1 /*
2  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
3  * Use is subject to license terms.
4  */
5 
6 
7 /*
8  * NAME
9  *    cred.c
10  *
11  * DESCRIPTION
12  *    Provide an interface to assemble and disassemble krb5_cred
13  *    structures.
14  *
15  */
16 #include "k5-int.h"
17 #include "cleanup.h"
18 #include "auth_con.h"
19 
20 #include <stddef.h>           /* NULL */
21 #include <stdlib.h>           /* malloc */
22 #include <errno.h>            /* ENOMEM */
23 
24 /*-------------------- encrypt_credencpart --------------------*/
25 
26 /*ARGSUSED*/
27 /*
28  * encrypt the enc_part of krb5_cred
29  */
30 static krb5_error_code
encrypt_credencpart(krb5_context context,krb5_cred_enc_part * pcredpart,krb5_keyblock * pkeyblock,krb5_enc_data * pencdata)31 encrypt_credencpart(krb5_context context, krb5_cred_enc_part *pcredpart, krb5_keyblock *pkeyblock, krb5_enc_data *pencdata)
32 {
33     krb5_error_code 	  retval;
34     krb5_data 		* scratch;
35 
36     /* start by encoding to-be-encrypted part of the message */
37     if ((retval = encode_krb5_enc_cred_part(pcredpart, &scratch)))
38     	return retval;
39 
40     /*
41      * If the keyblock is NULL, just copy the data from the encoded
42      * data to the ciphertext area.
43      */
44     if (pkeyblock == NULL) {
45 	    pencdata->ciphertext.data = scratch->data;
46 	    pencdata->ciphertext.length = scratch->length;
47 	    krb5_xfree(scratch);
48 	    return 0;
49     }
50 
51     /* call the encryption routine */
52     retval = krb5_encrypt_helper(context, pkeyblock,
53 				 KRB5_KEYUSAGE_KRB_CRED_ENCPART,
54 				 scratch, pencdata);
55 
56     if (retval) {
57     	memset(pencdata->ciphertext.data, 0, pencdata->ciphertext.length);
58         free(pencdata->ciphertext.data);
59         pencdata->ciphertext.length = 0;
60         pencdata->ciphertext.data = 0;
61     }
62 
63     memset(scratch->data, 0, scratch->length);
64     krb5_free_data(context, scratch);
65 
66     return retval;
67 }
68 
69 /*----------------------- krb5_mk_ncred_basic -----------------------*/
70 
71 static krb5_error_code
krb5_mk_ncred_basic(krb5_context context,krb5_creds ** ppcreds,krb5_int32 nppcreds,krb5_keyblock * keyblock,krb5_replay_data * replaydata,krb5_address * local_addr,krb5_address * remote_addr,krb5_cred * pcred)72 krb5_mk_ncred_basic(krb5_context context, krb5_creds **ppcreds, krb5_int32 nppcreds, krb5_keyblock *keyblock, krb5_replay_data *replaydata, krb5_address *local_addr, krb5_address *remote_addr, krb5_cred *pcred)
73 {
74     krb5_cred_enc_part 	  credenc;
75     krb5_error_code	  retval;
76     size_t		  size;
77     int			  i;
78 
79     credenc.magic = KV5M_CRED_ENC_PART;
80 
81     credenc.s_address = 0;
82     credenc.r_address = 0;
83     if (local_addr) krb5_copy_addr(context, local_addr, &credenc.s_address);
84     if (remote_addr) krb5_copy_addr(context, remote_addr, &credenc.r_address);
85 
86     credenc.nonce = replaydata->seq;
87     credenc.usec = replaydata->usec;
88     credenc.timestamp = replaydata->timestamp;
89 
90     /* Get memory for creds and initialize it */
91     size = sizeof(krb5_cred_info *) * (nppcreds + 1);
92     credenc.ticket_info = (krb5_cred_info **) malloc(size);
93     if (credenc.ticket_info == NULL)
94 	return ENOMEM;
95     memset(credenc.ticket_info, 0, size);
96 
97     /*
98      * For each credential in the list, initialize a cred info
99      * structure and copy the ticket into the ticket list.
