X-Git-Url: https://git.openssl.org/gitweb/?p=openssl.git;a=blobdiff_plain;f=crypto%2Fbn%2Fbn_lib.c;h=80f910c807793490908cb8abbba286787397c91f;hp=bbefd80309d096623a891cd7943bb478636cf4af;hb=dd41956d80686638d74fd203bd67060f90966280;hpb=d459e39012e9912e5e827338741e7894e7b2a876 diff --git a/crypto/bn/bn_lib.c b/crypto/bn/bn_lib.c index bbefd80309..80f910c807 100644 --- a/crypto/bn/bn_lib.c +++ b/crypto/bn/bn_lib.c @@ -1,77 +1,23 @@ -/* crypto/bn/bn_lib.c */ -/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) - * All rights reserved. +/* + * Copyright 1995-2018 The OpenSSL Project Authors. 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.] + * Licensed under the OpenSSL license (the "License"). You may not use + * this file except in compliance with the License. You can obtain a copy + * in the file LICENSE in the source distribution or at + * https://www.openssl.org/source/license.html */ -#ifndef BN_DEBUG -# undef NDEBUG /* avoid conflicting definitions */ -# define NDEBUG -#endif - #include #include -#include -#include "cryptlib.h" +#include "internal/cryptlib.h" #include "bn_lcl.h" - -const char *BN_version="Big Number" OPENSSL_VERSION_PTEXT; +#include +#include "internal/constant_time_locl.h" /* This stuff appears to be completely unused, so is deprecated */ -#ifndef OPENSSL_NO_DEPRECATED -/* For a 32 bit machine +#if OPENSSL_API_COMPAT < 0x00908000L +/*- + * For a 32 bit machine * 2 - 4 == 128 * 3 - 8 == 256 * 4 - 16 == 512 @@ -80,798 +26,963 @@ const char *BN_version="Big Number" OPENSSL_VERSION_PTEXT; * 7 - 128 == 4096 * 8 - 256 == 8192 */ -static int bn_limit_bits=0; -static int bn_limit_num=8; /* (1<= 0) - { - if (mult > (int)(sizeof(int)*8)-1) - mult=sizeof(int)*8-1; - bn_limit_bits=mult; - bn_limit_num=1<= 0) - { - if (high > (int)(sizeof(int)*8)-1) - high=sizeof(int)*8-1; - bn_limit_bits_high=high; - bn_limit_num_high=1<= 0) - { - if (low > (int)(sizeof(int)*8)-1) - low=sizeof(int)*8-1; - bn_limit_bits_low=low; - bn_limit_num_low=1<= 0) - { - if (mont > (int)(sizeof(int)*8)-1) - mont=sizeof(int)*8-1; - bn_limit_bits_mont=mont; - bn_limit_num_mont=1<= 0) { + if (mult > (int)(sizeof(int) * 8) - 1) + mult = sizeof(int) * 8 - 1; + bn_limit_bits = mult; + bn_limit_num = 1 << mult; + } + if (high >= 0) { + if (high > (int)(sizeof(int) * 8) - 1) + high = sizeof(int) * 8 - 1; + bn_limit_bits_high = high; + bn_limit_num_high = 1 << high; + } + if (low >= 0) { + if (low > (int)(sizeof(int) * 8) - 1) + low = sizeof(int) * 8 - 1; + bn_limit_bits_low = low; + bn_limit_num_low = 1 << low; + } + if (mont >= 0) { + if (mont > (int)(sizeof(int) * 8) - 1) + mont = sizeof(int) * 8 - 1; + bn_limit_bits_mont = mont; + bn_limit_num_mont = 1 << mont; + } +} int BN_get_params(int which) - { - if (which == 0) return(bn_limit_bits); - else if (which == 1) return(bn_limit_bits_high); - else if (which == 2) return(bn_limit_bits_low); - else if (which == 3) return(bn_limit_bits_mont); - else return(0); - } +{ + if (which == 0) + return bn_limit_bits; + else if (which == 1) + return bn_limit_bits_high; + else if (which == 2) + return bn_limit_bits_low; + else if (which == 3) + return bn_limit_bits_mont; + else + return 0; +} #endif const BIGNUM *BN_value_one(void) - { - static BN_ULONG data_one=1L; - static BIGNUM const_one={&data_one,1,1,0,BN_FLG_STATIC_DATA}; - - return(&const_one); - } - -char *BN_options(void) - { - static int init=0; - static char data[16]; - - if (!init) - { - init++; -#ifdef BN_LLONG - BIO_snprintf(data,sizeof data,"bn(%d,%d)", - (int)sizeof(BN_ULLONG)*8,(int)sizeof(BN_ULONG)*8); -#else - BIO_snprintf(data,sizeof data,"bn(%d,%d)", - (int)sizeof(BN_ULONG)*8,(int)sizeof(BN_ULONG)*8); -#endif - } - return(data); - } +{ + static const BN_ULONG data_one = 1L; + static const BIGNUM const_one = + { (BN_ULONG *)&data_one, 1, 1, 0, BN_FLG_STATIC_DATA }; + + return &const_one; +} int BN_num_bits_word(BN_ULONG l) - { - static const char bits[256]={ - 0,1,2,2,3,3,3,3,4,4,4,4,4,4,4,4, - 5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5, - 6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6, - 6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6, - 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7, - 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7, - 