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Deprecate the low level Diffie-Hellman functions.
[thirdparty/openssl.git] / ssl / tls_srp.c
1 /*
2 * Copyright 2004-2018 The OpenSSL Project Authors. All Rights Reserved.
3 * Copyright (c) 2004, EdelKey Project. All Rights Reserved.
4 *
5 * Licensed under the Apache License 2.0 (the "License"). You may not use
6 * this file except in compliance with the License. You can obtain a copy
7 * in the file LICENSE in the source distribution or at
8 * https://www.openssl.org/source/license.html
9 *
10 * Originally written by Christophe Renou and Peter Sylvester,
11 * for the EdelKey project.
12 */
13
14 #include <openssl/crypto.h>
15 #include <openssl/rand.h>
16 #include <openssl/err.h>
17 #include "ssl_local.h"
18
19 #ifndef OPENSSL_NO_SRP
20 # include <openssl/srp.h>
21
22 int SSL_CTX_SRP_CTX_free(struct ssl_ctx_st *ctx)
23 {
24 if (ctx == NULL)
25 return 0;
26 OPENSSL_free(ctx->srp_ctx.login);
27 OPENSSL_free(ctx->srp_ctx.info);
28 BN_free(ctx->srp_ctx.N);
29 BN_free(ctx->srp_ctx.g);
30 BN_free(ctx->srp_ctx.s);
31 BN_free(ctx->srp_ctx.B);
32 BN_free(ctx->srp_ctx.A);
33 BN_free(ctx->srp_ctx.a);
34 BN_free(ctx->srp_ctx.b);
35 BN_free(ctx->srp_ctx.v);
36 memset(&ctx->srp_ctx, 0, sizeof(ctx->srp_ctx));
37 ctx->srp_ctx.strength = SRP_MINIMAL_N;
38 return 1;
39 }
40
41 int SSL_SRP_CTX_free(struct ssl_st *s)
42 {
43 if (s == NULL)
44 return 0;
45 OPENSSL_free(s->srp_ctx.login);
46 OPENSSL_free(s->srp_ctx.info);
47 BN_free(s->srp_ctx.N);
48 BN_free(s->srp_ctx.g);
49 BN_free(s->srp_ctx.s);
50 BN_free(s->srp_ctx.B);
51 BN_free(s->srp_ctx.A);
52 BN_free(s->srp_ctx.a);
53 BN_free(s->srp_ctx.b);
54 BN_free(s->srp_ctx.v);
55 memset(&s->srp_ctx, 0, sizeof(s->srp_ctx));
56 s->srp_ctx.strength = SRP_MINIMAL_N;
57 return 1;
58 }
59
60 int SSL_SRP_CTX_init(struct ssl_st *s)
61 {
62 SSL_CTX *ctx;
63
64 if ((s == NULL) || ((ctx = s->ctx) == NULL))
65 return 0;
66
67 memset(&s->srp_ctx, 0, sizeof(s->srp_ctx));
68
69 s->srp_ctx.SRP_cb_arg = ctx->srp_ctx.SRP_cb_arg;
70 /* set client Hello login callback */
71 s->srp_ctx.TLS_ext_srp_username_callback =
72 ctx->srp_ctx.TLS_ext_srp_username_callback;
73 /* set SRP N/g param callback for verification */
74 s->srp_ctx.SRP_verify_param_callback =
75 ctx->srp_ctx.SRP_verify_param_callback;
76 /* set SRP client passwd callback */
77 s->srp_ctx.SRP_give_srp_client_pwd_callback =
78 ctx->srp_ctx.SRP_give_srp_client_pwd_callback;
79
80 s->srp_ctx.strength = ctx->srp_ctx.strength;
81
82 if (((ctx->srp_ctx.N != NULL) &&
83 ((s->srp_ctx.N = BN_dup(ctx->srp_ctx.N)) == NULL)) ||
