summaryrefslogtreecommitdiff
path: root/source4/heimdal/lib/krb5/get_for_creds.c
blob: 6eebf1fa8028411bf31e70ff3345137431579b0f (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
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
/*
 * Copyright (c) 1997 - 2004 Kungliga Tekniska Högskolan
 * (Royal Institute of Technology, Stockholm, Sweden). 
 * All rights reserved. 
 *
 * Redistribution and use in source and binary forms, with or without 
 * modification, are permitted provided that the following conditions 
 * are met: 
 *
 * 1. Redistributions of source code must retain the above copyright 
 *    notice, this list of conditions and the following disclaimer. 
 *
 * 2. Redistributions in binary form must reproduce the above copyright 
 *    notice, this list of conditions and the following disclaimer in the 
 *    documentation and/or other materials provided with the distribution. 
 *
 * 3. Neither the name of the Institute nor the names of its contributors 
 *    may be used to endorse or promote products derived from this software 
 *    without specific prior written permission. 
 *
 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND 
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE 
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 
 * SUCH DAMAGE. 
 */

#include <krb5_locl.h>

RCSID("$Id: get_for_creds.c,v 1.49 2006/04/10 09:28:15 lha Exp $");

static krb5_error_code
add_addrs(krb5_context context,
	  krb5_addresses *addr,
	  struct addrinfo *ai)
{
    krb5_error_code ret;
    unsigned n, i;
    void *tmp;
    struct addrinfo *a;

    n = 0;
    for (a = ai; a != NULL; a = a->ai_next)
	++n;

    tmp = realloc(addr->val, (addr->len + n) * sizeof(*addr->val));
    if (tmp == NULL && (addr->len + n) != 0) {
	krb5_set_error_string(context, "malloc: out of memory");
	ret = ENOMEM;
	goto fail;
    }
    addr->val = tmp;
    for (i = addr->len; i < (addr->len + n); ++i) {
	addr->val[i].addr_type = 0;
	krb5_data_zero(&addr->val[i].address);
    }
    i = addr->len;
    for (a = ai; a != NULL; a = a->ai_next) {
	krb5_address ad;

	ret = krb5_sockaddr2address (context, a->ai_addr, &ad);
	if (ret == 0) {
	    if (krb5_address_search(context, &ad, addr))
		krb5_free_address(context, &ad);
	    else
		addr->val[i++] = ad;
	}
	else if (ret == KRB5_PROG_ATYPE_NOSUPP)
	    krb5_clear_error_string (context);
	else
	    goto fail;
	addr->len = i;
    }
    return 0;
fail:
    krb5_free_addresses (context, addr);
    return ret;
}

/*
 * Forward credentials for `client' to host `hostname`,
 * making them forwardable if `forwardable', and returning the
 * blob of data to sent in `out_data'.
 * If hostname == NULL, pick it from `server'
 */

krb5_error_code KRB5_LIB_FUNCTION
krb5_fwd_tgt_creds (krb5_context	context,
		    krb5_auth_context	auth_context,
		    const char		*hostname,
		    krb5_principal	client,
		    krb5_principal	server,
		    krb5_ccache		ccache,
		    int			forwardable,
		    krb5_data		*out_data)
{
    krb5_flags flags = 0;
    krb5_creds creds;
    krb5_error_code ret;
    krb5_const_realm client_realm;

    flags |= KDC_OPT_FORWARDED;

    if (forwardable)
	flags |= KDC_OPT_FORWARDABLE;

    if (hostname == NULL &&
	krb5_principal_get_type(context, server) == KRB5_NT_SRV_HST) {
	const char *inst = krb5_principal_get_comp_string(context, server, 0);
	const char *host = krb5_principal_get_comp_string(context, server, 1);

	if (inst != NULL &&
	    strcmp(inst, "host") == 0 &&
	    host != NULL && 
	    krb5_principal_get_comp_string(context, server, 2) == NULL)
	    hostname = host;
    }

    client_realm = krb5_principal_get_realm(context, client);
    
    memset (&creds, 0, sizeof(creds));
    creds.client = client;

    ret = krb5_build_principal(context,
			       &creds.server,
			       strlen(client_realm),
			       client_realm,
			       KRB5_TGS_NAME,
			       client_realm,
			       NULL);
    if (ret)
	return ret;

    ret = krb5_get_forwarded_creds (context,
				    auth_context,
				    ccache,
				    flags,
				    hostname,
				    &creds,
				    out_data);
    return ret;
}

