1 /* ssl/tls_srp.c */
2 /* Written by Christophe Renou (christophe.renou@edelweb.fr) with
3 * the precious help of Peter Sylvester (peter.sylvester@edelweb.fr)
4 * for the EdelKey project and contributed to the OpenSSL project 2004.
5 */
6 /* ====================================================================
7 * Copyright (c) 2004-2011 The OpenSSL Project. All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 *
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 *
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in
18 * the documentation and/or other materials provided with the
19 * distribution.
20 *
21 * 3. All advertising materials mentioning features or use of this
22 * software must display the following acknowledgment:
23 * "This product includes software developed by the OpenSSL Project
24 * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
25 *
26 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
27 * endorse or promote products derived from this software without
28 * prior written permission. For written permission, please contact
29 * licensing@OpenSSL.org.
30 *
31 * 5. Products derived from this software may not be called "OpenSSL"
32 * nor may "OpenSSL" appear in their names without prior written
33 * permission of the OpenSSL Project.
34 *
35 * 6. Redistributions of any form whatsoever must retain the following
36 * acknowledgment:
37 * "This product includes software developed by the OpenSSL Project
38 * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
39 *
40 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
41 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
42 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
43 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
44 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
45 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
46 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
47 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
49 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
50 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
51 * OF THE POSSIBILITY OF SUCH DAMAGE.
52 * ====================================================================
53 *
54 * This product includes cryptographic software written by Eric Young
55 * (eay@cryptsoft.com). This product includes software written by Tim
56 * Hudson (tjh@cryptsoft.com).
57 *
58 */
59 #include "ssl_locl.h"
60 #ifndef OPENSSL_NO_SRP
61
62 #include <openssl/rand.h>
63 #include <openssl/srp.h>
64 #include <openssl/err.h>
65
SSL_CTX_SRP_CTX_free(struct ssl_ctx_st * ctx)66 int SSL_CTX_SRP_CTX_free(struct ssl_ctx_st *ctx)
67 {
68 if (ctx == NULL)
69 return 0;
70 OPENSSL_free(ctx->srp_ctx.login);
71 BN_free(ctx->srp_ctx.N);
72 BN_free(ctx->srp_ctx.g);
73 BN_free(ctx->srp_ctx.s);
74 BN_free(ctx->srp_ctx.B);
