xref: /freebsd/crypto/openssl/ssl/d1_srtp.c (revision f4b37ed0f8b307b1f3f0f630ca725d68f1dff30d)
1 /* ssl/t1_lib.c */
2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
3  * All rights reserved.
4  *
5  * This package is an SSL implementation written
6  * by Eric Young (eay@cryptsoft.com).
7  * The implementation was written so as to conform with Netscapes SSL.
8  *
9  * This library is free for commercial and non-commercial use as long as
10  * the following conditions are aheared to.  The following conditions
11  * apply to all code found in this distribution, be it the RC4, RSA,
12  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
13  * included with this distribution is covered by the same copyright terms
14  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
15  *
16  * Copyright remains Eric Young's, and as such any Copyright notices in
17  * the code are not to be removed.
18  * If this package is used in a product, Eric Young should be given attribution
19  * as the author of the parts of the library used.
20  * This can be in the form of a textual message at program startup or
21  * in documentation (online or textual) provided with the package.
22  *
23  * Redistribution and use in source and binary forms, with or without
24  * modification, are permitted provided that the following conditions
25  * are met:
26  * 1. Redistributions of source code must retain the copyright
27  *    notice, this list of conditions and the following disclaimer.
28  * 2. Redistributions in binary form must reproduce the above copyright
29  *    notice, this list of conditions and the following disclaimer in the
30  *    documentation and/or other materials provided with the distribution.
31  * 3. All advertising materials mentioning features or use of this software
32  *    must display the following acknowledgement:
33  *    "This product includes cryptographic software written by
34  *     Eric Young (eay@cryptsoft.com)"
35  *    The word 'cryptographic' can be left out if the rouines from the library
36  *    being used are not cryptographic related :-).
37  * 4. If you include any Windows specific code (or a derivative thereof) from
38  *    the apps directory (application code) you must include an acknowledgement:
39  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
40  *
41  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
42  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
43  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
44  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
45  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
46  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
47  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
49  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
50  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
51  * SUCH DAMAGE.
52  *
53  * The licence and distribution terms for any publically available version or
54  * derivative of this code cannot be changed.  i.e. this code cannot simply be
55  * copied and put under another distribution licence
56  * [including the GNU Public Licence.]
57  */
58 /* ====================================================================
59  * Copyright (c) 1998-2006 The OpenSSL Project.  All rights reserved.
60  *
61  * Redistribution and use in source and binary forms, with or without
62  * modification, are permitted provided that the following conditions
63  * are met:
64  *
65  * 1. Redistributions of source code must retain the above copyright
66  *    notice, this list of conditions and the following disclaimer.
67  *
68  * 2. Redistributions in binary form must reproduce the above copyright
69  *    notice, this list of conditions and the following disclaimer in
70  *    the documentation and/or other materials provided with the
71  *    distribution.
72  *
73  * 3. All advertising materials mentioning features or use of this
74  *    software must display the following acknowledgment:
75  *    "This product includes software developed by the OpenSSL Project
76  *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
77  *
78  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
79  *    endorse or promote products derived from this software without
80  *    prior written permission. For written permission, please contact
81  *    openssl-core@openssl.org.
82  *
83  * 5. Products derived from this software may not be called "OpenSSL"
84  *    nor may "OpenSSL" appear in their names without prior written
85  *    permission of the OpenSSL Project.
86  *
87  * 6. Redistributions of any form whatsoever must retain the following
88  *    acknowledgment:
89  *    "This product includes software developed by the OpenSSL Project
90  *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
91  *
92  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
93  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
94  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
95  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
96  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
97  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
98  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
99  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
100  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
101  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
102  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
103  * OF THE POSSIBILITY OF SUCH DAMAGE.
104  * ====================================================================
105  *
106  * This product includes cryptographic software written by Eric Young
107  * (eay@cryptsoft.com).  This product includes software written by Tim
108  * Hudson (tjh@cryptsoft.com).
