2 * Copyright 2004-2018 The OpenSSL Project Authors. All Rights Reserved.
3 * Copyright (c) 2004, EdelKey Project. All Rights Reserved.
5 * Licensed under the OpenSSL license (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
10 * Originally written by Christophe Renou and Peter Sylvester,
11 * for the EdelKey project.
14 #ifndef OPENSSL_NO_SRP
15 # include "internal/cryptlib.h"
16 # include <openssl/sha.h>
17 # include <openssl/srp.h>
18 # include <openssl/evp.h>
19 # include "internal/bn_srp.h"
21 /* calculate = SHA1(PAD(x) || PAD(y)) */
23 static BIGNUM *srp_Calc_xy(const BIGNUM *x, const BIGNUM *y, const BIGNUM *N)
25 unsigned char digest[SHA_DIGEST_LENGTH];
26 unsigned char *tmp = NULL;
27 int numN = BN_num_bytes(N);
29 if (x != N && BN_ucmp(x, N) >= 0)
31 if (y != N && BN_ucmp(y, N) >= 0)
33 if ((tmp = OPENSSL_malloc(numN * 2)) == NULL)
35 if (BN_bn2binpad(x, tmp, numN) < 0
36 || BN_bn2binpad(y, tmp + numN, numN) < 0
37 || !EVP_Digest(tmp, numN * 2, digest, NULL, EVP_sha1(), NULL))
39 res = BN_bin2bn(digest, sizeof(digest), NULL);
45 static BIGNUM *srp_Calc_k(const BIGNUM *N, const BIGNUM *g)
47 /* k = SHA1(N | PAD(g)) -- tls-srp draft 8 */
48 return srp_Calc_xy(N, g, N);
51 BIGNUM *SRP_Calc_u(const BIGNUM *A, const BIGNUM *B, const BIGNUM *N)
53 /* k = SHA1(PAD(A) || PAD(B) ) -- tls-srp draft 8 */
54 return srp_Calc_xy(A, B, N);
57 BIGNUM *SRP_Calc_server_key(const BIGNUM *A, const BIGNUM *v, const BIGNUM *u,
58 const BIGNUM *b, const BIGNUM *N)
60 BIGNUM *tmp = NULL, *S = NULL;
63 if (u == NULL || A == NULL || v == NULL || b == NULL || N == NULL)
66 if ((bn_ctx = BN_CTX_new()) == NULL || (tmp = BN_new()) == NULL)
69 /* S = (A*v**u) ** b */
71 if (!BN_mod_exp(tmp, v, u, N, bn_ctx))
73 if (!BN_mod_mul(tmp, A, tmp, N, bn_ctx))
77 if (S != NULL && !BN_mod_exp(S, tmp, b, N, bn_ctx)) {
87 BIGNUM *SRP_Calc_B(const BIGNUM *b, const BIGNUM *N, const BIGNUM *g,
90 BIGNUM *kv = NULL, *gb = NULL;
91 BIGNUM *B = NULL, *k = NULL;
94 if (b == NULL || N == NULL || g == NULL || v == NULL ||
95 (bn_ctx = BN_CTX_new()) == NULL)
98 if ((kv = BN_new()) == NULL ||
99 (gb = BN_new()) == NULL || (B = BN_new()) == NULL)
104 if (!BN_mod_exp(gb, g, b, N, bn_ctx)
105 || (k = srp_Calc_k(N, g)) == NULL
106 || !BN_mod_mul(kv, v, k, N, bn_ctx)
107 || !BN_mod_add(B, gb, kv, N, bn_ctx)) {
119 BIGNUM *SRP_Calc_x(const BIGNUM *s, const char *user, const char *pass)
121 unsigned char dig[SHA_DIGEST_LENGTH];
123 unsigned char *cs = NULL;
126 if ((s == NULL) || (user == NULL) || (pass == NULL))
129 ctxt = EVP_MD_CTX_new();
132 if ((cs = OPENSSL_malloc(BN_num_bytes(s))) == NULL)
135 if (!EVP_DigestInit_ex(ctxt, EVP_sha1(), NULL)
136 || !EVP_DigestUpdate(ctxt, user, strlen(user))
