s3:ntlmssp Use a TALLOC_CTX for ntlmssp_sign_packet() and ntlmssp_seal_packet()

This ensures the results can't be easily left to leak.

Andrew Bartlett

Signed-off-by: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Günther Deschner <gd@samba.org>

7 files changed, 67 insertions, 26 deletions

diff --git a/source3/auth/auth_ntlmssp.c b/source3/auth/auth_ntlmssp.c
index b455bc505f..e0e0003f9d 100644
--- a/source3/auth/auth_ntlmssp.c
+++ b/source3/auth/auth_ntlmssp.c
@@ -31,11 +31,12 @@ struct auth_ntlmssp_state {
 };
 
 NTSTATUS auth_ntlmssp_sign_packet(struct auth_ntlmssp_state *auth_ntlmssp_state,
+				  TALLOC_CTX *sig_mem_ctx,
 				  const uint8_t *data, size_t length,
 				  const uint8_t *whole_pdu, size_t pdu_length,
 				  DATA_BLOB *sig)
 {
-	return ntlmssp_sign_packet(auth_ntlmssp_state->ntlmssp_state, data, length, whole_pdu, pdu_length, sig);
+	return ntlmssp_sign_packet(auth_ntlmssp_state->ntlmssp_state, sig_mem_ctx, data, length, whole_pdu, pdu_length, sig);
 }
 
 NTSTATUS auth_ntlmssp_check_packet(struct auth_ntlmssp_state *auth_ntlmssp_state,
@@ -47,11 +48,12 @@ NTSTATUS auth_ntlmssp_check_packet(struct auth_ntlmssp_state *auth_ntlmssp_state
 }
 
 NTSTATUS auth_ntlmssp_seal_packet(struct auth_ntlmssp_state *auth_ntlmssp_state,
+				  TALLOC_CTX *sig_mem_ctx,
 				  uint8_t *data, size_t length,
 				  const uint8_t *whole_pdu, size_t pdu_length,
 				  DATA_BLOB *sig)
 {
-	return ntlmssp_seal_packet(auth_ntlmssp_state->ntlmssp_state, data, length, whole_pdu, pdu_length, sig);
+	return ntlmssp_seal_packet(auth_ntlmssp_state->ntlmssp_state, sig_mem_ctx, data, length, whole_pdu, pdu_length, sig);
 }
 
 NTSTATUS auth_ntlmssp_unseal_packet(struct auth_ntlmssp_state *auth_ntlmssp_state,
diff --git a/source3/include/proto.h b/source3/include/proto.h
index d479edbc9f..472e1793ca 100644
--- a/source3/include/proto.h
+++ b/source3/include/proto.h
@@ -67,6 +67,7 @@ void auth_ntlmssp_end(struct auth_ntlmssp_state **auth_ntlmssp_state);
 NTSTATUS auth_ntlmssp_update(struct auth_ntlmssp_state *auth_ntlmssp_state,
 			     const DATA_BLOB request, DATA_BLOB *reply) ;
 NTSTATUS auth_ntlmssp_sign_packet(struct auth_ntlmssp_state *auth_ntlmssp_state,
+				  TALLOC_CTX *sig_mem_ctx,
 				  const uint8_t *data, size_t length,
 				  const uint8_t *whole_pdu, size_t pdu_length,
 				  DATA_BLOB *sig);
@@ -75,6 +76,7 @@ NTSTATUS auth_ntlmssp_check_packet(struct auth_ntlmssp_state *auth_ntlmssp_state
 				   const uint8_t *whole_pdu, size_t pdu_length,
 				   const DATA_BLOB *sig) ;
 NTSTATUS auth_ntlmssp_seal_packet(struct auth_ntlmssp_state *auth_ntlmssp_state,
+				  TALLOC_CTX *sig_mem_ctx,
 				  uint8_t *data, size_t length,
 				  const uint8_t *whole_pdu, size_t pdu_length,
 				  DATA_BLOB *sig);
@@ -3162,6 +3164,7 @@ NTSTATUS ntlmssp_client_start(TALLOC_CTX *mem_ctx,
 /* The following definitions come from libsmb/ntlmssp_sign.c  */
 
