SMB signing updates - this gets NTLMSSP signing workin to the point where I

just need to get the verifiction code working - we get back a signiture from
the server, and just can't verify it yet.

This also brings the short-packet checks into common code, and breaks the
connection if the server sends a signed reply, on an established connection,
that fails the test.

This breaks our read/write code at the moment, as we need to keep a list
of outstanding packets.

(signing is not enabled by default, unless the server demands it)

Not for 3.0 till I fix the outstanding packet list.

Andrew Barlett
(This used to be commit 808d1fcf20153970d587cb631a08607beb09703a)

4 files changed, 39 insertions, 16 deletions

diff --git a/source3/include/smb.h b/source3/include/smb.h
index 4f37c38413..3bb6bf9237 100644
--- a/source3/include/smb.h
+++ b/source3/include/smb.h
@@ -78,6 +78,10 @@ typedef int BOOL;
 #define READ_EOF 2
 #define READ_ERROR 3
 
+/* This error code can go into the client smb_rw_error. */
+#define WRITE_ERROR 4
+#define READ_BAD_SIG 5
+
 #define DIR_STRUCT_SIZE 43
 
 /* these define the attribute byte as seen by DOS */
@@ -161,9 +165,6 @@ typedef uint16 smb_ucs2_t;
 typedef smb_ucs2_t wpstring[PSTRING_LEN];
 typedef smb_ucs2_t wfstring[FSTRING_LEN];
 
-/* This error code can go into the client smb_rw_error. */
-#define WRITE_ERROR 4
-
 #ifdef WORDS_BIGENDIAN
 #define UCS2_SHIFT 8
 #else
diff --git a/source3/libsmb/clientgen.c b/source3/libsmb/clientgen.c
index 0da9a8932f..fe9453e6f2 100644
--- a/source3/libsmb/clientgen.c
+++ b/source3/libsmb/clientgen.c
@@ -118,7 +118,10 @@ BOOL cli_receive_smb(struct cli_state *cli)
 	}
 
 	if (!cli_check_sign_mac(cli)) {
-		DEBUG(0, ("SMB Signiture verification failed on incoming packet!\n"));
+		DEBUG(0, ("SMB Signature verification failed on incoming packet!\n"));
+		cli->smb_rw_error = READ_BAD_SIG;
+		close(cli->fd);
+		cli->fd = -1;
 		return False;
 	};
 	return True;
diff --git a/source3/libsmb/ntlmssp_sign.c b/source3/libsmb/ntlmssp_sign.c
index 8f6bd0c691..5426263fb9 100644
--- a/source3/libsmb/ntlmssp_sign.c
+++ b/source3/libsmb/ntlmssp_sign.c
@@ -92,8 +92,14 @@ static void calc_ntlmv2_hash(unsigned char hash[16], char digest[16],
 	calc_hash(hash, digest, 16);
 }
 
+enum ntlmssp_direction {
+	NTLMSSP_SEND,
+	NTLMSSP_RECEIVE
+};
+
 static NTSTATUS ntlmssp_make_packet_signiture(NTLMSSP_CLIENT_STATE *ntlmssp_state,
 					      const uchar *data, size_t length, 
+					      enum ntlmssp_direction direction,
 					      DATA_BLOB *sig) 
 {
 	if (ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_NTLM2) {
@@ -110,8 +116,14 @@ static NTSTATUS ntlmssp_make_packet_signiture(NTLMSSP_CLIENT_STATE *ntlmssp_stat
 		if (!msrpc_gen(sig, "Bd", digest, sizeof(digest), ntlmssp_state->ntlmssp_seq_num)) {
 			return NT_STATUS_NO_MEMORY;
 		}
-	       
-		NTLMSSPcalc_ap(ntlmssp_state->cli_seal_hash,  sig->data, sig->length);
+		switch (direction) {
+		case NTLMSSP_SEND:
+			NTLMSSPcalc_ap(ntlmssp_state->cli_sign_hash,  sig->data, sig->length);
+			break;
+		case NTLMSSP_RECEIVE:
+			NTLMSSPcalc_ap(ntlmssp_state->cli_sign_hash,  sig->data, sig->length);
+			break;
+		}
 	} else {
 		uint32 crc;
 		crc = crc32_calc_buffer(data, length);
@@ -129,7 +141,7 @@ NTSTATUS ntlmssp_client_sign_packet(NTLMSSP_CLIENT_STATE *ntlmssp_state,
 					   DATA_BLOB *sig) 
 {
 	ntlmssp_state->ntlmssp_seq_num++;
-	return ntlmssp_make_packet_signiture(ntlmssp_state, data, length, sig);
+	return ntlmssp_make_packet_signiture(ntlmssp_state, data, length, NTLMSSP_SEND, sig);
 }
 
