Adding upstream version 2:4.17.12+dfsg.upstream/2%4.17.12+dfsgupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1140 insertions, 0 deletions

diff --git a/librpc/rpc/dcerpc_util.c b/librpc/rpc/dcerpc_util.c
new file mode 100644
index 0000000..e3c81b6
--- /dev/null
+++ b/librpc/rpc/dcerpc_util.c
@@ -0,0 +1,1140 @@
+/*
+   Unix SMB/CIFS implementation.
+   raw dcerpc operations
+
+   Copyright (C) Andrew Tridgell 2003-2005
+   Copyright (C) Jelmer Vernooij 2004-2005
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.
+*/
+
+#include "includes.h"
+#include "system/network.h"
+#include <tevent.h>
+#include "lib/tsocket/tsocket.h"
+#include "lib/util/tevent_ntstatus.h"
+#include "librpc/rpc/dcerpc.h"
+#include "librpc/rpc/dcerpc_util.h"
+#include "librpc/gen_ndr/ndr_dcerpc.h"
+#include "rpc_common.h"
+#include "lib/util/bitmap.h"
+
+#undef strncasecmp
+
+/* we need to be able to get/set the fragment length without doing a full
+   decode */
+void dcerpc_set_frag_length(DATA_BLOB *blob, uint16_t v)
+{
+	SMB_ASSERT(blob->length >= DCERPC_NCACN_PAYLOAD_OFFSET);
+
+	if (CVAL(blob->data,DCERPC_DREP_OFFSET) & DCERPC_DREP_LE) {
+		SSVAL(blob->data, DCERPC_FRAG_LEN_OFFSET, v);
+	} else {
+		RSSVAL(blob->data, DCERPC_FRAG_LEN_OFFSET, v);
+	}
+}
+
+uint16_t dcerpc_get_frag_length(const DATA_BLOB *blob)
+{
+	SMB_ASSERT(blob->length >= DCERPC_NCACN_PAYLOAD_OFFSET);
+
+	if (CVAL(blob->data,DCERPC_DREP_OFFSET) & DCERPC_DREP_LE) {
+		return SVAL(blob->data, DCERPC_FRAG_LEN_OFFSET);
+	} else {
+		return RSVAL(blob->data, DCERPC_FRAG_LEN_OFFSET);
+	}
+}
+
+void dcerpc_set_auth_length(DATA_BLOB *blob, uint16_t v)
+{
+	SMB_ASSERT(blob->length >= DCERPC_NCACN_PAYLOAD_OFFSET);
+
+	if (CVAL(blob->data,DCERPC_DREP_OFFSET) & DCERPC_DREP_LE) {
+		SSVAL(blob->data, DCERPC_AUTH_LEN_OFFSET, v);
+	} else {
+		RSSVAL(blob->data, DCERPC_AUTH_LEN_OFFSET, v);
+	}
+}
+
+uint16_t dcerpc_get_auth_length(const DATA_BLOB *blob)
+{
+	SMB_ASSERT(blob->length >= DCERPC_NCACN_PAYLOAD_OFFSET);
+
+	if (CVAL(blob->data,DCERPC_DREP_OFFSET) & DCERPC_DREP_LE) {
+		return SVAL(blob->data, DCERPC_AUTH_LEN_OFFSET);
+	} else {
+		return RSVAL(blob->data, DCERPC_AUTH_LEN_OFFSET);
+	}
+}
+
+uint8_t dcerpc_get_endian_flag(DATA_BLOB *blob)
+{
+	SMB_ASSERT(blob->length >= DCERPC_NCACN_PAYLOAD_OFFSET);
+
+	return blob->data[DCERPC_DREP_OFFSET];
+}
+
+static uint16_t dcerpc_get_auth_context_offset(const DATA_BLOB *blob)
+{
+	uint16_t frag_len = dcerpc_get_frag_length(blob);
+	uint16_t auth_len = dcerpc_get_auth_length(blob);
+	uint16_t min_offset;
+	uint16_t offset;
+
+	if (auth_len == 0) {
+		return 0;
+	}
+
+	if (frag_len > blob->length) {
+		return 0;
+	}
+
+	if (auth_len > frag_len) {
+		return 0;
+	}
+
+	min_offset = DCERPC_NCACN_PAYLOAD_OFFSET + DCERPC_AUTH_TRAILER_LENGTH;
+	offset = frag_len - auth_len;
+	if (offset < min_offset) {
+		return 0;
+	}
+	offset -= DCERPC_AUTH_TRAILER_LENGTH;
+
+	return offset;
+}
+
+uint8_t dcerpc_get_auth_type(const DATA_BLOB *blob)
+{
+	uint16_t offset;
+
+	offset = dcerpc_get_auth_context_offset(blob);
+	if (offset == 0) {
+		return 0;
+	}
+
+	/*
+	 * auth_typw is in the 1st byte
+	 * of the auth trailer
+	 */
+	offset += 0;
+
+	return blob->data[offset];
+}
+
+uint8_t dcerpc_get_auth_level(const DATA_BLOB *blob)
+{
+	uint16_t offset;
+
+	offset = dcerpc_get_auth_context_offset(blob);
+	if (offset == 0) {
+		return 0;
+	}
+
+	/*
+	 * auth_level is in 2nd byte
+	 * of the auth trailer
+	 */
+	offset += 1;
+
+	return blob->data[offset];
+}
+
+uint32_t dcerpc_get_auth_context_id(const DATA_BLOB *blob)
+{
+	uint16_t offset;
+
+	offset = dcerpc_get_auth_context_offset(blob);
+	if (offset == 0) {
+		return 0;
+	}
+
+	/*
+	 * auth_context_id is in the last 4 byte
+	 * of the auth trailer
+	 */
+	offset += 4;
+
+	if (CVAL(blob->data,DCERPC_DREP_OFFSET) & DCERPC_DREP_LE) {
+		return IVAL(blob->data, offset);
