1 /* ssl/tls_srp.c */ 2 /* Written by Christophe Renou (christophe.renou (at) edelweb.fr) with 3 * the precious help of Peter Sylvester (peter.sylvester (at) 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 (at) 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 (at) cryptsoft.com). This product includes software written by Tim 56 * Hudson (tjh (at) 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 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 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 } 129 130 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 } 197 198 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 */ 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 */ 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 } 276 277 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 } 342 343 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 */ 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 } 409 410 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 } 434 435 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 } 441 442 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 } 448 449 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 } 455 456 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 465 466 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 } 470 471 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 } 475 476 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 } 481 482 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 } 487 488 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 } 492 493 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 } 499 500 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