84 ((ctx->srp_ctx.g != NULL) &&
85 ((s->srp_ctx.g = BN_dup(ctx->srp_ctx.g)) == NULL)) ||
86 ((ctx->srp_ctx.s != NULL) &&
87 ((s->srp_ctx.s = BN_dup(ctx->srp_ctx.s)) == NULL)) ||
88 ((ctx->srp_ctx.B != NULL) &&
89 ((s->srp_ctx.B = BN_dup(ctx->srp_ctx.B)) == NULL)) ||
90 ((ctx->srp_ctx.A != NULL) &&
91 ((s->srp_ctx.A = BN_dup(ctx->srp_ctx.A)) == NULL)) ||
92 ((ctx->srp_ctx.a != NULL) &&
93 ((s->srp_ctx.a = BN_dup(ctx->srp_ctx.a)) == NULL)) ||
94 ((ctx->srp_ctx.v != NULL) &&
95 ((s->srp_ctx.v = BN_dup(ctx->srp_ctx.v)) == NULL)) ||
96 ((ctx->srp_ctx.b != NULL) &&
97 ((s->srp_ctx.b = BN_dup(ctx->srp_ctx.b)) == NULL))) {
98 SSLerr(SSL_F_SSL_SRP_CTX_INIT, ERR_R_BN_LIB);
99 goto err;
100 }
101 if ((ctx->srp_ctx.login != NULL) &&
102 ((s->srp_ctx.login = OPENSSL_strdup(ctx->srp_ctx.login)) == NULL)) {
103 SSLerr(SSL_F_SSL_SRP_CTX_INIT, ERR_R_INTERNAL_ERROR);
104 goto err;
105 }
106 if ((ctx->srp_ctx.info != NULL) &&
107 ((s->srp_ctx.info = OPENSSL_strdup(ctx->srp_ctx.info)) == NULL)) {
108 SSLerr(SSL_F_SSL_SRP_CTX_INIT, ERR_R_INTERNAL_ERROR);
109 goto err;
110 }
111 s->srp_ctx.srp_Mask = ctx->srp_ctx.srp_Mask;
112
113 return 1;
114 err:
115 OPENSSL_free(s->srp_ctx.login);
116 OPENSSL_free(s->srp_ctx.info);
117 BN_free(s->srp_ctx.N);
118 BN_free(s->srp_ctx.g);
119 BN_free(s->srp_ctx.s);
120 BN_free(s->srp_ctx.B);
121 BN_free(s->srp_ctx.A);
122 BN_free(s->srp_ctx.a);
123 BN_free(s->srp_ctx.b);
124 BN_free(s->srp_ctx.v);
125 memset(&s->srp_ctx, 0, sizeof(s->srp_ctx));
126 return 0;
127 }
128
129 int SSL_CTX_SRP_CTX_init(struct ssl_ctx_st *ctx)
130 {
131 if (ctx == NULL)
132 return 0;
133
134 memset(&ctx->srp_ctx, 0, sizeof(ctx->srp_ctx));
135 ctx->srp_ctx.strength = SRP_MINIMAL_N;
136
137 return 1;
138 }
139
140 /* server side */
141 int SSL_srp_server_param_with_username(SSL *s, int *ad)
142 {
143 unsigned char b[SSL_MAX_MASTER_KEY_LENGTH];
144 int al;
145
146 *ad = SSL_AD_UNKNOWN_PSK_IDENTITY;
147 if ((s->srp_ctx.TLS_ext_srp_username_callback != NULL) &&
148 ((al =
149 s->srp_ctx.TLS_ext_srp_username_callback(s, ad,
150 s->srp_ctx.SRP_cb_arg)) !=
151 SSL_ERROR_NONE))
152 return al;
153
154 *ad = SSL_AD_INTERNAL_ERROR;
155 if ((s->srp_ctx.N == NULL) ||
156 (s->srp_ctx.g == NULL) ||
157 (s->srp_ctx.s == NULL) || (s->srp_ctx.v == NULL))
158 return SSL3_AL_FATAL;
159
160 if (RAND_priv_bytes(b, sizeof(b)) <= 0)
161 return SSL3_AL_FATAL;
162 s->srp_ctx.b = BN_bin2bn(b, sizeof(b), NULL);
163 OPENSSL_cleanse(b, sizeof(b));
164
165 /* Calculate: B = (kv + g^b) % N */
166
167 return ((s->srp_ctx.B =
168 SRP_Calc_B(s->srp_ctx.b, s->srp_ctx.N, s->srp_ctx.g,
169 s->srp_ctx.v)) !=
