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Diffstat (limited to 'src/lib/libcrypto/bn/bn_mod.c')
| -rw-r--r-- | src/lib/libcrypto/bn/bn_mod.c | 301 |
1 files changed, 301 insertions, 0 deletions
diff --git a/src/lib/libcrypto/bn/bn_mod.c b/src/lib/libcrypto/bn/bn_mod.c new file mode 100644 index 0000000000..77d6ddb91a --- /dev/null +++ b/src/lib/libcrypto/bn/bn_mod.c | |||
| @@ -0,0 +1,301 @@ | |||
| 1 | /* crypto/bn/bn_mod.c */ | ||
| 2 | /* Includes code written by Lenka Fibikova <fibikova@exp-math.uni-essen.de> | ||
| 3 | * for the OpenSSL project. */ | ||
| 4 | /* ==================================================================== | ||
| 5 | * Copyright (c) 1998-2000 The OpenSSL Project. All rights reserved. | ||
| 6 | * | ||
| 7 | * Redistribution and use in source and binary forms, with or without | ||
| 8 | * modification, are permitted provided that the following conditions | ||
| 9 | * are met: | ||
| 10 | * | ||
| 11 | * 1. Redistributions of source code must retain the above copyright | ||
| 12 | * notice, this list of conditions and the following disclaimer. | ||
| 13 | * | ||
| 14 | * 2. Redistributions in binary form must reproduce the above copyright | ||
| 15 | * notice, this list of conditions and the following disclaimer in | ||
| 16 | * the documentation and/or other materials provided with the | ||
| 17 | * distribution. | ||
| 18 | * | ||
| 19 | * 3. All advertising materials mentioning features or use of this | ||
| 20 | * software must display the following acknowledgment: | ||
| 21 | * "This product includes software developed by the OpenSSL Project | ||
| 22 | * for use in the OpenSSL Toolkit. (http://www.openssl.org/)" | ||
| 23 | * | ||
| 24 | * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to | ||
| 25 | * endorse or promote products derived from this software without | ||
| 26 | * prior written permission. For written permission, please contact | ||
| 27 | * openssl-core@openssl.org. | ||
| 28 | * | ||
| 29 | * 5. Products derived from this software may not be called "OpenSSL" | ||
| 30 | * nor may "OpenSSL" appear in their names without prior written | ||
| 31 | * permission of the OpenSSL Project. | ||
| 32 | * | ||
| 33 | * 6. Redistributions of any form whatsoever must retain the following | ||
| 34 | * acknowledgment: | ||
| 35 | * "This product includes software developed by the OpenSSL Project | ||
| 36 | * for use in the OpenSSL Toolkit (http://www.openssl.org/)" | ||
| 37 | * | ||
| 38 | * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY | ||
| 39 | * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | ||
| 40 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR | ||
| 41 | * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR | ||
| 42 | * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, | ||
| 43 | * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT | ||
| 44 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; | ||
| 45 | * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | ||
| 46 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, | ||
| 47 | * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) | ||
| 48 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED | ||
| 49 | * OF THE POSSIBILITY OF SUCH DAMAGE. | ||