75 BN_free(ctx->srp_ctx.A);
76 BN_free(ctx->srp_ctx.a);
77 BN_free(ctx->srp_ctx.b);
78 BN_free(ctx->srp_ctx.v);
79 ctx->srp_ctx.TLS_ext_srp_username_callback = NULL;
80 ctx->srp_ctx.SRP_cb_arg = NULL;
81 ctx->srp_ctx.SRP_verify_param_callback = NULL;
82 ctx->srp_ctx.SRP_give_srp_client_pwd_callback = NULL;
83 ctx->srp_ctx.N = NULL;
84 ctx->srp_ctx.g = NULL;
85 ctx->srp_ctx.s = NULL;
86 ctx->srp_ctx.B = NULL;
87 ctx->srp_ctx.A = NULL;
88 ctx->srp_ctx.a = NULL;
89 ctx->srp_ctx.b = NULL;
90 ctx->srp_ctx.v = NULL;
91 ctx->srp_ctx.login = NULL;
92 ctx->srp_ctx.info = NULL;
93 ctx->srp_ctx.strength = SRP_MINIMAL_N;
94 ctx->srp_ctx.srp_Mask = 0;
95 return (1);
96 }
97
SSL_SRP_CTX_free(struct ssl_st * s)98 int SSL_SRP_CTX_free(struct ssl_st *s)
99 {
100 if (s == NULL)
101 return 0;
102 OPENSSL_free(s->srp_ctx.login);
103 BN_free(s->srp_ctx.N);
104 BN_free(s->srp_ctx.g);
105 BN_free(s->srp_ctx.s);
106 BN_free(s->srp_ctx.B);
107 BN_free(s->srp_ctx.A);
108 BN_free(s->srp_ctx.a);
109 BN_free(s->srp_ctx.b);
110 BN_free(s->srp_ctx.v);
111 s->srp_ctx.TLS_ext_srp_username_callback = NULL;
112 s->srp_ctx.SRP_cb_arg = NULL;
113 s->srp_ctx.SRP_verify_param_callback = NULL;
114 s->srp_ctx.SRP_give_srp_client_pwd_callback = NULL;
115 s->srp_ctx.N = NULL;
116 s->srp_ctx.g = NULL;
117 s->srp_ctx.s = NULL;
118 s->srp_ctx.B = NULL;
119 s->srp_ctx.A = NULL;
120 s->srp_ctx.a = NULL;
121 s->srp_ctx.b = NULL;
122 s->srp_ctx.v = NULL;
123 s->srp_ctx.login = NULL;
124 s->srp_ctx.info = NULL;
125 s->srp_ctx.strength = SRP_MINIMAL_N;
126 s->srp_ctx.srp_Mask = 0;
127 return (1);
128 }
129
SSL_SRP_CTX_init(struct ssl_st * s)130 int SSL_SRP_CTX_init(struct ssl_st *s)
131 {
132 SSL_CTX *ctx;
133
134 if ((s == NULL) || ((ctx = s->ctx) == NULL))
135 return 0;
136 s->srp_ctx.SRP_cb_arg = ctx->srp_ctx.SRP_cb_arg;
137 /* set client Hello login callback */
138 s->srp_ctx.TLS_ext_srp_username_callback = ctx->srp_ctx.TLS_ext_srp_username_callback;
139 /* set SRP N/g param callback for verification */
140 s->srp_ctx.SRP_verify_param_callback = ctx->srp_ctx.SRP_verify_param_callback;
141 /* set SRP client passwd callback */
142 s->srp_ctx.SRP_give_srp_client_pwd_callback = ctx->srp_ctx.SRP_give_srp_client_pwd_callback;
143
144 s->srp_ctx.N = NULL;
145 s->srp_ctx.g = NULL;
146 s->srp_ctx.s = NULL;
147 s->srp_ctx.B = NULL;
148 s->srp_ctx.A = NULL;
149 s->srp_ctx.a = NULL;
150 s->srp_ctx.b = NULL;
151 s->srp_ctx.v = NULL;
152 s->srp_ctx.login = NULL;
153 s->srp_ctx.info = ctx->srp_ctx.info;
154 s->srp_ctx.strength = ctx->srp_ctx.strength;
155
156 if (((ctx->srp_ctx.N != NULL) &&
157 ((s->srp_ctx.N = BN_dup(ctx->srp_ctx.N)) == NULL)) ||
158 ((ctx->srp_ctx.g != NULL) &&
159 ((s->srp_ctx.g = BN_dup(ctx->srp_ctx.g)) == NULL)) ||
160 ((ctx->srp_ctx.s != NULL) &&
161 ((s->srp_ctx.s = BN_dup(ctx->srp_ctx.s)) == NULL)) ||