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7, - 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7, - 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8, - 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8, - 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8, - 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8, - 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8, - 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8, - 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8, - 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8, - }; - -#if defined(SIXTY_FOUR_BIT_LONG) - if (l & 0xffffffff00000000L) - { - if (l & 0xffff000000000000L) - { - if (l & 0xff00000000000000L) - { - return(bits[(int)(l>>56)]+56); - } - else return(bits[(int)(l>>48)]+48); - } - else - { - if (l & 0x0000ff0000000000L) - { - return(bits[(int)(l>>40)]+40); - } - else return(bits[(int)(l>>32)]+32); - } - } - else -#else -#ifdef SIXTY_FOUR_BIT - if (l & 0xffffffff00000000LL) - { - if (l & 0xffff000000000000LL) - { - if (l & 0xff00000000000000LL) - { - return(bits[(int)(l>>56)]+56); - } - else return(bits[(int)(l>>48)]+48); - } - else - { - if (l & 0x0000ff0000000000LL) - { - return(bits[(int)(l>>40)]+40); - } - else return(bits[(int)(l>>32)]+32); - } - } - else -#endif -#endif - { -#if defined(THIRTY_TWO_BIT) || defined(SIXTY_FOUR_BIT) || defined(SIXTY_FOUR_BIT_LONG) - if (l & 0xffff0000L) - { - if (l & 0xff000000L) - return(bits[(int)(l>>24L)]+24); - else return(bits[(int)(l>>16L)]+16); - } - else +{ + BN_ULONG x, mask; + int bits = (l != 0); + +#if BN_BITS2 > 32 + x = l >> 32; + mask = (0 - x) & BN_MASK2; + mask = (0 - (mask >> (BN_BITS2 - 1))); + bits += 32 & mask; + l ^= (x ^ l) & mask; #endif - { -#if defined(SIXTEEN_BIT) || defined(THIRTY_TWO_BIT) || defined(SIXTY_FOUR_BIT) || defined(SIXTY_FOUR_BIT_LONG) - if (l & 0xff00L) - return(bits[(int)(l>>8)]+8); - else -#endif - return(bits[(int)(l )] ); - } - } - } + + x = l >> 16; + mask = (0 - x) & BN_MASK2; + mask = (0 - (mask >> (BN_BITS2 - 1))); + bits += 16 & mask; + l ^= (x ^ l) & mask; + + x = l >> 8; + mask = (0 - x) & BN_MASK2; + mask = (0 - (mask >> (BN_BITS2 - 1))); + bits += 8 & mask; + l ^= (x ^ l) & mask; + + x = l >> 4; + mask = (0 - x) & BN_MASK2; + mask = (0 - (mask >> (BN_BITS2 - 1))); + bits += 4 & mask; + l ^= (x ^ l) & mask; + + x = l >> 2; + mask = (0 - x) & BN_MASK2; + mask = (0 - (mask >> (BN_BITS2 - 1))); + bits += 2 & mask; + l ^= (x ^ l) & mask; + + x = l >> 1; + mask = (0 - x) & BN_MASK2; + mask = (0 - (mask >> (BN_BITS2 - 1))); + bits += 1 & mask; + + return bits; +} int BN_num_bits(const BIGNUM *a) - { - int i = a->top - 1; - bn_check_top(a); +{ + int i = a->top - 1; + bn_check_top(a); + + if (BN_is_zero(a)) + return 0; + return ((i * BN_BITS2) + BN_num_bits_word(a->d[i])); +} + +static void bn_free_d(BIGNUM *a) +{ + if (BN_get_flags(a, BN_FLG_SECURE)) + OPENSSL_secure_free(a->d); + else + OPENSSL_free(a->d); +} - if (BN_is_zero(a)) return 0; - return ((i*BN_BITS2) + BN_num_bits_word(a->d[i])); - } void BN_clear_free(BIGNUM *a) - { - int i; - - if (a == NULL) return; - bn_check_top(a); - if (a->d != NULL) - { - OPENSSL_cleanse(a->d,a->dmax*sizeof(a->d[0])); - if (!(BN_get_flags(a,BN_FLG_STATIC_DATA))) - OPENSSL_free(a->d); - } - i=BN_get_flags(a,BN_FLG_MALLOCED); - OPENSSL_cleanse(a,sizeof(BIGNUM)); - if (i) - OPENSSL_free(a); - } +{ + if (a == NULL) + return; + if (a->d != NULL && !BN_get_flags(a, BN_FLG_STATIC_DATA)) { + OPENSSL_cleanse(a->d, a->dmax * sizeof(a->d[0])); + bn_free_d(a); + } + if (BN_get_flags(a, BN_FLG_MALLOCED)) { + OPENSSL_cleanse(a, sizeof(*a)); + OPENSSL_free(a); + } +} void BN_free(BIGNUM *a) - { - if (a == NULL) return; - bn_check_top(a); - if ((a->d != NULL) && !