| /* crypto/dh/dh_key.c */ |
| /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) |
| * All rights reserved. |
| * |
| * This package is an SSL implementation written |
| * by Eric Young (eay@cryptsoft.com). |
| * The implementation was written so as to conform with Netscapes SSL. |
| * |
| * This library is free for commercial and non-commercial use as long as |
| * the following conditions are aheared to. The following conditions |
| * apply to all code found in this distribution, be it the RC4, RSA, |
| * lhash, DES, etc., code; not just the SSL code. The SSL documentation |
| * included with this distribution is covered by the same copyright terms |
| * except that the holder is Tim Hudson (tjh@cryptsoft.com). |
| * |
| * Copyright remains Eric Young's, and as such any Copyright notices in |
| * the code are not to be removed. |
| * If this package is used in a product, Eric Young should be given attribution |
| * as the author of the parts of the library used. |
| * This can be in the form of a textual message at program startup or |
| * in documentation (online or textual) provided with the package. |
| * |
| * 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 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 acknowledgement: |
| * "This product includes cryptographic software written by |
| * Eric Young (eay@cryptsoft.com)" |
| * The word 'cryptographic' can be left out if the rouines from the library |
| * being used are not cryptographic related :-). |
| * 4. If you include any Windows specific code (or a derivative thereof) from |
| * the apps directory (application code) you must include an acknowledgement: |
| * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" |
| * |
| * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND |
| * ANY EXPRESS 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 AUTHOR OR 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. |
| * |
| * The licence and distribution terms for any publically available version or |
| * derivative of this code cannot be changed. i.e. this code cannot simply be |
| * copied and put under another distribution licence |
| * [including the GNU Public Licence.] |
| */ |
| |
| #include <openssl/opensslconf.h> |
| #if !defined(OPENSSL_SYS_STARBOARD) |
| #include <stdio.h> |
| #endif // !defined(OPENSSL_SYS_STARBOARD) |
| #include "cryptlib.h" |
| #include <openssl/bn.h> |
| #include <openssl/rand.h> |
| #include <openssl/dh.h> |
| |
| static int generate_key(DH *dh); |
| static int compute_key(unsigned char *key, const BIGNUM *pub_key, DH *dh); |
| static int dh_bn_mod_exp(const DH *dh, BIGNUM *r, |
| const BIGNUM *a, const BIGNUM *p, |
| const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *m_ctx); |
| static int dh_init(DH *dh); |
| static int dh_finish(DH *dh); |
| |
| int DH_generate_key(DH *dh) |
| { |
| #ifdef OPENSSL_FIPS |
| if (FIPS_mode() && !(dh->meth->flags & DH_FLAG_FIPS_METHOD) |
| && !(dh->flags & DH_FLAG_NON_FIPS_ALLOW)) { |
| DHerr(DH_F_DH_GENERATE_KEY, DH_R_NON_FIPS_METHOD); |
| return 0; |
| } |
| #endif |
| return dh->meth->generate_key(dh); |
| } |
| |
| int DH_compute_key(unsigned char *key, const BIGNUM *pub_key, DH *dh) |
| { |
| #ifdef OPENSSL_FIPS |
| if (FIPS_mode() && !(dh->meth->flags & DH_FLAG_FIPS_METHOD) |
| && !(dh->flags & DH_FLAG_NON_FIPS_ALLOW)) { |
| DHerr(DH_F_DH_COMPUTE_KEY, DH_R_NON_FIPS_METHOD); |
| return 0; |
| } |
| #endif |
| return dh->meth->compute_key(key, pub_key, dh); |
| } |
| |
| static DH_METHOD dh_ossl = { |
| "OpenSSL DH Method", |
| generate_key, |
| compute_key, |
| dh_bn_mod_exp, |
| dh_init, |
| dh_finish, |
| 0, |
| NULL, |
| NULL |
| }; |
| |
| const DH_METHOD *DH_OpenSSL(void) |
| { |
| return &dh_ossl; |
| } |
| |
| static int generate_key(DH *dh) |
