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samba-mirror/source4/rpc_server/dcesrv_auth.c
2007-10-10 15:07:25 -05:00

527 lines
15 KiB
C

/*
Unix SMB/CIFS implementation.
server side dcerpc authentication code
Copyright (C) Andrew Tridgell 2003
Copyright (C) Stefan (metze) Metzmacher 2004
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 "rpc_server/dcerpc_server.h"
#include "librpc/gen_ndr/ndr_dcerpc.h"
#include "auth/credentials/credentials.h"
#include "auth/gensec/gensec.h"
#include "param/param.h"
/*
parse any auth information from a dcerpc bind request
return False if we can't handle the auth request for some
reason (in which case we send a bind_nak)
*/
BOOL dcesrv_auth_bind(struct dcesrv_call_state *call)
{
struct cli_credentials *server_credentials;
struct ncacn_packet *pkt = &call->pkt;
struct dcesrv_connection *dce_conn = call->conn;
struct dcesrv_auth *auth = &dce_conn->auth_state;
NTSTATUS status;
if (pkt->u.bind.auth_info.length == 0) {
dce_conn->auth_state.auth_info = NULL;
return True;
}
dce_conn->auth_state.auth_info = talloc(dce_conn, struct dcerpc_auth);
if (!dce_conn->auth_state.auth_info) {
return False;
}
status = ndr_pull_struct_blob(&pkt->u.bind.auth_info,
call,
dce_conn->auth_state.auth_info,
(ndr_pull_flags_fn_t)ndr_pull_dcerpc_auth);
if (!NT_STATUS_IS_OK(status)) {
return False;
}
status = gensec_server_start(dce_conn, call->event_ctx, call->msg_ctx, &auth->gensec_security);
if (!NT_STATUS_IS_OK(status)) {
DEBUG(1, ("Failed to start GENSEC for DCERPC server: %s\n", nt_errstr(status)));
return False;
}
server_credentials
= cli_credentials_init(call);
if (!server_credentials) {
DEBUG(1, ("Failed to init server credentials\n"));
return False;
}
cli_credentials_set_conf(server_credentials, global_loadparm);
status = cli_credentials_set_machine_account(server_credentials);
if (!NT_STATUS_IS_OK(status)) {
DEBUG(10, ("Failed to obtain server credentials, perhaps a standalone server?: %s\n", nt_errstr(status)));
talloc_free(server_credentials);
server_credentials = NULL;
}
gensec_set_credentials(auth->gensec_security, server_credentials);
status = gensec_start_mech_by_authtype(auth->gensec_security, auth->auth_info->auth_type,
auth->auth_info->auth_level);
if (!NT_STATUS_IS_OK(status)) {
DEBUG(1, ("Failed to start GENSEC mechanism for DCERPC server: auth_type=%d, auth_level=%d: %s\n",
(int)auth->auth_info->auth_type,
(int)auth->auth_info->auth_level,
nt_errstr(status)));
return False;
}
return True;
}
/*
add any auth information needed in a bind ack, and process the authentication
information found in the bind.
*/
NTSTATUS dcesrv_auth_bind_ack(struct dcesrv_call_state *call, struct ncacn_packet *pkt)
{
struct dcesrv_connection *dce_conn = call->conn;
NTSTATUS status;
if (!call->conn->auth_state.gensec_security) {
return NT_STATUS_OK;
}
status = gensec_update(dce_conn->auth_state.gensec_security,
call,
dce_conn->auth_state.auth_info->credentials,
&dce_conn->auth_state.auth_info->credentials);
if (NT_STATUS_IS_OK(status)) {
status = gensec_session_info(dce_conn->auth_state.gensec_security,
&dce_conn->auth_state.session_info);
if (!NT_STATUS_IS_OK(status)) {
DEBUG(1, ("Failed to establish session_info: %s\n", nt_errstr(status)));
return status;
}
/* Now that we are authenticated, go back to the generic session key... */
dce_conn->auth_state.session_key = dcesrv_generic_session_key;
return NT_STATUS_OK;
} else if (NT_STATUS_EQUAL(status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
dce_conn->auth_state.auth_info->auth_pad_length = 0;