 /**
@@ -151,7 +163,7 @@ NTSTATUS ntlmssp_client_check_packet(NTLMSSP_CLIENT_STATE *ntlmssp_state,
 	}
 
 	nt_status = ntlmssp_make_packet_signiture(ntlmssp_state, data, 
-						  length, &local_sig);
+						  length, NTLMSSP_RECEIVE, &local_sig);
 	
 	if (!NT_STATUS_IS_OK(nt_status)) {
 		DEBUG(0, ("NTLMSSP packet check failed with %s\n", nt_errstr(nt_status)));
@@ -161,6 +173,12 @@ NTSTATUS ntlmssp_client_check_packet(NTLMSSP_CLIENT_STATE *ntlmssp_state,
 	if (memcmp(sig->data, local_sig.data, MIN(sig->length, local_sig.length)) == 0) {
 		return NT_STATUS_OK;
 	} else {
+		DEBUG(5, ("BAD SIG: wanted signature of\n"));
+		dump_data(5, local_sig.data, local_sig.length);
+		
+		DEBUG(5, ("BAD SIG: got signature of\n"));
+		dump_data(5, sig->data, sig->length);
+
 		DEBUG(0, ("NTLMSSP packet check failed due to invalid signiture!\n"));
 		return NT_STATUS_ACCESS_DENIED;
 	}
diff --git a/source3/libsmb/smb_signing.c b/source3/libsmb/smb_signing.c
index 9bbf7ef91c..42c4d5574d 100644
--- a/source3/libsmb/smb_signing.c
+++ b/source3/libsmb/smb_signing.c
@@ -160,11 +160,6 @@ static BOOL cli_simple_check_incoming_message(struct cli_state *cli)
 	SIVAL(sequence_buf, 0, data->reply_seq_num);
 	SIVAL(sequence_buf, 4, 0);
 
-	if (smb_len(cli->inbuf) < (offset_end_of_sig - 4)) {
-		DEBUG(1, ("Can't check signature on short packet! smb_len = %u\n", smb_len(cli->inbuf)));
-		return False;
-	}
-
 	/* get a copy of the server-sent mac */
 	memcpy(server_sent_mac, &cli->inbuf[smb_ss_field], sizeof(server_sent_mac));
 	
@@ -275,7 +270,7 @@ static BOOL cli_ntlmssp_check_incoming_message(struct cli_state *cli)
 {
 	BOOL good;
 	NTSTATUS nt_status;
-	DATA_BLOB sig = data_blob(&cli->outbuf[smb_ss_field], 8);
+	DATA_BLOB sig = data_blob(&cli->inbuf[smb_ss_field], 8);
 
 	NTLMSSP_CLIENT_STATE *ntlmssp_state = cli->sign_info.signing_context;
 
@@ -460,8 +455,14 @@ void cli_caclulate_sign_mac(struct cli_state *cli)
 BOOL cli_check_sign_mac(struct cli_state *cli) 
 {
 	BOOL good;
-	good = cli->sign_info.check_incoming_message(cli);
-	
+
+	if (smb_len(cli->inbuf) < (smb_ss_field + 8 - 4)) {
+		DEBUG(1, ("Can't check signature on short packet! smb_len = %u\n", smb_len(cli->inbuf)));
+		good = False;
+	} else {
+		good = cli->sign_info.check_incoming_message(cli);
+	}
+
 	if (!good) {
 		if (cli->sign_info.doing_signing) {
 			return False;