137 || !EVP_DigestUpdate(ctxt, ":", 1)
138 || !EVP_DigestUpdate(ctxt, pass, strlen(pass))
139 || !EVP_DigestFinal_ex(ctxt, dig, NULL)
140 || !EVP_DigestInit_ex(ctxt, EVP_sha1(), NULL))
143 if (!EVP_DigestUpdate(ctxt, cs, BN_num_bytes(s)))
146 if (!EVP_DigestUpdate(ctxt, dig, sizeof(dig))
147 || !EVP_DigestFinal_ex(ctxt, dig, NULL))
150 res = BN_bin2bn(dig, sizeof(dig), NULL);
154 EVP_MD_CTX_free(ctxt);
158 BIGNUM *SRP_Calc_A(const BIGNUM *a, const BIGNUM *N, const BIGNUM *g)
163 if (a == NULL || N == NULL || g == NULL || (bn_ctx = BN_CTX_new()) == NULL)
166 if ((A = BN_new()) != NULL && !BN_mod_exp(A, g, a, N, bn_ctx)) {
174 BIGNUM *SRP_Calc_client_key(const BIGNUM *N, const BIGNUM *B, const BIGNUM *g,
175 const BIGNUM *x, const BIGNUM *a, const BIGNUM *u)
177 BIGNUM *tmp = NULL, *tmp2 = NULL, *tmp3 = NULL, *k = NULL, *K = NULL;
180 if (u == NULL || B == NULL || N == NULL || g == NULL || x == NULL
181 || a == NULL || (bn_ctx = BN_CTX_new()) == NULL)
184 if ((tmp = BN_new()) == NULL ||
185 (tmp2 = BN_new()) == NULL ||
186 (tmp3 = BN_new()) == NULL)
189 if (!BN_mod_exp(tmp, g, x, N, bn_ctx))
191 if ((k = srp_Calc_k(N, g)) == NULL)
193 if (!BN_mod_mul(tmp2, tmp, k, N, bn_ctx))
195 if (!BN_mod_sub(tmp, B, tmp2, N, bn_ctx))
197 if (!BN_mul(tmp3, u, x, bn_ctx))
199 if (!BN_add(tmp2, a, tmp3))
202 if (K != NULL && !BN_mod_exp(K, tmp, tmp2, N, bn_ctx)) {
216 int SRP_Verify_B_mod_N(const BIGNUM *B, const BIGNUM *N)
222 if (B == NULL || N == NULL || (bn_ctx = BN_CTX_new()) == NULL)
225 if ((r = BN_new()) == NULL)
227 /* Checks if B % N == 0 */
228 if (!BN_nnmod(r, B, N, bn_ctx))
230 ret = !BN_is_zero(r);
237 int SRP_Verify_A_mod_N(const BIGNUM *A, const BIGNUM *N)
239 /* Checks if A % N == 0 */
240 return SRP_Verify_B_mod_N(A, N);
243 static SRP_gN knowngN[] = {
244 {"8192", &bn_generator_19, &bn_group_8192},
245 {"6144", &bn_generator_5, &bn_group_6144},
246 {"4096", &bn_generator_5, &bn_group_4096},
247 {"3072", &bn_generator_5, &bn_group_3072},
248 {"2048", &bn_generator_2, &bn_group_2048},
249 {"1536", &bn_generator_2, &bn_group_1536},
250 {"1024", &bn_generator_2, &bn_group_1024},
253 # define KNOWN_GN_NUMBER sizeof(knowngN) / sizeof(SRP_gN)
256 * Check if G and N are known parameters. The values have been generated
257 * from the ietf-tls-srp draft version 8
259 char *SRP_check_known_gN_param(const BIGNUM *g, const BIGNUM *N)
262 if ((g == NULL) || (N == NULL))
265 for (i = 0; i < KNOWN_GN_NUMBER; i++) {
266 if (BN_cmp(knowngN[i].g, g) == 0 && BN_cmp(knowngN[i].N, N) == 0)
267 return knowngN[i].id;
272 SRP_gN *SRP_get_default_gN(const char *id)
278 for (i = 0; i < KNOWN_GN_NUMBER; i++) {
279 if (strcmp(knowngN[i].id, id) == 0)