+	} else {
+		return RIVAL(blob->data, offset);
+	}
+}
+
+/**
+* @brief Decodes a ncacn_packet
+*
+* @param mem_ctx	The memory context on which to allocate the packet
+*			elements
+* @param blob		The blob of data to decode
+* @param r		An empty ncacn_packet, must not be NULL
+*
+* @return a NTSTATUS error code
+*/
+NTSTATUS dcerpc_pull_ncacn_packet(TALLOC_CTX *mem_ctx,
+				  const DATA_BLOB *blob,
+				  struct ncacn_packet *r)
+{
+	enum ndr_err_code ndr_err;
+	struct ndr_pull *ndr;
+
+	ndr = ndr_pull_init_blob(blob, mem_ctx);
+	if (!ndr) {
+		return NT_STATUS_NO_MEMORY;
+	}
+
+	ndr_err = ndr_pull_ncacn_packet(ndr, NDR_SCALARS|NDR_BUFFERS, r);
+
+	if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+		talloc_free(ndr);
+		return ndr_map_error2ntstatus(ndr_err);
+	}
+	talloc_free(ndr);
+
+	if (r->frag_length != blob->length) {
+		return NT_STATUS_RPC_PROTOCOL_ERROR;
+	}
+
+	return NT_STATUS_OK;
+}
+
+/**
+* @brief	Pull a dcerpc_auth structure, taking account of any auth
+*		padding in the blob. For request/response packets we pass
+*		the whole data blob, so auth_data_only must be set to false
+*		as the blob contains data+pad+auth and no just pad+auth.
+*
+* @param pkt		- The ncacn_packet strcuture
+* @param mem_ctx	- The mem_ctx used to allocate dcerpc_auth elements
+* @param pkt_trailer	- The packet trailer data, usually the trailing
+*			  auth_info blob, but in the request/response case
+*			  this is the stub_and_verifier blob.
+* @param auth		- A preallocated dcerpc_auth *empty* structure
+* @param auth_length	- The length of the auth trail, sum of auth header
+*			  lenght and pkt->auth_length
+* @param auth_data_only	- Whether the pkt_trailer includes only the auth_blob
+*			  (+ padding) or also other data.
+*
+* @return		- A NTSTATUS error code.
+*/
+NTSTATUS dcerpc_pull_auth_trailer(const struct ncacn_packet *pkt,
+				  TALLOC_CTX *mem_ctx,
+				  const DATA_BLOB *pkt_trailer,
+				  struct dcerpc_auth *auth,
+				  uint32_t *_auth_length,
+				  bool auth_data_only)
+{
+	struct ndr_pull *ndr;
+	enum ndr_err_code ndr_err;
+	uint16_t data_and_pad;
+	uint16_t auth_length;
+	uint32_t tmp_length;
+	uint32_t max_pad_len = 0;
+
+	ZERO_STRUCTP(auth);
+	if (_auth_length != NULL) {
+		*_auth_length = 0;
+
+		if (auth_data_only) {
+			return NT_STATUS_INTERNAL_ERROR;
+		}
+	} else {
+		if (!auth_data_only) {
+			return NT_STATUS_INTERNAL_ERROR;
+		}
+	}
+
+	/* Paranoia checks for auth_length. The caller should check this... */
+	if (pkt->auth_length == 0) {
+		return NT_STATUS_INTERNAL_ERROR;
+	}
+
+	/* Paranoia checks for auth_length. The caller should check this... */
+	if (pkt->auth_length > pkt->frag_length) {
+		return NT_STATUS_INTERNAL_ERROR;
+	}
+	tmp_length = DCERPC_NCACN_PAYLOAD_OFFSET;
+	tmp_length += DCERPC_AUTH_TRAILER_LENGTH;
+	tmp_length += pkt->auth_length;
+	if (tmp_length > pkt->frag_length) {
+		return NT_STATUS_INTERNAL_ERROR;
+	}
+	if (pkt_trailer->length > UINT16_MAX) {
+		return NT_STATUS_INTERNAL_ERROR;
+	}
+
+	auth_length = DCERPC_AUTH_TRAILER_LENGTH + pkt->auth_length;
+	if (pkt_trailer->length < auth_length) {
+		return NT_STATUS_RPC_PROTOCOL_ERROR;
+	}
+
+	data_and_pad = pkt_trailer->length - auth_length;
+
+	ndr = ndr_pull_init_blob(pkt_trailer, mem_ctx);
+	if (!ndr) {
+		return NT_STATUS_NO_MEMORY;
+	}
+
+	if (!(pkt->drep[0] & DCERPC_DREP_LE)) {
+		ndr->flags |= LIBNDR_FLAG_BIGENDIAN;
+	}
+
+	ndr_err = ndr_pull_advance(ndr, data_and_pad);
+	if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+		talloc_free(ndr);
+		return ndr_map_error2ntstatus(ndr_err);
+	}
+
+	ndr_err = ndr_pull_dcerpc_auth(ndr, NDR_SCALARS|NDR_BUFFERS, auth);
+	if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+		talloc_free(ndr);
+		ZERO_STRUCTP(auth);
+		return ndr_map_error2ntstatus(ndr_err);
+	}
+
+	/*
+	 * Make sure the padding would not exceed
+	 * the frag_length.