 NTSTATUS ntlmssp_sign_packet(struct ntlmssp_state *ntlmssp_state,
+			     TALLOC_CTX *sig_mem_ctx,
 			     const uint8_t *data, size_t length,
 			     const uint8_t *whole_pdu, size_t pdu_length,
 			     DATA_BLOB *sig);
@@ -3170,6 +3173,7 @@ NTSTATUS ntlmssp_check_packet(struct ntlmssp_state *ntlmssp_state,
 			      const uint8_t *whole_pdu, size_t pdu_length,
 			      const DATA_BLOB *sig) ;
 NTSTATUS ntlmssp_seal_packet(struct ntlmssp_state *ntlmssp_state,
+			     TALLOC_CTX *sig_mem_ctx,
 			     uint8_t *data, size_t length,
 			     const uint8_t *whole_pdu, size_t pdu_length,
 			     DATA_BLOB *sig);
diff --git a/source3/libads/sasl.c b/source3/libads/sasl.c
index 8f7f6c11df..04b9a71d76 100644
--- a/source3/libads/sasl.c
+++ b/source3/libads/sasl.c
@@ -30,19 +30,23 @@ static ADS_STATUS ads_sasl_ntlmssp_wrap(ADS_STRUCT *ads, uint8 *buf, uint32 len)
 	ADS_STATUS status;
 	NTSTATUS nt_status;
 	DATA_BLOB sig;
+	TALLOC_CTX *frame;
 	uint8 *dptr = ads->ldap.out.buf + (4 + NTLMSSP_SIG_SIZE);
 
+	frame = talloc_stackframe();
 	/* copy the data to the right location */
 	memcpy(dptr, buf, len);
 
 	/* create the signature and may encrypt the data */
 	if (ntlmssp_state->neg_flags & NTLMSSP_NEGOTIATE_SEAL) {
 		nt_status = ntlmssp_seal_packet(ntlmssp_state,
+						frame,
 						dptr, len,
 						dptr, len,
 						&sig);
 	} else {
 		nt_status = ntlmssp_sign_packet(ntlmssp_state,
+						frame,
 						dptr, len,
 						dptr, len,
 						&sig);
@@ -54,7 +58,7 @@ static ADS_STATUS ads_sasl_ntlmssp_wrap(ADS_STRUCT *ads, uint8 *buf, uint32 len)
 	memcpy(ads->ldap.out.buf + 4,
 	       sig.data, NTLMSSP_SIG_SIZE);
 
-	data_blob_free(&sig);
+	TALLOC_FREE(frame);
 
 	/* set how many bytes must be written to the underlying socket */
 	ads->ldap.out.left = 4 + NTLMSSP_SIG_SIZE + len;
diff --git a/source3/libsmb/ntlmssp_sign.c b/source3/libsmb/ntlmssp_sign.c
index 20730928cc..8ae244b70b 100644
--- a/source3/libsmb/ntlmssp_sign.c
+++ b/source3/libsmb/ntlmssp_sign.c
@@ -81,6 +81,7 @@ union ntlmssp_crypt_state {
 };
 
 static NTSTATUS ntlmssp_make_packet_signature(struct ntlmssp_state *ntlmssp_state,
+					      TALLOC_CTX *sig_mem_ctx,
 					      const uint8_t *data, size_t length,
 					      const uint8_t *whole_pdu, size_t pdu_length,
 					      enum ntlmssp_direction direction,
@@ -91,7 +92,7 @@ static NTSTATUS ntlmssp_make_packet_signature(struct ntlmssp_state *ntlmssp_stat
 		uint8_t digest[16];
 		uint8_t seq_num[4];
 
-		*sig = data_blob(NULL, NTLMSSP_SIG_SIZE);
+		*sig = data_blob_talloc(sig_mem_ctx, NULL, NTLMSSP_SIG_SIZE);
 		if (!sig->data) {
 			return NT_STATUS_NO_MEMORY;
 		}
@@ -151,7 +152,7 @@ static NTSTATUS ntlmssp_make_packet_signature(struct ntlmssp_state *ntlmssp_stat
 
 		crc = crc32_calc_buffer(data, length);
 
