X-Git-Url: https://git.openssl.org/?p=openssl.git;a=blobdiff_plain;f=crypto%2Fdh%2Fdh_check.c;h=aff7e3718138efbb31680cfb1fe7881cd8e56c6d;hp=65602e494f1eb7fa1167f401b604184043257710;hb=a38c878c2e5e05016bc9faa8d0828eb96efba1c2;hpb=58964a492275ca9a59a0cd9c8155cb2491b4b909 diff --git a/crypto/dh/dh_check.c b/crypto/dh/dh_check.c index 65602e494f..aff7e37181 100644 --- a/crypto/dh/dh_check.c +++ b/crypto/dh/dh_check.c @@ -1,120 +1,213 @@ -/* crypto/dh/dh_check.c */ -/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) - * All rights reserved. +/* + * Copyright 1995-2019 The OpenSSL Project Authors. 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.] + * Licensed under the Apache License 2.0 (the "License"). You may not use + * this file except in compliance with the License. You can obtain a copy + * in the file LICENSE in the source distribution or at + * https://www.openssl.org/source/license.html */ #include -#include "cryptlib.h" -#include "bn.h" -#include "dh.h" - -/* Check that p is a strong prime and - * if g is 2, 3 or 5, check that is is a suitable generator - * where - * for 2, p mod 24 == 11 - * for 3, p mod 12 == 5 - * for 5, p mod 10 == 3 or 7 - * should hold. +#include "internal/cryptlib.h" +#include +#include "dh_locl.h" + +# define DH_NUMBER_ITERATIONS_FOR_PRIME 64 + +/*- + * Check that p and g are suitable enough + * + * p is odd + * 1 < g < p - 1 + */ +int DH_check_params_ex(const DH *dh) +{ + int errflags = 0; + + if (!DH_check_params(dh, &errflags)) + return 0; + + if ((errflags & DH_CHECK_P_NOT_PRIME) != 0) + DHerr(DH_F_DH_CHECK_PARAMS_EX, DH_R_CHECK_P_NOT_PRIME); + if ((errflags & DH_NOT_SUITABLE_GENERATOR) != 0) + DHerr(DH_F_DH_CHECK_PARAMS_EX, DH_R_NOT_SUITABLE_GENERATOR); + + return errflags == 0; +} + +int DH_check_params(const DH *dh, int *ret) +{ + int ok = 0; + BIGNUM *tmp = NULL; + BN_CTX *ctx = NULL; + + *ret = 0; + ctx = BN_CTX_new(); + if (ctx == NULL) + goto err; + BN_CTX_start(ctx); + tmp = BN_CTX_get(ctx); + if (tmp == NULL) + goto err; + + if (!BN_is_odd(dh->p)) + *ret |= DH_CHECK_P_NOT_PRIME; + if (BN_is_negative(dh->g) || BN_is_zero(dh->g) || BN_is_one(dh->g)) + *ret |= DH_NOT_SUITABLE_GENERATOR; + if (BN_copy(tmp, dh->p) == NULL || !BN_sub_word(tmp, 1)) + goto err; + if (BN_cmp(dh->g, tmp) >= 0) + *ret |= DH_NOT_SUITABLE_GENERATOR; + + ok = 1; + err: + BN_CTX_end(ctx); + BN_CTX_free(ctx); + return ok; +} + +/*- + * Check that p is a safe prime and + * g is a suitable generator. */ +int DH_check_ex(const DH *dh) +{ + int errflags = 0; + + if (!DH_check(dh, &errflags)) + return 0; + + if ((errflags & DH_NOT_SUITABLE_GENERATOR) != 0) + DHerr(DH_F_DH_CHECK_EX, DH_R_NOT_SUITABLE_GENERATOR); + if ((errflags & DH_CHECK_Q_NOT_PRIME) != 0) + DHerr(DH_F_DH_CHECK_EX, DH_R_CHECK_Q_NOT_PRIME); + if ((errflags & DH_CHECK_INVALID_Q_VALUE) != 0) + DHerr(DH_F_DH_CHECK_EX, DH_R_CHECK_INVALID_Q_VALUE); + if ((errflags & DH_CHECK_INVALID_J_VALUE) != 0) + DHerr(DH_F_DH_CHECK_EX, DH_R_CHECK_INVALID_J_VALUE); + if ((errflags & DH_UNABLE_TO_CHECK_GENERATOR) != 0) + DHerr(DH_F_DH_CHECK_EX, DH_R_UNABLE_TO_CHECK_GENERATOR); + if ((errflags & DH_CHECK_P_NOT_PRIME) != 0) + DHerr(DH_F_DH_CHECK_EX, DH_R_CHECK_P_NOT_PRIME); + if ((errflags & DH_CHECK_P_NOT_SAFE_PRIME) != 0) + DHerr(DH_F_DH_CHECK_EX, DH_R_CHECK_P_NOT_SAFE_PRIME); + + return errflags == 0; +} + +int DH_check(const DH *dh, int *ret) +{ + int ok = 0, r; + BN_CTX *ctx = NULL; + BIGNUM *t1 = NULL, *t2 = NULL; + + if (!DH_check_params(dh, ret)) + return 0; + + ctx = BN_CTX_new(); + if (ctx == NULL) + goto err; + BN_CTX_start(ctx); + t1 = BN_CTX_get(ctx); + t2 = BN_CTX_get(ctx); + if (t2 == NULL) + goto err; + + if (dh->q) { + if (BN_cmp(dh->g, BN_value_one()) <= 0) + *ret |= DH_NOT_SUITABLE_GENERATOR; + else if (BN_cmp(dh->g, dh->p) >= 0) + *ret |= DH_NOT_SUITABLE_GENERATOR; + else { + /* Check g^q == 1 mod p */ + if (!BN_mod_exp(t1, dh->g, dh->q, dh->p, ctx)) + goto err; + if (!BN_is_one(t1)) + *ret |= DH_NOT_SUITABLE_GENERATOR; + } + r = BN_is_prime_ex(dh->q, DH_NUMBER_ITERATIONS_FOR_PRIME, ctx, NULL); + if (r < 0) + goto err; + if (!r) + *ret |= DH_CHECK_Q_NOT_PRIME; + /* Check p == 1 mod q i.e. q divides p - 1 */ + if (!BN_div(t1, t2, dh->p, dh->q, ctx)) + goto err; + if (!BN_is_one(t2)) + *ret |= DH_CHECK_INVALID_Q_VALUE; + if (dh->j && BN_cmp(dh->j, t1)) + *ret |= DH_CHECK_INVALID_J_VALUE; + } + + r = BN_is_prime_ex(dh->p, DH_NUMBER_ITERATIONS_FOR_PRIME, ctx, NULL); + if (r < 0) + goto err; + if (!r) + *ret |= DH_CHECK_P_NOT_PRIME; + else if (!dh->q) { + if (!BN_rshift1(t1, dh->p)) + goto err; + r = BN_is_prime_ex(t1, DH_NUMBER_ITERATIONS_FOR_PRIME, ctx, NULL); + if (r < 0) + goto err; + if (!r) + *ret |= DH_CHECK_P_NOT_SAFE_PRIME; + } + ok = 1; + err: + BN_CTX_end(ctx); + BN_CTX_free(ctx); + return ok; +} + +int DH_check_pub_key_ex(const DH *dh, const BIGNUM *pub_key) +{ + int errflags = 0; + + (void)DH_check(dh, &errflags); + + if ((errflags & DH_CHECK_PUBKEY_TOO_SMALL) != 0) + DHerr(DH_F_DH_CHECK_PUB_KEY_EX, DH_R_CHECK_PUBKEY_TOO_SMALL); + if ((errflags & DH_CHECK_PUBKEY_TOO_LARGE) != 0) + DHerr(DH_F_DH_CHECK_PUB_KEY_EX, DH_R_CHECK_PUBKEY_TOO_LARGE); + if ((errflags & DH_CHECK_PUBKEY_INVALID) != 0) + DHerr(DH_F_DH_CHECK_PUB_KEY_EX, DH_R_CHECK_PUBKEY_INVALID); + + return errflags == 0; +} + +int DH_check_pub_key(const DH *dh, const BIGNUM *pub_key, int *ret) +{ + int ok = 0; + BIGNUM *tmp = NULL; + BN_CTX *ctx = NULL; + + *ret = 0; + ctx = BN_CTX_new(); + if (ctx == NULL) + goto err; + BN_CTX_start(ctx); + tmp = BN_CTX_get(ctx); + if (tmp == NULL || !BN_set_word(tmp, 1)) + goto err; + if (BN_cmp(pub_key, tmp) <= 0) + *ret |= DH_CHECK_PUBKEY_TOO_SMALL; + if (BN_copy(tmp, dh->p) == NULL || !BN_sub_word(tmp, 1)) + goto err; + if (BN_cmp(pub_key, tmp) >= 0) + *ret |= DH_CHECK_PUBKEY_TOO_LARGE; + + if (dh->q != NULL) { + /* Check pub_key^q == 1 mod p */ + if (!BN_mod_exp(tmp, pub_key, dh->q, dh->p, ctx)) + goto err; + if (!BN_is_one(tmp)) + *ret |= DH_CHECK_PUBKEY_INVALID; + } -int DH_check(dh,ret) -DH *dh; -int *ret; - { - int ok=0; - BN_CTX *ctx=NULL; - BN_ULONG l; - BIGNUM *q=NULL; - - *ret=0; - ctx=BN_CTX_new(); - if (ctx == NULL) goto err; - q=BN_new(); - if (q == NULL) goto err; - - if (BN_is_word(dh->g,DH_GENERATOR_2)) - { - l=BN_mod_word(dh->p,24); - if (l != 11) *ret|=DH_NOT_SUITABLE_GENERATOR; - } -/* else if (BN_is_word(dh->g,DH_GENERATOR_3)) - { - l=BN_mod_word(dh->p,12); - if (l != 5) *ret|=DH_NOT_SUITABLE_GENERATOR; - }*/ - else if (BN_is_word(dh->g,DH_GENERATOR_5)) - { - l=BN_mod_word(dh->p,10); - if ((l != 3) && (l != 7)) - *ret|=DH_NOT_SUITABLE_GENERATOR; - } - else - *ret|=DH_UNABLE_TO_CHECK_GENERATOR; - - if (!BN_is_prime(dh->p,BN_prime_checks,NULL,ctx,NULL)) - *ret|=DH_CHECK_P_NOT_PRIME; - else - { - if (!BN_rshift1(q,dh->p)) goto err; - if (!BN_is_prime(q,BN_prime_checks,NULL,ctx,NULL)) - *ret|=DH_CHECK_P_NOT_STRONG_PRIME; - } - ok=1; -err: - if (ctx != NULL) BN_CTX_free(ctx); - if (q != NULL) BN_free(q); - return(ok); - } + ok = 1; + err: + BN_CTX_end(ctx); + BN_CTX_free(ctx); + return ok; +}