+	 *
+	 * Here we assume at least 24 bytes for the
+	 * payload specific header the value of
+	 * DCERPC_{REQUEST,RESPONSE}_LENGTH.
+	 *
+	 * We use this also for BIND_*, ALTER_* and AUTH3 pdus.
+	 *
+	 * We need this check before we ignore possible
+	 * invalid values. See also bug #11982.
+	 *
+	 * This check is mainly used to generate the correct
+	 * error for BIND_*, ALTER_* and AUTH3 pdus.
+	 *
+	 * We always have the 'if (data_and_pad < auth->auth_pad_length)'
+	 * protection for REQUEST and RESPONSE pdus, where the
+	 * auth_pad_length field is actually used by the caller.
+	 */
+	tmp_length = DCERPC_REQUEST_LENGTH;
+	tmp_length += DCERPC_AUTH_TRAILER_LENGTH;
+	tmp_length += pkt->auth_length;
+	if (tmp_length < pkt->frag_length) {
+		max_pad_len = pkt->frag_length - tmp_length;
+	}
+	if (max_pad_len < auth->auth_pad_length) {
+		DEBUG(1, (__location__ ": ERROR: pad length to large. "
+			  "max %u got %u\n",
+			  (unsigned)max_pad_len,
+			  (unsigned)auth->auth_pad_length));
+		talloc_free(ndr);
+		ZERO_STRUCTP(auth);
+		return NT_STATUS_RPC_PROTOCOL_ERROR;
+	}
+
+	/*
+	 * This is a workarround for a bug in old
+	 * Samba releases. For BIND_ACK <= 3.5.x
+	 * and for ALTER_RESP <= 4.2.x (see bug #11061)
+	 *
+	 * See also bug #11982.
+	 */
+	if (auth_data_only && data_and_pad == 0 &&
+	    auth->auth_pad_length > 0) {
+		/*
+		 * we need to ignore invalid auth_pad_length
+		 * values for BIND_*, ALTER_* and AUTH3 pdus.
+		 */
+		auth->auth_pad_length = 0;
+	}
+
+	if (data_and_pad < auth->auth_pad_length) {
+		DBG_WARNING(__location__ ": ERROR: pad length too long. "
+			    "Calculated %u (pkt_trailer->length=%u - auth_length=%u) "
+			    "was less than auth_pad_length=%u\n",
+			    (unsigned)data_and_pad,
+			    (unsigned)pkt_trailer->length,
+			    (unsigned)auth_length,
+			    (unsigned)auth->auth_pad_length);
+		talloc_free(ndr);
+		ZERO_STRUCTP(auth);
+		return NT_STATUS_RPC_PROTOCOL_ERROR;
+	}
+
+	if (auth_data_only && data_and_pad > auth->auth_pad_length) {
+		DBG_WARNING(__location__ ": ERROR: auth_data_only pad length mismatch. "
+			    "Client sent a longer BIND packet than expected by %u bytes "
+			    "(pkt_trailer->length=%u - auth_length=%u) "
+			    "= %u auth_pad_length=%u\n",
+			    (unsigned)data_and_pad - (unsigned)auth->auth_pad_length,
+			    (unsigned)pkt_trailer->length,
+			    (unsigned)auth_length,
+			    (unsigned)data_and_pad,
+			    (unsigned)auth->auth_pad_length);
+		talloc_free(ndr);
+		ZERO_STRUCTP(auth);
+		return NT_STATUS_RPC_PROTOCOL_ERROR;
+	}
+
+	if (auth_data_only && data_and_pad != auth->auth_pad_length) {
+		DBG_WARNING(__location__ ": ERROR: auth_data_only pad length mismatch. "
+			    "Calculated %u (pkt_trailer->length=%u - auth_length=%u) "
+			    "but auth_pad_length=%u\n",
+			    (unsigned)data_and_pad,
+			    (unsigned)pkt_trailer->length,
+			    (unsigned)auth_length,
+			    (unsigned)auth->auth_pad_length);
+		talloc_free(ndr);
+		ZERO_STRUCTP(auth);
+		return NT_STATUS_RPC_PROTOCOL_ERROR;
+	}
+
+	DBG_DEBUG("auth_pad_length %u\n",
+		  (unsigned)auth->auth_pad_length);
+
+	talloc_steal(mem_ctx, auth->credentials.data);
+	talloc_free(ndr);
+
+	if (_auth_length != NULL) {
+		*_auth_length = auth_length;
+	}
+
+	return NT_STATUS_OK;
+}
+
+/**
+* @brief	Verify the fields in ncacn_packet header.