-		ok = msrpc_gen(ntlmssp_state,
+		ok = msrpc_gen(sig_mem_ctx,
 			       sig, "dddd",
 			       NTLMSSP_SIGN_VERSION, 0, crc,
 			       ntlmssp_state->crypt->ntlm.seq_num);
@@ -170,6 +171,7 @@ static NTSTATUS ntlmssp_make_packet_signature(struct ntlmssp_state *ntlmssp_stat
 }
 
 NTSTATUS ntlmssp_sign_packet(struct ntlmssp_state *ntlmssp_state,
+			     TALLOC_CTX *sig_mem_ctx,
 			     const uint8_t *data, size_t length,
 			     const uint8_t *whole_pdu, size_t pdu_length,
 			     DATA_BLOB *sig)
@@ -187,6 +189,7 @@ NTSTATUS ntlmssp_sign_packet(struct ntlmssp_state *ntlmssp_state,
 	}
 
 	nt_status = ntlmssp_make_packet_signature(ntlmssp_state,
+						  sig_mem_ctx,
 						  data, length,
 						  whole_pdu, pdu_length,
 						  NTLMSSP_SEND, sig, true);
@@ -207,6 +210,7 @@ NTSTATUS ntlmssp_check_packet(struct ntlmssp_state *ntlmssp_state,
 {
 	DATA_BLOB local_sig;
 	NTSTATUS nt_status;
+	TALLOC_CTX *tmp_ctx;
 
 	if (!ntlmssp_state->session_key.length) {
 		DEBUG(3, ("NO session key, cannot check packet signature\n"));
@@ -218,7 +222,13 @@ NTSTATUS ntlmssp_check_packet(struct ntlmssp_state *ntlmssp_state,
 			  (unsigned long)sig->length));
 	}
 
+	tmp_ctx = talloc_new(ntlmssp_state);
+	if (!tmp_ctx) {
+		return NT_STATUS_NO_MEMORY;
+	}
+
 	nt_status = ntlmssp_make_packet_signature(ntlmssp_state,
+						  tmp_ctx,
 						  data, length,
 						  whole_pdu, pdu_length,
 						  NTLMSSP_RECEIVE,
@@ -227,7 +237,7 @@ NTSTATUS ntlmssp_check_packet(struct ntlmssp_state *ntlmssp_state,
 	if (!NT_STATUS_IS_OK(nt_status)) {
 		DEBUG(0,("NTLMSSP packet sig creation failed with %s\n",
 			 nt_errstr(nt_status)));
-		data_blob_free(&local_sig);
+		talloc_free(tmp_ctx);
 		return nt_status;
 	}
 
@@ -241,7 +251,7 @@ NTSTATUS ntlmssp_check_packet(struct ntlmssp_state *ntlmssp_state,
 			dump_data(5, sig->data, sig->length);
 
 			DEBUG(0, ("NTLMSSP NTLM2 packet check failed due to invalid signature!\n"));
-			data_blob_free(&local_sig);
+			talloc_free(tmp_ctx);
 			return NT_STATUS_ACCESS_DENIED;
 		}
 	} else {
@@ -254,14 +264,14 @@ NTSTATUS ntlmssp_check_packet(struct ntlmssp_state *ntlmssp_state,
 			dump_data(5, sig->data, sig->length);
 
 			DEBUG(0, ("NTLMSSP NTLM1 packet check failed due to invalid signature!\n"));
-			data_blob_free(&local_sig);
+			talloc_free(tmp_ctx);
 			return NT_STATUS_ACCESS_DENIED;
 		}
 	}
 	dump_data_pw("checked ntlmssp signature\n", sig->data, sig->length);
 	DEBUG(10,("ntlmssp_check_packet: NTLMSSP signature OK !\n"));
 
-	data_blob_free(&local_sig);
+	talloc_free(tmp_ctx);
 	return NT_STATUS_OK;
 }
 
@@ -271,6 +281,7 @@ NTSTATUS ntlmssp_check_packet(struct ntlmssp_state *ntlmssp_state,
  */
 
