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| 1 /* crypto/bn/bn_exp2.c */ | |
| 2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) | |
| 3 * All rights reserved. | |
| 4 * | |
| 5 * This package is an SSL implementation written | |
| 6 * by Eric Young (eay@cryptsoft.com). | |
| 7 * The implementation was written so as to conform with Netscapes SSL. | |
| 8 * | |
| 9 * This library is free for commercial and non-commercial use as long as | |
| 10 * the following conditions are aheared to. The following conditions | |
| 11 * apply to all code found in this distribution, be it the RC4, RSA, | |
| 12 * lhash, DES, etc., code; not just the SSL code. The SSL documentation | |
| 13 * included with this distribution is covered by the same copyright terms | |
| 14 * except that the holder is Tim Hudson (tjh@cryptsoft.com). | |
| 15 * | |
| 16 * Copyright remains Eric Young's, and as such any Copyright notices in | |
| 17 * the code are not to be removed. | |
| 18 * If this package is used in a product, Eric Young should be given attribution | |
| 19 * as the author of the parts of the library used. | |
| 20 * This can be in the form of a textual message at program startup or | |
| 21 * in documentation (online or textual) provided with the package. | |
| 22 * | |
| 23 * Redistribution and use in source and binary forms, with or without | |
| 24 * modification, are permitted provided that the following conditions | |
| 25 * are met: | |
| 26 * 1. Redistributions of source code must retain the copyright | |
| 27 * notice, this list of conditions and the following disclaimer. | |
| 28 * 2. Redistributions in binary form must reproduce the above copyright | |
| 29 * notice, this list of conditions and the following disclaimer in the | |
| 30 * documentation and/or other materials provided with the distribution. | |
| 31 * 3. All advertising materials mentioning features or use of this software | |
| 32 * must display the following acknowledgement: | |
| 33 * "This product includes cryptographic software written by | |
| 34 * Eric Young (eay@cryptsoft.com)" | |
| 35 * The word 'cryptographic' can be left out if the rouines from the library | |
| 36 * being used are not cryptographic related :-). | |
| 37 * 4. If you include any Windows specific code (or a derivative thereof) from | |
| 38 * the apps directory (application code) you must include an acknowledgement: | |
| 39 * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" | |
| 40 * | |
| 41 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND | |
| 42 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
| 43 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE | |
| 44 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE | |
| 45 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |
| 46 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS | |
| 47 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
| 48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT | |
| 49 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY | |
| 50 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF | |
| 51 * SUCH DAMAGE. | |
| 52 * | |
| 53 * The licence and distribution terms for any publically available version or | |
| 54 * derivative of this code cannot be changed. i.e. this code cannot simply be | |
| 55 * copied and put under another distribution licence | |
| 56 * [including the GNU Public Licence.] | |
| 57 */ | |
| 58 /* ==================================================================== | |
| 59 * Copyright (c) 1998-2000 The OpenSSL Project. All rights reserved. | |
| 60 * | |
| 61 * Redistribution and use in source and binary forms, with or without | |
| 62 * modification, are permitted provided that the following conditions | |
| 63 * are met: | |
| 64 * | |
| 65 * 1. Redistributions of source code must retain the above copyright | |
| 66 * notice, this list of conditions and the following disclaimer. | |
| 67 * | |
| 68 * 2. Redistributions in binary form must reproduce the above copyright | |
| 69 * notice, this list of conditions and the following disclaimer in | |