| 50 | * ==================================================================== | ||
| 51 | * | ||
| 52 | * This product includes cryptographic software written by Eric Young | ||
| 53 | * (eay@cryptsoft.com). This product includes software written by Tim | ||
| 54 | * Hudson (tjh@cryptsoft.com). | ||
| 55 | * | ||
| 56 | */ | ||
| 57 | /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) | ||
| 58 | * All rights reserved. | ||
| 59 | * | ||
| 60 | * This package is an SSL implementation written | ||
| 61 | * by Eric Young (eay@cryptsoft.com). | ||
| 62 | * The implementation was written so as to conform with Netscapes SSL. | ||
| 63 | * | ||
| 64 | * This library is free for commercial and non-commercial use as long as | ||
| 65 | * the following conditions are aheared to. The following conditions | ||
| 66 | * apply to all code found in this distribution, be it the RC4, RSA, | ||
| 67 | * lhash, DES, etc., code; not just the SSL code. The SSL documentation | ||
| 68 | * included with this distribution is covered by the same copyright terms | ||
| 69 | * except that the holder is Tim Hudson (tjh@cryptsoft.com). | ||
| 70 | * | ||
| 71 | * Copyright remains Eric Young's, and as such any Copyright notices in | ||
| 72 | * the code are not to be removed. | ||
| 73 | * If this package is used in a product, Eric Young should be given attribution | ||
| 74 | * as the author of the parts of the library used. | ||
| 75 | * This can be in the form of a textual message at program startup or | ||
| 76 | * in documentation (online or textual) provided with the package. | ||
| 77 | * | ||
| 78 | * Redistribution and use in source and binary forms, with or without | ||
| 79 | * modification, are permitted provided that the following conditions | ||
| 80 | * are met: | ||
| 81 | * 1. Redistributions of source code must retain the copyright | ||
| 82 | * notice, this list of conditions and the following disclaimer. | ||
| 83 | * 2. Redistributions in binary form must reproduce the above copyright | ||
| 84 | * notice, this list of conditions and the following disclaimer in the | ||
| 85 | * documentation and/or other materials provided with the distribution. | ||
| 86 | * 3. All advertising materials mentioning features or use of this software | ||
| 87 | * must display the following acknowledgement: | ||
| 88 | * "This product includes cryptographic software written by | ||
| 89 | * Eric Young (eay@cryptsoft.com)" | ||
| 90 | * The word 'cryptographic' can be left out if the rouines from the library | ||
| 91 | * being used are not cryptographic related :-). | ||
| 92 | * 4. If you include any Windows specific code (or a derivative thereof) from | ||
| 93 | * the apps directory (application code) you must include an acknowledgement: | ||
| 94 | * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" | ||
| 95 | * | ||
| 96 | * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND | ||
| 97 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | ||
| 98 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | ||
| 99 | * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE | ||
| 100 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | ||
| 101 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | ||
