diff options
Diffstat (limited to 'crypto/srp/srp_lib.c')
-rw-r--r-- | crypto/srp/srp_lib.c | 357 |
1 files changed, 357 insertions, 0 deletions
diff --git a/crypto/srp/srp_lib.c b/crypto/srp/srp_lib.c new file mode 100644 index 0000000000..92cea98dcd --- /dev/null +++ b/crypto/srp/srp_lib.c @@ -0,0 +1,357 @@ +/* crypto/srp/srp_lib.c */ +/* Written by Christophe Renou (christophe.renou@edelweb.fr) with + * the precious help of Peter Sylvester (peter.sylvester@edelweb.fr) + * for the EdelKey project and contributed to the OpenSSL project 2004. + */ +/* ==================================================================== + * Copyright (c) 2004 The OpenSSL Project. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * + * 3. All advertising materials mentioning features or use of this + * software must display the following acknowledgment: + * "This product includes software developed by the OpenSSL Project + * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)" + * + * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to + * endorse or promote products derived from this software without + * prior written permission. For written permission, please contact + * licensing@OpenSSL.org. + * + * 5. Products derived from this software may not be called "OpenSSL" + * nor may "OpenSSL" appear in their names without prior written + * permission of the OpenSSL Project. + * + * 6. Redistributions of any form whatsoever must retain the following + * acknowledgment: + * "This product includes software developed by the OpenSSL Project + * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)" + * + * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY + * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR + * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR + * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT + * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; + * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, + * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) + * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED + * OF THE POSSIBILITY OF SUCH DAMAGE. + * ==================================================================== + * + * This product includes cryptographic software written by Eric Young + * (eay@cryptsoft.com). This product includes software written by Tim + * Hudson (tjh@cryptsoft.com). + * + */ +#ifndef OPENSSL_NO_SRP +#include "cryptlib.h" +#include "srp_lcl.h" +#include <openssl/srp.h> +#include <openssl/evp.h> + +#if (BN_BYTES == 8) +#define bn_pack4(a1,a2,a3,a4) 0x##a1##a2##a3##a4##ul +#endif +#if (BN_BYTES == 4) +#define bn_pack4(a1,a2,a3,a4) 0x##a3##a4##ul, 0x##a1##a2##ul +#endif +#if (BN_BYTES == 2) +#define bn_pack4(a1,a2,a3,a4) 0x##a4##u,0x##a3##u,0x##a2##u,0x##a1##u +#endif + + +#include "srp_grps.h" + +static BIGNUM *srp_Calc_k(BIGNUM *N, BIGNUM *g) + { + /* k = SHA1(N | PAD(g)) -- tls-srp draft 8 */ + + unsigned char digest[SHA_DIGEST_LENGTH]; + unsigned char *tmp; + EVP_MD_CTX