dce_conn->auth_state.auth_info->auth_reserved = 0;
return NT_STATUS_OK;
} else {
DEBUG(2, ("Failed to start dcesrv auth negotiate: %s\n", nt_errstr(status)));
return status;
}
}
/*
process the final stage of a auth request
*/
BOOL dcesrv_auth_auth3(struct dcesrv_call_state *call)
{
struct ncacn_packet *pkt = &call->pkt;
struct dcesrv_connection *dce_conn = call->conn;
NTSTATUS status;
/* We can't work without an existing gensec state, and an new blob to feed it */
if (!dce_conn->auth_state.auth_info ||
!dce_conn->auth_state.gensec_security ||
pkt->u.auth3.auth_info.length == 0) {
return False;
}
status = ndr_pull_struct_blob(&pkt->u.auth3.auth_info,
call,
dce_conn->auth_state.auth_info,
(ndr_pull_flags_fn_t)ndr_pull_dcerpc_auth);
if (!NT_STATUS_IS_OK(status)) {
return False;
}
/* Pass the extra data we got from the client down to gensec for processing */
status = gensec_update(dce_conn->auth_state.gensec_security,
call,
dce_conn->auth_state.auth_info->credentials,
&dce_conn->auth_state.auth_info->credentials);
if (NT_STATUS_IS_OK(status)) {
status = gensec_session_info(dce_conn->auth_state.gensec_security,
&dce_conn->auth_state.session_info);
if (!NT_STATUS_IS_OK(status)) {
DEBUG(1, ("Failed to establish session_info: %s\n", nt_errstr(status)));
return False;
}
/* Now that we are authenticated, go back to the generic session key... */
dce_conn->auth_state.session_key = dcesrv_generic_session_key;
return True;
} else {
DEBUG(4, ("dcesrv_auth_auth3: failed to authenticate: %s\n",
nt_errstr(status)));
return False;
}
return True;
}
/*
parse any auth information from a dcerpc alter request
return False if we can't handle the auth request for some
reason (in which case we send a bind_nak (is this true for here?))
*/
BOOL dcesrv_auth_alter(struct dcesrv_call_state *call)
{
struct ncacn_packet *pkt = &call->pkt;
struct dcesrv_connection *dce_conn = call->conn;
NTSTATUS status;
/* on a pure interface change there is no auth blob */
if (pkt->u.alter.auth_info.length == 0) {
return True;
}
/* We can't work without an existing gensec state */
if (!dce_conn->auth_state.gensec_security) {
return False;
}
dce_conn->auth_state.auth_info = talloc(dce_conn, struct dcerpc_auth);
if (!dce_conn->auth_state.auth_info) {
return False;
}
status = ndr_pull_struct_blob(&pkt->u.alter.auth_info,
call,
dce_conn->auth_state.auth_info,
(ndr_pull_flags_fn_t)ndr_pull_dcerpc_auth);
if (!NT_STATUS_IS_OK(status)) {
return False;
}
return True;
}
/*
add any auth information needed in a alter ack, and process the authentication
information found in the alter.
*/
NTSTATUS dcesrv_auth_alter_ack(struct dcesrv_call_state *call, struct ncacn_packet *pkt)
{
struct dcesrv_connection *dce_conn = call->conn;
NTSTATUS status;
/* on a pure interface change there is no auth_info structure
setup */
if (!call->conn->auth_state.auth_info ||
dce_conn->auth_state.auth_info->credentials.length == 0) {
return NT_STATUS_OK;
}
if (!call->conn->auth_state.gensec_security) {
return NT_STATUS_INVALID_PARAMETER;
}
status = gensec_update(dce_conn->auth_state.gensec_security,
call,
dce_conn->auth_state.auth_info->credentials,
&dce_conn->auth_state.auth_info->credentials);
if (NT_STATUS_IS_OK(status)) {
status = gensec_session_info(dce_conn->auth_state.gensec_security,
&dce_conn->auth_state.session_info);
if (!NT_STATUS_IS_OK(status)) {
DEBUG(1, ("Failed to establish session_info: %s\n", nt_errstr(status)));
return status;
}
/* Now that we are authenticated, got back to the generic session key... */
