1 /* crypto/srp/srp_lib.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.
6 /* ====================================================================
7 * Copyright (c) 2004 The OpenSSL Project. All rights reserved.
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
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
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/)"
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.
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.
35 * 6. Redistributions of any form whatsoever must retain the following
37 * "This product includes software developed by the OpenSSL Project
38 * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
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 * ====================================================================
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).
59 #ifndef OPENSSL_NO_SRP
62 #include <openssl/srp.h>
63 #include <openssl/evp.h>
64 #include "internal/bn_srp.h"
66 static BIGNUM *srp_Calc_k(BIGNUM *N, BIGNUM *g)
68 /* k = SHA1(N | PAD(g)) -- tls-srp draft 8 */
70 unsigned char digest[SHA_DIGEST_LENGTH];
74 int longN = BN_num_bytes(N);
76 if (BN_ucmp(g, N) >= 0)
79 if ((tmp = OPENSSL_malloc(longN)) == NULL)
83 EVP_MD_CTX_init(&ctxt);
84 EVP_DigestInit_ex(&ctxt, EVP_sha1(), NULL);
85 EVP_DigestUpdate(&ctxt, tmp, longN);
87 memset(tmp, 0, longN);
88 longg = BN_bn2bin(g,tmp) ;
89 /* use the zeros behind to pad on left */
90 EVP_DigestUpdate(&ctxt, tmp + longg, longN-longg);
91 EVP_DigestUpdate(&ctxt, tmp, longg);
94 EVP_DigestFinal_ex(&ctxt, digest, NULL);
95 EVP_MD_CTX_cleanup(&ctxt);
96 return BN_bin2bn(digest, sizeof(digest), NULL);
99 BIGNUM *SRP_Calc_u(BIGNUM *A, BIGNUM *B, BIGNUM *N)
101 /* k = SHA1(PAD(A) || PAD(B) ) -- tls-srp draft 8 */
104 unsigned char cu[SHA_DIGEST_LENGTH];
108 if ((A == NULL) ||(B == NULL) || (N == NULL))
111 if (BN_ucmp(A, N) >= 0 || BN_ucmp(B, N) >= 0)
114 longN= BN_num_bytes(N);
116 if ((cAB = OPENSSL_malloc(2*longN)) == NULL)
119 memset(cAB, 0, longN);
121 EVP_MD_CTX_init(&ctxt);
122 EVP_DigestInit_ex(&ctxt, EVP_sha1(), NULL);
123 EVP_DigestUpdate(&ctxt, cAB + BN_bn2bin(A,cAB+longN), longN);
124 EVP_DigestUpdate(&ctxt, cAB + BN_bn2bin(B,cAB+longN), longN);
126 EVP_DigestFinal_ex(&ctxt, cu, NULL);
127 EVP_MD_CTX_cleanup(&ctxt);
129 if (!(u = BN_bin2bn(cu, sizeof(cu), NULL)))
137 BIGNUM *SRP_Calc_server_key(BIGNUM *A, BIGNUM *v, BIGNUM *u, BIGNUM *b, BIGNUM *N)
139 BIGNUM *tmp = NULL, *S = NULL;
142 if (u == NULL || A == NULL || v == NULL || b == NULL || N == NULL)
145 if ((bn_ctx = BN_CTX_new()) == NULL ||
146 (tmp = BN_new()) == NULL ||
147 (S = BN_new()) == NULL )
150 /* S = (A*v**u) ** b */
152 if (!BN_mod_exp(tmp,v,u,N,bn_ctx))
154 if (!BN_mod_mul(tmp,A,tmp,N,bn_ctx))
156 if (!BN_mod_exp(S,tmp,b,N,bn_ctx))
164 BIGNUM *SRP_Calc_B(BIGNUM *b, BIGNUM *N, BIGNUM *g, BIGNUM *v)
