X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=crypto%2Fbn%2Fbn_exp2.c;h=517b9610234c4365f6fc74b23b4d942509bfb5c1;hb=3f6c7691870d1cd2ad0e0c83638cef3f35a0b548;hp=1132d533651e10b1479c4079a50802bccb411be1;hpb=6b691a5c85ddc4e407e32781841fee5c029506cd;p=oweals%2Fopenssl.git diff --git a/crypto/bn/bn_exp2.c b/crypto/bn/bn_exp2.c index 1132d53365..517b961023 100644 --- a/crypto/bn/bn_exp2.c +++ b/crypto/bn/bn_exp2.c @@ -1,195 +1,303 @@ +/* crypto/bn/bn_exp2.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.] + */ +/* ==================================================================== + * 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). + * + */ + #include -#include "cryptlib.h" +#include "internal/cryptlib.h" #include "bn_lcl.h" -/* I've done some timing with different table sizes. - * The main hassle is that even with bits set at 3, this requires - * 63 BIGNUMs to store the pre-calculated values. - * 512 1024 - * bits=1 75.4% 79.4% - * bits=2 61.2% 62.4% - * bits=3 61.3% 59.3% - * The lack of speed improvment is also a function of the pre-calculation - * which could be removed. - */ -#define EXP2_TABLE_BITS 2 /* 1 2 3 4 5 */ -#define EXP2_TABLE_SIZE 4 /* 2 4 8 16 32 */ - -int BN_mod_exp2_mont(BIGNUM *rr, BIGNUM *a1, BIGNUM *p1, BIGNUM *a2, - BIGNUM *p2, BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *in_mont) - { - int i,j,k,bits,bits1,bits2,ret=0,wstart,wend,window,xvalue,yvalue; - int start=1,ts=0,x,y; - BIGNUM *d,*aa1,*aa2,*r; - BIGNUM val[EXP2_TABLE_SIZE][EXP2_TABLE_SIZE]; - BN_MONT_CTX *mont=NULL; - - bn_check_top(a1); - bn_check_top(p1); - bn_check_top(a2); - bn_check_top(p2); - bn_check_top(m); - - if (!(m->d[0] & 1)) - { - BNerr(BN_F_BN_MOD_EXP_MONT,BN_R_CALLED_WITH_EVEN_MODULUS); - return(0); - } - d= &(ctx->bn[ctx->tos++]); - r= &(ctx->bn[ctx->tos++]); - bits1=BN_num_bits(p1); - bits2=BN_num_bits(p2); - if ((bits1 == 0) && (bits2 == 0)) - { - BN_one(r); - return(1); - } - bits=(bits1 > bits2)?bits1:bits2; - - /* If this is not done, things will break in the montgomery - * part */ - - if (in_mont != NULL) - mont=in_mont; - else - { - if ((mont=BN_MONT_CTX_new()) == NULL) goto err; - if (!BN_MONT_CTX_set(mont,m,ctx)) goto err; - } - - BN_init(&(val[0][0])); - BN_init(&(val[1][1])); - BN_init(&(val[0][1])); - BN_init(&(val[1][0])); - ts=1; - if (BN_ucmp(a1,m) >= 0) - { - BN_mod(&(val[1][0]),a1,m,ctx); - aa1= &(val[1][0]); - } - else - aa1=a1; - if (BN_ucmp(a2,m) >= 0) - { - BN_mod(&(val[0][1]),a2,m,ctx); - aa2= &(val[0][1]); - } - else - aa2=a2; - if (!BN_to_montgomery(&(val[1][0]),aa1,mont,ctx)) goto err; - if (!BN_to_montgomery(&(val[0][1]),aa2,mont,ctx)) goto err; - if (!BN_mod_mul_montgomery(&(val[1][1]), - &(val[1][0]),&(val[0][1]),mont,ctx)) - goto err; - -#if 0 - if (bits <= 20) /* This is probably 3 or 0x10001, so just do singles */ - window=1; - else if (bits > 250) - window=5; /* max size of window */ - else if (bits >= 120) - window=4; - else - window=3; -#else - window=EXP2_TABLE_BITS; -#endif - - k=1<= 2) - { - BN_init(&(val[x][0])); - BN_init(&(val[x][1])); - if (!BN_mod_mul_montgomery(&(val[x][0]), - &(val[1][0]),&(val[x-1][0]),mont,ctx)) goto err; - if (!BN_mod_mul_montgomery(&(val[x][1]), - &(val[1][0]),&(val[x-1][1]),mont,ctx)) goto err; - } - for (y=2; ytos-=2; - for (i=0; id[0] & 1)) { + BNerr(BN_F_BN_MOD_EXP2_MONT, BN_R_CALLED_WITH_EVEN_MODULUS); + return (0); + } + bits1 = BN_num_bits(p1); + bits2 = BN_num_bits(p2); + if ((bits1 == 0) && (bits2 == 0)) { + ret = BN_one(rr); + return