X-Git-Url: https://git.openssl.org/gitweb/?p=openssl.git;a=blobdiff_plain;f=crypto%2Fbn%2Fbn_lib.c;h=f0a3bf1e3d452a4f8e47c1098656a988a2f0020a;hp=b5f827a36cf8af9daaddaaa8591b584d5c2759bb;hb=9f9442918a;hpb=74924dcb3802640d7e2ae2e80ca6515d0a53de7a diff --git a/crypto/bn/bn_lib.c b/crypto/bn/bn_lib.c index b5f827a36c..f0a3bf1e3d 100644 --- a/crypto/bn/bn_lib.c +++ b/crypto/bn/bn_lib.c @@ -1,75 +1,20 @@ -/* crypto/bn/bn_lib.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. +/* + * Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved. * - * 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 "internal/cryptlib.h" #include "bn_lcl.h" - -const char BN_version[] = "Big Number" OPENSSL_VERSION_PTEXT; +#include /* This stuff appears to be completely unused, so is deprecated */ -#ifndef OPENSSL_NO_DEPRECATED +#if OPENSSL_API_COMPAT < 0x00908000L /*- * For a 32 bit machine * 2 - 4 == 128 @@ -223,6 +168,15 @@ int BN_num_bits(const BIGNUM *a) 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); +} + + void BN_clear_free(BIGNUM *a) { int i; @@ -232,15 +186,11 @@ void BN_clear_free(BIGNUM *a) 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))) { - if (BN_get_flags(a,BN_FLG_SECURE)) - OPENSSL_secure_free(a->d); - else - OPENSSL_free(a->d); - } + if (!BN_get_flags(a, BN_FLG_STATIC_DATA)) + bn_free_d(a); } i = BN_get_flags(a, BN_FLG_MALLOCED); - OPENSSL_cleanse(a, sizeof(BIGNUM)); + OPENSSL_cleanse(a, sizeof(*a)); if (i) OPENSSL_free(a); } @@ -251,25 +201,22 @@ void BN_free(BIGNUM *a) return; bn_check_top(a); if (!BN_get_flags(a, BN_FLG_STATIC_DATA)) - if ((a->d != NULL) && !(BN_get_flags(a, BN_FLG_STATIC_DATA))) { - if (BN_get_flags(a, BN_FLG_SECURE)) - OPENSSL_secure_free(a->d); - else - OPENSSL_free(a->d); - } + bn_free_d(a); if (a->flags & BN_FLG_MALLOCED) OPENSSL_free(a); else { -#ifndef OPENSSL_NO_DEPRECATED +#if OPENSSL_API_COMPAT < 0x00908000L a->flags |= BN_FLG_FREE; #endif a->d = NULL; } } -void BN_init(BIGNUM *a) +void bn_init(BIGNUM *a) { - memset(a, 0, sizeof(*a)); + static BIGNUM nilbn; + + *a = nilbn; bn_check_top(a); } @@ -277,15 +224,11 @@ BIGNUM *BN_new(void) { BIGNUM *ret; - if ((ret = OPENSSL_malloc(sizeof(*ret))) == NULL) { + if ((ret = OPENSSL_zalloc(sizeof(*ret))) == 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); } @@ -293,18 +236,16 @@ BIGNUM *BN_new(void) BIGNUM *BN_secure_new(void) { BIGNUM *ret = BN_new(); - if (ret) + if (ret != NULL) ret->flags |= BN_FLG_SECURE; return (ret); } -/* This is used both by bn_expand2() and bn_dup_expand() */ +/* 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_ULONG *a = NULL; bn_check_top(b); @@ -316,70 +257,20 @@ static BN_ULONG *bn_expand_internal(const BIGNUM *b, int words) BNerr(BN_F_BN_EXPAND_INTERNAL, BN_R_EXPAND_ON_STATIC_BIGNUM_DATA); return (NULL); } - if (BN_get_flags(b,BN_FLG_SECURE)) - a = A = OPENSSL_secure_malloc(words * sizeof(*a)); + if (BN_get_flags(b, BN_FLG_SECURE)) + a = OPENSSL_secure_zalloc(words * sizeof(*a)); else - a = A = OPENSSL_malloc(words * sizeof(*a)); - if (A == NULL) { + a = OPENSSL_zalloc(words * sizeof(*a)); + if (a == NULL) { BNerr(BN_F_BN_EXPAND_INTERNAL, ERR_R_MALLOC_FAILURE); return (NULL); } -#ifdef PURIFY - /* - * Valgrind complains in BN_consttime_swap because we process the whole - * array even if it's not initialised yet. This doesn't matter in that - * function - what's important is constant time operation (we're not - * actually going to use the data) - */ - memset(a, 0, sizeof(*a) * words); -#endif -#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; - } - /* - * 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 - */ - switch (b->top & 3) { - case 3: - A[2] = B[2]; - case 2: - A[1] = B[1]; - case 1: - A[0] = B[0]; - case 0: - ; - } - } -#else - memset(A, 0, sizeof(*A) * words); - memcpy(A, b->d, sizeof(b->d[0]) * b->top); -#endif + assert(b->top <= words); + if (b->top > 0) + memcpy(a, b->d, sizeof(*a) * b->top); - return (a); + return a; } /* @@ -399,10 +290,8 @@ BIGNUM *bn_expand2(BIGNUM *b, int words) if (!a) return NULL; if (b->d) { - if (BN_get_flags(b,BN_FLG_SECURE)) - OPENSSL_secure_free(b->d); - else - OPENSSL_free(b->d); + OPENSSL_cleanse(b->d, b->dmax * sizeof(b->d[0])); + bn_free_d(b); } b->d = a; b->dmax = words; @@ -433,49 +322,23 @@ BIGNUM *BN_dup(const BIGNUM *a) 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); + return a; if (bn_wexpand(a, b->top) == NULL) - return (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; - } - /* ultrix cc workaround, see comments in bn_expand_internal */ - switch (b->top & 3) { - case 3: - A[2] = B[2]; - case 2: - A[1] = B[1]; - case 1: - A[0] = B[0]; - case 0:; - } -#else - memcpy(a->d, b->d, sizeof(b->d[0]) * b->top); -#endif + if (b->top > 0) + memcpy(a->d, b->d, sizeof(b->d[0]) * b->top); + + if (BN_get_flags(b, BN_FLG_CONSTTIME) != 0) + BN_set_flags(a, BN_FLG_CONSTTIME); a->top = b->top; a->neg = b->neg; bn_check_top(a); - return (a); + return a; } void BN_swap(BIGNUM *a, BIGNUM *b) @@ -517,7 +380,7 @@ void BN_clear(BIGNUM *a) { bn_check_top(a); if (a->d != NULL) - memset(a->d, 0, sizeof(*a->d) * a->dmax); + OPENSSL_cleanse(a->d, sizeof(*a->d) * a->dmax); a->top = 0; a->neg = 0; } @@ -556,7 +419,9 @@ BIGNUM *BN_bin2bn(const unsigned char *s, int len, BIGNUM *ret) if (ret == NULL) return (NULL); bn_check_top(ret); - l = 0; + /* Skip leading zero's. */ + for ( ; len > 0 && *s == 0; s++, len--) + continue; n = len; if (n == 0) { ret->top = 0; @@ -570,6 +435,7 @@ BIGNUM *BN_bin2bn(const unsigned char *s, int len, BIGNUM *ret) } ret->top = i; ret->neg = 0; + l = 0; while (n--) { l = (l << 8L) | *(s++); if (m-- == 0) { @@ -587,18 +453,106 @@ BIGNUM *BN_bin2bn(const unsigned char *s, int len, BIGNUM *ret) } /* ignore negative */ -int BN_bn2bin(const BIGNUM *a, unsigned char *to) +static int bn2binpad(const BIGNUM *a, unsigned char *to, int tolen) { - int n, i; + int i; BN_ULONG l; bn_check_top(a); - n = i = BN_num_bytes(a); + i = BN_num_bytes(a); + if (tolen == -1) + tolen = i; + else if (tolen < i) + return -1; + /* Add leading zeroes if necessary */ + if (tolen > i) { + memset(to, 0, tolen - i); + to += tolen - i; + } while (i--) { l = a->d[i / BN_BYTES]; *(to++) = (unsigned char)(l >> (8 * (i % BN_BYTES))) & 0xff; } - return (n); + 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) +{ + 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) @@ -774,9 +728,9 @@ int bn_cmp_words(const BN_ULONG *a, const BN_ULONG *b, int n) /* * Here follows a specialised variants of bn_cmp_words(). It has the - * property of performing the operation on arrays of different sizes. 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 - * ( basicall, min(len(a),len(b)) ), and dl, which is the delta between the + * ( 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... */ @@ -929,7 +883,7 @@ int BN_to_montgomery(BIGNUM *r, const BIGNUM *a, BN_MONT_CTX *mont, return BN_mod_mul_montgomery(r, a, &(mont->RR), mont, ctx); } -void BN_with_flags(BIGNUM *dest, const BIGNUM *b, int n) +void BN_with_flags(BIGNUM *dest, const BIGNUM *b, int flags) { dest->d = b->d; dest->top = b->top; @@ -937,7 +891,7 @@ void BN_with_flags(BIGNUM *dest, const BIGNUM *b, int n) dest->neg = b->neg; dest->flags = ((dest->flags & BN_FLG_MALLOCED) | (b->flags & ~BN_FLG_MALLOCED) - | BN_FLG_STATIC_DATA | n); + | BN_FLG_STATIC_DATA | flags); } BN_GENCB *BN_GENCB_new(void) @@ -1005,10 +959,14 @@ void bn_correct_top(BIGNUM *a) int tmp_top = a->top; if (tmp_top > 0) { - for (ftl = &(a->d[tmp_top - 1]); tmp_top > 0; tmp_top--) - if (*(ftl--)) + 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; bn_pollute(a); }