162 ((ctx->srp_ctx.B != NULL) &&
163 ((s->srp_ctx.B = BN_dup(ctx->srp_ctx.B)) == NULL)) ||
164 ((ctx->srp_ctx.A != NULL) &&
165 ((s->srp_ctx.A = BN_dup(ctx->srp_ctx.A)) == NULL)) ||
166 ((ctx->srp_ctx.a != NULL) &&
167 ((s->srp_ctx.a = BN_dup(ctx->srp_ctx.a)) == NULL)) ||
168 ((ctx->srp_ctx.v != NULL) &&
169 ((s->srp_ctx.v = BN_dup(ctx->srp_ctx.v)) == NULL)) ||
170 ((ctx->srp_ctx.b != NULL) &&
171 ((s->srp_ctx.b = BN_dup(ctx->srp_ctx.b)) == NULL)))
172 {
173 SSLerr(SSL_F_SSL_SRP_CTX_INIT,ERR_R_BN_LIB);
174 goto err;
175 }
176 if ((ctx->srp_ctx.login != NULL) &&
177 ((s->srp_ctx.login = BUF_strdup(ctx->srp_ctx.login)) == NULL))
178 {
179 SSLerr(SSL_F_SSL_SRP_CTX_INIT,ERR_R_INTERNAL_ERROR);
180 goto err;
181 }
182 s->srp_ctx.srp_Mask = ctx->srp_ctx.srp_Mask;
183
184 return (1);
185 err:
186 OPENSSL_free(s->srp_ctx.login);
187 BN_free(s->srp_ctx.N);
188 BN_free(s->srp_ctx.g);
189 BN_free(s->srp_ctx.s);
190 BN_free(s->srp_ctx.B);
191 BN_free(s->srp_ctx.A);
192 BN_free(s->srp_ctx.a);
193 BN_free(s->srp_ctx.b);
194 BN_free(s->srp_ctx.v);
195 return (0);
196 }
197
SSL_CTX_SRP_CTX_init(struct ssl_ctx_st * ctx)198 int SSL_CTX_SRP_CTX_init(struct ssl_ctx_st *ctx)
199 {
200 if (ctx == NULL)
201 return 0;
202
203 ctx->srp_ctx.SRP_cb_arg = NULL;
204 /* set client Hello login callback */
205 ctx->srp_ctx.TLS_ext_srp_username_callback = NULL;
206 /* set SRP N/g param callback for verification */
207 ctx->srp_ctx.SRP_verify_param_callback = NULL;
208 /* set SRP client passwd callback */
209 ctx->srp_ctx.SRP_give_srp_client_pwd_callback = NULL;
210
211 ctx->srp_ctx.N = NULL;
212 ctx->srp_ctx.g = NULL;
213 ctx->srp_ctx.s = NULL;
214 ctx->srp_ctx.B = NULL;
215 ctx->srp_ctx.A = NULL;
216 ctx->srp_ctx.a = NULL;
217 ctx->srp_ctx.b = NULL;
218 ctx->srp_ctx.v = NULL;
219 ctx->srp_ctx.login = NULL;
220 ctx->srp_ctx.srp_Mask = 0;
221 ctx->srp_ctx.info = NULL;
222 ctx->srp_ctx.strength = SRP_MINIMAL_N;
223
224 return (1);
225 }
226
227 /* server side */
SSL_srp_server_param_with_username(SSL * s,int * ad)228 int SSL_srp_server_param_with_username(SSL *s, int *ad)
229 {
230 unsigned char b[SSL_MAX_MASTER_KEY_LENGTH];
231 int al;
232
233 *ad = SSL_AD_UNKNOWN_PSK_IDENTITY;
234 if ((s->srp_ctx.TLS_ext_srp_username_callback !=NULL) &&
235 ((al = s->srp_ctx.TLS_ext_srp_username_callback(s, ad, s->srp_ctx.SRP_cb_arg))!=SSL_ERROR_NONE))
236 return al;
237
238 *ad = SSL_AD_INTERNAL_ERROR;
239 if ((s->srp_ctx.N == NULL) ||
240 (s->srp_ctx.g == NULL) ||
241 (s->srp_ctx.s == NULL) ||
242 (s->srp_ctx.v == NULL))
243 return SSL3_AL_FATAL;
244
245 RAND_bytes(b, sizeof(b));
246 s->srp_ctx.b = BN_bin2bn(b,sizeof(b),NULL);
247 OPENSSL_cleanse(b,sizeof(b));
248
249 /* Calculate: B = (kv + g^b) % N */
250
251 return ((s->srp_ctx.B = SRP_Calc_B(s->srp_ctx.b, s->srp_ctx.N, s->srp_ctx.g, s->srp_ctx.v)) != NULL)?