(BN_get_flags(a,BN_FLG_STATIC_DATA))) - OPENSSL_free(a->d); - if (a->flags & BN_FLG_MALLOCED) - OPENSSL_free(a); - else - { -#ifndef OPENSSL_NO_DEPRECATED - a->flags|=BN_FLG_FREE; -#endif - a->d = NULL; - } - } - -void BN_init(BIGNUM *a) - { - memset(a,0,sizeof(BIGNUM)); - bn_check_top(a); - } +{ + if (a == NULL) + return; + if (!BN_get_flags(a, BN_FLG_STATIC_DATA)) + bn_free_d(a); + if (a->flags & BN_FLG_MALLOCED) + OPENSSL_free(a); +} + +void bn_init(BIGNUM *a) +{ + static BIGNUM nilbn; + + *a = nilbn; + bn_check_top(a); +} BIGNUM *BN_new(void) - { - BIGNUM *ret; - - if ((ret=(BIGNUM *)OPENSSL_malloc(sizeof(BIGNUM))) == NULL) - { - BNerr(BN_F_BN_NEW,ERR_R_MALLOC_FAILURE); - return(NULL); - } - ret->flags=BN_FLG_MALLOCED; - ret->top=0; - ret->neg=0; - ret->dmax=0; - ret->d=NULL; - bn_check_top(ret); - return(ret); - } - -/* This is used both by bn_expand2() and bn_dup_expand() */ +{ + BIGNUM *ret; + + if ((ret = OPENSSL_zalloc(sizeof(*ret))) == NULL) { + BNerr(BN_F_BN_NEW, ERR_R_MALLOC_FAILURE); + return NULL; + } + ret->flags = BN_FLG_MALLOCED; + bn_check_top(ret); + return ret; +} + + BIGNUM *BN_secure_new(void) + { + BIGNUM *ret = BN_new(); + if (ret != NULL) + ret->flags |= BN_FLG_SECURE; + return ret; + } + +/* This is used by bn_expand2() */ /* The caller MUST check that words > b->dmax before calling this */ static BN_ULONG *bn_expand_internal(const BIGNUM *b, int words) - { - BN_ULONG *A,*a = NULL; - const BN_ULONG *B; - int i; - - bn_check_top(b); - - if (words > (INT_MAX/(4*BN_BITS2))) - { - BNerr(BN_F_BN_EXPAND_INTERNAL,BN_R_BIGNUM_TOO_LONG); - return NULL; - } - if (BN_get_flags(b,BN_FLG_STATIC_DATA)) - { - BNerr(BN_F_BN_EXPAND_INTERNAL,BN_R_EXPAND_ON_STATIC_BIGNUM_DATA); - return(NULL); - } - a=A=(BN_ULONG *)OPENSSL_malloc(sizeof(BN_ULONG)*words); - if (A == NULL) - { - BNerr(BN_F_BN_EXPAND_INTERNAL,ERR_R_MALLOC_FAILURE); - return(NULL); - } -#if 1 - B=b->d; - /* Check if the previous number needs to be copied */ - if (B != NULL) - { - for (i=b->top>>2; i>0; i--,A+=4,B+=4) - { - /* - * The fact that the loop is unrolled - * 4-wise is a tribute to Intel. It's - * the one that doesn't have enough - * registers to accomodate more data. - * I'd unroll it 8-wise otherwise:-) - * - * - */ - BN_ULONG a0,a1,a2,a3; - a0=B[0]; a1=B[1]; a2=B[2]; a3=B[3]; - A[0]=a0; A[1]=a1; A[2]=a2; A[3]=a3; - } - switch (b->top&3) - { - case 3: A[2]=B[2]; - case 2: A[1]=B[1]; - case 1: A[0]=B[0]; - case 0: /* workaround for ultrix cc: without 'case 0', the optimizer does - * the switch table by doing a=top&3; a--; goto jump_table[a]; - * which fails for top== 0 */ - ; - } - } - -#else - memset(A,0,sizeof(BN_ULONG)*words); - memcpy(A,b->d,sizeof(b->d[0])*b->top); -#endif - - return(a); - } - -/* This is an internal function that can be used instead of bn_expand2() - * when there is a need to copy BIGNUMs instead of only expanding the - * data part, while still expanding them. - * Especially useful when needing to expand BIGNUMs that are declared - * 'const' and should therefore not be changed. - * The reason to use this instead of a BN_dup() followed by a bn_expand2() - * is memory allocation overhead. A BN_dup() followed by a bn_expand2() - * will allocate new memory for the BIGNUM data twice, and free it once, - * while bn_dup_expand() makes sure allocation is made only once. +{ + BN_ULONG *a = NULL; + + if (words > (INT_MAX / (4 * BN_BITS2))) { + BNerr(BN_F_BN_EXPAND_INTERNAL, BN_R_BIGNUM_TOO_LONG); + return NULL; + } + if (BN_get_flags(b, BN_FLG_STATIC_DATA)) { + BNerr(BN_F_BN_EXPAND_INTERNAL, BN_R_EXPAND_ON_STATIC_BIGNUM_DATA); + return NULL; + } + if (BN_get_flags(b, BN_FLG_SECURE)) + a = OPENSSL_secure_zalloc(words * sizeof(*a)); + else + a = OPENSSL_zalloc(words * sizeof(*a)); + if (a == NULL) { + BNerr(BN_F_BN_EXPAND_INTERNAL, ERR_R_MALLOC_FAILURE); + return NULL; + } + + assert(b->top <= words); + if (b->top > 0) + memcpy(a, b->d, sizeof(*a) * b->top); + + return a; +} + +/* + * This is an internal function that should not be used in applications. It + * ensures that 'b' has enough room for a 'words' word number and initialises + * any unused part of b->d with leading zeros. It is mostly used by the + * various BIGNUM routines. If there is an error, NULL is returned. If not, + * 'b' is returned. */ -#ifndef OPENSSL_NO_DEPRECATED -BIGNUM *bn_dup_expand(const BIGNUM *b, int words) - { - BIGNUM *r = NULL; - - bn_check_top(b); - - /* This function does not work if - * words <= b->dmax && top < words - * because BN_dup() does not preserve 'dmax'! - * (But bn_dup_expand() is not used anywhere yet.) - */ - - if (words > b->dmax) - { - BN_ULONG *a = bn_expand_internal(b, words); - - if (a) - { - r = BN_new(); - if (r) - { - r->top = b->top; - r->dmax = words; - r->neg = b->neg; - r->d = a; - } - else - { - /* r == NULL, BN_new