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- /* 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.] */
-
- #include <openssl/bn.h>
-
- #include <assert.h>
- #include <limits.h>
-
- #include "internal.h"
-
-
- BIGNUM *BN_bin2bn(const uint8_t *in, size_t len, BIGNUM *ret) {
- size_t num_words;
- unsigned m;
- BN_ULONG word = 0;
- BIGNUM *bn = NULL;
-
- if (ret == NULL) {
- ret = bn = BN_new();
- }
-
- if (ret == NULL) {
- return NULL;
- }
-
- if (len == 0) {
- ret->width = 0;
- return ret;
- }
-
- num_words = ((len - 1) / BN_BYTES) + 1;
- m = (len - 1) % BN_BYTES;
- if (!bn_wexpand(ret, num_words)) {
- if (bn) {
- BN_free(bn);
- }
- return NULL;
- }
-
- // |bn_wexpand| must check bounds on |num_words| to write it into
- // |ret->dmax|.
- assert(num_words <= INT_MAX);
- ret->width = (int)num_words;
- ret->neg = 0;
-
- while (len--) {
- word = (word << 8) | *(in++);
- if (m-- == 0) {
- ret->d[--num_words] = word;
- word = 0;
- m = BN_BYTES - 1;
- }
- }
-
- return ret;
- }
-
- BIGNUM *BN_le2bn(const uint8_t *in, size_t len, BIGNUM *ret) {
- BIGNUM *bn = NULL;
- if (ret == NULL) {
- bn = BN_new();
- ret = bn;
- }
-
- if (ret == NULL) {
- return NULL;
- }
-
- if (len == 0) {
- ret->width = 0;
- ret->neg = 0;
- return ret;
- }
-
- // Reserve enough space in |ret|.
- size_t num_words = ((len - 1) / BN_BYTES) + 1;
- if (!bn_wexpand(ret, num_words)) {
- BN_free(bn);
- return NULL;
- }
- ret->width = num_words;
-
- // Make sure the top bytes will be zeroed.
- ret->d[num_words - 1] = 0;
-
- // We only support little-endian platforms, so we can simply memcpy the
- // internal representation.
- OPENSSL_memcpy(ret->d, in, len);
- return ret;
- }
-
- size_t BN_bn2bin(const BIGNUM *in, uint8_t *out) {
- size_t n, i;
- BN_ULONG l;
-
- n = i = BN_num_bytes(in);
- while (i--) {
- l = in->d[i / BN_BYTES];
- *(out++) = (unsigned char)(l >> (8 * (i % BN_BYTES))) & 0xff;
- }
- return n;
- }
-
- static int fits_in_bytes(const uint8_t *bytes, size_t num_bytes, size_t len) {
- uint8_t mask = 0;
- for (size_t i = len; i < num_bytes; i++) {
- mask |= bytes[i];
- }
- return mask == 0;
- }
-
- int BN_bn2le_padded(uint8_t *out, size_t len, const BIGNUM *in) {
- const uint8_t *bytes = (const uint8_t *)in->d;
- size_t num_bytes = in->width * BN_BYTES;
- if (len < num_bytes) {
- if (!fits_in_bytes(bytes, num_bytes, len)) {
- return 0;
- }
- num_bytes = len;
- }
-
- // We only support little-endian platforms, so we can simply memcpy into the
- // internal representation.
- OPENSSL_memcpy(out, bytes, num_bytes);
- // Pad out the rest of the buffer with zeroes.
- OPENSSL_memset(out + num_bytes, 0, len - num_bytes);
- return 1;
- }
-
- int BN_bn2bin_padded(uint8_t *out, size_t len, const BIGNUM *in) {
- const uint8_t *bytes = (const uint8_t *)in->d;
- size_t num_bytes = in->width * BN_BYTES;
- if (len < num_bytes) {
- if (!fits_in_bytes(bytes, num_bytes, len)) {
- return 0;
- }
- num_bytes = len;
- }
-
- // We only support little-endian platforms, so we can simply write the buffer
- // in reverse.
- for (size_t i = 0; i < num_bytes; i++) {
- out[len - i - 1] = bytes[i];
- }
- // Pad out the rest of the buffer with zeroes.
- OPENSSL_memset(out, 0, len - num_bytes);
- return 1;
- }
-
- BN_ULONG BN_get_word(const BIGNUM *bn) {
- switch (bn_minimal_width(bn)) {
- case 0:
- return 0;
- case 1:
- return bn->d[0];
- default:
- return BN_MASK2;
- }
- }
-
- int BN_get_u64(const BIGNUM *bn, uint64_t *out) {
- switch (bn_minimal_width(bn)) {
- case 0:
- *out = 0;
- return 1;
- case 1:
- *out = bn->d[0];
- return 1;
- #if defined(OPENSSL_32_BIT)
- case 2:
- *out = (uint64_t) bn->d[0] | (((uint64_t) bn->d[1]) << 32);
- return 1;
- #endif
- default:
- return 0;
- }
- }
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