| 70 * the documentation and/or other materials provided with the | |
| 71 * distribution. | |
| 72 * | |
| 73 * 3. All advertising materials mentioning features or use of this | |
| 74 * software must display the following acknowledgment: | |
| 75 * "This product includes software developed by the OpenSSL Project | |
| 76 * for use in the OpenSSL Toolkit. (http://www.openssl.org/)" | |
| 77 * | |
| 78 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to | |
| 79 * endorse or promote products derived from this software without | |
| 80 * prior written permission. For written permission, please contact | |
| 81 * openssl-core@openssl.org. | |
| 82 * | |
| 83 * 5. Products derived from this software may not be called "OpenSSL" | |
| 84 * nor may "OpenSSL" appear in their names without prior written | |
| 85 * permission of the OpenSSL Project. | |
| 86 * | |
| 87 * 6. Redistributions of any form whatsoever must retain the following | |
| 88 * acknowledgment: | |
| 89 * "This product includes software developed by the OpenSSL Project | |
| 90 * for use in the OpenSSL Toolkit (http://www.openssl.org/)" | |
| 91 * | |
| 92 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY | |
| 93 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
| 94 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR | |
| 95 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR | |
| 96 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, | |
| 97 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT | |
| 98 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; | |
| 99 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | |
| 100 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, | |
| 101 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) | |
| 102 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED | |
| 103 * OF THE POSSIBILITY OF SUCH DAMAGE. | |
| 104 * ==================================================================== | |
| 105 * | |
| 106 * This product includes cryptographic software written by Eric Young | |
| 107 * (eay@cryptsoft.com). This product includes software written by Tim | |
| 108 * Hudson (tjh@cryptsoft.com). | |
| 109 * | |
| 110 */ | |
| 111 | |
| 112 #include <stdio.h> | |
| 113 #include "cryptlib.h" | |
| 114 #include "bn_lcl.h" | |
| 115 | |
| 116 #define TABLE_SIZE 32 | |
| 117 | |
| 118 int BN_mod_exp2_mont(BIGNUM *rr, const BIGNUM *a1, const BIGNUM *p1, | |
| 119 const BIGNUM *a2, const BIGNUM *p2, const BIGNUM *m, | |
| 120 BN_CTX *ctx, BN_MONT_CTX *in_mont) | |
| 121 { | |
| 122 int i,j,bits,b,bits1,bits2,ret=0,wpos1,wpos2,window1,window2,wvalue1,wva
lue2; | |
| 123 int r_is_one=1; | |
| 124 BIGNUM *d,*r; | |
| 125 const BIGNUM *a_mod_m; | |
| 126 /* Tables of variables obtained from 'ctx' */ | |
| 127 BIGNUM *val1[TABLE_SIZE], *val2[TABLE_SIZE]; | |
| 128 BN_MONT_CTX *mont=NULL; | |
| 129 | |
| 130 bn_check_top(a1); | |
| 131 bn_check_top(p1); | |
| 132 bn_check_top(a2); | |
| 133 bn_check_top(p2); | |
| 134 bn_check_top(m); | |
| 135 | |
| 136 if (!(m->d[0] & 1)) | |
| 137 { | |
| 138 BNerr(BN_F_BN_MOD_EXP2_MONT,BN_R_CALLED_WITH_EVEN_MODULUS); | |
| 139 return(0); | |
| 140 } | |
| 141 bits1=BN_num_bits(p1); | |
| 142 bits2=BN_num_bits(p2); | |
| 143 if ((bits1 == 0) && (bits2 == 0)) | |
| 144 { | |
| 145 ret = BN_one(rr); | |
| 146 return ret; | |
| 147 } | |
| 148 | |
| 149 bits=(bits1 > bits2)?bits1:bits2; | |
| 150 | |
| 151 BN_CTX_start(ctx); | |
| 152 d = BN_CTX_get(ctx); | |
| 153 r = BN_CTX_get(ctx); | |
| 154 val1[0] = BN_CTX_get(ctx); | |
| 155 val2[0] = BN_CTX_get(ctx); | |
| 156 if(!d || !r || !val1[0] || !val2[0]) goto err; | |
| 157 | |
| 158 if (in_mont != NULL) | |
| 159 mont=in_mont; | |
| 160 else | |
| 161 { | |
| 162 if ((mont=BN_MONT_CTX_new()) == NULL) goto err; | |
| 163 if (!BN_MONT_CTX_set(mont,m,ctx)) goto err; | |
| 164 } | |
| 165 | |
| 166 window1 = BN_window_bits_for_exponent_size(bits1); | |
| 167 window2 = BN_window_bits_for_exponent_size(bits2); | |
| 168 | |
| 169 /* | |
| 170 * Build table for a1: val1[i] := a1^(2*i + 1) mod m for i = 0 .. 2^(
window1-1) | |
| 171 */ | |
| 172 if (a1->neg || BN_ucmp(a1,m) >= 0) | |
