7428b99b2d
[skip ci] Reviewed-by: Matt Caswell <matt@openssl.org> (Merged from https://github.com/openssl/openssl/pull/7819)
284 lines
7.3 KiB
C
284 lines
7.3 KiB
C
/*
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* Copyright 2004-2018 The OpenSSL Project Authors. All Rights Reserved.
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* Copyright (c) 2004, EdelKey Project. All Rights Reserved.
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*
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* Licensed under the Apache License 2.0 (the "License"). You may not use
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* this file except in compliance with the License. You can obtain a copy
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* in the file LICENSE in the source distribution or at
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* https://www.openssl.org/source/license.html
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*
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* Originally written by Christophe Renou and Peter Sylvester,
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* for the EdelKey project.
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*/
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#ifndef OPENSSL_NO_SRP
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# include "internal/cryptlib.h"
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# include <openssl/sha.h>
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# include <openssl/srp.h>
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# include <openssl/evp.h>
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# include "internal/bn_srp.h"
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/* calculate = SHA1(PAD(x) || PAD(y)) */
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static BIGNUM *srp_Calc_xy(const BIGNUM *x, const BIGNUM *y, const BIGNUM *N)
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{
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unsigned char digest[SHA_DIGEST_LENGTH];
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unsigned char *tmp = NULL;
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int numN = BN_num_bytes(N);
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BIGNUM *res = NULL;
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if (x != N && BN_ucmp(x, N) >= 0)
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return NULL;
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if (y != N && BN_ucmp(y, N) >= 0)
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return NULL;
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if ((tmp = OPENSSL_malloc(numN * 2)) == NULL)
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goto err;
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if (BN_bn2binpad(x, tmp, numN) < 0
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|| BN_bn2binpad(y, tmp + numN, numN) < 0
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|| !EVP_Digest(tmp, numN * 2, digest, NULL, EVP_sha1(), NULL))
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goto err;
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res = BN_bin2bn(digest, sizeof(digest), NULL);
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err:
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OPENSSL_free(tmp);
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return res;
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}
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static BIGNUM *srp_Calc_k(const BIGNUM *N, const BIGNUM *g)
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{
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/* k = SHA1(N | PAD(g)) -- tls-srp RFC 5054 */
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return srp_Calc_xy(N, g, N);
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}
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BIGNUM *SRP_Calc_u(const BIGNUM *A, const BIGNUM *B, const BIGNUM *N)
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{
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/* u = SHA1(PAD(A) || PAD(B) ) -- tls-srp RFC 5054 */
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return srp_Calc_xy(A, B, N);
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}
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BIGNUM *SRP_Calc_server_key(const BIGNUM *A, const BIGNUM *v, const BIGNUM *u,
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const BIGNUM *b, const BIGNUM *N)
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{
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BIGNUM *tmp = NULL, *S = NULL;
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BN_CTX *bn_ctx;
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if (u == NULL || A == NULL || v == NULL || b == NULL || N == NULL)
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return NULL;
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if ((bn_ctx = BN_CTX_new()) == NULL || (tmp = BN_new()) == NULL)
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goto err;
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/* S = (A*v**u) ** b */
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if (!BN_mod_exp(tmp, v, u, N, bn_ctx))
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goto err;
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if (!BN_mod_mul(tmp, A, tmp, N, bn_ctx))
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goto err;
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S = BN_new();
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if (S != NULL && !BN_mod_exp(S, tmp, b, N, bn_ctx)) {
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BN_free(S);
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S = NULL;
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}
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err:
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BN_CTX_free(bn_ctx);
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BN_clear_free(tmp);
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return S;
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}
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BIGNUM *SRP_Calc_B(const BIGNUM *b, const BIGNUM *N, const BIGNUM *g,
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const BIGNUM *v)
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{
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BIGNUM *kv = NULL, *gb = NULL;
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BIGNUM *B = NULL, *k = NULL;
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BN_CTX *bn_ctx;
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if (b == NULL || N == NULL || g == NULL || v == NULL ||
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(bn_ctx = BN_CTX_new()) == NULL)
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return NULL;
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if ((kv = BN_new()) == NULL ||
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(gb = BN_new()) == NULL || (B = BN_new()) == NULL)
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goto err;
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/* B = g**b + k*v */
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if (!BN_mod_exp(gb, g, b, N, bn_ctx)
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|| (k = srp_Calc_k(N, g)) == NULL
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|| !BN_mod_mul(kv, v, k, N, bn_ctx)
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|| !BN_mod_add(B, gb, kv, N, bn_ctx)) {
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BN_free(B);
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B = NULL;
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}
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err:
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BN_CTX_free(bn_ctx);
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BN_clear_free(kv);
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BN_clear_free(gb);
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BN_free(k);
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return B;
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}
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BIGNUM *SRP_Calc_x(const BIGNUM *s, const char *user, const char *pass)
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{
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unsigned char dig[SHA_DIGEST_LENGTH];
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EVP_MD_CTX *ctxt;
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unsigned char *cs = NULL;
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BIGNUM *res = NULL;
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if ((s == NULL) || (user == NULL) || (pass == NULL))
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return NULL;
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ctxt = EVP_MD_CTX_new();
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if (ctxt == NULL)
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return NULL;
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if ((cs = OPENSSL_malloc(BN_num_bytes(s))) == NULL)
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goto err;
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if (!EVP_DigestInit_ex(ctxt, EVP_sha1(), NULL)
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|| !EVP_DigestUpdate(ctxt, user, strlen(user))
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|| !EVP_DigestUpdate(ctxt, ":", 1)
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|| !EVP_DigestUpdate(ctxt, pass, strlen(pass))