 NTSTATUS ntlmssp_seal_packet(struct ntlmssp_state *ntlmssp_state,
+			     TALLOC_CTX *sig_mem_ctx,
 			     uint8_t *data, size_t length,
 			     const uint8_t *whole_pdu, size_t pdu_length,
 			     DATA_BLOB *sig)
@@ -297,6 +308,7 @@ NTSTATUS ntlmssp_seal_packet(struct ntlmssp_state *ntlmssp_state,
 		 * updated with each iteration
 		 */
 		nt_status = ntlmssp_make_packet_signature(ntlmssp_state,
+							  sig_mem_ctx,
 							  data, length,
 							  whole_pdu, pdu_length,
 							  NTLMSSP_SEND,
@@ -317,7 +329,7 @@ NTSTATUS ntlmssp_seal_packet(struct ntlmssp_state *ntlmssp_state,
 
 		crc = crc32_calc_buffer(data, length);
 
-		ok = msrpc_gen(ntlmssp_state,
+		ok = msrpc_gen(sig_mem_ctx,
 			       sig, "dddd",
 			       NTLMSSP_SIGN_VERSION, 0, crc,
 			       ntlmssp_state->crypt->ntlm.seq_num);
@@ -362,6 +374,7 @@ NTSTATUS ntlmssp_unseal_packet(struct ntlmssp_state *ntlmssp_state,
 			       const uint8_t *whole_pdu, size_t pdu_length,
 			       const DATA_BLOB *sig)
 {
+	NTSTATUS status;
 	if (!ntlmssp_state->session_key.length) {
 		DEBUG(3, ("NO session key, cannot unseal packet\n"));
 		return NT_STATUS_NO_USER_SESSION_KEY;
@@ -380,7 +393,16 @@ NTSTATUS ntlmssp_unseal_packet(struct ntlmssp_state *ntlmssp_state,
 				   data, length);
 		dump_data_pw("ntlmv1 clear data\n", data, length);
 	}
-	return ntlmssp_check_packet(ntlmssp_state, data, length, whole_pdu, pdu_length, sig);
+	status = ntlmssp_check_packet(ntlmssp_state,
+				      data, length,
+				      whole_pdu, pdu_length,
+				      sig);
+
+	if (!NT_STATUS_IS_OK(status)) {
+		DEBUG(1,("NTLMSSP packet check for unseal failed due to invalid signature on %llu bytes of input:\n",
+			 (unsigned long long)length));
+	}
+	return status;
 }
 
 /**
diff --git a/source3/libsmb/smb_seal.c b/source3/libsmb/smb_seal.c
index cff237bc8b..92d7fef651 100644
--- a/source3/libsmb/smb_seal.c
+++ b/source3/libsmb/smb_seal.c
@@ -117,13 +117,14 @@ NTSTATUS common_ntlm_encrypt_buffer(struct ntlmssp_state *ntlmssp_state,
 	char *buf_out;
 	size_t data_len = smb_len(buf) - 4; /* Ignore the 0xFF SMB bytes. */
 	DATA_BLOB sig;
-
+	TALLOC_CTX *frame;
 	*ppbuf_out = NULL;
 
 	if (data_len == 0) {
 		return NT_STATUS_BUFFER_TOO_SMALL;
 	}
 
+	frame = talloc_stackframe();
 	/* 
 	 * We know smb_len can't return a value > 128k, so no int overflow
 	 * check needed.
@@ -140,6 +141,7 @@ NTSTATUS common_ntlm_encrypt_buffer(struct ntlmssp_state *ntlmssp_state,
 	ZERO_STRUCT(sig);
 
 	status = ntlmssp_seal_packet(ntlmssp_state,
+				     frame,
 		(unsigned char *)buf_out + 8 + NTLMSSP_SIG_SIZE, /* 4 byte len + 0xFF 'S' <enc> <ctx> */
 		data_len,
 		(unsigned char *)buf_out + 8 + NTLMSSP_SIG_SIZE,
@@ -147,14 +149,14 @@ NTSTATUS common_ntlm_encrypt_buffer(struct ntlmssp_state *ntlmssp_state,
 		&sig);
 
 	if (!NT_STATUS_IS_OK(status)) {
-		data_blob_free(&sig);
+		talloc_free(frame);
 		SAFE_FREE(buf_out);
 		return status;
 	}
 
