/* 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) 1998-2001 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 <openssl/bn.h>
#include <string.h>
#include <openssl/err.h>
#include <openssl/mem.h>
#include <openssl/rand.h>
#include <openssl/sha.h>
#include "../internal.h"
int BN_rand(BIGNUM *rnd, int bits, int top, int bottom) {
uint8_t *buf = NULL;
int ret = 0, bit, bytes, mask;
if (rnd == NULL) {
return 0;
}
if (top != BN_RAND_TOP_ANY && top != BN_RAND_TOP_ONE &&
top != BN_RAND_TOP_TWO) {
OPENSSL_PUT_ERROR(BN, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
return 0;
}
if (bottom != BN_RAND_BOTTOM_ANY && bottom != BN_RAND_BOTTOM_ODD) {
OPENSSL_PUT_ERROR(BN, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
return 0;
}
if (bits == 0) {
BN_zero(rnd);
return 1;
}
bytes = (bits + 7) / 8;
bit = (bits - 1) % 8;
mask = 0xff << (bit + 1);
buf = OPENSSL_malloc(bytes);
if (buf == NULL) {
OPENSSL_PUT_ERROR(BN, ERR_R_MALLOC_FAILURE);
goto err;
}
/* Make a random number and set the top and bottom bits. */
if (!RAND_bytes(buf, bytes)) {
goto err;
}
if (top != BN_RAND_TOP_ANY) {
if (top == BN_RAND_TOP_TWO && bits > 1) {
if (bit == 0) {
buf[0] = 1;
buf[1] |= 0x80;
} else {
buf[0] |= (3 << (bit - 1));
}
} else {
buf[0] |= (1 << bit);
}
}
buf[0] &= ~mask;
/* Set the bottom bit if requested, */
if (bottom == BN_RAND_BOTTOM_ODD) {
buf[bytes - 1] |= 1;
}
if (!BN_bin2bn(buf, bytes, rnd)) {
goto err;
}
ret = 1;
err:
if (buf != NULL) {
OPENSSL_cleanse(buf, bytes);
OPENSSL_free(buf);
}
return (ret);
}
int BN_pseudo_rand(BIGNUM *rnd, int bits, int top, int bottom) {
return BN_rand(rnd, bits, top, bottom);
}
int BN_rand_range_ex(BIGNUM *r, BN_ULONG min_inclusive,
const BIGNUM *max_exclusive) {
unsigned n;
unsigned count = 100;
if (BN_cmp_word(max_exclusive, min_inclusive) <= 0) {
OPENSSL_PUT_ERROR(BN, BN_R_INVALID_RANGE);
return 0;
}
n = BN_num_bits(max_exclusive); /* n > 0 */
/* BN_is_bit_set(range, n - 1) always holds */
if (n == 1) {
BN_zero(r);
return 1;
}
do {
if (!--count) {
OPENSSL_PUT_ERROR(BN, BN_R_TOO_MANY_ITERATIONS);
return 0;
}
if (!BN_is_bit_set(max_exclusive, n - 2) &&
!BN_is_bit_set(max_exclusive, n - 3)) {
/* range = 100..._2, so 3*range (= 11..._2) is exactly one bit longer
* than range. This is a common scenario when generating a random value
* modulo an RSA public modulus, e.g. for RSA base blinding. */
if (!BN_rand(r, n + 1, BN_RAND_TOP_ANY, BN_RAND_BOTTOM_ANY)) {
return 0;
}
/* If r < 3*range, use r := r MOD range (which is either r, r - range, or
* r - 2*range). Otherwise, iterate again. Since 3*range = 11..._2, each
* iteration succeeds with probability >= .75. */
if (BN_cmp(r, max_exclusive) >= 0) {
if (!BN_sub(r, r, max_exclusive)) {
return 0;
}
if (BN_cmp(r, max_exclusive) >= 0) {
if (!BN_sub(r, r, max_exclusive)) {
return 0;
}
}
}
} else {
/* range = 11..._2 or range = 101..._2 */
if (!BN_rand(r, n, BN_RAND_TOP_ANY, BN_RAND_BOTTOM_ANY)) {
return 0;
}
}
} while (BN_cmp_word(r, min_inclusive) < 0 ||
BN_cmp(r, max_exclusive) >= 0);
return 1;
}
int BN_rand_range(BIGNUM *r, const BIGNUM *range) {
return BN_rand_range_ex(r, 0, range);
}
int BN_pseudo_rand_range(BIGNUM *r, const BIGNUM *range) {
return BN_rand_range(r, range);
}
int BN_generate_dsa_nonce(BIGNUM *out, const BIGNUM *range, const BIGNUM *priv,
const uint8_t *message, size_t message_len,
BN_CTX *ctx) {
SHA512_CTX sha;
/* We use 512 bits of random data per iteration to
* ensure that we have at least |range| bits of randomness. */
uint8_t random_bytes[64];
uint8_t digest[SHA512_DIGEST_LENGTH];
size_t done, todo, attempt;
const unsigned num_k_bytes = BN_num_bytes(range);
const unsigned bits_to_mask = (8 - (BN_num_bits(range) % 8)) % 8;
uint8_t private_bytes[96];
uint8_t *k_bytes = NULL;
int ret = 0;
if (out == NULL) {
return 0;
}
if (BN_is_zero(range)) {
OPENSSL_PUT_ERROR(BN, BN_R_DIV_BY_ZERO);
goto err;
}
k_bytes = OPENSSL_malloc(num_k_bytes);
if (!k_bytes) {
OPENSSL_PUT_ERROR(BN, ERR_R_MALLOC_FAILURE);
goto err;
}
/* We copy |priv| into a local buffer to avoid furthur exposing its
* length. */
todo = sizeof(priv->d[0]) * priv->top;
if (todo > sizeof(private_bytes)) {
/* No reasonable DSA or ECDSA key should have a private key
* this large and we don't handle this case in order to avoid
* leaking the length of the private key. */
OPENSSL_PUT_ERROR(BN, BN_R_PRIVATE_KEY_TOO_LARGE);
goto err;
}
OPENSSL_memcpy(private_bytes, priv->d, todo);
OPENSSL_memset(private_bytes + todo, 0, sizeof(private_bytes) - todo);
for (attempt = 0;; attempt++) {
for (done = 0; done < num_k_bytes;) {
if (!RAND_bytes(random_bytes, sizeof(random_bytes))) {
goto err;
}
SHA512_Init(&sha);
SHA512_Update(&sha, &attempt, sizeof(attempt));
SHA512_Update(&sha, &done, sizeof(done));
SHA512_Update(&sha, private_bytes, sizeof(private_bytes));
SHA512_Update(&sha, message, message_len);
SHA512_Update(&sha, random_bytes, sizeof(random_bytes));
SHA512_Final(digest, &sha);
todo = num_k_bytes - done;
if (todo > SHA512_DIGEST_LENGTH) {
todo = SHA512_DIGEST_LENGTH;
}
OPENSSL_memcpy(k_bytes + done, digest, todo);
done += todo;
}
k_bytes[0] &= 0xff >> bits_to_mask;
if (!BN_bin2bn(k_bytes, num_k_bytes, out)) {
goto err;
}
if (BN_cmp(out, range) < 0) {
break;
}
}
ret = 1;
err:
OPENSSL_free(k_bytes);
return ret;
}