ret; + } + + bits = (bits1 > bits2) ? bits1 : bits2; + + BN_CTX_start(ctx); + d = BN_CTX_get(ctx); + r = BN_CTX_get(ctx); + val1[0] = BN_CTX_get(ctx); + val2[0] = BN_CTX_get(ctx); + if (!d || !r || !val1[0] || !val2[0]) + goto err; + + if (in_mont != NULL) + mont = in_mont; + else { + if ((mont = BN_MONT_CTX_new()) == NULL) + goto err; + if (!BN_MONT_CTX_set(mont, m, ctx)) + goto err; + } + + window1 = BN_window_bits_for_exponent_size(bits1); + window2 = BN_window_bits_for_exponent_size(bits2); + + /* + * Build table for a1: val1[i] := a1^(2*i + 1) mod m for i = 0 .. 2^(window1-1) + */ + if (a1->neg || BN_ucmp(a1, m) >= 0) { + if (!BN_mod(val1[0], a1, m, ctx)) + goto err; + a_mod_m = val1[0]; + } else + a_mod_m = a1; + if (BN_is_zero(a_mod_m)) { + BN_zero(rr); + ret = 1; + goto err; + } + + if (!BN_to_montgomery(val1[0], a_mod_m, mont, ctx)) + goto err; + if (window1 > 1) { + if (!BN_mod_mul_montgomery(d, val1[0], val1[0], mont, ctx)) + goto err; + + j = 1 << (window1 - 1); + for (i = 1; i < j; i++) { + if (((val1[i] = BN_CTX_get(ctx)) == NULL) || + !BN_mod_mul_montgomery(val1[i], val1[i - 1], d, mont, ctx)) + goto err; + } + } + + /* + * Build table for a2: val2[i] := a2^(2*i + 1) mod m for i = 0 .. 2^(window2-1) + */ + if (a2->neg || BN_ucmp(a2, m) >= 0) { + if (!BN_mod(val2[0], a2, m, ctx)) + goto err; + a_mod_m = val2[0]; + } else + a_mod_m = a2; + if (BN_is_zero(a_mod_m)) { + BN_zero(rr); + ret = 1; + goto err; + } + if (!BN_to_montgomery(val2[0], a_mod_m, mont, ctx)) + goto err; + if (window2 > 1) { + if (!BN_mod_mul_montgomery(d, val2[0], val2[0], mont, ctx)) + goto err; + + j = 1 << (window2 - 1); + for (i = 1; i < j; i++) { + if (((val2[i] = BN_CTX_get(ctx)) == NULL) || + !BN_mod_mul_montgomery(val2[i], val2[i - 1], d, mont, ctx)) + goto err; + } + } + + /* Now compute the power product, using independent windows. */ + r_is_one = 1; + wvalue1 = 0; /* The 'value' of the first window */ + wvalue2 = 0; /* The 'value' of the second window */ + wpos1 = 0; /* If wvalue1 > 0, the bottom bit of the + * first window */ + wpos2 = 0; /* If wvalue2 > 0, the bottom bit of the + * second window */ + + if (!BN_to_montgomery(r, BN_value_one(), mont, ctx)) + goto err; + for (b = bits - 1; b >= 0; b--) { + if (!r_is_one) { + if (!BN_mod_mul_montgomery(r, r, r, mont, ctx)) + goto err; + } + + if (!wvalue1) + if (BN_is_bit_set(p1, b)) { + /* + * consider bits b-window1+1 .. b for this window + */ + i = b - window1 + 1; + while (!BN_is_bit_set(p1, i)) /* works for i<0 */ + i++; + wpos1 = i; + wvalue1 = 1; + for (i = b - 1; i >= wpos1; i--) { + wvalue1 <<= 1; + if (BN_is_bit_set(p1, i)) + wvalue1++; + } + } + + if (!wvalue2) + if (BN_is_bit_set(p2, b)) { + /* + * consider bits b-window2+1 .. b for this window + */ + i = b - window2 + 1; + while (!BN_is_bit_set(p2, i)) + i++; + wpos2 = i; + wvalue2 = 1; + for (i = b - 1; i >= wpos2; i--) { + wvalue2 <<= 1; + if (BN_is_bit_set(p2, i)) + wvalue2++; + } + } + + if (wvalue1 && b == wpos1) { + /* wvalue1 is odd and < 2^window1 */ + if (!BN_mod_mul_montgomery(r, r, val1[wvalue1 >> 1], mont, ctx)) + goto err; + wvalue1 = 0; + r_is_one = 0; + } + + if (wvalue2 && b == wpos2) { + /* wvalue2 is odd and < 2^window2 */ + if (!BN_mod_mul_montgomery(r, r, val2[wvalue2 >> 1], mont, ctx)) + goto err; + wvalue2 = 0; + r_is_one = 0; + } + } + if (!BN_from_montgomery(rr, r, mont, ctx)) + goto err; + ret = 1; + err: + if (in_mont == NULL) + BN_MONT_CTX_free(mont); + BN_CTX_end(ctx); + bn_check_top(rr); + return (ret); +}