/*
 *
 */

krb5_error_code KRB5_LIB_FUNCTION
krb5_get_forwarded_creds (krb5_context	    context,
			  krb5_auth_context auth_context,
			  krb5_ccache       ccache,
			  krb5_flags        flags,
			  const char        *hostname,
			  krb5_creds        *in_creds,
			  krb5_data         *out_data)
{
    krb5_error_code ret;
    krb5_creds *out_creds;
    krb5_addresses addrs, *paddrs;
    KRB_CRED cred;
    KrbCredInfo *krb_cred_info;
    EncKrbCredPart enc_krb_cred_part;
    size_t len;
    unsigned char *buf;
    size_t buf_size;
    krb5_kdc_flags kdc_flags;
    krb5_crypto crypto;
    struct addrinfo *ai;
    int save_errno;
    krb5_creds *ticket;
    char *realm;

    realm = in_creds->client->realm;

    addrs.len = 0;
    addrs.val = NULL;
    paddrs = &addrs;

    {
	krb5_boolean noaddr;
	krb5_appdefault_boolean(context, NULL, realm,
				"no-addresses", KRB5_ADDRESSLESS_DEFAULT,
				&noaddr);
	if (noaddr)
	    paddrs = NULL;
    }
	
    /*
     * If tickets are address-less, forward address-less tickets.
     */

    if (paddrs) {
	ret = _krb5_get_krbtgt (context,
				ccache,
				realm,
				&ticket);
	if(ret == 0) {
	    if (ticket->addresses.len == 0)
		paddrs = NULL;
	    krb5_free_creds (context, ticket);
	}
    }
    
    if (paddrs != NULL) {

	ret = getaddrinfo (hostname, NULL, NULL, &ai);
	if (ret) {
	    save_errno = errno;
	    krb5_set_error_string(context, "resolving %s: %s",
				  hostname, gai_strerror(ret));
	    return krb5_eai_to_heim_errno(ret, save_errno);
	}
	
	ret = add_addrs (context, &addrs, ai);
	freeaddrinfo (ai);
	if (ret)
	    return ret;
    }
    
    kdc_flags.b = int2KDCOptions(flags);

    ret = krb5_get_kdc_cred (context,
			     ccache,
			     kdc_flags,
			     paddrs,
			     NULL,
			     in_creds,
			     &out_creds);
    krb5_free_addresses (context, &addrs);
    if (ret) {
	return ret;
    }

    memset (&cred, 0, sizeof(cred));
    cred.pvno = 5;
    cred.msg_type = krb_cred;
    ALLOC_SEQ(&cred.tickets, 1);
    if (cred.tickets.val == NULL) {
	ret = ENOMEM;
	krb5_set_error_string(context, "malloc: out of memory");
	goto out2;
    }
    ret = decode_Ticket(out_creds->ticket.data,
			out_creds->ticket.length,
			cred.tickets.val, &len);
    if (ret)
	goto out3;

    memset (&enc_krb_cred_part, 0, sizeof(enc_krb_cred_part));
    ALLOC_SEQ(&enc_krb_cred_part.ticket_info, 1);
    if (enc_krb_cred_part.ticket_info.val == NULL) {
	ret = ENOMEM;
	krb5_set_error_string(context, "malloc: out of memory");
	goto out4;
    }
    
    if (auth_context->flags & KRB5_AUTH_CONTEXT_DO_TIME) {
	krb5_timestamp sec;
	int32_t usec;
	
	krb5_us_timeofday (context, &sec, &usec);
	
	ALLOC(enc_krb_cred_part.timestamp, 1);
	if (enc_krb_cred_part.timestamp == NULL) {
	    ret = ENOMEM;
	    krb5_set_error_string(context, "malloc: out of memory");
	    goto out4;
	}
	*enc_krb_cred_part.timestamp = sec;
	ALLOC(enc_krb_cred_part.usec, 1);
	if (enc_krb_cred_part.usec == NULL) {
	    ret = ENOMEM;
	    krb5_set_error_string(context, "malloc: out of memory");
	    goto out4;
	}
	*enc_krb_cred_part.usec      = usec;
    } else {
	enc_krb_cred_part.timestamp = NULL;
	enc_krb_cred_part.usec = NULL;
    }

    if (auth_context->local_address && auth_context->local_port && paddrs) {

	ret = krb5_make_addrport (context,
				  &enc_krb_cred_part.s_address,
				  auth_context->local_address,
				  auth_context->local_port);
	if (ret)
	    goto out4;
    }

    if (auth_context->remote_address) {
	if (auth_context->remote_port) {
	    krb5_boolean noaddr;
	    krb5_const_realm srealm;

