get_for_creds.c revision 103423 
1/*
2 * Copyright (c) 1997 - 2002 Kungliga Tekniska H�gskolan
3 * (Royal Institute of Technology, Stockholm, Sweden).
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 *
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 *
13 * 2. Redistributions in binary form must reproduce the above copyright
14 *    notice, this list of conditions and the following disclaimer in the
15 *    documentation and/or other materials provided with the distribution.
16 *
17 * 3. Neither the name of the Institute nor the names of its contributors
18 *    may be used to endorse or promote products derived from this software
19 *    without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34#include <krb5_locl.h>
35
36RCSID("$Id: get_for_creds.c,v 1.34 2002/09/04 16:26:04 joda Exp $");
37
38static krb5_error_code
39add_addrs(krb5_context context,
40	  krb5_addresses *addr,
41	  struct addrinfo *ai)
42{
43    krb5_error_code ret;
44    unsigned n, i, j;
45    void *tmp;
46    struct addrinfo *a;
47
48    n = 0;
49    for (a = ai; a != NULL; a = a->ai_next)
50	++n;
51
52    i = addr->len;
53    addr->len += n;
54    tmp = realloc(addr->val, addr->len * sizeof(*addr->val));
55    if (tmp == NULL) {
56	krb5_set_error_string(context, "malloc: out of memory");
57	ret = ENOMEM;
58	goto fail;
59    }
60    addr->val = tmp;
61    for (j = i; j < addr->len; ++j) {
62	addr->val[i].addr_type = 0;
63	krb5_data_zero(&addr->val[i].address);
64    }
65    for (a = ai; a != NULL; a = a->ai_next) {
66	ret = krb5_sockaddr2address (context, a->ai_addr, &addr->val[i]);
67	if (ret == 0)
68	    ++i;
69	else if (ret == KRB5_PROG_ATYPE_NOSUPP)
70	    krb5_clear_error_string (context);
71	else
72	    goto fail;
73    }
74    addr->len = i;
75    return 0;
76fail:
77    krb5_free_addresses (context, addr);
78    return ret;
79}
80
81/*
82 * Forward credentials for `client' to host `hostname`,
83 * making them forwardable if `forwardable', and returning the
84 * blob of data to sent in `out_data'.
85 * If hostname == NULL, pick it from `server'
86 */
87
88krb5_error_code
89krb5_fwd_tgt_creds (krb5_context	context,
90		    krb5_auth_context	auth_context,
91		    const char		*hostname,
92		    krb5_principal	client,
93		    krb5_principal	server,
94		    krb5_ccache		ccache,
95		    int			forwardable,
96		    krb5_data		*out_data)
97{
98    krb5_flags flags = 0;
99    krb5_creds creds;
100    krb5_error_code ret;
101    krb5_const_realm client_realm;
102
103    flags |= KDC_OPT_FORWARDED;
104
105    if (forwardable)
106	flags |= KDC_OPT_FORWARDABLE;
107
108    if (hostname == NULL &&
109	krb5_principal_get_type(context, server) == KRB5_NT_SRV_HST) {
110	const char *inst = krb5_principal_get_comp_string(context, server, 0);
111	const char *host = krb5_principal_get_comp_string(context, server, 1);
112
113	if (inst != NULL &&
114	    strcmp(inst, "host") == 0 &&
115	    host != NULL &&
116	    krb5_principal_get_comp_string(context, server, 2) == NULL)
117	    hostname = host;
118    }
119
120    client_realm = krb5_principal_get_realm(context, client);
121
122    memset (&creds, 0, sizeof(creds));
123    creds.client = client;
124
125    ret = krb5_build_principal(context,
126			       &creds.server,
127			       strlen(client_realm),
128			       client_realm,
129			       KRB5_TGS_NAME,
130			       client_realm,
131			       NULL);
132    if (ret)
133	return ret;
134
135    ret = krb5_get_forwarded_creds (context,
136				    auth_context,
137				    ccache,
138				    flags,