 	/* First 16 data bytes are signature for SSPI compatibility. */
 	memcpy(buf_out + 8, sig.data, NTLMSSP_SIG_SIZE);
-	data_blob_free(&sig);
+	talloc_free(frame);
 	*ppbuf_out = buf_out;
 	return NT_STATUS_OK;
 }
diff --git a/source3/rpc_client/cli_pipe.c b/source3/rpc_client/cli_pipe.c
index 0cd4d60b5d..e248133de3 100644
--- a/source3/rpc_client/cli_pipe.c
+++ b/source3/rpc_client/cli_pipe.c
@@ -1976,11 +1976,14 @@ static NTSTATUS add_ntlmssp_auth_footer(struct rpc_pipe_client *cli,
 	NTSTATUS status;
 	DATA_BLOB auth_blob = data_blob_null;
 	uint16 data_and_pad_len = prs_offset(outgoing_pdu) - RPC_HEADER_LEN - RPC_HDR_RESP_LEN;
+	TALLOC_CTX *frame;
 
 	if (!cli->auth->a_u.ntlmssp_state) {
 		return NT_STATUS_INVALID_PARAMETER;
 	}
 
+	frame = talloc_stackframe();
+
 	/* Init and marshall the auth header. */
 	init_rpc_hdr_auth(&auth_info,
 			map_pipe_auth_type_to_rpc_auth_type(
@@ -1991,7 +1994,7 @@ static NTSTATUS add_ntlmssp_auth_footer(struct rpc_pipe_client *cli,
 
 	if(!smb_io_rpc_hdr_auth("hdr_auth", &auth_info, outgoing_pdu, 0)) {
 		DEBUG(0,("add_ntlmssp_auth_footer: failed to marshall RPC_HDR_AUTH.\n"));
-		data_blob_free(&auth_blob);
+		talloc_free(frame);
 		return NT_STATUS_NO_MEMORY;
 	}
 
@@ -1999,13 +2002,14 @@ static NTSTATUS add_ntlmssp_auth_footer(struct rpc_pipe_client *cli,
 		case DCERPC_AUTH_LEVEL_PRIVACY:
 			/* Data portion is encrypted. */
 			status = ntlmssp_seal_packet(cli->auth->a_u.ntlmssp_state,
+						     frame,
 					(unsigned char *)prs_data_p(outgoing_pdu) + RPC_HEADER_LEN + RPC_HDR_RESP_LEN,
 					data_and_pad_len,
 					(unsigned char *)prs_data_p(outgoing_pdu),
 					(size_t)prs_offset(outgoing_pdu),
 					&auth_blob);
 			if (!NT_STATUS_IS_OK(status)) {
-				data_blob_free(&auth_blob);
+				talloc_free(frame);
 				return status;
 			}
 			break;
@@ -2013,13 +2017,14 @@ static NTSTATUS add_ntlmssp_auth_footer(struct rpc_pipe_client *cli,
 		case DCERPC_AUTH_LEVEL_INTEGRITY:
 			/* Data is signed. */
 			status = ntlmssp_sign_packet(cli->auth->a_u.ntlmssp_state,
+						     frame,
 					(unsigned char *)prs_data_p(outgoing_pdu) + RPC_HEADER_LEN + RPC_HDR_RESP_LEN,
 					data_and_pad_len,
 					(unsigned char *)prs_data_p(outgoing_pdu),
 					(size_t)prs_offset(outgoing_pdu),
 					&auth_blob);
 			if (!NT_STATUS_IS_OK(status)) {
-				data_blob_free(&auth_blob);
+				talloc_free(frame);
 				return status;
 			}
 			break;
@@ -2036,11 +2041,11 @@ static NTSTATUS add_ntlmssp_auth_footer(struct rpc_pipe_client *cli,
 	if (!prs_copy_data_in(outgoing_pdu, (const char *)auth_blob.data, NTLMSSP_SIG_SIZE)) {
 		DEBUG(0,("add_ntlmssp_auth_footer: failed to add %u bytes auth blob.\n",
 			(unsigned int)NTLMSSP_SIG_SIZE));
-		data_blob_free(&auth_blob);
+		talloc_free(frame);
 		return NT_STATUS_NO_MEMORY;
 	}
 