dce_conn->auth_state.session_key = dcesrv_generic_session_key;
return NT_STATUS_OK;
} else if (NT_STATUS_EQUAL(status, NT_STATUS_MORE_PROCESSING_REQUIRED)) {
dce_conn->auth_state.auth_info->auth_pad_length = 0;
dce_conn->auth_state.auth_info->auth_reserved = 0;
return NT_STATUS_OK;
}
DEBUG(2, ("Failed to finish dcesrv auth alter_ack: %s\n", nt_errstr(status)));
return status;
}
/*
generate a CONNECT level verifier
*/
static NTSTATUS dcesrv_connect_verifier(TALLOC_CTX *mem_ctx, DATA_BLOB *blob)
{
*blob = data_blob_talloc(mem_ctx, NULL, 16);
if (blob->data == NULL) {
return NT_STATUS_NO_MEMORY;
}
SIVAL(blob->data, 0, 1);
memset(blob->data+4, 0, 12);
return NT_STATUS_OK;
}
/*
generate a CONNECT level verifier
*/
static NTSTATUS dcesrv_check_connect_verifier(DATA_BLOB *blob)
{
if (blob->length != 16 ||
IVAL(blob->data, 0) != 1) {
return NT_STATUS_ACCESS_DENIED;
}
return NT_STATUS_OK;
}
/*
check credentials on a request
*/
BOOL dcesrv_auth_request(struct dcesrv_call_state *call, DATA_BLOB *full_packet)
{
struct ncacn_packet *pkt = &call->pkt;
struct dcesrv_connection *dce_conn = call->conn;
DATA_BLOB auth_blob;
struct dcerpc_auth auth;
struct ndr_pull *ndr;
NTSTATUS status;
if (!dce_conn->auth_state.auth_info ||
!dce_conn->auth_state.gensec_security) {
return True;
}
auth_blob.length = 8 + pkt->auth_length;
/* check for a valid length */
if (pkt->u.request.stub_and_verifier.length < auth_blob.length) {
return False;
}
auth_blob.data =
pkt->u.request.stub_and_verifier.data +
pkt->u.request.stub_and_verifier.length - auth_blob.length;
pkt->u.request.stub_and_verifier.length -= auth_blob.length;
/* pull the auth structure */
ndr = ndr_pull_init_blob(&auth_blob, call);
if (!ndr) {
return False;
}
if (!(pkt->drep[0] & DCERPC_DREP_LE)) {
ndr->flags |= LIBNDR_FLAG_BIGENDIAN;
}
status = ndr_pull_dcerpc_auth(ndr, NDR_SCALARS|NDR_BUFFERS, &auth);
if (!NT_STATUS_IS_OK(status)) {
talloc_free(ndr);
return False;
}
/* check signature or unseal the packet */
switch (dce_conn->auth_state.auth_info->auth_level) {
case DCERPC_AUTH_LEVEL_PRIVACY:
status = gensec_unseal_packet(dce_conn->auth_state.gensec_security,
call,
full_packet->data + DCERPC_REQUEST_LENGTH,
pkt->u.request.stub_and_verifier.length,
full_packet->data,
full_packet->length-auth.credentials.length,
&auth.credentials);
memcpy(pkt->u.request.stub_and_verifier.data,
full_packet->data + DCERPC_REQUEST_LENGTH,
pkt->u.request.stub_and_verifier.length);
break;
case DCERPC_AUTH_LEVEL_INTEGRITY:
status = gensec_check_packet(dce_conn->auth_state.gensec_security,
call,
pkt->u.request.stub_and_verifier.data,
pkt->u.request.stub_and_verifier.length,
full_packet->data,
full_packet->length-auth.credentials.length,
&auth.credentials);
break;
case DCERPC_AUTH_LEVEL_CONNECT:
status = dcesrv_check_connect_verifier(&auth.credentials);
break;
default:
status = NT_STATUS_INVALID_LEVEL;
break;
}
/* remove the indicated amount of padding */
if (pkt->u.request.stub_and_verifier.length < auth.auth_pad_length) {
talloc_free(ndr);
return False;
}
pkt->u.request.stub_and_verifier.length -= auth.auth_pad_length;
talloc_free(ndr);
return NT_STATUS_IS_OK(status);
}
/*
push a signed or sealed dcerpc request packet into a blob
*/
BOOL dcesrv_auth_response(struct dcesrv_call_state *call,
DATA_BLOB *blob, struct ncacn_packet *pkt)
{
struct dcesrv_connection *dce_conn = call->conn;
NTSTATUS status;
struct ndr_push *ndr;
uint32_t payload_length;
DATA_BLOB creds2;
/* non-signed packets are simple */
