diff options
Diffstat (limited to 'openssl/crypto/bn/bn_mod.c')
| -rw-r--r-- | openssl/crypto/bn/bn_mod.c | 301 |
1 files changed, 301 insertions, 0 deletions
diff --git a/openssl/crypto/bn/bn_mod.c b/openssl/crypto/bn/bn_mod.c new file mode 100644 index 000000000..77d6ddb91 --- /dev/null +++ b/openssl/crypto/bn/bn_mod.c @@ -0,0 +1,301 @@ +/* crypto/bn/bn_mod.c */ +/* Includes code written by Lenka Fibikova <fibikova@exp-math.uni-essen.de> + * for the OpenSSL project. */ +/* ==================================================================== + * Copyright (c) 1998-2000 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 + * openssl-core@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). + * + */ +/* 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 "cryptlib.h" +#include "bn_lcl.h" + + +#if 0 /* now just a #define */ +int BN_mod(BIGNUM *rem, const BIGNUM *m, const BIGNUM *d, BN_CTX *ctx) + { + return(BN_div(NULL,rem,m,d,ctx)); + /* note that rem->neg == m->neg (unless the remainder is zero) */ + } +#endif + + +int BN_nnmod(BIGNUM *r, const BIGNUM *m, const BIGNUM *d, BN_CTX *ctx) + { + /* like BN_mod, but returns non-negative remainder + * (i.e., 0 <= r < |d| always holds) */ + + if (!(BN_mod(r,m,d,ctx))) + return 0; + if (!r->neg) + return 1; + /* now -|d| < r < 0, so we have to set r := r + |d| */ + return (d->neg ? BN_sub : BN_add)(r, r, d); +} + + +int BN_mod_add(BIGNUM *r, const BIGNUM *a, const BIGNUM *b, const BIGNUM *m, BN_CTX *ctx) + { + if (!BN_add(r, a, b)) return 0; + return BN_nnmod(r, r, m, ctx); + } + + +/* BN_mod_add variant that may be used if both a and b are non-negative + * and less than m */ +int BN_mod_add_quick(BIGNUM *r, const BIGNUM *a, const BIGNUM *b, const BIGNUM *m) + { + if (!BN_uadd(r, a, b)) return 0; + if (BN_ucmp(r, m) >= 0) + return BN_usub(r, r, m); + return 1; + } + + +int BN_mod_sub(BIGNUM *r, const BIGNUM *a, const BIGNUM *b, const BIGNUM *m, BN_CTX *ctx) + { + if (!BN_sub(r, a, b)) return 0; + return BN_nnmod(r, r, m, ctx); + } + + +/* BN_mod_sub variant that may be used if both a and b are non-negative + * and less than m */ +int BN_mod_sub_quick(BIGNUM *r, const BIGNUM *a, const BIGNUM *b, const BIGNUM *m) + { + if (!BN_sub(r, a, b)) return 0; + if (r->neg) + return BN_add(r, r, m); + return 1; + } + + +/* slow but works */ +int BN_mod_mul(BIGNUM *r, const BIGNUM *a, const BIGNUM *b, const BIGNUM *m, + BN_CTX *ctx) + { + BIGNUM *t; + int ret=0; + + bn_check_top(a); + bn_check_top(b); + bn_check_top(m); + + BN_CTX_start(ctx); + if ((t = BN_CTX_get(ctx)) == NULL) goto err; + if (a == b) + { if (!BN_sqr(t,a,ctx)) goto err; } + else + { if (!BN_mul(t,a,b,ctx)) goto err; } + if (!BN_nnmod(r,t,m,ctx)) goto err; + bn_check_top(r); + ret=1; +err: + BN_CTX_end(ctx); + return(ret); + } + + +int BN_mod_sqr(BIGNUM *r, const BIGNUM *a, const BIGNUM *m, BN_CTX *ctx) + { + if (!BN_sqr(r, a, ctx)) return 0; + /* r->neg == 0, thus we don't need BN_nnmod */ + return BN_mod(r, r, m, ctx); + } + + +int BN_mod_lshift1(BIGNUM *r, const BIGNUM *a, const BIGNUM *m, BN_CTX *ctx) + { + if (!BN_lshift1(r, a)) return 0; + bn_check_top(r); + return BN_nnmod(r, r, m, ctx); + } + + +/* BN_mod_lshift1 variant that may be used if a is non-negative + * and less than m */ +int BN_mod_lshift1_quick(BIGNUM *r, const BIGNUM *a, const BIGNUM *m) + { + if (!BN_lshift1(r, a)) return 0; + bn_check_top(r); + if (BN_cmp(r, m) >= 0) + return BN_sub(r, r, m); + return 1; + } + + +int BN_mod_lshift(BIGNUM *r, const BIGNUM *a, int n, const BIGNUM *m, BN_CTX *ctx) + { + BIGNUM *abs_m = NULL; + int ret; + + if (!BN_nnmod(r, a, m, ctx)) return 0; + + if (m->neg) + { + abs_m = BN_dup(m); + if (abs_m == NULL) return 0; + abs_m->neg = 0; + } + + ret = BN_mod_lshift_quick(r, r, n, (abs_m ? abs_m : m)); + bn_check_top(r); + + if (abs_m) + BN_free(abs_m); + return ret; + } + + +/* BN_mod_lshift variant that may be used if a is non-negative + * and less than m */ +int BN_mod_lshift_quick(BIGNUM *r, const BIGNUM *a, int n, const BIGNUM *m) + { + if (r != a) + { + if (BN_copy(r, a) == NULL) return 0; + } + + while (n > 0) + { + int max_shift; + + /* 0 < r < m */ + max_shift = BN_num_bits(m) - BN_num_bits(r); + /* max_shift >= 0 */ + + if (max_shift < 0) + { + BNerr(BN_F_BN_MOD_LSHIFT_QUICK, BN_R_INPUT_NOT_REDUCED); + return 0; + } + + if (max_shift > n) + max_shift = n; + + if (max_shift) + { + if (!BN_lshift(r, r, max_shift)) return 0; + n -= max_shift; + } + else + { + if (!BN_lshift1(r, r)) return 0; + --n; + } + + /* BN_num_bits(r) <= BN_num_bits(m) */ + + if (BN_cmp(r, m) >= 0) + { + if (!BN_sub(r, r, m)) return 0; + } + } + bn_check_top(r); + + return 1; + } |