109  *
110  */
111 /*
112  * DTLS code by Eric Rescorla <ekr@rtfm.com>
113  *
114  * Copyright (C) 2006, Network Resonance, Inc. Copyright (C) 2011, RTFM, Inc.
115  */
116 
117 #include <stdio.h>
118 #include <openssl/objects.h>
119 #include "ssl_locl.h"
120 
121 #ifndef OPENSSL_NO_SRTP
122 
123 # include "srtp.h"
124 
125 static SRTP_PROTECTION_PROFILE srtp_known_profiles[] = {
126     {
127      "SRTP_AES128_CM_SHA1_80",
128      SRTP_AES128_CM_SHA1_80,
129      },
130     {
131      "SRTP_AES128_CM_SHA1_32",
132      SRTP_AES128_CM_SHA1_32,
133      },
134 # if 0
135     {
136      "SRTP_NULL_SHA1_80",
137      SRTP_NULL_SHA1_80,
138      },
139     {
140      "SRTP_NULL_SHA1_32",
141      SRTP_NULL_SHA1_32,
142      },
143 # endif
144     {0}
145 };
146 
147 static int find_profile_by_name(char *profile_name,
148                                 SRTP_PROTECTION_PROFILE **pptr, unsigned len)
149 {
150     SRTP_PROTECTION_PROFILE *p;
151 
152     p = srtp_known_profiles;
153     while (p->name) {
154         if ((len == strlen(p->name)) && !strncmp(p->name, profile_name, len)) {
155             *pptr = p;
156             return 0;
157         }
158 
159         p++;
160     }
161 
162     return 1;
163 }
164 
165 static int ssl_ctx_make_profiles(const char *profiles_string,
166                                  STACK_OF(SRTP_PROTECTION_PROFILE) **out)
167 {
168     STACK_OF(SRTP_PROTECTION_PROFILE) *profiles;
169 
170     char *col;
171     char *ptr = (char *)profiles_string;
172 
173     SRTP_PROTECTION_PROFILE *p;
174 
175     if (!(profiles = sk_SRTP_PROTECTION_PROFILE_new_null())) {
176         SSLerr(SSL_F_SSL_CTX_MAKE_PROFILES,
177                SSL_R_SRTP_COULD_NOT_ALLOCATE_PROFILES);
178         return 1;
179     }
180 
181     do {
182         col = strchr(ptr, ':');
183 
184         if (!find_profile_by_name(ptr, &p,
185                                   col ? col - ptr : (int)strlen(ptr))) {
186             if (sk_SRTP_PROTECTION_PROFILE_find(profiles, p) >= 0) {
187                 SSLerr(SSL_F_SSL_CTX_MAKE_PROFILES,
188                        SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);
189                 sk_SRTP_PROTECTION_PROFILE_free(profiles);
190                 return 1;
191             }
192 
193             sk_SRTP_PROTECTION_PROFILE_push(profiles, p);
194         } else {
195             SSLerr(SSL_F_SSL_CTX_MAKE_PROFILES,
196                    SSL_R_SRTP_UNKNOWN_PROTECTION_PROFILE);
197             sk_SRTP_PROTECTION_PROFILE_free(profiles);
198             return 1;
199         }
200 
201         if (col)
202             ptr = col + 1;
203     } while (col);
204 
205     *out = profiles;
206 
207     return 0;
208 }
209 
210 int SSL_CTX_set_tlsext_use_srtp(SSL_CTX *ctx, const char *profiles)
211 {
212     return ssl_ctx_make_profiles(profiles, &ctx->srtp_profiles);
213 }
214 
215 int SSL_set_tlsext_use_srtp(SSL *s, const char *profiles)
216 {
217     return ssl_ctx_make_profiles(profiles, &s->srtp_profiles);
218 }
219 
220 STACK_OF(SRTP_PROTECTION_PROFILE) *SSL_get_srtp_profiles(SSL *s)
221 {
222     if (s != NULL) {
223         if (s->srtp_profiles != NULL) {
224             return s->srtp_profiles;
225         } else if ((s->ctx != NULL) && (s->ctx->srtp_profiles != NULL)) {