166 BIGNUM *kv = NULL, *gb = NULL;
167 BIGNUM *B = NULL, *k = NULL;
170 if (b == NULL || N == NULL || g == NULL || v == NULL ||
171 (bn_ctx = BN_CTX_new()) == NULL)
174 if ( (kv = BN_new()) == NULL ||
175 (gb = BN_new()) == NULL ||
176 (B = BN_new())== NULL)
181 if (!BN_mod_exp(gb,g,b,N,bn_ctx) ||
182 !(k = srp_Calc_k(N,g)) ||
183 !BN_mod_mul(kv,v,k,N,bn_ctx) ||
184 !BN_mod_add(B,gb,kv,N,bn_ctx))
197 BIGNUM *SRP_Calc_x(BIGNUM *s, const char *user, const char *pass)
199 unsigned char dig[SHA_DIGEST_LENGTH];
208 if ((cs = OPENSSL_malloc(BN_num_bytes(s))) == NULL)
211 EVP_MD_CTX_init(&ctxt);
212 EVP_DigestInit_ex(&ctxt, EVP_sha1(), NULL);
213 EVP_DigestUpdate(&ctxt, user, strlen(user));
214 EVP_DigestUpdate(&ctxt, ":", 1);
215 EVP_DigestUpdate(&ctxt, pass, strlen(pass));
216 EVP_DigestFinal_ex(&ctxt, dig, NULL);
218 EVP_DigestInit_ex(&ctxt, EVP_sha1(), NULL);
220 EVP_DigestUpdate(&ctxt, cs, BN_num_bytes(s));
222 EVP_DigestUpdate(&ctxt, dig, sizeof(dig));
223 EVP_DigestFinal_ex(&ctxt, dig, NULL);
224 EVP_MD_CTX_cleanup(&ctxt);
226 return BN_bin2bn(dig, sizeof(dig), NULL);
229 BIGNUM *SRP_Calc_A(BIGNUM *a, BIGNUM *N, BIGNUM *g)
234 if (a == NULL || N == NULL || g == NULL ||
235 (bn_ctx = BN_CTX_new()) == NULL)
238 if ((A = BN_new()) != NULL &&
239 !BN_mod_exp(A,g,a,N,bn_ctx))
249 BIGNUM *SRP_Calc_client_key(BIGNUM *N, BIGNUM *B, BIGNUM *g, BIGNUM *x, BIGNUM *a, BIGNUM *u)
251 BIGNUM *tmp = NULL, *tmp2 = NULL, *tmp3 = NULL , *k = NULL, *K = NULL;
254 if (u == NULL || B == NULL || N == NULL || g == NULL || x == NULL || a == NULL ||
255 (bn_ctx = BN_CTX_new()) == NULL)
258 if ((tmp = BN_new()) == NULL ||
259 (tmp2 = BN_new())== NULL ||
260 (tmp3 = BN_new())== NULL ||
261 (K = BN_new()) == NULL)
264 if (!BN_mod_exp(tmp,g,x,N,bn_ctx))
266 if (!(k = srp_Calc_k(N,g)))
268 if (!BN_mod_mul(tmp2,tmp,k,N,bn_ctx))
270 if (!BN_mod_sub(tmp,B,tmp2,N,bn_ctx))
273 if (!BN_mod_mul(tmp3,u,x,N,bn_ctx))
275 if (!BN_mod_add(tmp2,a,tmp3,N,bn_ctx))
277 if (!BN_mod_exp(K,tmp,tmp2,N,bn_ctx))
289 int SRP_Verify_B_mod_N(BIGNUM *B, BIGNUM *N)
295 if (B == NULL || N == NULL ||
296 (bn_ctx = BN_CTX_new()) == NULL)
299 if ((r = BN_new()) == NULL)
301 /* Checks if B % N == 0 */
302 if (!BN_nnmod(r,B,N,bn_ctx))
304 ret = !BN_is_zero(r);
311 int SRP_Verify_A_mod_N(BIGNUM *A, BIGNUM *N)
313 /* Checks if A % N == 0 */
314 return SRP_Verify_B_mod_N(A,N) ;
318 /* Check if G and N are kwown parameters.
319 The values have been generated from the ietf-tls-srp draft version 8
321 char * SRP_check_known_gN_param(BIGNUM* g, BIGNUM* N)
324 if ((g == NULL) || (N == NULL))
330 for(i = 0; i < KNOWN_GN_NUMBER; i++)
332 if (BN_cmp(knowngN[i].g, g) == 0 && BN_cmp(knowngN[i].N, N) == 0)
333 return knowngN[i].id;
338 SRP_gN *SRP_get_default_gN(const char *id)
344 for(i = 0; i < KNOWN_GN_NUMBER; i++)
346 if (strcmp(knowngN[i].id, id)==0)