170 NULL) ? SSL_ERROR_NONE : SSL3_AL_FATAL;
171 }
172
173 /*
174 * If the server just has the raw password, make up a verifier entry on the
175 * fly
176 */
177 int SSL_set_srp_server_param_pw(SSL *s, const char *user, const char *pass,
178 const char *grp)
179 {
180 SRP_gN *GN = SRP_get_default_gN(grp);
181 if (GN == NULL)
182 return -1;
183 s->srp_ctx.N = BN_dup(GN->N);
184 s->srp_ctx.g = BN_dup(GN->g);
185 BN_clear_free(s->srp_ctx.v);
186 s->srp_ctx.v = NULL;
187 BN_clear_free(s->srp_ctx.s);
188 s->srp_ctx.s = NULL;
189 if (!SRP_create_verifier_BN
190 (user, pass, &s->srp_ctx.s, &s->srp_ctx.v, GN->N, GN->g))
191 return -1;
192
193 return 1;
194 }
195
196 int SSL_set_srp_server_param(SSL *s, const BIGNUM *N, const BIGNUM *g,
197 BIGNUM *sa, BIGNUM *v, char *info)
198 {
199 if (N != NULL) {
200 if (s->srp_ctx.N != NULL) {
201 if (!BN_copy(s->srp_ctx.N, N)) {
202 BN_free(s->srp_ctx.N);
203 s->srp_ctx.N = NULL;
204 }
205 } else
206 s->srp_ctx.N = BN_dup(N);
207 }
208 if (g != NULL) {
209 if (s->srp_ctx.g != NULL) {
210 if (!BN_copy(s->srp_ctx.g, g)) {
211 BN_free(s->srp_ctx.g);
212 s->srp_ctx.g = NULL;
213 }
214 } else
215 s->srp_ctx.g = BN_dup(g);
216 }
217 if (sa != NULL) {
218 if (s->srp_ctx.s != NULL) {
219 if (!BN_copy(s->srp_ctx.s, sa)) {
220 BN_free(s->srp_ctx.s);
221 s->srp_ctx.s = NULL;
222 }
223 } else
224 s->srp_ctx.s = BN_dup(sa);
225 }
226 if (v != NULL) {
227 if (s->srp_ctx.v != NULL) {
228 if (!BN_copy(s->srp_ctx.v, v)) {
229 BN_free(s->srp_ctx.v);
230 s->srp_ctx.v = NULL;
231 }
232 } else
233 s->srp_ctx.v = BN_dup(v);
234 }
235 if (info != NULL) {
236 if (s->srp_ctx.info)
237 OPENSSL_free(s->srp_ctx.info);
238 if ((s->srp_ctx.info = OPENSSL_strdup(info)) == NULL)
239 return -1;
240 }
241
242 if (!(s->srp_ctx.N) ||
243 !(s->srp_ctx.g) || !(s->srp_ctx.s) || !(s->srp_ctx.v))
244 return -1;
245
246 return 1;
247 }
248
249 int srp_generate_server_master_secret(SSL *s)
250 {
251 BIGNUM *K = NULL, *u = NULL;
252 int ret = -1, tmp_len = 0;
253 unsigned char *tmp = NULL;
254
255 if (!SRP_Verify_A_mod_N(s->srp_ctx.A, s->srp_ctx.N))
256 goto err;
257 if ((u = SRP_Calc_u(s->srp_ctx.A, s->srp_ctx.B, s->srp_ctx.N)) == NULL)
258 goto err;
259 if ((K = SRP_Calc_server_key(s->srp_ctx.A, s->srp_ctx.v, u, s->srp_ctx.b,
260 s->srp_ctx.N)) == NULL)
261 goto err;
262
263 tmp_len = BN_num_bytes(K);
264 if ((tmp = OPENSSL_malloc(tmp_len)) == NULL) {
265 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
266 SSL_F_SRP_GENERATE_SERVER_MASTER_SECRET, ERR_R_MALLOC_FAILURE);
267 goto err;
268 }
269 BN_bn2bin(K, tmp);
270 /* Calls SSLfatal() as required */