226             return s->ctx->srtp_profiles;
227         }
228     }
229 
230     return NULL;
231 }
232 
233 SRTP_PROTECTION_PROFILE *SSL_get_selected_srtp_profile(SSL *s)
234 {
235     return s->srtp_profile;
236 }
237 
238 /*
239  * Note: this function returns 0 length if there are no profiles specified
240  */
241 int ssl_add_clienthello_use_srtp_ext(SSL *s, unsigned char *p, int *len,
242                                      int maxlen)
243 {
244     int ct = 0;
245     int i;
246     STACK_OF(SRTP_PROTECTION_PROFILE) *clnt = 0;
247     SRTP_PROTECTION_PROFILE *prof;
248 
249     clnt = SSL_get_srtp_profiles(s);
250     ct = sk_SRTP_PROTECTION_PROFILE_num(clnt); /* -1 if clnt == 0 */
251 
252     if (p) {
253         if (ct == 0) {
254             SSLerr(SSL_F_SSL_ADD_CLIENTHELLO_USE_SRTP_EXT,
255                    SSL_R_EMPTY_SRTP_PROTECTION_PROFILE_LIST);
256             return 1;
257         }
258 
259         if ((2 + ct * 2 + 1) > maxlen) {
260             SSLerr(SSL_F_SSL_ADD_CLIENTHELLO_USE_SRTP_EXT,
261                    SSL_R_SRTP_PROTECTION_PROFILE_LIST_TOO_LONG);
262             return 1;
263         }
264 
265         /* Add the length */
266         s2n(ct * 2, p);
267         for (i = 0; i < ct; i++) {
268             prof = sk_SRTP_PROTECTION_PROFILE_value(clnt, i);
269             s2n(prof->id, p);
270         }
271 
272         /* Add an empty use_mki value */
273         *p++ = 0;
274     }
275 
276     *len = 2 + ct * 2 + 1;
277 
278     return 0;
279 }
280 
281 int ssl_parse_clienthello_use_srtp_ext(SSL *s, unsigned char *d, int len,
282                                        int *al)
283 {
284     SRTP_PROTECTION_PROFILE *sprof;
285     STACK_OF(SRTP_PROTECTION_PROFILE) *srvr;
286     int ct;
287     int mki_len;
288     int i, srtp_pref;
289     unsigned int id;
290 
291     /* Length value + the MKI length */
292     if (len < 3) {
293         SSLerr(SSL_F_SSL_PARSE_CLIENTHELLO_USE_SRTP_EXT,
294                SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);
295         *al = SSL_AD_DECODE_ERROR;
296         return 1;
297     }
298 
299     /* Pull off the length of the cipher suite list */
300     n2s(d, ct);
301     len -= 2;
302 
303     /* Check that it is even */
304     if (ct % 2) {
305         SSLerr(SSL_F_SSL_PARSE_CLIENTHELLO_USE_SRTP_EXT,
306                SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);
307         *al = SSL_AD_DECODE_ERROR;
308         return 1;
309     }
310 
311     /* Check that lengths are consistent */
312     if (len < (ct + 1)) {
313         SSLerr(SSL_F_SSL_PARSE_CLIENTHELLO_USE_SRTP_EXT,
314                SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);
315         *al = SSL_AD_DECODE_ERROR;
316         return 1;
317     }
318 
319     srvr = SSL_get_srtp_profiles(s);
320     s->srtp_profile = NULL;
321     /* Search all profiles for a match initially */
322     srtp_pref = sk_SRTP_PROTECTION_PROFILE_num(srvr);
323 
324     while (ct) {
325         n2s(d, id);
326         ct -= 2;
327         len -= 2;
328 
329         /*
330          * Only look for match in profiles of higher preference than
331          * current match.
332          * If no profiles have been have been configured then this
333          * does nothing.
