| /* crypto/dh/dh_check.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 <stdio.h> |
| #include <openssl/bn.h> |
| #include <openssl/dh.h> |
| #include <openssl/err.h> |
| #include <openssl/fips.h> |
| |
| /* Check that p is a safe 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. |
| */ |
| |
| #ifdef OPENSSL_FIPS |
| |
| int DH_check(const 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; |
| } |
| #if 0 |
| 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; |
| } |
| #endif |
| 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_ex(dh->p,BN_prime_checks,ctx,NULL)) |
| *ret|=DH_CHECK_P_NOT_PRIME; |
| else |
| { |
| if (!BN_rshift1(q,dh->p)) goto err; |
| if (!BN_is_prime_ex(q,BN_prime_checks,ctx,NULL)) |
| *ret|=DH_CHECK_P_NOT_SAFE_PRIME; |
| } |
| ok=1; |
| err: |
| if (ctx != NULL) BN_CTX_free(ctx); |
| if (q != NULL) BN_free(q); |
| return(ok); |
| } |
| |
| int DH_check_pub_key(const DH *dh, const BIGNUM *pub_key, int *ret) |
| { |
| int ok=0; |
| BIGNUM *q=NULL; |
| |
| *ret=0; |
| q=BN_new(); |
| if (q == NULL) goto err; |
| BN_set_word(q,1); |
| if (BN_cmp(pub_key,q) <= 0) |
| *ret|=DH_CHECK_PUBKEY_TOO_SMALL; |
| BN_copy(q,dh->p); |
| BN_sub_word(q,1); |
| if (BN_cmp(pub_key,q) >= 0) |
| *ret|=DH_CHECK_PUBKEY_TOO_LARGE; |
| |
| ok = 1; |
| err: |
| if (q != NULL) BN_free(q); |
| return(ok); |
| } |
| |
| #endif |
