-/* crypto/dh/dh_check.c */
-/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
- * All rights reserved.
+/*
+ * Copyright 1995-2016 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 OpenSSL license (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 <stdio.h>
-#include "cryptlib.h"
-#include "bn.h"
-#include "dh.h"
+#include "internal/cryptlib.h"
+#include <openssl/bn.h>
+#include "dh_locl.h"
-/* Check that p is a strong prime and
- * if g is 2, 3 or 5, check that is is a suitable generator
+/*-
+ * Check that p is a safe prime and
+ * if g is 2, 3 or 5, check that it is a suitable generator
* where
* for 2, p mod 24 == 11
* for 3, p mod 12 == 5
* should hold.
*/
-int DH_check(dh,ret)
-DH *dh;
-int *ret;
- {
- int ok=0;
- BN_CTX *ctx=NULL;
- BN_ULONG l;
- BIGNUM *q=NULL;
+int DH_check(const DH *dh, int *ret)
+{
+ int ok = 0, r;
+ BN_CTX *ctx = NULL;
+ BN_ULONG l;
+ BIGNUM *t1 = NULL, *t2 = NULL;
- *ret=0;
- ctx=BN_CTX_new();
- if (ctx == NULL) goto err;
- q=BN_new();
- if (q == NULL) goto err;
+ *ret = 0;
+ ctx = BN_CTX_new();
+ if (ctx == NULL)
+ goto err;
+ BN_CTX_start(ctx);
+ t1 = BN_CTX_get(ctx);
+ if (t1 == NULL)
+ goto err;
+ t2 = BN_CTX_get(ctx);
+ if (t2 == 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 (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, BN_prime_checks, 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;
- 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);
- }
+ } else 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_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;
+
+ r = BN_is_prime_ex(dh->p, BN_prime_checks, 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, BN_prime_checks, ctx, NULL);
+ if (r < 0)
+ goto err;
+ if (!r)
+ *ret |= DH_CHECK_P_NOT_SAFE_PRIME;
+ }
+ ok = 1;
+ err:
+ if (ctx != NULL) {
+ BN_CTX_end(ctx);
+ BN_CTX_free(ctx);
+ }
+ return (ok);
+}
+
+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;
+ }
+
+ ok = 1;
+ err:
+ if (ctx != NULL) {
+ BN_CTX_end(ctx);
+ BN_CTX_free(ctx);
+ }
+ return (ok);
+}
projects / openssl.git / blobdiff