252 SSL_ERROR_NONE:SSL3_AL_FATAL;
253 }
254
255 /* If the server just has the raw password, make up a verifier entry on the fly */
SSL_set_srp_server_param_pw(SSL * s,const char * user,const char * pass,const char * grp)256 int SSL_set_srp_server_param_pw(SSL *s, const char *user, const char *pass, const char *grp)
257 {
258 SRP_gN *GN = SRP_get_default_gN(grp);
259 if(GN == NULL) return -1;
260 s->srp_ctx.N = BN_dup(GN->N);
261 s->srp_ctx.g = BN_dup(GN->g);
262 if(s->srp_ctx.v != NULL)
263 {
264 BN_clear_free(s->srp_ctx.v);
265 s->srp_ctx.v = NULL;
266 }
267 if(s->srp_ctx.s != NULL)
268 {
269 BN_clear_free(s->srp_ctx.s);
270 s->srp_ctx.s = NULL;
271 }
272 if(!SRP_create_verifier_BN(user, pass, &s->srp_ctx.s, &s->srp_ctx.v, GN->N, GN->g)) return -1;
273
274 return 1;
275 }
276
SSL_set_srp_server_param(SSL * s,const BIGNUM * N,const BIGNUM * g,BIGNUM * sa,BIGNUM * v,char * info)277 int SSL_set_srp_server_param(SSL *s, const BIGNUM *N, const BIGNUM *g,
278 BIGNUM *sa, BIGNUM *v, char *info)
279 {
280 if (N!= NULL)
281 {
282 if (s->srp_ctx.N != NULL)
283 {
284 if (!BN_copy(s->srp_ctx.N,N))
285 {
286 BN_free(s->srp_ctx.N);
287 s->srp_ctx.N = NULL;
288 }
289 }
290 else
291 s->srp_ctx.N = BN_dup(N);
292 }
293 if (g!= NULL)
294 {
295 if (s->srp_ctx.g != NULL)
296 {
297 if (!BN_copy(s->srp_ctx.g,g))
298 {
299 BN_free(s->srp_ctx.g);
300 s->srp_ctx.g = NULL;
301 }
302 }
303 else
304 s->srp_ctx.g = BN_dup(g);
305 }
306 if (sa!= NULL)
307 {
308 if (s->srp_ctx.s != NULL)
309 {
310 if (!BN_copy(s->srp_ctx.s,sa))
311 {
312 BN_free(s->srp_ctx.s);
313 s->srp_ctx.s = NULL;
314 }
315 }
316 else
317 s->srp_ctx.s = BN_dup(sa);
318 }
319 if (v!= NULL)
320 {
321 if (s->srp_ctx.v != NULL)
322 {
323 if (!BN_copy(s->srp_ctx.v,v))
324 {
325 BN_free(s->srp_ctx.v);
326 s->srp_ctx.v = NULL;
327 }
328 }
329 else
330 s->srp_ctx.v = BN_dup(v);
331 }
332 s->srp_ctx.info = info;
333
334 if (!(s->srp_ctx.N) ||
335 !(s->srp_ctx.g) ||
336 !(s->srp_ctx.s) ||
337 !(s->srp_ctx.v))
338 return -1;
339
340 return 1;
341 }
342
SRP_generate_server_master_secret(SSL * s,unsigned char * master_key)343 int SRP_generate_server_master_secret(SSL *s,unsigned char *master_key)
344 {
345 BIGNUM *K = NULL, *u = NULL;
346 int ret = -1, tmp_len;
347 unsigned char *tmp = NULL;
348
349 if (!SRP_Verify_A_mod_N(s->srp_ctx.A,s->srp_ctx.N))
350 goto err;
351 if (!(u = SRP_Calc_u(s->srp_ctx.A,s->srp_ctx.B,s->srp_ctx.N)))
352 goto err;
353 if (!(K = SRP_Calc_server_key(s->srp_ctx.A, s->srp_ctx.v, u, s->srp_ctx.b, s->srp_ctx.N)))