| 102 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | ||
| 103 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | ||
| 104 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | ||
| 105 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | ||
| 106 | * SUCH DAMAGE. | ||
| 107 | * | ||
| 108 | * The licence and distribution terms for any publically available version or | ||
| 109 | * derivative of this code cannot be changed. i.e. this code cannot simply be | ||
| 110 | * copied and put under another distribution licence | ||
| 111 | * [including the GNU Public Licence.] | ||
| 112 | */ | ||
| 113 | |||
| 114 | #include "cryptlib.h" | ||
| 115 | #include "bn_lcl.h" | ||
| 116 | |||
| 117 | |||
| 118 | #if 0 /* now just a #define */ | ||
| 119 | int BN_mod(BIGNUM *rem, const BIGNUM *m, const BIGNUM *d, BN_CTX *ctx) | ||
| 120 | { | ||
| 121 | return(BN_div(NULL,rem,m,d,ctx)); | ||
| 122 | /* note that rem->neg == m->neg (unless the remainder is zero) */ | ||
| 123 | } | ||
| 124 | #endif | ||
| 125 | |||
| 126 | |||
| 127 | int BN_nnmod(BIGNUM *r, const BIGNUM *m, const BIGNUM *d, BN_CTX *ctx) | ||
| 128 | { | ||
| 129 | /* like BN_mod, but returns non-negative remainder | ||
| 130 | * (i.e., 0 <= r < |d| always holds) */ | ||
| 131 | |||
| 132 | if (!(BN_mod(r,m,d,ctx))) | ||
| 133 | return 0; | ||
| 134 | if (!r->neg) | ||
| 135 | return 1; | ||
| 136 | /* now -|d| < r < 0, so we have to set r := r + |d| */ | ||
| 137 | return (d->neg ? BN_sub : BN_add)(r, r, d); | ||
| 138 | } | ||
| 139 | |||
| 140 | |||
| 141 | int BN_mod_add(BIGNUM *r, const BIGNUM *a, const BIGNUM *b, const BIGNUM *m, BN_CTX *ctx) | ||
| 142 | { | ||
| 143 | if (!BN_add(r, a, b)) return 0; | ||
| 144 | return BN_nnmod(r, r, m, ctx); | ||
| 145 | } | ||
| 146 | |||
| 147 | |||
| 148 | /* BN_mod_add variant that may be used if both a and b are non-negative | ||
| 149 | * and less than m */ | ||
| 150 | int BN_mod_add_quick(BIGNUM *r, const BIGNUM *a, const BIGNUM *b, const BIGNUM *m) | ||
| 151 | { | ||
| 152 | if (!BN_uadd(r, a, b)) return 0; | ||
| 153 | if (BN_ucmp(r, m) >= 0) | ||
| 154 | return BN_usub(r, r, m); | ||
| 155 | return 1; | ||
| 156 | } | ||
| 157 | |||
| 158 | |||
| 159 | int BN_mod_sub(BIGNUM *r, const BIGNUM *a, const BIGNUM *b, const BIGNUM *m, BN_CTX *ctx) | ||
| 160 | { | ||
| 161 | if (!BN_sub(r, a, b)) return 0; | ||
| 162 | return BN_nnmod(r, r, m, ctx); | ||
| 163 | } | ||
| 164 | |||
| 165 | |||
| 166 | /* BN_mod_sub variant that may be used if both a and b are non-negative | ||
| 167 | * and less than m */ | ||
| 168 | int BN_mod_sub_quick(BIGNUM *r, const BIGNUM *a, const BIGNUM *b, const BIGNUM *m) | ||
| 169 | { | ||
| 170 | if (!BN_sub(r, a, b)) return 0; | ||
| 171 | if (r->neg) | ||
| 172 | return BN_add(r, r, m); | ||
| 173 | return 1; | ||
| 174 | } | ||
| 175 | |||
| 176 | |||
| 177 | /* slow but works */ | ||
| 178 | int BN_mod_mul(BIGNUM *r, const BIGNUM *a, const BIGNUM *b, const BIGNUM *m, | ||
| 179 | BN_CTX *ctx) | ||
| 180 | { | ||
| 181 | BIGNUM *t; | ||
| 182 | int ret=0; | ||
| 183 | |||
| 184 | bn_check_top(a); | ||
| 185 | bn_check_top(b); | ||
| 186 | bn_check_top(m); | ||
| 187 | |||
| 188 | BN_CTX_start(ctx); | ||
| 189 | if ((t = BN_CTX_get(ctx)) == NULL) goto err; | ||
| 190 | if (a == b) | ||