ctxt; + int longg ; + int longN = BN_num_bytes(N); + + if ((tmp = OPENSSL_malloc(longN)) == NULL) + return NULL; + BN_bn2bin(N,tmp) ; + + EVP_MD_CTX_init(&ctxt); + EVP_DigestInit_ex(&ctxt, EVP_sha1(), NULL); + EVP_DigestUpdate(&ctxt, tmp, longN); + + memset(tmp, 0, longN); + longg = BN_bn2bin(g,tmp) ; + /* use the zeros behind to pad on left */ + EVP_DigestUpdate(&ctxt, tmp + longg, longN-longg); + EVP_DigestUpdate(&ctxt, tmp, longg); + OPENSSL_free(tmp); + + EVP_DigestFinal_ex(&ctxt, digest, NULL); + EVP_MD_CTX_cleanup(&ctxt); + return BN_bin2bn(digest, sizeof(digest), NULL); + } + +BIGNUM *SRP_Calc_u(BIGNUM *A, BIGNUM *B, BIGNUM *N) + { + /* k = SHA1(PAD(A) || PAD(B) ) -- tls-srp draft 8 */ + + BIGNUM *u; + unsigned char cu[SHA_DIGEST_LENGTH]; + unsigned char *cAB; + EVP_MD_CTX ctxt; + int longN; + if ((A == NULL) ||(B == NULL) || (N == NULL)) + return NULL; + + longN= BN_num_bytes(N); + + if ((cAB = OPENSSL_malloc(2*longN)) == NULL) + return NULL; + + memset(cAB, 0, longN); + + EVP_MD_CTX_init(&ctxt); + EVP_DigestInit_ex(&ctxt, EVP_sha1(), NULL); + EVP_DigestUpdate(&ctxt, cAB + BN_bn2bin(A,cAB+longN), longN); + EVP_DigestUpdate(&ctxt, cAB + BN_bn2bin(B,cAB+longN), longN); + OPENSSL_free(cAB); + EVP_DigestFinal_ex(&ctxt, cu, NULL); + EVP_MD_CTX_cleanup(&ctxt); + + if (!(u = BN_bin2bn(cu, sizeof(cu), NULL))) + return NULL; + if (!BN_is_zero(u)) + return u; + BN_free(u); + return NULL; +} + +BIGNUM *SRP_Calc_server_key(BIGNUM *A, BIGNUM *v, BIGNUM *u, BIGNUM *b, BIGNUM *N) + { + BIGNUM *tmp = NULL, *S = NULL; + BN_CTX *bn_ctx; + + if (u == NULL || A == NULL || v == NULL || b == NULL || N == NULL) + return NULL; + + if ((bn_ctx = BN_CTX_new()) == NULL || + (tmp = BN_new()) == NULL || + (S = BN_new()) == NULL ) + goto err; + + /* S = (A*v**u) ** b */ + + if (!BN_mod_exp(tmp,v,u,N,bn_ctx)) + goto err; + if (!BN_mod_mul(tmp,A,tmp,N,bn_ctx)) + goto err; + if (!BN_mod_exp(S,tmp,b,N,bn_ctx)) + goto err; +err: + BN_CTX_free(bn_ctx); + BN_clear_free(tmp); + return S; + } + +BIGNUM *SRP_Calc_B(BIGNUM *b, BIGNUM *N, BIGNUM *g, BIGNUM *v) + { + BIGNUM *kv = NULL, *gb = NULL; + BIGNUM *B = NULL, *k = NULL; + BN_CTX *bn_ctx; + + if (b == NULL || N == NULL || g == NULL || v == NULL || + (bn_ctx = BN_CTX_new()) == NULL) + return NULL; + + if ( (kv = BN_new()) == NULL || + (gb = BN_new()) == NULL || + (B = BN_new())== NULL) + goto err; + + /* B = g**b + k*v */ + + if (!BN_mod_exp(gb,g,b,N,bn_ctx) || + !(k = srp_Calc_k(N,g)) || + !BN_mod_mul(kv,v,k,N,bn_ctx) || + !BN_mod_add(B,gb,kv,N,bn_ctx)) + { + BN_free(B); + B = NULL; + } +err: + BN_CTX_free(bn_ctx); + BN_clear_free(kv); + BN_clear_free(gb); + BN_free(k); + return B; + } + +BIGNUM *SRP_Calc_x(BIGNUM *s, const char *user, const char *pass) + { + unsigned char dig[SHA_DIGEST_LENGTH]; + EVP_MD_CTX ctxt; + unsigned char *cs; + + if ((s == NULL) || + (user == NULL) || + (pass == NULL)) + return NULL; + + if ((cs = OPENSSL_malloc(BN_num_bytes(s))) == NULL) + return