diff options
Diffstat (limited to 'openssl/crypto/bn/bn_x931p.c')
-rw-r--r-- | openssl/crypto/bn/bn_x931p.c | 272 |
1 files changed, 272 insertions, 0 deletions
diff --git a/openssl/crypto/bn/bn_x931p.c b/openssl/crypto/bn/bn_x931p.c new file mode 100644 index 000000000..04c5c874e --- /dev/null +++ b/openssl/crypto/bn/bn_x931p.c @@ -0,0 +1,272 @@ +/* bn_x931p.c */ +/* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL + * project 2005. + */ +/* ==================================================================== + * Copyright (c) 2005 The OpenSSL Project. All rights reserved. + * + * 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 above 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 acknowledgment: + * "This product includes software developed by the OpenSSL Project + * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)" + * + * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to + * endorse or promote products derived from this software without + * prior written permission. For written permission, please contact + * licensing@OpenSSL.org. + * + * 5. Products derived from this software may not be called "OpenSSL" + * nor may "OpenSSL" appear in their names without prior written + * permission of the OpenSSL Project. + * + * 6. Redistributions of any form whatsoever must retain the following + * acknowledgment: + * "This product includes software developed by the OpenSSL Project + * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)" + * + * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY + * EXPRESSED 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 OpenSSL PROJECT OR + * ITS 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. + * ==================================================================== + * + * This product includes cryptographic software written by Eric Young + * (eay@cryptsoft.com). This product includes software written by Tim + * Hudson (tjh@cryptsoft.com). + * + */ + +#include <stdio.h> +#include <openssl/bn.h> + +/* X9.31 routines for prime derivation */ + +/* X9.31 prime derivation. This is used to generate the primes pi + * (p1, p2, q1, q2) from a parameter Xpi by checking successive odd + * integers. + */ + +static int bn_x931_derive_pi(BIGNUM *pi, const BIGNUM *Xpi, BN_CTX *ctx, + BN_GENCB *cb) + { + int i = 0; + if (!BN_copy(pi, Xpi)) + return 0; + if (!BN_is_odd(pi) && !BN_add_word(pi, 1)) + return 0; + for(;;) + { + i++; + BN_GENCB_call(cb, 0, i); + /* NB 27 MR is specificed in X9.31 */ + if (BN_is_prime_fasttest_ex(pi, 27, ctx, 1, cb)) + break; + if (!BN_add_word(pi, 2)) + return 0; + } + BN_GENCB_call(cb, 2, i); + return 1; + } + +/* This is the main X9.31 prime derivation function. From parameters + * Xp1, Xp2 and Xp derive the prime p. If the parameters p1 or p2 are + * not NULL they will be returned too: this is needed for testing. + */ + +int BN_X931_derive_prime_ex(BIGNUM *p, BIGNUM *p1, BIGNUM *p2, + const BIGNUM *Xp, const BIGNUM *Xp1, const BIGNUM *Xp2, + const BIGNUM *e, BN_CTX *ctx, BN_GENCB *cb) + { + int ret = 0; + + BIGNUM *t, *p1p2, *pm1; + + /* Only even e supported */ + if (!BN_is_odd(e)) + return 