failure */ - OPENSSL_free(a); - } - } - /* If a == NULL, there was an error in allocation in - bn_expand_internal(), and NULL should be returned */ - } - else - { - r = BN_dup(b); - } - - bn_check_top(r); - return r; - } -#endif - -/* This is an internal function that should not be used in applications. - * It ensures that 'b' has enough room for a 'words' word number - * and initialises any unused part of b->d with leading zeros. - * It is mostly used by the various BIGNUM routines. If there is an error, - * NULL is returned. If not, 'b' is returned. */ - BIGNUM *bn_expand2(BIGNUM *b, int words) - { - bn_check_top(b); - - if (words > b->dmax) - { - BN_ULONG *a = bn_expand_internal(b, words); - if(!a) return NULL; - if(b->d) OPENSSL_free(b->d); - b->d=a; - b->dmax=words; - } - -/* None of this should be necessary because of what b->top means! */ -#if 0 - /* NB: bn_wexpand() calls this only if the BIGNUM really has to grow */ - if (b->top < b->dmax) - { - int i; - BN_ULONG *A = &(b->d[b->top]); - for (i=(b->dmax - b->top)>>3; i>0; i--,A+=8) - { - A[0]=0; A[1]=0; A[2]=0; A[3]=0; - A[4]=0; A[5]=0; A[6]=0; A[7]=0; - } - for (i=(b->dmax - b->top)&7; i>0; i--,A++) - A[0]=0; - assert(A == &(b->d[b->dmax])); - } -#endif - bn_check_top(b); - return b; - } +{ + if (words > b->dmax) { + BN_ULONG *a = bn_expand_internal(b, words); + if (!a) + return NULL; + if (b->d) { + OPENSSL_cleanse(b->d, b->dmax * sizeof(b->d[0])); + bn_free_d(b); + } + b->d = a; + b->dmax = words; + } + + return b; +} BIGNUM *BN_dup(const BIGNUM *a) - { - BIGNUM *t; - - if (a == NULL) return NULL; - bn_check_top(a); - - t = BN_new(); - if (t == NULL) return NULL; - if(!BN_copy(t, a)) - { - BN_free(t); - return NULL; - } - bn_check_top(t); - return t; - } +{ + BIGNUM *t; + + if (a == NULL) + return NULL; + bn_check_top(a); + + t = BN_get_flags(a, BN_FLG_SECURE) ? BN_secure_new() : BN_new(); + if (t == NULL) + return NULL; + if (!BN_copy(t, a)) { + BN_free(t); + return NULL; + } + bn_check_top(t); + return t; +} BIGNUM *BN_copy(BIGNUM *a, const BIGNUM *b) - { - int i; - BN_ULONG *A; - const BN_ULONG *B; - - bn_check_top(b); - - if (a == b) return(a); - if (bn_wexpand(a,b->top) == NULL) return(NULL); - -#if 1 - A=a->d; - B=b->d; - for (i=b->top>>2; i>0; i--,A+=4,B+=4) - { - BN_ULONG a0,a1,a2,a3; - a0=B[0]; a1=B[1]; a2=B[2]; a3=B[3]; - A[0]=a0; A[1]=a1; A[2]=a2; A[3]=a3; - } - switch (b->top&3) - { - case 3: A[2]=B[2]; - case 2: A[1]=B[1]; - case 1: A[0]=B[0]; - case 0: ; /* ultrix cc workaround, see comments in bn_expand_internal */ - } -#else - memcpy(a->d,b->d,sizeof(b->d[0])*b->top); -#endif - - a->top=b->top; - a->neg=b->neg; - bn_check_top(a); - return(a); - } - -BIGNUM *BN_ncopy(BIGNUM *a, const BIGNUM *b, size_t n) - { - int i, min; - BN_ULONG *A; - const BN_ULONG *B; - - bn_check_top(b); - if (a == b) - return a; - - min = (b->top < (int)n)? b->top: (int)n; - if (!min) - { - BN_zero(a); - return a; - } - if (bn_wexpand(a, min) == NULL) - return NULL; - - A=a->d; - B=b->d; - for (i=min>>2; i>0; i--, A+=4, B+=4) - { - BN_ULONG a0,a1,a2,a3; - a0=B[0]; a1=B[1]; a2=B[2]; a3=B[3]; - A[0]=a0; A[1]=a1; A[2]=a2; A[3]=a3; - } - switch (min&3) - { - case 3: A[2]=B[2]; - case 2: A[1]=B[1]; - case 1: A[0]=B[0]; - case 0: ; - } - a->top = min; - a->neg = b->neg; - bn_correct_top(a); - return(a); - } +{ + bn_check_top(b); + + if (a == b) + return a; + if (bn_wexpand(a, b->top) == NULL) + return NULL; + + if (b->top > 0) + memcpy(a->d, b->d, sizeof(b->d[0]) * b->top); + + a->neg = b->neg; + a->top = b->top; + a->flags |= b->flags & BN_FLG_FIXED_TOP; + bn_check_top(a); + return a; +} + +#define FLAGS_DATA(flags) ((flags) & (BN_FLG_STATIC_DATA \ + | BN_FLG_CONSTTIME \ + | BN_FLG_SECURE \ + | BN_FLG_FIXED_TOP)) +#define FLAGS_STRUCT(flags) ((flags) & (BN_FLG_MALLOCED)) void BN_swap(BIGNUM *a, BIGNUM *b) - { - int flags_old_a, flags_old_b; - BN_ULONG *tmp_d; - int tmp_top, tmp_dmax, tmp_neg; - - bn_check_top(a); - bn_check_top(b); - - flags_old_a = a->flags; - flags_old_b = b->flags; - - tmp_d = a->d; - tmp_top = a->top; - tmp_dmax = a->dmax; - tmp_neg = a->neg; - - a->d = b->d; - a->top = b->top; - a->dmax = b->dmax; - a->neg = b->neg; - - b->d = tmp_d; - b->top = tmp_top; - b->dmax = tmp_dmax; - b->neg = tmp_neg; - - a->flags = (flags_old_a & BN_FLG_MALLOCED) | (flags_old_b & BN_FLG_STATIC_DATA); - b->flags = (flags_old_b & BN_FLG_MALLOCED) | (flags_old_a & BN_FLG_STATIC_DATA); - bn_check_top(a); - bn_check_top(b); - } +{ + int flags_old_a, flags_old_b; + BN_ULONG *tmp_d; + int tmp_top, tmp_dmax, tmp_neg; + + bn_check_top(a); + bn_check_top(b); + + flags_old_a = a->flags; + flags_old_b = b->flags; + + tmp_d = a->d; + tmp_top = a->top; + tmp_dmax = a->dmax; + tmp_neg = a->neg; + + a->d = b->d; + a->top = b->top; + a->dmax = b->dmax; + a->neg = b->neg; + + b->d = tmp_d; + b->top = tmp_top; + b->dmax = tmp_dmax; + b->neg = tmp_neg; + + a->flags = FLAGS_STRUCT(flags_old_a) | FLAGS_DATA(flags_old_b); + b->flags = FLAGS_STRUCT(flags_old_b) | FLAGS_DATA(flags_old_a); + bn_check_top(a); + bn_check_top(b); +} void BN_clear(BIGNUM *a) - { - bn_check_top(a); - if (a->d != NULL) - memset(a->d,0,a->dmax*sizeof(a->d[0])); - a->top=0; - a->neg=0; - } +{ + bn_check_top(a); + if (a->d != NULL) + OPENSSL_cleanse(a->d, sizeof(*a->d) * a->dmax); + a->neg = 0; + a->top = 0; + a->flags &= ~BN_FLG_FIXED_TOP; +} BN_ULONG BN_get_word(const BIGNUM *a) - { - if (a->top > 1) - return BN_MASK2; - else if (a->top == 1) - return a->d[0]; - /* a->top == 0 */ - return 0; - } +{ + if (a->top > 1) + return BN_MASK2; + else if (a->top == 1) + return a->d[0]; + /* a->top == 0 */ + return 0; +} int BN_set_word(BIGNUM *a, BN_ULONG w) - { - bn_check_top(a); - if (bn_expand(a,(int)sizeof(BN_ULONG)*8) == NULL) return(0); - a->neg = 0; - a->d[0] = w; - a->top = (w ? 1 : 0); - bn_check_top(a); - return(1); - } +{ + bn_check_top(a); + if (bn_expand(a, (int)sizeof(BN_ULONG) * 8) == NULL) + return 0; + a->neg = 0; + a->d[0] = w; + a->top = (w ? 1 : 0); + a->flags &= ~BN_FLG_FIXED_TOP; + bn_check_top(a); + return 1; +} BIGNUM *BN_bin2bn(const unsigned char *s, int len, BIGNUM *ret) - { - unsigned int i,m; - unsigned int n; - BN_ULONG l; - BIGNUM *bn = NULL; - - if (ret == NULL) - ret = bn = BN_new(); - if (ret == NULL) return(NULL); - bn_check_top(ret); - l=0; - n=len; - if (n == 0) - { - ret->top=0; - return(ret); - } - i=((n-1)/BN_BYTES)+1; - m=((n-1)%(BN_BYTES)); - if (bn_wexpand(ret, (int)i) == NULL) - { - if (bn) BN_free(bn); - return NULL; - } - ret->top=i; - ret->neg=0; - while (n--) - { - l=(l<<8L)| *(s++); - if (m-- == 0) - { - ret->d[--i]=l; - l=0; - m=BN_BYTES-1; - } - } - /* need to call this due to clear byte at top if avoiding - * having the top bit set (-ve number) */ - bn_correct_top(ret); - return(ret); - } +{ + unsigned int i, m; + unsigned int n; + BN_ULONG l; + BIGNUM *bn = NULL; + + if (ret == NULL) + ret = bn = BN_new(); + if (ret == NULL) + return NULL; + bn_check_top(ret); + /* Skip leading zero's. */ + for ( ; len > 0 && *s == 0; s++, len--) + continue; + n = len; + if (n == 0) { + ret->top = 0; + return ret; + } + i = ((n - 1) / BN_BYTES) + 1; + m = ((n - 1) % (BN_BYTES)); + if (bn_wexpand(ret, (int)i) == NULL) { + BN_free(bn); + return NULL; + } + ret->top = i; + ret->neg = 0; + l = 0; + while (n--) { + l = (l << 8L) | *(s++); + if (m-- == 0) { + ret->d[--i] = l; + l = 0; + m = BN_BYTES - 1; + } + } + /* + * need to call this due to clear byte at top if avoiding having the top + * bit set (-ve number) + */ + bn_correct_top(ret); + return ret; +} /* ignore negative */ +static int bn2binpad(const BIGNUM *a, unsigned char *to, int tolen) +{ + int n; + size_t i, lasti, j, atop, mask; + BN_ULONG l; + + /* + * In case |a| is fixed-top, BN_num_bytes can return bogus length, + * but it's assumed that fixed-top inputs ought to be "nominated" + * even for padded output, so it works out... + */ + n = BN_num_bytes(a); + if (tolen == -1) { + tolen = n; + } else if (tolen < n) { /* uncommon/unlike case */ + BIGNUM temp = *a; + + bn_correct_top(&temp); + n = BN_num_bytes(&temp); + if (tolen < n) + return -1; + } + + /* Swipe through whole available data and don't give away padded zero. */ + atop = a->dmax * BN_BYTES; + if (atop == 0) { + OPENSSL_cleanse(to, tolen); + return tolen; + } + + lasti = atop - 1; + atop = a->top * BN_BYTES; + for (i = 0, j = 0, to += tolen; j < (size_t)tolen; j++) { + l = a->d[i / BN_BYTES]; + mask = 0 - ((j - atop) >> (8 * sizeof(i) - 1)); + *--to = (unsigned char)(l >> (8 * (i % BN_BYTES)) & mask); + i += (i - lasti) >> (8 * sizeof(i) - 