+*
+* @param pkt		- The ncacn_packet strcuture
+* @param ptype		- The expected PDU type
+* @param max_auth_info	- The maximum size of a possible auth trailer
+* @param required_flags	- The required flags for the pdu.
+* @param optional_flags	- The possible optional flags for the pdu.
+*
+* @return		- A NTSTATUS error code.
+*/
+NTSTATUS dcerpc_verify_ncacn_packet_header(const struct ncacn_packet *pkt,
+					   enum dcerpc_pkt_type ptype,
+					   size_t max_auth_info,
+					   uint8_t required_flags,
+					   uint8_t optional_flags)
+{
+	if (pkt->rpc_vers != 5) {
+		return NT_STATUS_RPC_PROTOCOL_ERROR;
+	}
+
+	if (pkt->rpc_vers_minor != 0) {
+		return NT_STATUS_RPC_PROTOCOL_ERROR;
+	}
+
+	if (pkt->auth_length > pkt->frag_length) {
+		return NT_STATUS_RPC_PROTOCOL_ERROR;
+	}
+
+	if (pkt->ptype != ptype) {
+		return NT_STATUS_RPC_PROTOCOL_ERROR;
+	}
+
+	if (max_auth_info > UINT16_MAX) {
+		return NT_STATUS_INTERNAL_ERROR;
+	}
+
+	if (pkt->auth_length > 0) {
+		size_t max_auth_length;
+
+		if (max_auth_info <= DCERPC_AUTH_TRAILER_LENGTH) {
+			return NT_STATUS_RPC_PROTOCOL_ERROR;
+		}
+		max_auth_length = max_auth_info - DCERPC_AUTH_TRAILER_LENGTH;
+
+		if (pkt->auth_length > max_auth_length) {
+			return NT_STATUS_RPC_PROTOCOL_ERROR;
+		}
+	}
+
+	if ((pkt->pfc_flags & required_flags) != required_flags) {
+		return NT_STATUS_RPC_PROTOCOL_ERROR;
+	}
+	if (pkt->pfc_flags & ~(optional_flags|required_flags)) {
+		return NT_STATUS_RPC_PROTOCOL_ERROR;
+	}
+
+	if (pkt->drep[0] & ~DCERPC_DREP_LE) {
+		return NT_STATUS_RPC_PROTOCOL_ERROR;
+	}
+	if (pkt->drep[1] != 0) {
+		return NT_STATUS_RPC_PROTOCOL_ERROR;
+	}
+	if (pkt->drep[2] != 0) {
+		return NT_STATUS_RPC_PROTOCOL_ERROR;
+	}
+	if (pkt->drep[3] != 0) {
+		return NT_STATUS_RPC_PROTOCOL_ERROR;
+	}
+
+	return NT_STATUS_OK;
+}
+
+struct dcerpc_read_ncacn_packet_state {
+#if 0
+	struct {
+	} caller;
+#endif
+	DATA_BLOB buffer;
+	struct ncacn_packet *pkt;
+};
+
+static int dcerpc_read_ncacn_packet_next_vector(struct tstream_context *stream,
+						void *private_data,
+						TALLOC_CTX *mem_ctx,
+						struct iovec **_vector,
+						size_t *_count);
+static void dcerpc_read_ncacn_packet_done(struct tevent_req *subreq);
+
+struct tevent_req *dcerpc_read_ncacn_packet_send(TALLOC_CTX *mem_ctx,
+						 struct tevent_context *ev,
+						 struct tstream_context *stream)
+{
+	struct tevent_req *req;
+	struct dcerpc_read_ncacn_packet_state *state;
+	struct tevent_req *subreq;
+
+	req = tevent_req_create(mem_ctx, &state,
+				struct dcerpc_read_ncacn_packet_state);
+	if (req == NULL) {
+		return NULL;
+	}
+
+	state->pkt = talloc_zero(state, struct ncacn_packet);
+	if (tevent_req_nomem(state->pkt, req)) {
+		goto post;
+	}
+
+	subreq = tstream_readv_pdu_send(state, ev,
+					stream,
+					dcerpc_read_ncacn_packet_next_vector,
+					state);
+	if (tevent_req_nomem(subreq, req)) {
+		goto post;
+	}
+	tevent_req_set_callback(subreq, dcerpc_read_ncacn_packet_done, req);
+
+	return req;
+ post:
+	tevent_req_post(req, ev);
+	return req;
+}
+
+static int dcerpc_read_ncacn_packet_next_vector(struct tstream_context *stream,
+						void *private_data,
+						TALLOC_CTX *mem_ctx,
+						struct iovec **_vector,
+						size_t *_count)
+{
+	struct dcerpc_read_ncacn_packet_state *state =
+		talloc_get_type_abort(private_data,
+		struct dcerpc_read_ncacn_packet_state);
+	struct iovec *vector;
+	off_t ofs = 0;
+
+	if (state->buffer.length == 0) {
+		/*
+		 * first get enough to read the fragment length
+		 *
+		 * We read the full fixed ncacn_packet header
+		 * in order to make wireshark happy with
+		 * pcap files from socket_wrapper.