354 goto err;
355
356 tmp_len = BN_num_bytes(K);
357 if ((tmp = OPENSSL_malloc(tmp_len)) == NULL)
358 goto err;
359 BN_bn2bin(K, tmp);
360 ret = s->method->ssl3_enc->generate_master_secret(s,master_key,tmp,tmp_len);
361 err:
362 if (tmp)
363 {
364 OPENSSL_cleanse(tmp,tmp_len) ;
365 OPENSSL_free(tmp);
366 }
367 BN_clear_free(K);
368 BN_clear_free(u);
369 return ret;
370 }
371
372 /* client side */
SRP_generate_client_master_secret(SSL * s,unsigned char * master_key)373 int SRP_generate_client_master_secret(SSL *s,unsigned char *master_key)
374 {
375 BIGNUM *x = NULL, *u = NULL, *K = NULL;
376 int ret = -1, tmp_len;
377 char *passwd = NULL;
378 unsigned char *tmp = NULL;
379
380 /* Checks if b % n == 0
381 */
382 if (SRP_Verify_B_mod_N(s->srp_ctx.B,s->srp_ctx.N)==0) goto err;
383 if (!(u = SRP_Calc_u(s->srp_ctx.A,s->srp_ctx.B,s->srp_ctx.N))) goto err;
384 if (s->srp_ctx.SRP_give_srp_client_pwd_callback == NULL) goto err;
385 if (!(passwd = s->srp_ctx.SRP_give_srp_client_pwd_callback(s, s->srp_ctx.SRP_cb_arg))) goto err;
386 if (!(x = SRP_Calc_x(s->srp_ctx.s,s->srp_ctx.login,passwd))) goto err;
387 if (!(K = SRP_Calc_client_key(s->srp_ctx.N, s->srp_ctx.B, s->srp_ctx.g, x, s->srp_ctx.a, u))) goto err;
388
389 tmp_len = BN_num_bytes(K);
390 if ((tmp = OPENSSL_malloc(tmp_len)) == NULL) goto err;
391 BN_bn2bin(K, tmp);
392 ret = s->method->ssl3_enc->generate_master_secret(s,master_key,tmp,tmp_len);
393 err:
394 if (tmp)
395 {
396 OPENSSL_cleanse(tmp,tmp_len) ;
397 OPENSSL_free(tmp);
398 }
399 BN_clear_free(K);
400 BN_clear_free(x);
401 if (passwd)
402 {
403 OPENSSL_cleanse(passwd,strlen(passwd)) ;
404 OPENSSL_free(passwd);
405 }
406 BN_clear_free(u);
407 return ret;
408 }
409
SRP_Calc_A_param(SSL * s)410 int SRP_Calc_A_param(SSL *s)
411 {
412 unsigned char rnd[SSL_MAX_MASTER_KEY_LENGTH];
413
414 if (BN_num_bits(s->srp_ctx.N) < s->srp_ctx.strength)
415 return -1;
416
417 if (s->srp_ctx.SRP_verify_param_callback ==NULL &&
418 !SRP_check_known_gN_param(s->srp_ctx.g,s->srp_ctx.N))
419 return -1 ;
420
421 RAND_bytes(rnd, sizeof(rnd));
422 s->srp_ctx.a = BN_bin2bn(rnd, sizeof(rnd), s->srp_ctx.a);
423 OPENSSL_cleanse(rnd, sizeof(rnd));
424
425 if (!(s->srp_ctx.A = SRP_Calc_A(s->srp_ctx.a,s->srp_ctx.N,s->srp_ctx.g)))
426 return -1;
427
428 /* We can have a callback to verify SRP param!! */
429 if (s->srp_ctx.SRP_verify_param_callback !=NULL)
430 return s->srp_ctx.SRP_verify_param_callback(s,s->srp_ctx.SRP_cb_arg);