| 191 | { if (!BN_sqr(t,a,ctx)) goto err; } | ||
| 192 | else | ||
| 193 | { if (!BN_mul(t,a,b,ctx)) goto err; } | ||
| 194 | if (!BN_nnmod(r,t,m,ctx)) goto err; | ||
| 195 | bn_check_top(r); | ||
| 196 | ret=1; | ||
| 197 | err: | ||
| 198 | BN_CTX_end(ctx); | ||
| 199 | return(ret); | ||
| 200 | } | ||
| 201 | |||
| 202 | |||
| 203 | int BN_mod_sqr(BIGNUM *r, const BIGNUM *a, const BIGNUM *m, BN_CTX *ctx) | ||
| 204 | { | ||
| 205 | if (!BN_sqr(r, a, ctx)) return 0; | ||
| 206 | /* r->neg == 0, thus we don't need BN_nnmod */ | ||
| 207 | return BN_mod(r, r, m, ctx); | ||
| 208 | } | ||
| 209 | |||
| 210 | |||
| 211 | int BN_mod_lshift1(BIGNUM *r, const BIGNUM *a, const BIGNUM *m, BN_CTX *ctx) | ||
| 212 | { | ||
| 213 | if (!BN_lshift1(r, a)) return 0; | ||
| 214 | bn_check_top(r); | ||
| 215 | return BN_nnmod(r, r, m, ctx); | ||
| 216 | } | ||
| 217 | |||
| 218 | |||
| 219 | /* BN_mod_lshift1 variant that may be used if a is non-negative | ||
| 220 | * and less than m */ | ||
| 221 | int BN_mod_lshift1_quick(BIGNUM *r, const BIGNUM *a, const BIGNUM *m) | ||
| 222 | { | ||
| 223 | if (!BN_lshift1(r, a)) return 0; | ||
| 224 | bn_check_top(r); | ||
| 225 | if (BN_cmp(r, m) >= 0) | ||
| 226 | return BN_sub(r, r, m); | ||
| 227 | return 1; | ||
| 228 | } | ||
| 229 | |||
| 230 | |||
| 231 | int BN_mod_lshift(BIGNUM *r, const BIGNUM *a, int n, const BIGNUM *m, BN_CTX *ctx) | ||
| 232 | { | ||
| 233 | BIGNUM *abs_m = NULL; | ||
| 234 | int ret; | ||
| 235 | |||
| 236 | if (!BN_nnmod(r, a, m, ctx)) return 0; | ||
| 237 | |||
| 238 | if (m->neg) | ||
| 239 | { | ||
| 240 | abs_m = BN_dup(m); | ||
| 241 | if (abs_m == NULL) return 0; | ||
| 242 | abs_m->neg = 0; | ||
| 243 | } | ||
| 244 | |||
| 245 | ret = BN_mod_lshift_quick(r, r, n, (abs_m ? abs_m : m)); | ||
| 246 | bn_check_top(r); | ||
| 247 | |||
| 248 | if (abs_m) | ||
| 249 | BN_free(abs_m); | ||
| 250 | return ret; | ||
| 251 | } | ||
| 252 | |||
| 253 | |||
| 254 | /* BN_mod_lshift variant that may be used if a is non-negative | ||
| 255 | * and less than m */ | ||
| 256 | int BN_mod_lshift_quick(BIGNUM *r, const BIGNUM *a, int n, const BIGNUM *m) | ||
| 257 | { | ||
| 258 | if (r != a) | ||
| 259 | { | ||
| 260 | if (BN_copy(r, a) == NULL) return 0; | ||
| 261 | } | ||
| 262 | |||
| 263 | while (n > 0) | ||
| 264 | { | ||
| 265 | int max_shift; | ||
| 266 | |||
| 267 | /* 0 < r < m */ | ||
| 268 | max_shift = BN_num_bits(m) - BN_num_bits(r); | ||
| 269 | /* max_shift >= 0 */ | ||
| 270 | |||
| 271 | if (max_shift < 0) | ||
| 272 | { | ||
| 273 | BNerr(BN_F_BN_MOD_LSHIFT_QUICK, BN_R_INPUT_NOT_REDUCED); | ||
| 274 | return 0; | ||
| 275 | } | ||
| 276 | |||
| 277 | if (max_shift > n) | ||
| 278 | max_shift = n; | ||
| 279 | |||
| 280 | if (max_shift) | ||
| 281 | { | ||
| 282 | if (!BN_lshift(r, r, max_shift)) return 0; | ||
| 283 | n -= max_shift; | ||
| 284 | } | ||
| 285 | else | ||
| 286 | { | ||
| 287 | if (!BN_lshift1(r, r)) return 0; | ||
| 288 | --n; | ||
| 289 | } | ||
| 290 | |||
| 291 | /* BN_num_bits(r) <= BN_num_bits(m) */ | ||
| 292 | |||
| 293 | if (BN_cmp(r, m) >= 0) | ||
| 294 | { | ||
| 295 | if (!BN_sub(r, r, m)) return 0; | ||
| 296 | } | ||
| 297 | } | ||
| 298 | bn_check_top(r); | ||
| 299 | |||
| 300 | return 1; | ||
| 301 | } | ||