139				    hostname,
140				    &creds,
141				    out_data);
142    return ret;
143}
144
145/*
146 *
147 */
148
149krb5_error_code
150krb5_get_forwarded_creds (krb5_context	    context,
151			  krb5_auth_context auth_context,
152			  krb5_ccache       ccache,
153			  krb5_flags        flags,
154			  const char        *hostname,
155			  krb5_creds        *in_creds,
156			  krb5_data         *out_data)
157{
158    krb5_error_code ret;
159    krb5_creds *out_creds;
160    krb5_addresses addrs;
161    KRB_CRED cred;
162    KrbCredInfo *krb_cred_info;
163    EncKrbCredPart enc_krb_cred_part;
164    size_t len;
165    unsigned char *buf;
166    size_t buf_size;
167    int32_t sec, usec;
168    krb5_kdc_flags kdc_flags;
169    krb5_crypto crypto;
170    struct addrinfo *ai;
171    int save_errno;
172    krb5_keyblock *key;
173
174    addrs.len = 0;
175    addrs.val = NULL;
176
177    ret = getaddrinfo (hostname, NULL, NULL, &ai);
178    if (ret) {
179	save_errno = errno;
180	krb5_set_error_string(context, "resolving %s: %s",
181			      hostname, gai_strerror(ret));
182	return krb5_eai_to_heim_errno(ret, save_errno);
183    }
184
185    ret = add_addrs (context, &addrs, ai);
186    freeaddrinfo (ai);
187    if (ret)
188	return ret;
189
190    kdc_flags.i = flags;
191
192    ret = krb5_get_kdc_cred (context,
193			     ccache,
194			     kdc_flags,
195			     &addrs,
196			     NULL,
197			     in_creds,
198			     &out_creds);
199    krb5_free_addresses (context, &addrs);
200    if (ret) {
201	return ret;
202    }
203
204    memset (&cred, 0, sizeof(cred));
205    cred.pvno = 5;
206    cred.msg_type = krb_cred;
207    ALLOC_SEQ(&cred.tickets, 1);
208    if (cred.tickets.val == NULL) {
209	ret = ENOMEM;
210	krb5_set_error_string(context, "malloc: out of memory");
211	goto out2;
212    }
213    ret = decode_Ticket(out_creds->ticket.data,
214			out_creds->ticket.length,
215			cred.tickets.val, &len);
216    if (ret)
217	goto out3;
218
219    memset (&enc_krb_cred_part, 0, sizeof(enc_krb_cred_part));
220    ALLOC_SEQ(&enc_krb_cred_part.ticket_info, 1);
221    if (enc_krb_cred_part.ticket_info.val == NULL) {
222	ret = ENOMEM;
223	krb5_set_error_string(context, "malloc: out of memory");
224	goto out4;
225    }
226
227    krb5_us_timeofday (context, &sec, &usec);
228
229    ALLOC(enc_krb_cred_part.timestamp, 1);
230    if (enc_krb_cred_part.timestamp == NULL) {
231	ret = ENOMEM;
232	krb5_set_error_string(context, "malloc: out of memory");
233	goto out4;
234    }
235    *enc_krb_cred_part.timestamp = sec;
236    ALLOC(enc_krb_cred_part.usec, 1);
237    if (enc_krb_cred_part.usec == NULL) {
238 	ret = ENOMEM;
239	krb5_set_error_string(context, "malloc: out of memory");
240	goto out4;
241    }
242    *enc_krb_cred_part.usec      = usec;
243
244    if (auth_context->local_address && auth_context->local_port) {
245	krb5_boolean noaddr;
246	const krb5_realm *realm;
247
248	realm = krb5_princ_realm(context, out_creds->server);
249	krb5_appdefault_boolean(context, NULL, *realm, "no-addresses", FALSE,
250				&noaddr);
251	if (!noaddr) {
252	    ret = krb5_make_addrport (context,
253				      &enc_krb_cred_part.s_address,
254				      auth_context->local_address,
255				      auth_context->local_port);
256	    if (ret)
257		goto out4;
258	}
259    }
260
261    if (auth_context->remote_address) {
262	if (auth_context->remote_port) {
263	    krb5_boolean noaddr;
264	    const krb5_realm *realm;
265
266	    realm = krb5_princ_realm(context, out_creds->server);
267	    krb5_appdefault_boolean(context, NULL, *realm, "no-addresses",