+		 */
+		ofs = 0;
+		state->buffer.length = DCERPC_NCACN_PAYLOAD_OFFSET;
+		state->buffer.data = talloc_array(state, uint8_t,
+						  state->buffer.length);
+		if (!state->buffer.data) {
+			return -1;
+		}
+	} else if (state->buffer.length == DCERPC_NCACN_PAYLOAD_OFFSET) {
+		/* now read the fragment length and allocate the full buffer */
+		size_t frag_len = dcerpc_get_frag_length(&state->buffer);
+
+		ofs = state->buffer.length;
+
+		if (frag_len <= ofs) {
+			/*
+			 * With frag_len == ofs, we are done, this is likely
+			 * a DCERPC_PKT_CO_CANCEL and DCERPC_PKT_ORPHANED
+			 * without any payload.
+			 *
+			 * Otherwise it's a broken packet and we
+			 * let the caller deal with it.
+			 */
+			*_vector = NULL;
+			*_count = 0;
+			return 0;
+		}
+
+		state->buffer.data = talloc_realloc(state,
+						    state->buffer.data,
+						    uint8_t, frag_len);
+		if (!state->buffer.data) {
+			return -1;
+		}
+		state->buffer.length = frag_len;
+	} else {
+		/* if we reach this we have a full fragment */
+		*_vector = NULL;
+		*_count = 0;
+		return 0;
+	}
+
+	/* now create the vector that we want to be filled */
+	vector = talloc_array(mem_ctx, struct iovec, 1);
+	if (!vector) {
+		return -1;
+	}
+
+	vector[0].iov_base = (void *) (state->buffer.data + ofs);
+	vector[0].iov_len = state->buffer.length - ofs;
+
+	*_vector = vector;
+	*_count = 1;
+	return 0;
+}
+
+static void dcerpc_read_ncacn_packet_done(struct tevent_req *subreq)
+{
+	struct tevent_req *req = tevent_req_callback_data(subreq,
+				 struct tevent_req);
+	struct dcerpc_read_ncacn_packet_state *state = tevent_req_data(req,
+					struct dcerpc_read_ncacn_packet_state);
+	int ret;
+	int sys_errno;
+	NTSTATUS status;
+
+	ret = tstream_readv_pdu_recv(subreq, &sys_errno);
+	TALLOC_FREE(subreq);
+	if (ret == -1) {
+		status = map_nt_error_from_unix_common(sys_errno);
+		tevent_req_nterror(req, status);
+		return;
+	}
+
+	status = dcerpc_pull_ncacn_packet(state->pkt,
+					  &state->buffer,
+					  state->pkt);
+	if (tevent_req_nterror(req, status)) {
+		return;
+	}
+
+	tevent_req_done(req);
+}
+
+NTSTATUS dcerpc_read_ncacn_packet_recv(struct tevent_req *req,
+				       TALLOC_CTX *mem_ctx,
+				       struct ncacn_packet **pkt,
+				       DATA_BLOB *buffer)
+{
+	struct dcerpc_read_ncacn_packet_state *state = tevent_req_data(req,
+					struct dcerpc_read_ncacn_packet_state);
+	NTSTATUS status;
+
+	if (tevent_req_is_nterror(req, &status)) {
+		tevent_req_received(req);
+		return status;
+	}
+
+	*pkt = talloc_move(mem_ctx, &state->pkt);
+	if (buffer) {
+		buffer->data = talloc_move(mem_ctx, &state->buffer.data);
+		buffer->length = state->buffer.length;
+	}
+
+	tevent_req_received(req);
+	return NT_STATUS_OK;
+}
+
+const char *dcerpc_default_transport_endpoint(TALLOC_CTX *mem_ctx,
+					      enum dcerpc_transport_t transport,
+					      const struct ndr_interface_table *table)
+{
+	NTSTATUS status;
+	const char *p = NULL;
+	const char *endpoint = NULL;
+	uint32_t i;
+	struct dcerpc_binding *default_binding = NULL;
+	TALLOC_CTX *frame = talloc_stackframe();
+
+	/* Find one of the default pipes for this interface */
+
+	for (i = 0; i < table->endpoints->count; i++) {
+		enum dcerpc_transport_t dtransport;
+		const char *dendpoint;
+
+		status = dcerpc_parse_binding(frame, table->endpoints->names[i],
+					      &default_binding);
+		if (!NT_STATUS_IS_OK(status)) {
+			continue;
+		}
+
+		dtransport = dcerpc_binding_get_transport(default_binding);