271 ret = ssl_generate_master_secret(s, tmp, tmp_len, 1);
272 err:
273 BN_clear_free(K);
274 BN_clear_free(u);
275 return ret;
276 }
277
278 /* client side */
279 int srp_generate_client_master_secret(SSL *s)
280 {
281 BIGNUM *x = NULL, *u = NULL, *K = NULL;
282 int ret = -1, tmp_len = 0;
283 char *passwd = NULL;
284 unsigned char *tmp = NULL;
285
286 /*
287 * Checks if b % n == 0
288 */
289 if (SRP_Verify_B_mod_N(s->srp_ctx.B, s->srp_ctx.N) == 0
290 || (u = SRP_Calc_u(s->srp_ctx.A, s->srp_ctx.B, s->srp_ctx.N))
291 == NULL
292 || s->srp_ctx.SRP_give_srp_client_pwd_callback == NULL) {
293 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
294 SSL_F_SRP_GENERATE_CLIENT_MASTER_SECRET, ERR_R_INTERNAL_ERROR);
295 goto err;
296 }
297 if ((passwd = s->srp_ctx.SRP_give_srp_client_pwd_callback(s,
298 s->srp_ctx.SRP_cb_arg))
299 == NULL) {
300 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
301 SSL_F_SRP_GENERATE_CLIENT_MASTER_SECRET,
302 SSL_R_CALLBACK_FAILED);
303 goto err;
304 }
305 if ((x = SRP_Calc_x(s->srp_ctx.s, s->srp_ctx.login, passwd)) == NULL
306 || (K = SRP_Calc_client_key(s->srp_ctx.N, s->srp_ctx.B,
307 s->srp_ctx.g, x,
308 s->srp_ctx.a, u)) == NULL) {
309 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
310 SSL_F_SRP_GENERATE_CLIENT_MASTER_SECRET, ERR_R_INTERNAL_ERROR);
311 goto err;
312 }
313
314 tmp_len = BN_num_bytes(K);
315 if ((tmp = OPENSSL_malloc(tmp_len)) == NULL) {
316 SSLfatal(s, SSL_AD_INTERNAL_ERROR,
317 SSL_F_SRP_GENERATE_CLIENT_MASTER_SECRET, ERR_R_MALLOC_FAILURE);
318 goto err;
319 }
320 BN_bn2bin(K, tmp);
321 /* Calls SSLfatal() as required */
322 ret = ssl_generate_master_secret(s, tmp, tmp_len, 1);
323 err:
324 BN_clear_free(K);
325 BN_clear_free(x);
326 if (passwd != NULL)
327 OPENSSL_clear_free(passwd, strlen(passwd));
328 BN_clear_free(u);
329 return ret;
330 }
331
332 int srp_verify_server_param(SSL *s)
333 {
334 SRP_CTX *srp = &s->srp_ctx;
335 /*
336 * Sanity check parameters: we can quickly check B % N == 0 by checking B
337 * != 0 since B < N
338 */
339 if (BN_ucmp(srp->g, srp->N) >= 0 || BN_ucmp(srp->B, srp->N) >= 0
340 || BN_is_zero(srp->B)) {
341 SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_F_SRP_VERIFY_SERVER_PARAM,
342 SSL_R_BAD_DATA);
343 return 0;
344 }
345
346 if (BN_num_bits(srp->N) < srp->strength) {
347 SSLfatal(s, SSL_AD_INSUFFICIENT_SECURITY, SSL_F_SRP_VERIFY_SERVER_PARAM,
348 SSL_R_INSUFFICIENT_SECURITY);
349 return 0;
350 }
351
352 if (srp->SRP_verify_param_callback) {
353 if (srp->SRP_verify_param_callback(s, srp->SRP_cb_arg) <= 0) {
354 SSLfatal(s, SSL_AD_INSUFFICIENT_SECURITY,
