Delete bundled copy of OpenSSL and replace with README.

openssl/crypto/dh/dh_gen.c

-/* crypto/dh/dh_gen.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.]
- */
-
-/* NB: These functions have been upgraded - the previous prototypes are in
- * dh_depr.c as wrappers to these ones.
- *  - Geoff
- */
-
-#include <stdio.h>
-#include "cryptlib.h"
-#include <openssl/bn.h>
-#include <openssl/dh.h>
-
-#ifdef OPENSSL_FIPS
-#include <openssl/fips.h>
-#endif
-
-static int dh_builtin_genparams(DH *ret, int prime_len, int generator, BN_GENCB *cb);
-
-int DH_generate_parameters_ex(DH *ret, int prime_len, int generator, BN_GENCB *cb)
-        {
-#ifdef OPENSSL_FIPS
-        if (FIPS_mode() && !(ret->meth->flags & DH_FLAG_FIPS_METHOD)
-                        && !(ret->flags & DH_FLAG_NON_FIPS_ALLOW))
-                {
-                DHerr(DH_F_DH_GENERATE_PARAMETERS_EX, DH_R_NON_FIPS_METHOD);
-                return 0;
-                }
-#endif
-        if(ret->meth->generate_params)
-                return ret->meth->generate_params(ret, prime_len, generator, cb);
-#ifdef OPENSSL_FIPS
-        if (FIPS_mode())
-                return FIPS_dh_generate_parameters_ex(ret, prime_len,
-                                                        generator, cb);
-#endif
-        return dh_builtin_genparams(ret, prime_len, generator, cb);
-        }
-
-/* We generate DH parameters as follows
- * find a prime q which is prime_len/2 bits long.
- * p=(2*q)+1 or (p-1)/2 = q
- * For this case, g is a generator if
- * g^((p-1)/q) mod p != 1 for values of q which are the factors of p-1.
- * Since the factors of p-1 are q and 2, we just need to check
- * g^2 mod p != 1 and g^q mod p != 1.
- *
- * Having said all that,
- * there is another special case method for the generators 2, 3 and 5.
- * for 2, p mod 24 == 11
- * for 3, p mod 12 == 5  <<<<< does not work for safe primes.
- * for 5, p mod 10 == 3 or 7
- *
- * Thanks to Phil Karn <karn@qualcomm.com> for the pointers about the
- * special generators and for answering some of my questions.
- *
- * I've implemented the second simple method :-).
- * Since DH should be using a safe prime (both p and q are prime),
- * this generator function can take a very very long time to run.
- */
-/* Actually there is no reason to insist that 'generator' be a generator.
- * It's just as OK (and in some sense better) to use a generator of the
- * order-q subgroup.
- */
-static int dh_builtin_genparams(DH *ret, int prime_len, int generator, BN_GENCB *cb)
-        {
-        BIGNUM *t1,*t2;
-        int g,ok= -1;
-        BN_CTX *ctx=NULL;
-
-        ctx=BN_CTX_new();
-        if (ctx == NULL) goto err;
-        BN_CTX_start(ctx);
-        t1 = BN_CTX_get(ctx);
-        t2 = BN_CTX_get(ctx);
-        if (t1 == NULL || t2 == NULL) goto err;
-
-        /* Make sure 'ret' has the necessary elements */
-        if(!ret->p && ((ret->p = BN_new()) == NULL)) goto err;
-        if(!ret->g && ((ret->g = BN_new()) == NULL)) goto err;
-        
-        if (generator <= 1)
-                {
-                DHerr(DH_F_DH_BUILTIN_GENPARAMS, DH_R_BAD_GENERATOR);
-                goto err;
-                }
-        if (generator == DH_GENERATOR_2)
-                {
-                if (!BN_set_word(t1,24)) goto err;
-                if (!BN_set_word(t2,11)) goto err;
-                g=2;
-                }
-#if 0 /* does not work for safe primes */
-        else if (generator == DH_GENERATOR_3)
-                {
-                if (!BN_set_word(t1,12)) goto err;
-                if (!BN_set_word(t2,5)) goto err;
-                g=3;
-                }
-#endif
-        else if (generator == DH_GENERATOR_5)
-                {
-                if (!BN_set_word(t1,10)) goto err;
-                if (!BN_set_word(t2,3)) goto err;
-                /* BN_set_word(t3,7); just have to miss
-                 * out on these ones :-( */
-                g=5;
-                }
-        else
-                {
-                /* in the general case, don't worry if 'generator' is a
-                 * generator or not: since we are using safe primes,
-                 * it will generate either an order-q or an order-2q group,
-                 * which both is OK */
-                if (!BN_set_word(t1,2)) goto err;
-                if (!BN_set_word(t2,1)) goto err;
-                g=generator;
-                }
-        
-        if(!BN_generate_prime_ex(ret->p,prime_len,1,t1,t2,cb)) goto err;
-        if(!BN_GENCB_call(cb, 3, 0)) goto err;
-        if (!BN_set_word(ret->g,g)) goto err;
-        ok=1;
-err:
-        if (ok == -1)
-                {
-                DHerr(DH_F_DH_BUILTIN_GENPARAMS,ERR_R_BN_LIB);
-                ok=0;
-                }
-
-        if (ctx != NULL)
-                {
-                BN_CTX_end(ctx);
-                BN_CTX_free(ctx);
-                }
-        return ok;
-        }