1); /* stay on last limb */ + } + + return tolen; +} + +int BN_bn2binpad(const BIGNUM *a, unsigned char *to, int tolen) +{ + if (tolen < 0) + return -1; + return bn2binpad(a, to, tolen); +} + int BN_bn2bin(const BIGNUM *a, unsigned char *to) - { - int n,i; - BN_ULONG l; - - bn_check_top(a); - n=i=BN_num_bytes(a); - while (i--) - { - l=a->d[i/BN_BYTES]; - *(to++)=(unsigned char)(l>>(8*(i%BN_BYTES)))&0xff; - } - return(n); - } +{ + return bn2binpad(a, to, -1); +} + +BIGNUM *BN_lebin2bn(const unsigned char *s, int len, BIGNUM *ret) +{ + unsigned int i, m; + unsigned int n; + BN_ULONG l; + BIGNUM *bn = NULL; + + if (ret == NULL) + ret = bn = BN_new(); + if (ret == NULL) + return NULL; + bn_check_top(ret); + s += len; + /* Skip trailing zeroes. */ + for ( ; len > 0 && s[-1] == 0; s--, len--) + continue; + n = len; + if (n == 0) { + ret->top = 0; + return ret; + } + i = ((n - 1) / BN_BYTES) + 1; + m = ((n - 1) % (BN_BYTES)); + if (bn_wexpand(ret, (int)i) == NULL) { + BN_free(bn); + return NULL; + } + ret->top = i; + ret->neg = 0; + l = 0; + while (n--) { + s--; + l = (l << 8L) | *s; + if (m-- == 0) { + ret->d[--i] = l; + l = 0; + m = BN_BYTES - 1; + } + } + /* + * need to call this due to clear byte at top if avoiding having the top + * bit set (-ve number) + */ + bn_correct_top(ret); + return ret; +} + +int BN_bn2lebinpad(const BIGNUM *a, unsigned char *to, int tolen) +{ + int i; + BN_ULONG l; + bn_check_top(a); + i = BN_num_bytes(a); + if (tolen < i) + return -1; + /* Add trailing zeroes if necessary */ + if (tolen > i) + memset(to + i, 0, tolen - i); + to += i; + while (i--) { + l = a->d[i / BN_BYTES]; + to--; + *to = (unsigned char)(l >> (8 * (i % BN_BYTES))) & 0xff; + } + return tolen; +} int BN_ucmp(const BIGNUM *a, const BIGNUM *b) - { - int i; - BN_ULONG t1,t2,*ap,*bp; - - bn_check_top(a); - bn_check_top(b); - - i=a->top-b->top; - if (i != 0) return(i); - ap=a->d; - bp=b->d; - for (i=a->top-1; i>=0; i--) - { - t1= ap[i]; - t2= bp[i]; - if (t1 != t2) - return((t1 > t2) ? 1 : -1); - } - return(0); - } +{ + int i; + BN_ULONG t1, t2, *ap, *bp; + + bn_check_top(a); + bn_check_top(b); + + i = a->top - b->top; + if (i != 0) + return i; + ap = a->d; + bp = b->d; + for (i = a->top - 1; i >= 0; i--) { + t1 = ap[i]; + t2 = bp[i]; + if (t1 != t2) + return ((t1 > t2) ? 1 : -1); + } + return 0; +} int BN_cmp(const BIGNUM *a, const BIGNUM *b) - { - int i; - int gt,lt; - BN_ULONG t1,t2; - - if ((a == NULL) || (b == NULL)) - { - if (a != NULL) - return(-1); - else if (b != NULL) - return(1); - else - return(0); - } - - bn_check_top(a); - bn_check_top(b); - - if (a->neg != b->neg) - { - if (a->neg) - return(-1); - else return(1); - } - if (a->neg == 0) - { gt=1; lt= -1; } - else { gt= -1; lt=1; } - - if (a->top > b->top) return(gt); - if (a->top < b->top) return(lt); - for (i=a->top-1; i>=0; i--) - { - t1=a->d[i]; - t2=b->d[i]; - if (t1 > t2) return(gt); - if (t1 < t2) return(lt); - } - return(0); - } +{ + int i; + int gt, lt; + BN_ULONG t1, t2; + + if ((a == NULL) || (b == NULL)) { + if (a != NULL) + return -1; + else if (b != NULL) + return 1; + else + return 0; + } + + bn_check_top(a); + bn_check_top(b); + + if (a->neg != b->neg) { + if (a->neg) + return -1; + else + return 1; + } + if (a->neg == 0) { + gt = 1; + lt = -1; + } else { + gt = -1; + lt = 1; + } + + if (a->top > b->top) + return gt; + if (a->top < b->top) + return lt; + for (i = a->top - 1; i >= 0; i--) { + t1 = a->d[i]; + t2 = b->d[i]; + if (t1 > t2) + return gt; + if (t1 < t2) + return lt; + } + return 0; +} int BN_set_bit(BIGNUM *a, int n) - { - int i,j,k; - - if (n < 0) - return 0; - - i=n/BN_BITS2; - j=n%BN_BITS2; - if (a->top <= i) - { - if (bn_wexpand(a,i+1) == NULL) return(0); - for(k=a->top; kd[k]=0; - a->top=i+1; - } - - a->d[i]|=(((BN_ULONG)1)<top <= i) { + if (bn_wexpand(a, i + 1) == NULL) + return 0; + for (k = a->top; k < i + 1; k++) + a->d[k] = 0; + a->top = i + 1; + a->flags &= ~BN_FLG_FIXED_TOP; + } + + a->d[i] |= (((BN_ULONG)1) << j); + bn_check_top(a); + return 1; +} int BN_clear_bit(BIGNUM *a, int n) - { - int i,j; +{ + int i, j; - bn_check_top(a); - if (n < 0) return 0; + bn_check_top(a); + if (n < 0) + return 0; - i=n/BN_BITS2; - j=n%BN_BITS2; - if (a->top <= i) return(0); + i = n / BN_BITS2; + j = n % BN_BITS2; + if (a->top <= i) + return 0; - a->d[i]&=(~(((BN_ULONG)1)<d[i] &= (~(((BN_ULONG)1) << j)); + bn_correct_top(a); + return 1; +} int BN_is_bit_set(const BIGNUM *a, int n) - { - int i,j; - - bn_check_top(a); - if (n < 0) return 0; - i=n/BN_BITS2; - j=n%BN_BITS2; - if (a->top <= i) return 0; - return((a->d[i]&(((BN_ULONG)1)<top <= i) + return 0; + return (int)(((a->d[i]) >> j) & ((BN_ULONG)1)); +} int BN_mask_bits(BIGNUM *a, int n) - { - int b,w; - - bn_check_top(a); - if (n < 0) return 0; - - w=n/BN_BITS2; - b=n%BN_BITS2; - if (w >= a->top) return 0; - if (b == 0) - a->top=w; - else - { - a->top=w+1; - a->d[w]&= ~(BN_MASK2<= a->top) + return 0; + if (b == 0) + a->top = w; + else { + a->top = w + 1; + a->d[w] &= ~(BN_MASK2 << b); + } + bn_correct_top(a); + return 1; +} + +void BN_set_negative(BIGNUM *a, int b) +{ + if (b && !BN_is_zero(a)) + a->neg = 1; + else + a->neg = 0; +} int bn_cmp_words(const BN_ULONG *a, const BN_ULONG *b, int n) - { - int i; - BN_ULONG aa,bb; - - aa=a[n-1]; - bb=b[n-1]; - if (aa != bb) return((aa > bb)?1:-1); - for (i=n-2; i>=0; i--) - { - aa=a[i]; - bb=b[i]; - if (aa != bb) return((aa > bb)?1:-1); - } - return(0); - } - -/* Here follows a specialised variants of bn_cmp_words(). It has the - property of performing the operation on arrays of different sizes. - The sizes of those arrays is expressed through cl, which is the - common length ( basicall, min(len(a),len(b)) ), and dl, which is the - delta between the two lengths, calculated as len(a)-len(b). - All lengths are the number of BN_ULONGs... */ - -int bn_cmp_part_words(const BN_ULONG *a, const BN_ULONG *b, - int cl, int dl) - { - int n,i; - n = cl-1; - - if (dl < 0) - { - for (i=dl; i<0; i++) - { - if (b[n-i] != 0) - return -1; /* a < b */ - } - } - if (dl > 0) - { - for (i=dl; i>0; i--) - { - if (a[n+i] != 0) - return 1; /* a > b */ - } - } - return bn_cmp_words(a,b,cl); - } +{ + int i; + BN_ULONG aa, bb; + + aa = a[n - 1]; + bb = b[n - 1]; + if (aa != bb) + return ((aa > bb) ? 1 : -1); + for (i = n - 2; i >= 0; i--) { + aa = a[i]; + bb = b[i]; + if (aa != bb) + return ((aa > bb) ? 1 : -1); + } + return 0; +} + +/* + * Here follows a specialised variants of bn_cmp_words(). It has the + * capability of performing the operation on arrays of different sizes. The + * sizes of those arrays is expressed through cl, which is the common length + * ( basically, min(len(a),len(b)) ), and dl, which is the delta between the + * two lengths, calculated as len(a)-len(b). All lengths are the number of + * BN_ULONGs... + */ + +int bn_cmp_part_words(const BN_ULONG *a, const BN_ULONG *b, int cl, int dl) +{ + int n, i; + n = cl - 1; + + if (dl < 0) { + for (i = dl; i < 0; i++) { + if (b[n - i] != 0) + return -1; /* a < b */ + } + } + if (dl > 0) { + for (i = dl; i > 0; i--) { + if (a[n + i] != 0) + return 1; /* a > b */ + } + } + return bn_cmp_words(a, b, cl); +} + +/* + * Constant-time conditional swap of a and b. + * a and b are swapped if condition is not 0. The code assumes that at most one bit of condition is set. + * nwords is the number of words to swap. The code assumes that at least nwords are allocated in both a and b, + * and that no more than nwords are used by either a or b. + * a and b cannot be the same number + */ +void BN_consttime_swap(BN_ULONG condition, BIGNUM *a, BIGNUM *b, int nwords) +{ + BN_ULONG t; + int i; + + bn_wcheck_size(a, nwords); + bn_wcheck_size(b, nwords); + + assert(a != b); + assert((condition & (condition - 1)) == 0); + assert(sizeof(BN_ULONG) >= sizeof(int)); + + condition = ((condition - 1) >> (BN_BITS2 - 1)) - 1; + + t = (a->top ^ b->top) & condition; + a->top ^= t; + b->top ^= t; + + t = (a->neg ^ b->neg) & condition; + a->neg ^= t; + b->neg ^= t; + + /*- + * BN_FLG_STATIC_DATA: indicates that data may not be written to. Intention + * is actually to treat it as it's read-only data, and some (if not most) + * of it does reside in read-only segment. In other words observation of + * BN_FLG_STATIC_DATA in BN_consttime_swap should be treated as fatal + * condition. It would either cause SEGV or effectively cause data + * corruption. + * + * BN_FLG_MALLOCED: refers to BN structure itself, and hence must be + * preserved. + * + * BN_FLG_SECURE: must be preserved, because it determines how x->d was + * allocated and hence how to free it. + * + * BN_FLG_CONSTTIME: sufficient to mask and swap + * + * BN_FLG_FIXED_TOP: indicates that we haven't called bn_correct_top() on + * the data, so the d array may be padded with additional 0 values (i.e. + * top could be greater than the minimal value that it could be). We should + * be swapping it + */ + +#define BN_CONSTTIME_SWAP_FLAGS (BN_FLG_CONSTTIME | BN_FLG_FIXED_TOP) + + t = ((a->flags ^ b->flags) & BN_CONSTTIME_SWAP_FLAGS) & condition; + a->flags ^= t; + b->flags ^= t; + +#define BN_CONSTTIME_SWAP(ind) \ + do { \ + t = (a->d[ind] ^ b->d[ind]) & condition; \ + a->d[ind] ^= t; \ + b->d[ind] ^= t; \ + } while (0) + + switch (nwords) { + default: + for (i = 10; i < nwords; i++) + BN_CONSTTIME_SWAP(i); + /* Fallthrough */ + case 10: + BN_CONSTTIME_SWAP(9); /* Fallthrough */ + case 9: + BN_CONSTTIME_SWAP(8); /* Fallthrough */ + case 8: + BN_CONSTTIME_SWAP(7); /* Fallthrough */ + case 7: + BN_CONSTTIME_SWAP(6); /* Fallthrough */ + case 6: + BN_CONSTTIME_SWAP(5); /* Fallthrough */ + case 5: + BN_CONSTTIME_SWAP(4); /* Fallthrough */ + case 4: + BN_CONSTTIME_SWAP(3); /* Fallthrough */ + case 3: + BN_CONSTTIME_SWAP(2); /* Fallthrough */ + case 2: + BN_CONSTTIME_SWAP(1); /* Fallthrough */ + case 1: + BN_CONSTTIME_SWAP(0); + } +#undef BN_CONSTTIME_SWAP +} + +/* Bits of security, see SP800-57 */ + +int BN_security_bits(int L, int N) +{ + int secbits, bits; + if (L >= 15360) + secbits = 256; + else if (L >= 7680) + secbits = 192; + else if (L >= 3072) + secbits = 128; + else if (L >= 2048) + secbits = 112; + else if (L >= 1024) + secbits = 80; + else + return 0; + if (N == -1) + return secbits; + bits = N / 2; + if (bits < 80) + return 0; + return bits >= secbits ? secbits : bits; +} + +void BN_zero_ex(BIGNUM *a) +{ + a->neg = 0; + a->top = 0; + a->flags &= ~BN_FLG_FIXED_TOP; +} + +int BN_abs_is_word(const BIGNUM *a, const BN_ULONG w) +{ + return ((a->top == 1) && (a->d[0] == w)) || ((w == 0) && (a->top == 0)); +} + +int BN_is_zero(const BIGNUM *a) +{ + return a->top == 0; +} + +int BN_is_one(const BIGNUM *a) +{ + return BN_abs_is_word(a, 1) && !a->neg; +} + +int BN_is_word(const BIGNUM *a, const BN_ULONG w) +{ + return BN_abs_is_word(a, w) && (!w || !a->neg); +} + +int BN_is_odd(const BIGNUM *a) +{ + return (a->top > 0) && (a->d[0] & 1); +} + +int BN_is_negative(const BIGNUM *a) +{ + return (a->neg != 0); +} + +int BN_to_montgomery(BIGNUM *r, const BIGNUM *a, BN_MONT_CTX *mont, + BN_CTX *ctx) +{ + return BN_mod_mul_montgomery(r, a, &(mont->RR), mont, ctx); +} + +void BN_with_flags(BIGNUM *dest, const BIGNUM *b, int flags) +{ + dest->d = b->d; + dest->top = b->top; + dest->dmax = b->dmax; + dest->neg = b->neg; + dest->flags = ((dest->flags & BN_FLG_MALLOCED) + | (b->flags & ~BN_FLG_MALLOCED) + | BN_FLG_STATIC_DATA | flags); +} + +BN_GENCB *BN_GENCB_new(void) +{ + BN_GENCB *ret; + + if ((ret = OPENSSL_malloc(sizeof(*ret))) == NULL) { + BNerr(BN_F_BN_GENCB_NEW, ERR_R_MALLOC_FAILURE); + return NULL; + } + + return ret; +} + +void BN_GENCB_free(BN_GENCB *cb) +{ + if (cb == NULL) + return; + OPENSSL_free(cb); +} + +void BN_set_flags(BIGNUM *b, int n) +{ + b->flags |= n; +} + +int BN_get_flags(const BIGNUM *b, int n) +{ + return b->flags & n; +} + +/* Populate a BN_GENCB structure with an "old"-style callback */ +void BN_GENCB_set_old(BN_GENCB *gencb, void (*callback) (int, int, void *), + void *cb_arg) +{ + BN_GENCB *tmp_gencb = gencb; + tmp_gencb->ver = 1; + tmp_gencb->arg = cb_arg; + tmp_gencb->cb.cb_1 = callback; +} + +/* Populate a BN_GENCB structure with a "new"-style callback */ +void BN_GENCB_set(BN_GENCB *gencb, int (*callback) (int, int, BN_GENCB *), + void *cb_arg) +{ + BN_GENCB *tmp_gencb = gencb; + tmp_gencb->ver = 2; + tmp_gencb->arg = cb_arg; + tmp_gencb->cb.cb_2 = callback; +} + +void *BN_GENCB_get_arg(BN_GENCB *cb) +{ + return cb->arg; +} + +BIGNUM *bn_wexpand(BIGNUM *a, int words) +{ + return (words <= a->dmax) ? a : bn_expand2(a, words); +} + +void bn_correct_top(BIGNUM *a) +{ + BN_ULONG *ftl; + int tmp_top = a->top; + + if (tmp_top > 0) { + for (ftl = &(a->d[tmp_top]); tmp_top > 0; tmp_top--) { + ftl--; + if (*ftl != 0) + break; + } + a->top = tmp_top; + } + if (a->top == 0) + a->neg = 0; + a->flags &= ~BN_FLG_FIXED_TOP; + bn_pollute(a); +}