355 SSL_F_SRP_VERIFY_SERVER_PARAM,
356 SSL_R_CALLBACK_FAILED);
357 return 0;
358 }
359 } else if (!SRP_check_known_gN_param(srp->g, srp->N)) {
360 SSLfatal(s, SSL_AD_INSUFFICIENT_SECURITY, SSL_F_SRP_VERIFY_SERVER_PARAM,
361 SSL_R_INSUFFICIENT_SECURITY);
362 return 0;
363 }
364
365 return 1;
366 }
367
368 int SRP_Calc_A_param(SSL *s)
369 {
370 unsigned char rnd[SSL_MAX_MASTER_KEY_LENGTH];
371
372 if (RAND_priv_bytes(rnd, sizeof(rnd)) <= 0)
373 return 0;
374 s->srp_ctx.a = BN_bin2bn(rnd, sizeof(rnd), s->srp_ctx.a);
375 OPENSSL_cleanse(rnd, sizeof(rnd));
376
377 if (!(s->srp_ctx.A = SRP_Calc_A(s->srp_ctx.a, s->srp_ctx.N, s->srp_ctx.g)))
378 return 0;
379
380 return 1;
381 }
382
383 BIGNUM *SSL_get_srp_g(SSL *s)
384 {
385 if (s->srp_ctx.g != NULL)
386 return s->srp_ctx.g;
387 return s->ctx->srp_ctx.g;
388 }
389
390 BIGNUM *SSL_get_srp_N(SSL *s)
391 {
392 if (s->srp_ctx.N != NULL)
393 return s->srp_ctx.N;
394 return s->ctx->srp_ctx.N;
395 }
396
397 char *SSL_get_srp_username(SSL *s)
398 {
399 if (s->srp_ctx.login != NULL)
400 return s->srp_ctx.login;
401 return s->ctx->srp_ctx.login;
402 }
403
404 char *SSL_get_srp_userinfo(SSL *s)
405 {
406 if (s->srp_ctx.info != NULL)
407 return s->srp_ctx.info;
408 return s->ctx->srp_ctx.info;
409 }
410
411 # define tls1_ctx_ctrl ssl3_ctx_ctrl
412 # define tls1_ctx_callback_ctrl ssl3_ctx_callback_ctrl
413
414 int SSL_CTX_set_srp_username(SSL_CTX *ctx, char *name)
415 {
416 return tls1_ctx_ctrl(ctx, SSL_CTRL_SET_TLS_EXT_SRP_USERNAME, 0, name);
417 }
418
419 int SSL_CTX_set_srp_password(SSL_CTX *ctx, char *password)
420 {
421 return tls1_ctx_ctrl(ctx, SSL_CTRL_SET_TLS_EXT_SRP_PASSWORD, 0, password);
422 }
423
424 int SSL_CTX_set_srp_strength(SSL_CTX *ctx, int strength)
425 {
426 return tls1_ctx_ctrl(ctx, SSL_CTRL_SET_TLS_EXT_SRP_STRENGTH, strength,
427 NULL);
428 }
429
430 int SSL_CTX_set_srp_verify_param_callback(SSL_CTX *ctx,
431 int (*cb) (SSL *, void *))
432 {
433 return tls1_ctx_callback_ctrl(ctx, SSL_CTRL_SET_SRP_VERIFY_PARAM_CB,
434 (void (*)(void))cb);
435 }
436
437 int SSL_CTX_set_srp_cb_arg(SSL_CTX *ctx, void *arg)
438 {
439 return tls1_ctx_ctrl(ctx, SSL_CTRL_SET_SRP_ARG, 0, arg);
440 }
441
442 int SSL_CTX_set_srp_username_callback(SSL_CTX *ctx,
443 int (*cb) (SSL *, int *, void *))
444 {
445 return tls1_ctx_callback_ctrl(ctx, SSL_CTRL_SET_TLS_EXT_SRP_USERNAME_CB,
446 (void (*)(void))cb);
447 }
448
449 int SSL_CTX_set_srp_client_pwd_callback(SSL_CTX *ctx,
450 char *(*cb) (SSL *, void *))
451 {
452 return tls1_ctx_callback_ctrl(ctx, SSL_CTRL_SET_SRP_GIVE_CLIENT_PWD_CB,
453 (void (*)(void))cb);
454 }
455
456 #endif