0; + + BN_CTX_start(ctx); + if (!p1) + p1 = BN_CTX_get(ctx); + + if (!p2) + p2 = BN_CTX_get(ctx); + + t = BN_CTX_get(ctx); + + p1p2 = BN_CTX_get(ctx); + + pm1 = BN_CTX_get(ctx); + + if (!bn_x931_derive_pi(p1, Xp1, ctx, cb)) + goto err; + + if (!bn_x931_derive_pi(p2, Xp2, ctx, cb)) + goto err; + + if (!BN_mul(p1p2, p1, p2, ctx)) + goto err; + + /* First set p to value of Rp */ + + if (!BN_mod_inverse(p, p2, p1, ctx)) + goto err; + + if (!BN_mul(p, p, p2, ctx)) + goto err; + + if (!BN_mod_inverse(t, p1, p2, ctx)) + goto err; + + if (!BN_mul(t, t, p1, ctx)) + goto err; + + if (!BN_sub(p, p, t)) + goto err; + + if (p->neg && !BN_add(p, p, p1p2)) + goto err; + + /* p now equals Rp */ + + if (!BN_mod_sub(p, p, Xp, p1p2, ctx)) + goto err; + + if (!BN_add(p, p, Xp)) + goto err; + + /* p now equals Yp0 */ + + for (;;) + { + int i = 1; + BN_GENCB_call(cb, 0, i++); + if (!BN_copy(pm1, p)) + goto err; + if (!BN_sub_word(pm1, 1)) + goto err; + if (!BN_gcd(t, pm1, e, ctx)) + goto err; + if (BN_is_one(t) + /* X9.31 specifies 8 MR and 1 Lucas test or any prime test + * offering similar or better guarantees 50 MR is considerably + * better. + */ + && BN_is_prime_fasttest_ex(p, 50, ctx, 1, cb)) + break; + if (!BN_add(p, p, p1p2)) + goto err; + } + + BN_GENCB_call(cb, 3, 0); + + ret = 1; + + err: + + BN_CTX_end(ctx); + + return ret; + } + +/* Generate pair of paramters Xp, Xq for X9.31 prime generation. + * Note: nbits paramter is sum of number of bits in both. + */ + +int BN_X931_generate_Xpq(BIGNUM *Xp, BIGNUM *Xq, int nbits, BN_CTX *ctx) + { + BIGNUM *t; + int i; + /* Number of bits for each prime is of the form + * 512+128s for s = 0, 1, ... + */ + if ((nbits < 1024) || (nbits & 0xff)) + return 0; + nbits >>= 1; + /* The random value Xp must be between sqrt(2) * 2^(nbits-1) and + * 2^nbits - 1. By setting the top two bits we ensure that the lower + * bound is exceeded. + */ + if (!BN_rand(Xp, nbits, 1, 0)) + return 0; + + BN_CTX_start(ctx); + t = BN_CTX_get(ctx); + + for (i = 0; i < 1000; i++) + { + if (!BN_rand(Xq, nbits, 1, 0)) + return 0; + /* Check that |Xp - Xq| > 2^(nbits - 100) */ + BN_sub(t, Xp, Xq); + if (BN_num_bits(t) > (nbits - 100)) + break; + } + + BN_CTX_end(ctx); + + if (i < 1000) + return 1; + + return 0; + + } + +/* Generate primes using X9.31 algorithm. Of the values p, p1, p2, Xp1 + * and Xp2 only 'p' needs to be non-NULL. If any of the others are not NULL + * the relevant parameter will be stored in it. + * + * Due to the fact that |Xp - Xq| > 2^(nbits - 100) must be satisfied Xp and Xq + * are generated using the previous function and supplied as input. + */ + +int BN_X931_generate_prime_ex(BIGNUM *p, BIGNUM *p1, BIGNUM *p2, + BIGNUM *Xp1, BIGNUM *Xp2, + const BIGNUM *Xp, + const BIGNUM *e, BN_CTX *ctx, + BN_GENCB *cb) + { + int ret = 0; + + BN_CTX_start(ctx); + if (!Xp1) + Xp1 = BN_CTX_get(ctx); + if (!Xp2) + Xp2 = BN_CTX_get(ctx); + + if (!BN_rand(Xp1, 101, 0, 0)) + goto error; + if (!BN_rand(Xp2, 101, 0, 0)) + goto error; + if (!BN_X931_derive_prime_ex(p, p1, p2, Xp, Xp1, Xp2, e, ctx, cb)) + goto error; + + ret = 1; + + error: + BN_CTX_end(ctx); + + return ret; + + } + |