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|| !EVP_DigestFinal_ex(ctxt, dig, NULL)
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|| !EVP_DigestInit_ex(ctxt, EVP_sha1(), NULL))
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goto err;
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BN_bn2bin(s, cs);
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if (!EVP_DigestUpdate(ctxt, cs, BN_num_bytes(s)))
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goto err;
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if (!EVP_DigestUpdate(ctxt, dig, sizeof(dig))
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|| !EVP_DigestFinal_ex(ctxt, dig, NULL))
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goto err;
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res = BN_bin2bn(dig, sizeof(dig), NULL);
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err:
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OPENSSL_free(cs);
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EVP_MD_CTX_free(ctxt);
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return res;
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}
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BIGNUM *SRP_Calc_A(const BIGNUM *a, const BIGNUM *N, const BIGNUM *g)
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{
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BN_CTX *bn_ctx;
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BIGNUM *A = NULL;
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if (a == NULL || N == NULL || g == NULL || (bn_ctx = BN_CTX_new()) == NULL)
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return NULL;
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if ((A = BN_new()) != NULL && !BN_mod_exp(A, g, a, N, bn_ctx)) {
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BN_free(A);
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A = NULL;
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}
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BN_CTX_free(bn_ctx);
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return A;
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}
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BIGNUM *SRP_Calc_client_key(const BIGNUM *N, const BIGNUM *B, const BIGNUM *g,
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const BIGNUM *x, const BIGNUM *a, const BIGNUM *u)
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{
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BIGNUM *tmp = NULL, *tmp2 = NULL, *tmp3 = NULL, *k = NULL, *K = NULL;
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BN_CTX *bn_ctx;
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if (u == NULL || B == NULL || N == NULL || g == NULL || x == NULL
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|| a == NULL || (bn_ctx = BN_CTX_new()) == NULL)
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return NULL;
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if ((tmp = BN_new()) == NULL ||
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(tmp2 = BN_new()) == NULL ||
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(tmp3 = BN_new()) == NULL)
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goto err;
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if (!BN_mod_exp(tmp, g, x, N, bn_ctx))
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goto err;
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if ((k = srp_Calc_k(N, g)) == NULL)
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goto err;
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if (!BN_mod_mul(tmp2, tmp, k, N, bn_ctx))
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goto err;
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if (!BN_mod_sub(tmp, B, tmp2, N, bn_ctx))
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goto err;
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if (!BN_mul(tmp3, u, x, bn_ctx))
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goto err;
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if (!BN_add(tmp2, a, tmp3))
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goto err;
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K = BN_new();
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if (K != NULL && !BN_mod_exp(K, tmp, tmp2, N, bn_ctx)) {
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BN_free(K);
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K = NULL;
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}
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err:
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BN_CTX_free(bn_ctx);
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BN_clear_free(tmp);
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BN_clear_free(tmp2);
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BN_clear_free(tmp3);
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BN_free(k);
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return K;
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}
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int SRP_Verify_B_mod_N(const BIGNUM *B, const BIGNUM *N)
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{
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BIGNUM *r;
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BN_CTX *bn_ctx;
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int ret = 0;
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if (B == NULL || N == NULL || (bn_ctx = BN_CTX_new()) == NULL)
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return 0;
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if ((r = BN_new()) == NULL)
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goto err;
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/* Checks if B % N == 0 */
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if (!BN_nnmod(r, B, N, bn_ctx))
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goto err;
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ret = !BN_is_zero(r);
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err:
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BN_CTX_free(bn_ctx);
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BN_free(r);
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return ret;
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}
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int SRP_Verify_A_mod_N(const BIGNUM *A, const BIGNUM *N)
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{
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/* Checks if A % N == 0 */
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return SRP_Verify_B_mod_N(A, N);
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}
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static SRP_gN knowngN[] = {
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{"8192", &bn_generator_19, &bn_group_8192},
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{"6144", &bn_generator_5, &bn_group_6144},
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{"4096", &bn_generator_5, &bn_group_4096},
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{"3072", &bn_generator_5, &bn_group_3072},
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{"2048", &bn_generator_2, &bn_group_2048},
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{"1536", &bn_generator_2, &bn_group_1536},
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{"1024", &bn_generator_2, &bn_group_1024},
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};
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# define KNOWN_GN_NUMBER sizeof(knowngN) / sizeof(SRP_gN)
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/*
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* Check if G and N are known parameters. The values have been generated
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* from the IETF RFC 5054
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*/
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char *SRP_check_known_gN_param(const BIGNUM *g, const BIGNUM *N)
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{
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size_t i;
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if ((g == NULL) || (N == NULL))
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return NULL;
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for (i = 0; i < KNOWN_GN_NUMBER; i++) {
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if (BN_cmp(knowngN[i].g, g) == 0 && BN_cmp(knowngN[i].N, N) == 0)
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return knowngN[i].id;
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}
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return NULL;
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}
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SRP_gN *SRP_get_default_gN(const char *id)
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{
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size_t i;
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if (id == NULL)
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return knowngN;
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for (i = 0; i < KNOWN_GN_NUMBER; i++) {
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if (strcmp(knowngN[i].id, id) == 0)
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return knowngN + i;
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}
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return NULL;
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}
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#endif
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