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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.]
- */
- /* ====================================================================
- * 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>
-
- 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 (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 != -1) {
- if (top && 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 bottom bit if requested */
- if (bottom) {
- 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(BIGNUM *r, const BIGNUM *range) {
- unsigned n;
- unsigned count = 100;
-
- if (range->neg || BN_is_zero(range)) {
- OPENSSL_PUT_ERROR(BN, BN_R_INVALID_RANGE);
- return 0;
- }
-
- n = BN_num_bits(range); /* n > 0 */
-
- /* BN_is_bit_set(range, n - 1) always holds */
- if (n == 1) {
- BN_zero(r);
- } else if (!BN_is_bit_set(range, n - 2) && !BN_is_bit_set(range, n - 3)) {
- /* range = 100..._2,
- * so 3*range (= 11..._2) is exactly one bit longer than range */
- do {
- if (!BN_rand(r, n + 1, -1 /* don't set most significant bits */,
- 0 /* don't set least significant bits */)) {
- 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, range) >= 0) {
- if (!BN_sub(r, r, range)) {
- return 0;
- }
- if (BN_cmp(r, range) >= 0) {
- if (!BN_sub(r, r, range)) {
- return 0;
- }
- }
- }
-
- if (!--count) {
- OPENSSL_PUT_ERROR(BN, BN_R_TOO_MANY_ITERATIONS);
- return 0;
- }
- } while (BN_cmp(r, range) >= 0);
- } else {
- do {
- /* range = 11..._2 or range = 101..._2 */
- if (!BN_rand(r, n, -1, 0)) {
- return 0;
- }
-
- if (!--count) {
- OPENSSL_PUT_ERROR(BN, BN_R_TOO_MANY_ITERATIONS);
- return 0;
- }
- } while (BN_cmp(r, range) >= 0);
- }
-
- return 1;
- }
-
- 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;
- }
- memcpy(private_bytes, priv->d, todo);
- 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;
- }
- 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;
- }
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