-	data_blob_free(&auth_blob);
+	talloc_free(frame);
 	return NT_STATUS_OK;
 }
 
diff --git a/source3/rpc_server/srv_pipe.c b/source3/rpc_server/srv_pipe.c
index ce087a4e03..50914acfbd 100644
--- a/source3/rpc_server/srv_pipe.c
+++ b/source3/rpc_server/srv_pipe.c
@@ -68,6 +68,7 @@ static bool create_next_pdu_ntlmssp(pipes_struct *p)
 	RPC_HDR_AUTH auth_info;
 	uint8 auth_type, auth_level;
 	struct auth_ntlmssp_state *a = p->auth.a_u.auth_ntlmssp_state;
+	TALLOC_CTX *frame;
 
 	/*
 	 * If we're in the fault state, keep returning fault PDU's until
@@ -222,11 +223,12 @@ static bool create_next_pdu_ntlmssp(pipes_struct *p)
 
 	/* Generate the sign blob. */
 
+	frame = talloc_stackframe();
 	switch (p->auth.auth_level) {
 		case DCERPC_AUTH_LEVEL_PRIVACY:
 			/* Data portion is encrypted. */
 			status = auth_ntlmssp_seal_packet(
-				a,
+				a, frame,
 				(uint8_t *)prs_data_p(&p->out_data.frag)
 				+ RPC_HEADER_LEN + RPC_HDR_RESP_LEN,
 				data_len + ss_padding_len,
@@ -234,7 +236,7 @@ static bool create_next_pdu_ntlmssp(pipes_struct *p)
 				(size_t)prs_offset(&p->out_data.frag),
 				&auth_blob);
 			if (!NT_STATUS_IS_OK(status)) {
-				data_blob_free(&auth_blob);
+				talloc_free(frame);
 				prs_mem_free(&p->out_data.frag);
 				return False;
 			}
@@ -242,7 +244,7 @@ static bool create_next_pdu_ntlmssp(pipes_struct *p)
 		case DCERPC_AUTH_LEVEL_INTEGRITY:
 			/* Data is signed. */
 			status = auth_ntlmssp_sign_packet(
-				a,
+				a, frame,
 				(unsigned char *)prs_data_p(&p->out_data.frag)
 				+ RPC_HEADER_LEN + RPC_HDR_RESP_LEN,
 				data_len + ss_padding_len,
@@ -250,12 +252,13 @@ static bool create_next_pdu_ntlmssp(pipes_struct *p)
 				(size_t)prs_offset(&p->out_data.frag),
 				&auth_blob);
 			if (!NT_STATUS_IS_OK(status)) {
-				data_blob_free(&auth_blob);
+				talloc_free(frame);
 				prs_mem_free(&p->out_data.frag);
 				return False;
 			}
 			break;
 		default:
+			talloc_free(frame);
 			prs_mem_free(&p->out_data.frag);
 			return False;
 	}
@@ -265,12 +268,11 @@ static bool create_next_pdu_ntlmssp(pipes_struct *p)
 			      NTLMSSP_SIG_SIZE)) {
 		DEBUG(0,("create_next_pdu_ntlmssp: failed to add %u bytes auth blob.\n",
 				(unsigned int)NTLMSSP_SIG_SIZE));
-		data_blob_free(&auth_blob);
+		talloc_free(frame);
 		prs_mem_free(&p->out_data.frag);
 		return False;
 	}
-
-	data_blob_free(&auth_blob);
+	talloc_free(frame);
 
 	/*
 	 * Setup the counts for this PDU.