summaryrefslogtreecommitdiff
path: root/source4/rpc_server/dcesrv_auth.c
blob: 84a5460d6887b55ab4da711ebc3e8878582cd997 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
/* 
   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 2 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, write to the Free Software
   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/

#include "includes.h"

/*
  startup the cryptographic side of an authenticated dcerpc server
*/
NTSTATUS dcesrv_crypto_select_type(struct dcesrv_connection *dce_conn,
			       struct dcesrv_auth *auth)
{
	NTSTATUS status;
	if (auth->auth_info->auth_level != DCERPC_AUTH_LEVEL_INTEGRITY &&
	    auth->auth_info->auth_level != DCERPC_AUTH_LEVEL_PRIVACY) {
		DEBUG(2,("auth_level %d not supported in dcesrv auth\n", 
			 auth->auth_info->auth_level));
		return NT_STATUS_INVALID_PARAMETER;
	}

	if (auth->gensec_security != NULL) {
		/* TODO:
		 * this this function should not be called
		 * twice per dcesrv_connection!
		 * 
		 * so we need to find out the right
		 * dcerpc error to return
		 */
	}

	status = gensec_server_start(&auth->gensec_security);
	if (!NT_STATUS_IS_OK(status)) {
		DEBUG(1, ("Failed to start GENSEC server code: %s\n", nt_errstr(status)));
		return status;
	}

	status = gensec_start_mech_by_authtype(auth->gensec_security, auth->auth_info->auth_type);

	if (!NT_STATUS_IS_OK(status)) {
		DEBUG(1, ("Failed to start GENSEC mech-specific server code (%d): %s\n", 
			  (int)auth->auth_info->auth_type,
			  nt_errstr(status)));
		return status;
	}

	return status;
}

/*
  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 dcerpc_packet *pkt = &call->pkt;
	struct dcesrv_connection *dce_conn = call->conn;
	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_p(dce_conn->mem_ctx, struct dcerpc_auth);
	if (!dce_conn->auth_state.auth_info) {
		return False;
	}

	status = ndr_pull_struct_blob(&pkt->u.bind.auth_info,
				      call->mem_ctx,
				      dce_conn->auth_state.auth_info,
				      (ndr_pull_flags_fn_t)ndr_pull_dcerpc_auth);
	if (!NT_STATUS_IS_OK(status)) {
		return False;
	}

	status = dcesrv_crypto_select_type(dce_conn, &dce_conn->auth_state);
	if (!NT_STATUS_IS_OK(status)) {
		return False;
	}

	return True;
}

/*
  add any auth information needed in a bind ack, and process the authentication
  information found in the bind.
*/
BOOL dcesrv_auth_bind_ack(struct dcesrv_call_state *call, struct dcerpc_packet *pkt)
{
	struct dcesrv_connection *dce_conn = call->conn;
	NTSTATUS status;

	if (!call->conn->auth_state.gensec_security) {
		return True;
	}

	status = gensec_update(dce_conn->auth_state.gensec_security,
			       call->mem_ctx,
			       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;
		}
		return True;
	} 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 True;
	} else {
		DEBUG(2, ("Failed to start dcesrv auth negotiate: %s\n", nt_errstr(status)));
		return False;
	}
}


/*
  process the final stage of a auth request
*/
BOOL dcesrv_auth_auth3(struct dcesrv_call_state *call)
{
	struct dcerpc_packet *pkt = &call->pkt;
	struct dcesrv_connection *dce_conn = call->conn;
	NTSTATUS status;

	if (!dce_conn->auth_state.auth_info ||
	    !dce_conn->auth_state.gensec_security ||
	    pkt->u.auth.auth_info.length == 0) {
		return False;
	}

	status = ndr_pull_struct_blob(&pkt->u.auth.auth_info,
				      call->mem_ctx,
				      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_update(dce_conn->auth_state.gensec_security,
			       call->mem_ctx,
			       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;
		}
		return True;
	} else {
		DEBUG(4, ("dcesrv_auth_auth3: failed to authenticate: %s\n", 
			  nt_errstr(status)));
		return False;
	}

	return True;
}


/*
  check credentials on a request
*/
BOOL dcesrv_auth_request(struct dcesrv_call_state *call)
{
	struct dcerpc_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->mem_ctx);
	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)) {
		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->mem_ctx,
					      pkt->u.request.stub_and_verifier.data, 
					      pkt->u.request.stub_and_verifier.length, 
					      &auth.credentials);
		break;

	case DCERPC_AUTH_LEVEL_INTEGRITY:
		status = gensec_check_packet(dce_conn->auth_state.gensec_security,
					     call->mem_ctx,
					     pkt->u.request.stub_and_verifier.data, 
					     pkt->u.request.stub_and_verifier.length,
					     &auth.credentials);
		break;

	default:
		status = NT_STATUS_INVALID_LEVEL;
		break;
	}

	/* remove the indicated amount of paddiing */
	if (pkt->u.request.stub_and_verifier.length < auth.auth_pad_length) {
		return False;
	}
	pkt->u.request.stub_and_verifier.length -= auth.auth_pad_length;

	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 dcerpc_packet *pkt)
{
	struct dcesrv_connection *dce_conn = call->conn;
	NTSTATUS status;
	struct ndr_push *ndr;

	/* non-signed packets are simple */
	if (!dce_conn->auth_state.auth_info || !dce_conn->auth_state.gensec_security) {
		status = dcerpc_push_auth(blob, call->mem_ctx, pkt, NULL);
		return NT_STATUS_IS_OK(status);
	}

	ndr = ndr_push_init_ctx(call->mem_ctx);
	if (!ndr) {
		return False;
	}

	if (!(pkt->drep[0] & DCERPC_DREP_LE)) {
		ndr->flags |= LIBNDR_FLAG_BIGENDIAN;
	}

	status = ndr_push_dcerpc_packet(ndr, NDR_SCALARS|NDR_BUFFERS, pkt);
	if (!NT_STATUS_IS_OK(status)) {
		return False;
	}

	/* pad to 8 byte multiple */
	dce_conn->auth_state.auth_info->auth_pad_length = NDR_ALIGN(ndr, 8);
	ndr_push_zero(ndr, dce_conn->auth_state.auth_info->auth_pad_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->mem_ctx,
					      ndr->data + DCERPC_REQUEST_LENGTH, 
					      ndr->offset - DCERPC_REQUEST_LENGTH,
					      &dce_conn->auth_state.auth_info->credentials);
		break;

	case DCERPC_AUTH_LEVEL_INTEGRITY:
		status = gensec_sign_packet(dce_conn->auth_state.gensec_security, 
					    call->mem_ctx,
					    ndr->data + DCERPC_REQUEST_LENGTH, 
					    ndr->offset - DCERPC_REQUEST_LENGTH,
					    &dce_conn->auth_state.auth_info->credentials);
		break;
	default:
		status = NT_STATUS_INVALID_LEVEL;
		break;
	}

	if (!NT_STATUS_IS_OK(status)) {
		return False;
	}	

	/* 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);
	dcerpc_set_auth_length(blob, dce_conn->auth_state.auth_info->credentials.length);

	data_blob_free(&dce_conn->auth_state.auth_info->credentials);

	return True;
}