100      */
101     for (i = 0; i < nppcreds; i++) {
102     	credenc.ticket_info[i] = malloc(sizeof(krb5_cred_info));
103 	if (credenc.ticket_info[i] == NULL) {
104 	    retval = ENOMEM;
105 	    goto cleanup;
106 	}
107 	credenc.ticket_info[i+1] = NULL;
108 
109         credenc.ticket_info[i]->magic = KV5M_CRED_INFO;
110         credenc.ticket_info[i]->times = ppcreds[i]->times;
111         credenc.ticket_info[i]->flags = ppcreds[i]->ticket_flags;
112 
113     	if ((retval = decode_krb5_ticket(&ppcreds[i]->ticket,
114 					 &pcred->tickets[i])))
115 	    goto cleanup;
116 
117 	if ((retval = krb5_copy_keyblock(context, &ppcreds[i]->keyblock,
118 					 &credenc.ticket_info[i]->session)))
119             goto cleanup;
120 
121         if ((retval = krb5_copy_principal(context, ppcreds[i]->client,
122 					  &credenc.ticket_info[i]->client)))
123             goto cleanup;
124 
125       	if ((retval = krb5_copy_principal(context, ppcreds[i]->server,
126 					  &credenc.ticket_info[i]->server)))
127             goto cleanup;
128 
129       	if ((retval = krb5_copy_addresses(context, ppcreds[i]->addresses,
130 					  &credenc.ticket_info[i]->caddrs)))
131             goto cleanup;
132     }
133 
134     /*
135      * NULL terminate the lists.
136      */
137     pcred->tickets[i] = NULL;
138 
139     /* encrypt the credential encrypted part */
140     retval = encrypt_credencpart(context, &credenc, keyblock,
141 				 &pcred->enc_part);
142 
143 cleanup:
144     krb5_free_cred_enc_part(context, &credenc);
145     return retval;
146 }
147 
148 /*----------------------- krb5_mk_ncred -----------------------*/
149 
150 /*
151  * This functions takes as input an array of krb5_credentials, and
152  * outputs an encoded KRB_CRED message suitable for krb5_rd_cred
153  */
154 krb5_error_code KRB5_CALLCONV
krb5_mk_ncred(krb5_context context,krb5_auth_context auth_context,krb5_creds ** ppcreds,krb5_data ** ppdata,krb5_replay_data * outdata)155 krb5_mk_ncred(krb5_context context, krb5_auth_context auth_context, krb5_creds **ppcreds, krb5_data **ppdata, krb5_replay_data *outdata)
156 {
157     krb5_address * premote_fulladdr = NULL;
158     krb5_address * plocal_fulladdr = NULL;
159     krb5_address remote_fulladdr;
160     krb5_address local_fulladdr;
161     krb5_error_code 	retval;
162     krb5_keyblock	 * keyblock;
163     krb5_replay_data    replaydata;
164     krb5_cred 		 * pcred;
165     krb5_int32		ncred;
166 
167     local_fulladdr.contents = 0;
168     remote_fulladdr.contents = 0;
169     memset(&replaydata, 0, sizeof(krb5_replay_data));
170 
171     if (ppcreds == NULL) {
172     	return KRB5KRB_AP_ERR_BADADDR;
173     }
174 
175     /*
176      * Allocate memory for a NULL terminated list of tickets.
177      */
178     for (ncred = 0; ppcreds[ncred]; ncred++);
179 
180     if ((pcred = (krb5_cred *)malloc(sizeof(krb5_cred))) == NULL)
181         return ENOMEM;
182     memset(pcred, 0, sizeof(krb5_cred));
183 
184     if ((pcred->tickets
185       = (krb5_ticket **)malloc(sizeof(krb5_ticket *) * (ncred + 1))) == NULL) {
186 	retval = ENOMEM;
187 	free(pcred);
188     }
189     memset(pcred->tickets, 0, sizeof(krb5_ticket *) * (ncred +1));
190 
191     /* Get keyblock */
192     if ((keyblock = auth_context->send_subkey) == NULL)
193 	keyblock = auth_context->keyblock;
194 
195     /* Get replay info */
196     if ((auth_context->auth_context_flags & KRB5_AUTH_CONTEXT_DO_TIME) &&
197       (auth_context->rcache == NULL))
198         return KRB5_RC_REQUIRED;
199 
200     if (((auth_context->auth_context_flags & KRB5_AUTH_CONTEXT_RET_TIME) ||
201       (auth_context->auth_context_flags & KRB5_AUTH_CONTEXT_RET_SEQUENCE)) &&
202       (outdata == NULL))
203         /* Need a better error */
204         return KRB5_RC_REQUIRED;
205 
206     if ((retval = krb5_us_timeofday(context, &replaydata.timestamp,