| 173 { | |
| 174 if (!BN_mod(val1[0],a1,m,ctx)) | |
| 175 goto err; | |
| 176 a_mod_m = val1[0]; | |
| 177 } | |
| 178 else | |
| 179 a_mod_m = a1; | |
| 180 if (BN_is_zero(a_mod_m)) | |
| 181 { | |
| 182 BN_zero(rr); | |
| 183 ret = 1; | |
| 184 goto err; | |
| 185 } | |
| 186 | |
| 187 if (!BN_to_montgomery(val1[0],a_mod_m,mont,ctx)) goto err; | |
| 188 if (window1 > 1) | |
| 189 { | |
| 190 if (!BN_mod_mul_montgomery(d,val1[0],val1[0],mont,ctx)) goto err
; | |
| 191 | |
| 192 j=1<<(window1-1); | |
| 193 for (i=1; i<j; i++) | |
| 194 { | |
| 195 if(((val1[i] = BN_CTX_get(ctx)) == NULL) || | |
| 196 !BN_mod_mul_montgomery(val1[i],val1[i-1]
, | |
| 197 d,mont,ctx)) | |
| 198 goto err; | |
| 199 } | |
| 200 } | |
| 201 | |
| 202 | |
| 203 /* | |
| 204 * Build table for a2: val2[i] := a2^(2*i + 1) mod m for i = 0 .. 2^(
window2-1) | |
| 205 */ | |
| 206 if (a2->neg || BN_ucmp(a2,m) >= 0) | |
| 207 { | |
| 208 if (!BN_mod(val2[0],a2,m,ctx)) | |
| 209 goto err; | |
| 210 a_mod_m = val2[0]; | |
| 211 } | |
| 212 else | |
| 213 a_mod_m = a2; | |
| 214 if (BN_is_zero(a_mod_m)) | |
| 215 { | |
| 216 BN_zero(rr); | |
| 217 ret = 1; | |
| 218 goto err; | |
| 219 } | |
| 220 if (!BN_to_montgomery(val2[0],a_mod_m,mont,ctx)) goto err; | |
| 221 if (window2 > 1) | |
| 222 { | |
| 223 if (!BN_mod_mul_montgomery(d,val2[0],val2[0],mont,ctx)) goto err
; | |
| 224 | |
| 225 j=1<<(window2-1); | |
| 226 for (i=1; i<j; i++) | |
| 227 { | |
| 228 if(((val2[i] = BN_CTX_get(ctx)) == NULL) || | |
| 229 !BN_mod_mul_montgomery(val2[i],val2[i-1]
, | |
| 230 d,mont,ctx)) | |
| 231 goto err; | |
| 232 } | |
| 233 } | |
| 234 | |
| 235 | |
| 236 /* Now compute the power product, using independent windows. */ | |
| 237 r_is_one=1; | |
| 238 wvalue1=0; /* The 'value' of the first window */ | |
| 239 wvalue2=0; /* The 'value' of the second window */ | |
| 240 wpos1=0; /* If wvalue1 > 0, the bottom bit of the first window */ | |
| 241 wpos2=0; /* If wvalue2 > 0, the bottom bit of the second window */ | |
| 242 | |
| 243 if (!BN_to_montgomery(r,BN_value_one(),mont,ctx)) goto err; | |
| 244 for (b=bits-1; b>=0; b--) | |
| 245 { | |
| 246 if (!r_is_one) | |
| 247 { | |
| 248 if (!BN_mod_mul_montgomery(r,r,r,mont,ctx)) | |
| 249 goto err; | |
| 250 } | |
| 251 | |
| 252 if (!wvalue1) | |
| 253 if (BN_is_bit_set(p1, b)) | |
| 254 { | |
| 255 /* consider bits b-window1+1 .. b for this windo
w */ | |
| 256 i = b-window1+1; | |
| 257 while (!BN_is_bit_set(p1, i)) /* works for i<0 *
/ | |
| 258 i++; | |
| 259 wpos1 = i; | |
| 260 wvalue1 = 1; | |
| 261 for (i = b-1; i >= wpos1; i--) | |
| 262 { | |
| 263 wvalue1 <<= 1; | |
| 264 if (BN_is_bit_set(p1, i)) | |
| 265 wvalue1++; | |
| 266 } | |
| 267 } | |
| 268 | |
| 269 if (!wvalue2) | |
| 270 if (BN_is_bit_set(p2, b)) | |
| 271 { | |
| 272 /* consider bits b-window2+1 .. b for this windo
w */ | |
| 273 i = b-window2+1; | |
| 274 while (!BN_is_bit_set(p2, i)) | |
| 275 i++; | |
| 276 wpos2 = i; | |
| 277 wvalue2 = 1; | |
| 278 for (i = b-1; i >= wpos2; i--) | |
| 279 { | |
| 280 wvalue2 <<= 1; | |
| 281 if (BN_is_bit_set(p2, i)) | |
| 282 wvalue2++; | |
| 283 } | |
| 284 } | |
| 285 | |
| 286 if (wvalue1 && b == wpos1) | |
| 287 { | |
| 288 /* wvalue1 is odd and < 2^window1 */ | |
| 289 if (!BN_mod_mul_montgomery(r,r,val1[wvalue1>>1],mont,ctx
)) | |
| 290 goto err; | |
| 291 wvalue1 = 0; | |
| 292 r_is_one = 0; | |
| 293 } | |
| 294 | |
| 295 if (wvalue2 && b == wpos2) | |
| 296 { | |
| 297 /* wvalue2 is odd and < 2^window2 */ | |
| 298 if (!BN_mod_mul_montgomery(r,r,val2[wvalue2>>1],mont,ctx
)) | |
| 299 goto err; | |
| 300 wvalue2 = 0; | |
| 301 r_is_one = 0; | |
| 302 } | |
| 303 } | |
| 304 if (!BN_from_montgomery(rr,r,mont,ctx)) | |
| 305 goto err; | |
| 306 ret=1; | |
| 307 err: | |
| 308 if ((in_mont == NULL) && (mont != NULL)) BN_MONT_CTX_free(mont); | |
| 309 BN_CTX_end(ctx); | |
| 310 bn_check_top(rr); | |
| 311 return(ret); | |
| 312 } | |
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Issue 2072073002:
Delete bundled copy of OpenSSL and replace with README. (Closed)
Base URL: https://chromium.googlesource.com/chromium/deps/openssl@master