268				    FALSE, &noaddr);
269	    if (!noaddr) {
270		ret = krb5_make_addrport (context,
271					  &enc_krb_cred_part.r_address,
272					  auth_context->remote_address,
273					  auth_context->remote_port);
274		if (ret)
275		    goto out4;
276	    }
277	} else {
278	    ALLOC(enc_krb_cred_part.r_address, 1);
279	    if (enc_krb_cred_part.r_address == NULL) {
280		ret = ENOMEM;
281		krb5_set_error_string(context, "malloc: out of memory");
282		goto out4;
283	    }
284
285	    ret = krb5_copy_address (context, auth_context->remote_address,
286				     enc_krb_cred_part.r_address);
287	    if (ret)
288		goto out4;
289	}
290    }
291
292    /* fill ticket_info.val[0] */
293
294    enc_krb_cred_part.ticket_info.len = 1;
295
296    krb_cred_info = enc_krb_cred_part.ticket_info.val;
297
298    copy_EncryptionKey (&out_creds->session, &krb_cred_info->key);
299    ALLOC(krb_cred_info->prealm, 1);
300    copy_Realm (&out_creds->client->realm, krb_cred_info->prealm);
301    ALLOC(krb_cred_info->pname, 1);
302    copy_PrincipalName(&out_creds->client->name, krb_cred_info->pname);
303    ALLOC(krb_cred_info->flags, 1);
304    *krb_cred_info->flags          = out_creds->flags.b;
305    ALLOC(krb_cred_info->authtime, 1);
306    *krb_cred_info->authtime       = out_creds->times.authtime;
307    ALLOC(krb_cred_info->starttime, 1);
308    *krb_cred_info->starttime      = out_creds->times.starttime;
309    ALLOC(krb_cred_info->endtime, 1);
310    *krb_cred_info->endtime        = out_creds->times.endtime;
311    ALLOC(krb_cred_info->renew_till, 1);
312    *krb_cred_info->renew_till = out_creds->times.renew_till;
313    ALLOC(krb_cred_info->srealm, 1);
314    copy_Realm (&out_creds->server->realm, krb_cred_info->srealm);
315    ALLOC(krb_cred_info->sname, 1);
316    copy_PrincipalName (&out_creds->server->name, krb_cred_info->sname);
317    ALLOC(krb_cred_info->caddr, 1);
318    copy_HostAddresses (&out_creds->addresses, krb_cred_info->caddr);
319
320    krb5_free_creds (context, out_creds);
321
322    /* encode EncKrbCredPart */
323
324    ASN1_MALLOC_ENCODE(EncKrbCredPart, buf, buf_size,
325		       &enc_krb_cred_part, &len, ret);
326    free_EncKrbCredPart (&enc_krb_cred_part);
327    if (ret) {
328	free_KRB_CRED(&cred);
329	return ret;
330    }
331    if(buf_size != len)
332	krb5_abortx(context, "internal error in ASN.1 encoder");
333
334    if (auth_context->local_subkey)
335	key = auth_context->local_subkey;
336    else if (auth_context->remote_subkey)
337	key = auth_context->remote_subkey;
338    else
339	key = auth_context->keyblock;
340
341    ret = krb5_crypto_init(context, key, 0, &crypto);
342    if (ret) {
343	free(buf);
344	free_KRB_CRED(&cred);
345	return ret;
346    }
347    ret = krb5_encrypt_EncryptedData (context,
348				      crypto,
349				      KRB5_KU_KRB_CRED,
350				      buf,
351				      len,
352				      0,
353				      &cred.enc_part);
354    free(buf);
355    krb5_crypto_destroy(context, crypto);
356    if (ret) {
357	free_KRB_CRED(&cred);
358	return ret;
359    }
360
361    ASN1_MALLOC_ENCODE(KRB_CRED, buf, buf_size, &cred, &len, ret);
362    free_KRB_CRED (&cred);
363    if (ret)
364	return ret;
365    if(buf_size != len)
366	krb5_abortx(context, "internal error in ASN.1 encoder");
367    out_data->length = len;
368    out_data->data   = buf;
369    return 0;
370out4:
371    free_EncKrbCredPart(&enc_krb_cred_part);
372out3:
373    free_KRB_CRED(&cred);
374out2:
375    krb5_free_creds (context, out_creds);
376    return ret;
377}
378