334          */
335         for (i = 0; i < srtp_pref; i++) {
336             sprof = sk_SRTP_PROTECTION_PROFILE_value(srvr, i);
337             if (sprof->id == id) {
338                 s->srtp_profile = sprof;
339                 srtp_pref = i;
340                 break;
341             }
342         }
343     }
344 
345     /*
346      * Now extract the MKI value as a sanity check, but discard it for now
347      */
348     mki_len = *d;
349     d++;
350     len--;
351 
352     if (mki_len != len) {
353         SSLerr(SSL_F_SSL_PARSE_CLIENTHELLO_USE_SRTP_EXT,
354                SSL_R_BAD_SRTP_MKI_VALUE);
355         *al = SSL_AD_DECODE_ERROR;
356         return 1;
357     }
358 
359     return 0;
360 }
361 
362 int ssl_add_serverhello_use_srtp_ext(SSL *s, unsigned char *p, int *len,
363                                      int maxlen)
364 {
365     if (p) {
366         if (maxlen < 5) {
367             SSLerr(SSL_F_SSL_ADD_SERVERHELLO_USE_SRTP_EXT,
368                    SSL_R_SRTP_PROTECTION_PROFILE_LIST_TOO_LONG);
369             return 1;
370         }
371 
372         if (s->srtp_profile == 0) {
373             SSLerr(SSL_F_SSL_ADD_SERVERHELLO_USE_SRTP_EXT,
374                    SSL_R_USE_SRTP_NOT_NEGOTIATED);
375             return 1;
376         }
377         s2n(2, p);
378         s2n(s->srtp_profile->id, p);
379         *p++ = 0;
380     }
381     *len = 5;
382 
383     return 0;
384 }
385 
386 int ssl_parse_serverhello_use_srtp_ext(SSL *s, unsigned char *d, int len,
387                                        int *al)
388 {
389     unsigned id;
390     int i;
391     int ct;
392 
393     STACK_OF(SRTP_PROTECTION_PROFILE) *clnt;
394     SRTP_PROTECTION_PROFILE *prof;
395 
396     if (len != 5) {
397         SSLerr(SSL_F_SSL_PARSE_SERVERHELLO_USE_SRTP_EXT,
398                SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);
399         *al = SSL_AD_DECODE_ERROR;
400         return 1;
401     }
402 
403     n2s(d, ct);
404     if (ct != 2) {
405         SSLerr(SSL_F_SSL_PARSE_SERVERHELLO_USE_SRTP_EXT,
406                SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);
407         *al = SSL_AD_DECODE_ERROR;
408         return 1;
409     }
410 
411     n2s(d, id);
412     if (*d) {                   /* Must be no MKI, since we never offer one */
413         SSLerr(SSL_F_SSL_PARSE_SERVERHELLO_USE_SRTP_EXT,
414                SSL_R_BAD_SRTP_MKI_VALUE);
415         *al = SSL_AD_ILLEGAL_PARAMETER;
416         return 1;
417     }
418 
419     clnt = SSL_get_srtp_profiles(s);
420 
421     /* Throw an error if the server gave us an unsolicited extension */
422     if (clnt == NULL) {
423         SSLerr(SSL_F_SSL_PARSE_SERVERHELLO_USE_SRTP_EXT,
424                SSL_R_NO_SRTP_PROFILES);
425         *al = SSL_AD_DECODE_ERROR;
426         return 1;
427     }
428 
429     /*
430      * Check to see if the server gave us something we support (and
431      * presumably offered)
432      */
433     for (i = 0; i < sk_SRTP_PROTECTION_PROFILE_num(clnt); i++) {
434         prof = sk_SRTP_PROTECTION_PROFILE_value(clnt, i);
435 
436         if (prof->id == id) {
437             s->srtp_profile = prof;
438             *al = 0;
439             return 0;
440         }
441     }
442 
443     SSLerr(SSL_F_SSL_PARSE_SERVERHELLO_USE_SRTP_EXT,
444            SSL_R_BAD_SRTP_PROTECTION_PROFILE_LIST);
445     *al = SSL_AD_DECODE_ERROR;
446     return 1;
447 }
448 
449 #endif
450