if (!dce_conn->auth_state.auth_info || !dce_conn->auth_state.gensec_security) {
status = ncacn_push_auth(blob, call, pkt, NULL);
return NT_STATUS_IS_OK(status);
}
ndr = ndr_push_init_ctx(call);
if (!ndr) {
return False;
}
if (!(pkt->drep[0] & DCERPC_DREP_LE)) {
ndr->flags |= LIBNDR_FLAG_BIGENDIAN;
}
status = ndr_push_ncacn_packet(ndr, NDR_SCALARS|NDR_BUFFERS, pkt);
if (!NT_STATUS_IS_OK(status)) {
return False;
}
/* pad to 16 byte multiple, match win2k3 */
dce_conn->auth_state.auth_info->auth_pad_length = NDR_ALIGN(ndr, 16);
ndr_push_zero(ndr, dce_conn->auth_state.auth_info->auth_pad_length);
payload_length = ndr->offset - DCERPC_REQUEST_LENGTH;
if (dce_conn->auth_state.auth_info->auth_level == DCERPC_AUTH_LEVEL_CONNECT) {
status = dcesrv_connect_verifier(call,
&dce_conn->auth_state.auth_info->credentials);
if (!NT_STATUS_IS_OK(status)) {
return False;
}
} else {
/* We hope this length is accruate. If must be if the
* GENSEC mech does AEAD signing of the packet
* headers */
dce_conn->auth_state.auth_info->credentials
= data_blob_talloc(call, NULL,
gensec_sig_size(dce_conn->auth_state.gensec_security,
payload_length));
data_blob_clear(&dce_conn->auth_state.auth_info->credentials);
}
/* add the auth verifier */
status = ndr_push_dcerpc_auth(ndr, NDR_SCALARS|NDR_BUFFERS,
dce_conn->auth_state.auth_info);
if (!NT_STATUS_IS_OK(status)) {
return False;
}
/* extract the whole packet as a blob */
*blob = ndr_push_blob(ndr);
/* fill in the fragment length and auth_length, we can't fill
in these earlier as we don't know the signature length (it
could be variable length) */
dcerpc_set_frag_length(blob, blob->length);
/* We hope this value is accruate. If must be if the GENSEC
* mech does AEAD signing of the packet headers */
dcerpc_set_auth_length(blob, dce_conn->auth_state.auth_info->credentials.length);
/* sign or seal the packet */
switch (dce_conn->auth_state.auth_info->auth_level) {
case DCERPC_AUTH_LEVEL_PRIVACY:
status = gensec_seal_packet(dce_conn->auth_state.gensec_security,
call,
ndr->data + DCERPC_REQUEST_LENGTH,
payload_length,
blob->data,
blob->length - dce_conn->auth_state.auth_info->credentials.length,
&creds2);
if (NT_STATUS_IS_OK(status)) {
blob->length -= dce_conn->auth_state.auth_info->credentials.length;
if (!data_blob_append(call, blob, creds2.data, creds2.length))
status = NT_STATUS_NO_MEMORY;
else
status = NT_STATUS_OK;
}
/* If we did AEAD signing of the packet headers, then we hope
* this value didn't change... */
dcerpc_set_auth_length(blob, creds2.length);
dcerpc_set_frag_length(blob, dcerpc_get_frag_length(blob)+creds2.length);
data_blob_free(&creds2);
break;
case DCERPC_AUTH_LEVEL_INTEGRITY:
status = gensec_sign_packet(dce_conn->auth_state.gensec_security,
call,
ndr->data + DCERPC_REQUEST_LENGTH,
payload_length,
blob->data,
blob->length - dce_conn->auth_state.auth_info->credentials.length,
&creds2);
if (NT_STATUS_IS_OK(status)) {
blob->length -= dce_conn->auth_state.auth_info->credentials.length;
if (!data_blob_append(call, blob, creds2.data, creds2.length))
status = NT_STATUS_NO_MEMORY;
else
status = NT_STATUS_OK;
}
/* If we did AEAD signing of the packet headers, then we hope
* this value didn't change... */
dcerpc_set_auth_length(blob, creds2.length);
dcerpc_set_frag_length(blob, dcerpc_get_frag_length(blob)+creds2.length);
data_blob_free(&creds2);
break;
case DCERPC_AUTH_LEVEL_CONNECT:
break;
default:
status = NT_STATUS_INVALID_LEVEL;
break;
}
data_blob_free(&dce_conn->auth_state.auth_info->credentials);
if (!NT_STATUS_IS_OK(status)) {
return False;
}
return True;
}