NULL; + + EVP_MD_CTX_init(&ctxt); + EVP_DigestInit_ex(&ctxt, EVP_sha1(), NULL); + EVP_DigestUpdate(&ctxt, user, strlen(user)); + EVP_DigestUpdate(&ctxt, ":", 1); + EVP_DigestUpdate(&ctxt, pass, strlen(pass)); + EVP_DigestFinal_ex(&ctxt, dig, NULL); + + EVP_DigestInit_ex(&ctxt, EVP_sha1(), NULL); + BN_bn2bin(s,cs); + EVP_DigestUpdate(&ctxt, cs, BN_num_bytes(s)); + OPENSSL_free(cs); + EVP_DigestUpdate(&ctxt, dig, sizeof(dig)); + EVP_DigestFinal_ex(&ctxt, dig, NULL); + EVP_MD_CTX_cleanup(&ctxt); + + return BN_bin2bn(dig, sizeof(dig), NULL); + } + +BIGNUM *SRP_Calc_A(BIGNUM *a, BIGNUM *N, BIGNUM *g) + { + BN_CTX *bn_ctx; + BIGNUM * A = NULL; + + if (a == NULL || N == NULL || g == NULL || + (bn_ctx = BN_CTX_new()) == NULL) + return NULL; + + if ((A = BN_new()) != NULL && + !BN_mod_exp(A,g,a,N,bn_ctx)) + { + BN_free(A); + A = NULL; + } + BN_CTX_free(bn_ctx); + return A; + } + + +BIGNUM *SRP_Calc_client_key(BIGNUM *N, BIGNUM *B, BIGNUM *g, BIGNUM *x, BIGNUM *a, BIGNUM *u) + { + BIGNUM *tmp = NULL, *tmp2 = NULL, *tmp3 = NULL , *k = NULL, *K = NULL; + BN_CTX *bn_ctx; + + if (u == NULL || B == NULL || N == NULL || g == NULL || x == NULL || a == NULL || + (bn_ctx = BN_CTX_new()) == NULL) + return NULL; + + if ((tmp = BN_new()) == NULL || + (tmp2 = BN_new())== NULL || + (tmp3 = BN_new())== NULL || + (K = BN_new()) == NULL) + goto err; + + if (!BN_mod_exp(tmp,g,x,N,bn_ctx)) + goto err; + if (!(k = srp_Calc_k(N,g))) + goto err; + if (!BN_mod_mul(tmp2,tmp,k,N,bn_ctx)) + goto err; + if (!BN_mod_sub(tmp,B,tmp2,N,bn_ctx)) + goto err; + + if (!BN_mod_mul(tmp3,u,x,N,bn_ctx)) + goto err; + if (!BN_mod_add(tmp2,a,tmp3,N,bn_ctx)) + goto err; + if (!BN_mod_exp(K,tmp,tmp2,N,bn_ctx)) + goto err; + +err : + BN_CTX_free(bn_ctx); + BN_clear_free(tmp); + BN_clear_free(tmp2); + BN_clear_free(tmp3); + BN_free(k); + return K; + } + +int SRP_Verify_B_mod_N(BIGNUM *B, BIGNUM *N) + { + BIGNUM *r; + BN_CTX *bn_ctx; + int ret = 0; + + if (B == NULL || N == NULL || + (bn_ctx = BN_CTX_new()) == NULL) + return 0; + + if ((r = BN_new()) == NULL) + goto err; + /* Checks if B % N == 0 */ + if (!BN_nnmod(r,B,N,bn_ctx)) + goto err; + ret = !BN_is_zero(r); +err: + BN_CTX_free(bn_ctx); + BN_free(r); + return ret; + } + +int SRP_Verify_A_mod_N(BIGNUM *A, BIGNUM *N) + { + /* Checks if A % N == 0 */ + return SRP_Verify_B_mod_N(A,N) ; + } + + +/* Check if G and N are kwown parameters. + The values have been generated from the ietf-tls-srp draft version 8 +*/ +char *SRP_check_known_gN_param(BIGNUM *g, BIGNUM *N) + { + size_t i; + if ((g == NULL) || (N == NULL)) + return 0; + + srp_bn_print(g); + srp_bn_print(N); + + for(i = 0; i < KNOWN_GN_NUMBER; i++) + { + if (BN_cmp(knowngN[i].g, g) == 0 && BN_cmp(knowngN[i].N, N) == 0) + return knowngN[i].id; + } + return NULL; + } + +SRP_gN *SRP_get_default_gN(const char *id) + { + size_t i; + + if (id == NULL) + return knowngN; + for(i = 0; i < KNOWN_GN_NUMBER; i++) + { + if (strcmp(knowngN[i].id, id)==0) + return knowngN + i; + } + return NULL; + } +#endif |