207 				    &replaydata.usec)))
208 	return retval;
209     if (auth_context->auth_context_flags & KRB5_AUTH_CONTEXT_RET_TIME) {
210 	outdata->timestamp = replaydata.timestamp;
211 	outdata->usec = replaydata.usec;
212     }
213     if ((auth_context->auth_context_flags & KRB5_AUTH_CONTEXT_DO_SEQUENCE) ||
214         (auth_context->auth_context_flags & KRB5_AUTH_CONTEXT_RET_SEQUENCE)) {
215         replaydata.seq = auth_context->local_seq_number;
216         if (auth_context->auth_context_flags & KRB5_AUTH_CONTEXT_DO_SEQUENCE) {
217             auth_context->local_seq_number++;
218         } else {
219             outdata->seq = replaydata.seq;
220         }
221     }
222 
223     if (auth_context->local_addr) {
224     	if (auth_context->local_port) {
225             if ((retval = krb5_make_fulladdr(context, auth_context->local_addr,
226 					     auth_context->local_port,
227 					     &local_fulladdr)))
228 		goto error;
229 	    plocal_fulladdr = &local_fulladdr;
230 	} else {
231             plocal_fulladdr = auth_context->local_addr;
232         }
233     }
234 
235     if (auth_context->remote_addr) {
236     	if (auth_context->remote_port) {
237             if ((retval = krb5_make_fulladdr(context,auth_context->remote_addr,
238                                  	      auth_context->remote_port,
239 					      &remote_fulladdr)))
240 		goto error;
241 	    premote_fulladdr = &remote_fulladdr;
242 	} else {
243             premote_fulladdr = auth_context->remote_addr;
244         }
245     }
246 
247     /* Setup creds structure */
248     if ((retval = krb5_mk_ncred_basic(context, ppcreds, ncred, keyblock,
249 				      &replaydata, plocal_fulladdr,
250 				      premote_fulladdr, pcred))) {
251 	goto error;
252     }
253 
254     if (auth_context->auth_context_flags & KRB5_AUTH_CONTEXT_DO_TIME) {
255         krb5_donot_replay replay;
256 
257         if ((retval = krb5_gen_replay_name(context, auth_context->local_addr,
258 					   "_forw", &replay.client)))
259             goto error;
260 
261         replay.server = "";             /* XXX */
262         replay.cusec = replaydata.usec;
263         replay.ctime = replaydata.timestamp;
264         if ((retval = krb5_rc_store(context, auth_context->rcache, &replay))) {
265             /* should we really error out here? XXX */
266             krb5_xfree(replay.client);
267             goto error;
268         }
269         krb5_xfree(replay.client);
270     }
271 
272     /* Encode creds structure */
273     retval = encode_krb5_cred(pcred, ppdata);
274 
275 error:
276     if (local_fulladdr.contents)
277 	free(local_fulladdr.contents);
278     if (remote_fulladdr.contents)
279 	free(remote_fulladdr.contents);
280     krb5_free_cred(context, pcred);
281 
282     if (retval) {
283 	if ((auth_context->auth_context_flags & KRB5_AUTH_CONTEXT_DO_SEQUENCE)
284 	 || (auth_context->auth_context_flags & KRB5_AUTH_CONTEXT_RET_SEQUENCE))
285             auth_context->local_seq_number--;
286     }
287     return retval;
288 }
289 
290 /*----------------------- krb5_mk_1cred -----------------------*/
291 
292 /*
293  * A convenience function that calls krb5_mk_ncred.
294  */
295 krb5_error_code KRB5_CALLCONV
krb5_mk_1cred(krb5_context context,krb5_auth_context auth_context,krb5_creds * pcreds,krb5_data ** ppdata,krb5_replay_data * outdata)296 krb5_mk_1cred(krb5_context context, krb5_auth_context auth_context, krb5_creds *pcreds, krb5_data **ppdata, krb5_replay_data *outdata)
297 {
298     krb5_error_code retval;
299     krb5_creds **ppcreds;
300 
301     if ((ppcreds = (krb5_creds **)malloc(sizeof(*ppcreds) * 2)) == NULL) {
302 	return ENOMEM;
303     }
304 
305     ppcreds[0] = pcreds;
306     ppcreds[1] = NULL;
307 
308     retval = krb5_mk_ncred(context, auth_context, ppcreds,
309 			   ppdata, outdata);
310 
311     free(ppcreds);
312     return retval;
313 }
314 
315