+		dendpoint = dcerpc_binding_get_string_option(default_binding,
+							     "endpoint");
+		if (dendpoint == NULL) {
+			TALLOC_FREE(default_binding);
+			continue;
+		}
+
+		if (transport == NCA_UNKNOWN) {
+			transport = dtransport;
+		}
+
+		if (transport != dtransport) {
+			TALLOC_FREE(default_binding);
+			continue;
+		}
+
+		p = dendpoint;
+		break;
+	}
+
+	if (p == NULL) {
+		goto done;
+	}
+
+	/*
+	 * extract the pipe name without \\pipe from for example
+	 * ncacn_np:[\\pipe\\epmapper]
+	 */
+	if (transport == NCACN_NP) {
+		if (strncasecmp(p, "\\pipe\\", 6) == 0) {
+			p += 6;
+		}
+		if (strncmp(p, "\\", 1) == 0) {
+			p += 1;
+		}
+	}
+
+	endpoint = talloc_strdup(mem_ctx, p);
+
+ done:
+	talloc_free(frame);
+	return endpoint;
+}
+
+struct dcerpc_sec_vt_header2 dcerpc_sec_vt_header2_from_ncacn_packet(const struct ncacn_packet *pkt)
+{
+	struct dcerpc_sec_vt_header2 ret;
+
+	ZERO_STRUCT(ret);
+	ret.ptype = pkt->ptype;
+	memcpy(&ret.drep, pkt->drep, sizeof(ret.drep));
+	ret.call_id = pkt->call_id;
+
+	switch (pkt->ptype) {
+	case DCERPC_PKT_REQUEST:
+		ret.context_id = pkt->u.request.context_id;
+		ret.opnum      = pkt->u.request.opnum;
+		break;
+
+	case DCERPC_PKT_RESPONSE:
+		ret.context_id = pkt->u.response.context_id;
+		break;
+
+	case DCERPC_PKT_FAULT:
+		ret.context_id = pkt->u.fault.context_id;
+		break;
+
+	default:
+		break;
+	}
+
+	return ret;
+}
+
+bool dcerpc_sec_vt_header2_equal(const struct dcerpc_sec_vt_header2 *v1,
+				 const struct dcerpc_sec_vt_header2 *v2)
+{
+	if (v1->ptype != v2->ptype) {
+		return false;
+	}
+
+	if (memcmp(v1->drep, v2->drep, sizeof(v1->drep)) != 0) {
+		return false;
+	}
+
+	if (v1->call_id != v2->call_id) {
+		return false;
+	}
+
+	if (v1->context_id != v2->context_id) {
+		return false;
+	}
+
+	if (v1->opnum != v2->opnum) {
+		return false;
+	}
+
+	return true;
+}
+
+static bool dcerpc_sec_vt_is_valid(const struct dcerpc_sec_verification_trailer *r)
+{
+	bool ret = false;
+	TALLOC_CTX *frame = talloc_stackframe();
+	struct bitmap *commands_seen;
+	int i;
+
+	if (r->count.count == 0) {
+		ret = true;
+		goto done;
+	}
+
+	if (memcmp(r->magic, DCERPC_SEC_VT_MAGIC, sizeof(r->magic)) != 0) {
+		goto done;
+	}
+
+	commands_seen = bitmap_talloc(frame, DCERPC_SEC_VT_COMMAND_ENUM + 1);
+	if (commands_seen == NULL) {
+		goto done;
+	}
+
+	for (i=0; i < r->count.count; i++) {
+		enum dcerpc_sec_vt_command_enum cmd =
+			r->commands[i].command & DCERPC_SEC_VT_COMMAND_ENUM;
+
+		if (bitmap_query(commands_seen, cmd)) {
+			/* Each command must appear at most once. */
+			goto done;
+		}
+		bitmap_set(commands_seen, cmd);
+
+		switch (cmd) {
+		case DCERPC_SEC_VT_COMMAND_BITMASK1:
+		case DCERPC_SEC_VT_COMMAND_PCONTEXT:
+		case DCERPC_SEC_VT_COMMAND_HEADER2:
+			break;
+		default:
+			if ((r->commands[i].u._unknown.length % 4) != 0) {
+				goto done;
+			}
+			break;
+		}
+	}
+	ret = true;
+done:
+	TALLOC_FREE(frame);
+	return ret;
+}
+
+static bool dcerpc_sec_vt_bitmask_check(const uint32_t *bitmask1,
+					struct dcerpc_sec_vt *c)
+{
+	if (bitmask1 == NULL) {
+		if (c->command & DCERPC_SEC_VT_MUST_PROCESS) {
+			DEBUG(10, ("SEC_VT check Bitmask1 must_process_command "
+				   "failed\n"));
+			return false;
+		}
+
+		return true;
+	}
+
+	if ((c->u.bitmask1 & DCERPC_SEC_VT_CLIENT_SUPPORTS_HEADER_SIGNING)
+	 && (!(*bitmask1 & DCERPC_SEC_VT_CLIENT_SUPPORTS_HEADER_SIGNING))) {
+		DEBUG(10, ("SEC_VT check Bitmask1 client_header_signing "
+			   "failed\n"));
+		return false;