431
432 return 1;
433 }
434
SSL_get_srp_g(SSL * s)435 BIGNUM *SSL_get_srp_g(SSL *s)
436 {
437 if (s->srp_ctx.g != NULL)
438 return s->srp_ctx.g;
439 return s->ctx->srp_ctx.g;
440 }
441
SSL_get_srp_N(SSL * s)442 BIGNUM *SSL_get_srp_N(SSL *s)
443 {
444 if (s->srp_ctx.N != NULL)
445 return s->srp_ctx.N;
446 return s->ctx->srp_ctx.N;
447 }
448
SSL_get_srp_username(SSL * s)449 char *SSL_get_srp_username(SSL *s)
450 {
451 if (s->srp_ctx.login != NULL)
452 return s->srp_ctx.login;
453 return s->ctx->srp_ctx.login;
454 }
455
SSL_get_srp_userinfo(SSL * s)456 char *SSL_get_srp_userinfo(SSL *s)
457 {
458 if (s->srp_ctx.info != NULL)
459 return s->srp_ctx.info;
460 return s->ctx->srp_ctx.info;
461 }
462
463 #define tls1_ctx_ctrl ssl3_ctx_ctrl
464 #define tls1_ctx_callback_ctrl ssl3_ctx_callback_ctrl
465
SSL_CTX_set_srp_username(SSL_CTX * ctx,char * name)466 int SSL_CTX_set_srp_username(SSL_CTX *ctx,char *name)
467 {
468 return tls1_ctx_ctrl(ctx,SSL_CTRL_SET_TLS_EXT_SRP_USERNAME,0,name);
469 }
470
SSL_CTX_set_srp_password(SSL_CTX * ctx,char * password)471 int SSL_CTX_set_srp_password(SSL_CTX *ctx,char *password)
472 {
473 return tls1_ctx_ctrl(ctx,SSL_CTRL_SET_TLS_EXT_SRP_PASSWORD,0,password);
474 }
475
SSL_CTX_set_srp_strength(SSL_CTX * ctx,int strength)476 int SSL_CTX_set_srp_strength(SSL_CTX *ctx, int strength)
477 {
478 return tls1_ctx_ctrl(ctx, SSL_CTRL_SET_TLS_EXT_SRP_STRENGTH, strength,
479 NULL);
480 }
481
SSL_CTX_set_srp_verify_param_callback(SSL_CTX * ctx,int (* cb)(SSL *,void *))482 int SSL_CTX_set_srp_verify_param_callback(SSL_CTX *ctx, int (*cb)(SSL *,void *))
483 {
484 return tls1_ctx_callback_ctrl(ctx,SSL_CTRL_SET_SRP_VERIFY_PARAM_CB,
485 (void (*)(void))cb);
486 }
487
SSL_CTX_set_srp_cb_arg(SSL_CTX * ctx,void * arg)488 int SSL_CTX_set_srp_cb_arg(SSL_CTX *ctx, void *arg)
489 {
490 return tls1_ctx_ctrl(ctx,SSL_CTRL_SET_SRP_ARG,0,arg);
491 }
492
SSL_CTX_set_srp_username_callback(SSL_CTX * ctx,int (* cb)(SSL *,int *,void *))493 int SSL_CTX_set_srp_username_callback(SSL_CTX *ctx,
494 int (*cb)(SSL *,int *,void *))
495 {
496 return tls1_ctx_callback_ctrl(ctx,SSL_CTRL_SET_TLS_EXT_SRP_USERNAME_CB,
497 (void (*)(void))cb);
498 }
499
SSL_CTX_set_srp_client_pwd_callback(SSL_CTX * ctx,char * (* cb)(SSL *,void *))500 int SSL_CTX_set_srp_client_pwd_callback(SSL_CTX *ctx, char *(*cb)(SSL *,void *))
501 {
502 return tls1_ctx_callback_ctrl(ctx,SSL_CTRL_SET_SRP_GIVE_CLIENT_PWD_CB,
503 (void (*)(void))cb);
504 }
505
506 #endif
507