntlmssp_client_state *ntlmssp_st
 		       ntlmssp_state->domain, 
 		       ntlmssp_state->user, 
 		       ntlmssp_state->get_global_myname(), 
-		       datagram_sess_key, 16,
+		       datagram_sess_key, datagram_sess_key_len,
 		       ntlmssp_state->neg_flags)) {
 		
 		data_blob_free(&lm_response);
@@ -575,6 +633,8 @@ NTSTATUS ntlmssp_client_start(NTLMSSP_CLIENT_STATE **ntlmssp_state)
 
 	(*ntlmssp_state)->unicode = True;
 
+	(*ntlmssp_state)->use_ntlmv2 = lp_client_ntlmv2_auth();
+
 	(*ntlmssp_state)->neg_flags = 
 		NTLMSSP_NEGOTIATE_128 |
 		NTLMSSP_NEGOTIATE_NTLM |
@@ -596,6 +656,7 @@ NTSTATUS ntlmssp_client_end(NTLMSSP_CLIENT_STATE **ntlmssp_state)
 		data_blob_free(&(*ntlmssp_state)->lm_resp);
 		data_blob_free(&(*ntlmssp_state)->nt_resp);
 		data_blob_free(&(*ntlmssp_state)->session_key);
+		data_blob_free(&(*ntlmssp_state)->stored_response);
 		talloc_destroy(mem_ctx);
 	}
 
@@ -606,12 +667,18 @@ NTSTATUS ntlmssp_client_end(NTLMSSP_CLIENT_STATE **ntlmssp_state)
 NTSTATUS ntlmssp_client_update(NTLMSSP_CLIENT_STATE *ntlmssp_state, 
 			       DATA_BLOB reply, DATA_BLOB *next_request) 
 {
+	NTSTATUS nt_status = NT_STATUS_INVALID_PARAMETER;
 	uint32 ntlmssp_command;
 	*next_request = data_blob(NULL, 0);
 
 	if (!reply.length) {
-		return ntlmssp_client_initial(ntlmssp_state, reply, next_request);
-	} 		
+		/* If there is a cached reply, use it - otherwise this is the first packet */
+		if (!ntlmssp_state->stored_response.length) {
+			return ntlmssp_client_initial(ntlmssp_state, reply, next_request);
+		}
+		
+		reply = ntlmssp_state->stored_response;
+	}
 
 	if (!msrpc_parse(&reply, "Cd",
 			 "NTLMSSP",
@@ -620,9 +687,12 @@ NTSTATUS ntlmssp_client_update(NTLMSSP_CLIENT_STATE *ntlmssp_state,
 	}
 
 	if (ntlmssp_command == NTLMSSP_CHALLENGE) {
-		return ntlmssp_client_challenge(ntlmssp_state, reply, next_request);
+		nt_status = ntlmssp_client_challenge(ntlmssp_state, reply, next_request);
 	}
-	return NT_STATUS_INVALID_PARAMETER;
+	if (ntlmssp_state->stored_response.length) {
+		data_blob_free(&ntlmssp_state->stored_response);
+	}
+	return nt_status;
 }
 
 NTSTATUS ntlmssp_set_username(NTLMSSP_CLIENT_STATE *ntlmssp_state, const char *user) 
@@ -651,3 +721,16 @@ NTSTATUS ntlmssp_set_domain(NTLMSSP_CLIENT_STATE *ntlmssp_state, const char *dom
 	}
 	return NT_STATUS_OK;
 }
+
+/**
+ *  Store a DATA_BLOB containing an NTLMSSP response, for use later.
+ *  This 'keeps' the data blob - the caller must *not* free it.
+ */
+
+NTSTATUS ntlmssp_client_store_response(NTLMSSP_CLIENT_STATE *ntlmssp_state,
+				       DATA_BLOB response) 
+{
+	data_blob_free(&ntlmssp_state->stored_response);
+	ntlmssp_state->stored_response = response;
+	return NT_STATUS_OK;
+}