+	}
+	return true;
+}
+
+static bool dcerpc_sec_vt_pctx_check(const struct dcerpc_sec_vt_pcontext *pcontext,
+				     struct dcerpc_sec_vt *c)
+{
+	bool ok;
+
+	if (pcontext == NULL) {
+		if (c->command & DCERPC_SEC_VT_MUST_PROCESS) {
+			DEBUG(10, ("SEC_VT check Pcontext must_process_command "
+				   "failed\n"));
+			return false;
+		}
+
+		return true;
+	}
+
+	ok = ndr_syntax_id_equal(&pcontext->abstract_syntax,
+				 &c->u.pcontext.abstract_syntax);
+	if (!ok) {
+		struct ndr_syntax_id_buf buf1, buf2;
+		DEBUG(10, ("SEC_VT check pcontext abstract_syntax failed: "
+			   "%s vs. %s\n",
+			   ndr_syntax_id_buf_string(
+				   &pcontext->abstract_syntax, &buf1),
+			   ndr_syntax_id_buf_string(
+				   &c->u.pcontext.abstract_syntax, &buf2)));
+		return false;
+	}
+	ok = ndr_syntax_id_equal(&pcontext->transfer_syntax,
+				 &c->u.pcontext.transfer_syntax);
+	if (!ok) {
+		struct ndr_syntax_id_buf buf1, buf2;
+		DEBUG(10, ("SEC_VT check pcontext transfer_syntax failed: "
+			   "%s vs. %s\n",
+			   ndr_syntax_id_buf_string(
+				   &pcontext->transfer_syntax, &buf1),
+			   ndr_syntax_id_buf_string(
+				   &c->u.pcontext.transfer_syntax, &buf2)));
+		return false;
+	}
+
+	return true;
+}
+
+static bool dcerpc_sec_vt_hdr2_check(const struct dcerpc_sec_vt_header2 *header2,
+				     struct dcerpc_sec_vt *c)
+{
+	if (header2 == NULL) {
+		if (c->command & DCERPC_SEC_VT_MUST_PROCESS) {
+			DEBUG(10, ("SEC_VT check Header2 must_process_command failed\n"));
+			return false;
+		}
+
+		return true;
+	}
+
+	if (!dcerpc_sec_vt_header2_equal(header2, &c->u.header2)) {
+		DEBUG(10, ("SEC_VT check Header2 failed\n"));
+		return false;
+	}
+
+	return true;
+}
+
+bool dcerpc_sec_verification_trailer_check(
+		const struct dcerpc_sec_verification_trailer *vt,
+		const uint32_t *bitmask1,
+		const struct dcerpc_sec_vt_pcontext *pcontext,
+		const struct dcerpc_sec_vt_header2 *header2)
+{
+	size_t i;
+
+	if (!dcerpc_sec_vt_is_valid(vt)) {
+		return false;
+	}
+
+	for (i=0; i < vt->count.count; i++) {
+		bool ok;
+		struct dcerpc_sec_vt *c = &vt->commands[i];
+
+		switch (c->command & DCERPC_SEC_VT_COMMAND_ENUM) {
+		case DCERPC_SEC_VT_COMMAND_BITMASK1:
+			ok = dcerpc_sec_vt_bitmask_check(bitmask1, c);
+			if (!ok) {
+				return false;
+			}
+			break;
+
+		case DCERPC_SEC_VT_COMMAND_PCONTEXT:
+			ok = dcerpc_sec_vt_pctx_check(pcontext, c);
+			if (!ok) {
+				return false;
+			}
+			break;
+
+		case DCERPC_SEC_VT_COMMAND_HEADER2: {
+			ok = dcerpc_sec_vt_hdr2_check(header2, c);
+			if (!ok) {
+				return false;
+			}
+			break;
+		}
+
+		default:
+			if (c->command & DCERPC_SEC_VT_MUST_PROCESS) {
+				DEBUG(10, ("SEC_VT check Unknown must_process_command failed\n"));
+				return false;
+			}
+
+			break;
+		}
+	}
+
+	return true;
+}
+
+static const struct ndr_syntax_id dcerpc_bind_time_features_prefix  = {
+	.uuid = {
+		.time_low = 0x6cb71c2c,
+		.time_mid = 0x9812,
+		.time_hi_and_version = 0x4540,
+		.clock_seq = {0x00, 0x00},
+		.node = {0x00,0x00,0x00,0x00,0x00,0x00}
+	},
+	.if_version = 1,
+};
+
+bool dcerpc_extract_bind_time_features(struct ndr_syntax_id s, uint64_t *_features)
+{
+	uint8_t values[8];
+	uint64_t features = 0;
+
+	values[0] = s.uuid.clock_seq[0];
+	values[1] = s.uuid.clock_seq[1];
+	values[2] = s.uuid.node[0];
+	values[3] = s.uuid.node[1];
+	values[4] = s.uuid.node[2];
+	values[5] = s.uuid.node[3];
+	values[6] = s.uuid.node[4];
+	values[7] = s.uuid.node[5];
+
+	ZERO_STRUCT(s.uuid.clock_seq);