	    srealm = krb5_principal_get_realm(context, out_creds->server);
	    /* Is this correct, and should we use the paddrs == NULL
               trick here as well? Having an address-less ticket may
               indicate that we don't know our own global address, but
               it does not necessary mean that we don't know the
               server's. */
	    krb5_appdefault_boolean(context, NULL, srealm, "no-addresses",
				    FALSE, &noaddr);
	    if (!noaddr) {
		ret = krb5_make_addrport (context,
					  &enc_krb_cred_part.r_address,
					  auth_context->remote_address,
					  auth_context->remote_port);
		if (ret)
		    goto out4;
	    }
	} else {
	    ALLOC(enc_krb_cred_part.r_address, 1);
	    if (enc_krb_cred_part.r_address == NULL) {
		ret = ENOMEM;
		krb5_set_error_string(context, "malloc: out of memory");
		goto out4;
	    }

	    ret = krb5_copy_address (context, auth_context->remote_address,
				     enc_krb_cred_part.r_address);
	    if (ret)
		goto out4;
	}
    }

    /* fill ticket_info.val[0] */

    enc_krb_cred_part.ticket_info.len = 1;

    krb_cred_info = enc_krb_cred_part.ticket_info.val;

    copy_EncryptionKey (&out_creds->session, &krb_cred_info->key);
    ALLOC(krb_cred_info->prealm, 1);
    copy_Realm (&out_creds->client->realm, krb_cred_info->prealm);
    ALLOC(krb_cred_info->pname, 1);
    copy_PrincipalName(&out_creds->client->name, krb_cred_info->pname);
    ALLOC(krb_cred_info->flags, 1);
    *krb_cred_info->flags          = out_creds->flags.b;
    ALLOC(krb_cred_info->authtime, 1);
    *krb_cred_info->authtime       = out_creds->times.authtime;
    ALLOC(krb_cred_info->starttime, 1);
    *krb_cred_info->starttime      = out_creds->times.starttime;
    ALLOC(krb_cred_info->endtime, 1);
    *krb_cred_info->endtime        = out_creds->times.endtime;
    ALLOC(krb_cred_info->renew_till, 1);
    *krb_cred_info->renew_till = out_creds->times.renew_till;
    ALLOC(krb_cred_info->srealm, 1);
    copy_Realm (&out_creds->server->realm, krb_cred_info->srealm);
    ALLOC(krb_cred_info->sname, 1);
    copy_PrincipalName (&out_creds->server->name, krb_cred_info->sname);
    ALLOC(krb_cred_info->caddr, 1);
    copy_HostAddresses (&out_creds->addresses, krb_cred_info->caddr);

    krb5_free_creds (context, out_creds);

    /* encode EncKrbCredPart */

    ASN1_MALLOC_ENCODE(EncKrbCredPart, buf, buf_size, 
		       &enc_krb_cred_part, &len, ret);
    free_EncKrbCredPart (&enc_krb_cred_part);
    if (ret) {
	free_KRB_CRED(&cred);
	return ret;
    }
    if(buf_size != len)
	krb5_abortx(context, "internal error in ASN.1 encoder");

    if (auth_context->flags & KRB5_AUTH_CONTEXT_CLEAR_FORWARDED_CRED) {
	cred.enc_part.etype = ENCTYPE_NULL;
	cred.enc_part.kvno = NULL;
	cred.enc_part.cipher.data = buf;
	cred.enc_part.cipher.length = buf_size;
    } else {
	/* 
	 * Here older versions then 0.7.2 of Heimdal used the local or
	 * remote subkey. That is wrong, the session key should be
	 * used. Heimdal 0.7.2 and newer have code to try both in the
	 * receiving end.
	 */
	
	ret = krb5_crypto_init(context, auth_context->keyblock, 0, &crypto);
	if (ret) {
	    free(buf);
	    free_KRB_CRED(&cred);
	    return ret;
	}
	ret = krb5_encrypt_EncryptedData (context,
					  crypto,
					  KRB5_KU_KRB_CRED,
					  buf,
					  len,
					  0,
					  &cred.enc_part);
	free(buf);
	krb5_crypto_destroy(context, crypto);
	if (ret) {
	    free_KRB_CRED(&cred);
	    return ret;
	}
    }

    ASN1_MALLOC_ENCODE(KRB_CRED, buf, buf_size, &cred, &len, ret);
    free_KRB_CRED (&cred);
    if (ret)
	return ret;
    if(buf_size != len)
	krb5_abortx(context, "internal error in ASN.1 encoder");
    out_data->length = len;
    out_data->data   = buf;
    return 0;
 out4:
    free_EncKrbCredPart(&enc_krb_cred_part);
 out3:
    free_KRB_CRED(&cred);
 out2:
    krb5_free_creds (context, out_creds);
    return ret;
}