| { |
| int ok = 0; |
| int generate_new_key = 0; |
| unsigned l; |
| BN_CTX *ctx; |
| BN_MONT_CTX *mont = NULL; |
| BIGNUM *pub_key = NULL, *priv_key = NULL; |
| |
| ctx = BN_CTX_new(); |
| if (ctx == NULL) |
| goto err; |
| |
| if (dh->priv_key == NULL) { |
| priv_key = BN_new(); |
| if (priv_key == NULL) |
| goto err; |
| generate_new_key = 1; |
| } else |
| priv_key = dh->priv_key; |
| |
| if (dh->pub_key == NULL) { |
| pub_key = BN_new(); |
| if (pub_key == NULL) |
| goto err; |
| } else |
| pub_key = dh->pub_key; |
| |
| if (dh->flags & DH_FLAG_CACHE_MONT_P) { |
| mont = BN_MONT_CTX_set_locked(&dh->method_mont_p, |
| CRYPTO_LOCK_DH, dh->p, ctx); |
| if (!mont) |
| goto err; |
| } |
| |
| if (generate_new_key) { |
| if (dh->q) { |
| do { |
| if (!BN_rand_range(priv_key, dh->q)) |
| goto err; |
| } |
| while (BN_is_zero(priv_key) || BN_is_one(priv_key)); |
| } else { |
| /* secret exponent length */ |
| l = dh->length ? dh->length : BN_num_bits(dh->p) - 1; |
| if (!BN_rand(priv_key, l, 0, 0)) |
| goto err; |
| } |
| } |
| |
| { |
| BIGNUM local_prk; |
| BIGNUM *prk; |
| |
| if ((dh->flags & DH_FLAG_NO_EXP_CONSTTIME) == 0) { |
| BN_init(&local_prk); |
| prk = &local_prk; |
| BN_with_flags(prk, priv_key, BN_FLG_CONSTTIME); |
| } else |
| prk = priv_key; |
| |
| if (!dh->meth->bn_mod_exp(dh, pub_key, dh->g, prk, dh->p, ctx, mont)) |
| goto err; |
| } |
| |
| dh->pub_key = pub_key; |
| dh->priv_key = priv_key; |
| ok = 1; |
| err: |
| if (ok != 1) |
| DHerr(DH_F_GENERATE_KEY, ERR_R_BN_LIB); |
| |
| if ((pub_key != NULL) && (dh->pub_key == NULL)) |
| BN_free(pub_key); |
| if ((priv_key != NULL) && (dh->priv_key == NULL)) |
| BN_free(priv_key); |
| BN_CTX_free(ctx); |
| return (ok); |
| } |
| |
| static int compute_key(unsigned char *key, const BIGNUM *pub_key, DH *dh) |
| { |
| BN_CTX *ctx = NULL; |
| BN_MONT_CTX *mont = NULL; |
| BIGNUM *tmp; |
| int ret = -1; |
| int check_result; |
| |
| if (BN_num_bits(dh->p) > OPENSSL_DH_MAX_MODULUS_BITS) { |
| DHerr(DH_F_COMPUTE_KEY, DH_R_MODULUS_TOO_LARGE); |
| goto err; |
| } |
| |
| ctx = BN_CTX_new(); |
| if (ctx == NULL) |
| goto err; |
| BN_CTX_start(ctx); |
| tmp = BN_CTX_get(ctx); |
| |
| if (dh->priv_key == NULL) { |
| DHerr(DH_F_COMPUTE_KEY, DH_R_NO_PRIVATE_VALUE); |
| goto err; |
| } |
| |
| if (dh->flags & DH_FLAG_CACHE_MONT_P) { |
| mont = BN_MONT_CTX_set_locked(&dh->method_mont_p, |
| CRYPTO_LOCK_DH, dh->p, ctx); |
| if ((dh->flags & DH_FLAG_NO_EXP_CONSTTIME) == 0) { |
| /* XXX */ |
| BN_set_flags(dh->priv_key, BN_FLG_CONSTTIME); |
| } |
| if (!mont) |
| goto err; |
| } |
| |
| if (!DH_check_pub_key(dh, pub_key, &check_result) || check_result) { |
| DHerr(DH_F_COMPUTE_KEY, DH_R_INVALID_PUBKEY); |
| goto err; |
| } |
| |
| if (!dh-> |
| meth->bn_mod_exp(dh, tmp, pub_key, dh->priv_key, dh->p, ctx, mont)) { |
| DHerr(DH_F_COMPUTE_KEY, ERR_R_BN_LIB); |
| goto err; |
| } |
| |
| ret = BN_bn2bin(tmp, key); |
| err: |
| if (ctx != NULL) { |
| BN_CTX_end(ctx); |
| BN_CTX_free(ctx); |
| } |
| return (ret); |
| } |
| |
| static int dh_bn_mod_exp(const DH *dh, BIGNUM *r, |
| const BIGNUM *a, const BIGNUM *p, |
| const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *m_ctx) |
| { |
| /* |
| * If a is only one word long and constant time is false, use the faster |
| * exponenentiation function. |
| */ |
| if (a->top == 1 && ((dh->flags & DH_FLAG_NO_EXP_CONSTTIME) != 0)) { |
| BN_ULONG A = a->d[0]; |
| return BN_mod_exp_mont_word(r, A, p, m, ctx, m_ctx); |
| } else |
| return BN_mod_exp_mont(r, a, p, m, ctx, m_ctx); |
| } |
| |
| static int dh_init(DH *dh) |
| { |
| dh->flags |= DH_FLAG_CACHE_MONT_P; |
| return (1); |
| } |
| |
| static int dh_finish(DH *dh) |
| { |
| if (dh->method_mont_p) |
| BN_MONT_CTX_free(dh->method_mont_p); |
| return (1); |
| } |