+	ZERO_STRUCT(s.uuid.node);
+
+	if (!ndr_syntax_id_equal(&s, &dcerpc_bind_time_features_prefix)) {
+		if (_features != NULL) {
+			*_features = 0;
+		}
+		return false;
+	}
+
+	features = BVAL(values, 0);
+
+	if (_features != NULL) {
+		*_features = features;
+	}
+
+	return true;
+}
+
+struct ndr_syntax_id dcerpc_construct_bind_time_features(uint64_t features)
+{
+	struct ndr_syntax_id s = dcerpc_bind_time_features_prefix;
+	uint8_t values[8];
+
+	SBVAL(values, 0, features);
+
+	s.uuid.clock_seq[0] = values[0];
+	s.uuid.clock_seq[1] = values[1];
+	s.uuid.node[0]      = values[2];
+	s.uuid.node[1]      = values[3];
+	s.uuid.node[2]      = values[4];
+	s.uuid.node[3]      = values[5];
+	s.uuid.node[4]      = values[6];
+	s.uuid.node[5]      = values[7];
+
+	return s;
+}
+
+NTSTATUS dcerpc_generic_session_key(DATA_BLOB *session_key)
+{
+	*session_key = data_blob_null;
+
+	/* this took quite a few CPU cycles to find ... */
+	session_key->data = discard_const_p(unsigned char, "SystemLibraryDTC");
+	session_key->length = 16;
+	return NT_STATUS_OK;
+}
+
+/*
+   push a ncacn_packet into a blob, potentially with auth info
+*/
+NTSTATUS dcerpc_ncacn_push_auth(DATA_BLOB *blob,
+				TALLOC_CTX *mem_ctx,
+				struct ncacn_packet *pkt,
+				struct dcerpc_auth *auth_info)
+{
+	struct ndr_push *ndr;
+	enum ndr_err_code ndr_err;
+
+	ndr = ndr_push_init_ctx(mem_ctx);
+	if (!ndr) {
+		return NT_STATUS_NO_MEMORY;
+	}
+
+	if (auth_info) {
+		pkt->auth_length = auth_info->credentials.length;
+	} else {
+		pkt->auth_length = 0;
+	}
+
+	ndr_err = ndr_push_ncacn_packet(ndr, NDR_SCALARS|NDR_BUFFERS, pkt);
+	if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+		return ndr_map_error2ntstatus(ndr_err);
+	}
+
+	if (auth_info) {
+#if 0
+		/* the s3 rpc server doesn't handle auth padding in
+		   bind requests. Use zero auth padding to keep us
+		   working with old servers */
+		uint32_t offset = ndr->offset;
+		ndr_err = ndr_push_align(ndr, 16);
+		if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+			return ndr_map_error2ntstatus(ndr_err);
+		}
+		auth_info->auth_pad_length = ndr->offset - offset;
+#else
+		auth_info->auth_pad_length = 0;
+#endif
+		ndr_err = ndr_push_dcerpc_auth(ndr, NDR_SCALARS|NDR_BUFFERS, auth_info);
+		if (!NDR_ERR_CODE_IS_SUCCESS(ndr_err)) {
+			return ndr_map_error2ntstatus(ndr_err);
+		}
+	}
+
+	*blob = ndr_push_blob(ndr);
+
+	/* fill in the frag length */
+	dcerpc_set_frag_length(blob, blob->length);
+
+	return NT_STATUS_OK;
+}
+
+/*
+  log a rpc packet in a format suitable for ndrdump. This is especially useful
+  for sealed packets, where ethereal cannot easily see the contents
+
+  this triggers if "dcesrv:stubs directory" is set and present
+  for all packets that fail to parse
+*/
+void dcerpc_log_packet(const char *packet_log_dir,
+		       const char *interface_name,
+		       uint32_t opnum, uint32_t flags,
+		       const DATA_BLOB *pkt,
+		       const char *why)
+{
+	const int num_examples = 20;
+	int i;
+
+	if (packet_log_dir == NULL) {
+		return;
+	}
+
+	for (i=0;i<num_examples;i++) {
+		char *name=NULL;
+		int ret;
+		bool saved;
+		ret = asprintf(&name, "%s/%s-%u.%d.%s.%s",
+			       packet_log_dir, interface_name, opnum, i,
+			       (flags&NDR_IN)?"in":"out",
+			       why);
+		if (ret == -1) {
+			return;
+		}
+
+		saved = file_save(name, pkt->data, pkt->length);
+		if (saved) {
+			DBG_DEBUG("Logged rpc packet to %s\n", name);
+			free(name);
+			break;
+		}
+		free(name);
+	}
+}