-/* crypto/bn/bn_rand.c */
-/* Copyright (C) 1995-1997 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 Apache License 2.0 (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
*/
#include <stdio.h>
#include <time.h>
-#include "cryptlib.h"
+#include "internal/cryptlib.h"
#include "bn_lcl.h"
-#include "rand.h"
-
-int BN_rand(rnd, bits, top, bottom)
-BIGNUM *rnd;
-int bits;
-int top;
-int bottom;
- {
- unsigned char *buf=NULL;
- int ret=0,bit,bytes,mask;
- time_t tim;
-
- bytes=(bits+7)/8;
- bit=(bits-1)%8;
- mask=0xff<<bit;
-
- buf=(unsigned char *)Malloc(bytes);
- if (buf == NULL)
- {
- BNerr(BN_F_BN_RAND,ERR_R_MALLOC_FAILURE);
- goto err;
- }
-
- /* make a random number and set the top and bottom bits */
- time(&tim);
- RAND_seed((unsigned char *)&tim,sizeof(tim));
-
- RAND_bytes(buf,(int)bytes);
- if (top)
- {
- if (bit == 0)
- {
- buf[0]=1;
- buf[1]|=0x80;
- }
- else
- {
- buf[0]|=(3<<(bit-1));
- buf[0]&= ~(mask<<1);
- }
- }
- else
- {
- buf[0]|=(1<<bit);
- buf[0]&= ~(mask<<1);
- }
- if (bottom) /* set bottom bits to whatever odd is */
- buf[bytes-1]|=1;
- if (!BN_bin2bn(buf,bytes,rnd)) goto err;
- ret=1;
-err:
- if (buf != NULL)
- {
- memset(buf,0,bytes);
- Free(buf);
- }
- return(ret);
- }
+#include <openssl/rand.h>
+#include <openssl/sha.h>
+typedef enum bnrand_flag_e {
+ NORMAL, TESTING, PRIVATE
+} BNRAND_FLAG;
+
+static int bnrand(BNRAND_FLAG flag, BIGNUM *rnd, int bits, int top, int bottom)
+{
+ unsigned char *buf = NULL;
+ int b, ret = 0, bit, bytes, mask;
+
+ if (bits == 0) {
+ if (top != BN_RAND_TOP_ANY || bottom != BN_RAND_BOTTOM_ANY)
+ goto toosmall;
+ BN_zero(rnd);
+ return 1;
+ }
+ if (bits < 0 || (bits == 1 && top > 0))
+ goto toosmall;
+
+ bytes = (bits + 7) / 8;
+ bit = (bits - 1) % 8;
+ mask = 0xff << (bit + 1);
+
+ buf = OPENSSL_malloc(bytes);
+ if (buf == NULL) {
+ BNerr(BN_F_BNRAND, ERR_R_MALLOC_FAILURE);
+ goto err;
+ }
+
+ /* make a random number and set the top and bottom bits */
+ b = flag == NORMAL ? RAND_bytes(buf, bytes) : RAND_priv_bytes(buf, bytes);
+ if (b <= 0)
+ goto err;
+
+ if (flag == TESTING) {
+ /*
+ * generate patterns that are more likely to trigger BN library bugs
+ */
+ int i;
+ unsigned char c;
+
+ for (i = 0; i < bytes; i++) {
+ if (RAND_bytes(&c, 1) <= 0)
+ goto err;
+ if (c >= 128 && i > 0)
+ buf[i] = buf[i - 1];
+ else if (c < 42)
+ buf[i] = 0;
+ else if (c < 84)
+ buf[i] = 255;
+ }
+ }
+
+ if (top >= 0) {
+ if (top) {
+ if (bit == 0) {
+ buf[0] = 1;
+ buf[1] |= 0x80;
+ } else {
+ buf[0] |= (3 << (bit - 1));
+ }
+ } else {
+ buf[0] |= (1 << bit);
+ }
+ }
+ buf[0] &= ~mask;
+ if (bottom) /* set bottom bit if requested */
+ buf[bytes - 1] |= 1;
+ if (!BN_bin2bn(buf, bytes, rnd))
+ goto err;
+ ret = 1;
+ err:
+ OPENSSL_clear_free(buf, bytes);
+ bn_check_top(rnd);
+ return ret;
+
+toosmall:
+ BNerr(BN_F_BNRAND, BN_R_BITS_TOO_SMALL);
+ return 0;
+}
+
+int BN_rand(BIGNUM *rnd, int bits, int top, int bottom)
+{
+ return bnrand(NORMAL, rnd, bits, top, bottom);
+}
+
+int BN_bntest_rand(BIGNUM *rnd, int bits, int top, int bottom)
+{
+ return bnrand(TESTING, rnd, bits, top, bottom);
+}
+
+int BN_priv_rand(BIGNUM *rnd, int bits, int top, int bottom)
+{
+ return bnrand(PRIVATE, rnd, bits, top, bottom);
+}
+
+/* random number r: 0 <= r < range */
+static int bnrand_range(BNRAND_FLAG flag, BIGNUM *r, const BIGNUM *range)
+{
+ int n;
+ int count = 100;
+
+ if (range->neg || BN_is_zero(range)) {
+ BNerr(BN_F_BNRAND_RANGE, 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 (!bnrand(flag, 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 once more. 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) {
+ BNerr(BN_F_BNRAND_RANGE, BN_R_TOO_MANY_ITERATIONS);
+ return 0;
+ }
+
+ }
+ while (BN_cmp(r, range) >= 0);
+ } else {
+ do {
+ /* range = 11..._2 or range = 101..._2 */
+ if (!bnrand(flag, r, n, BN_RAND_TOP_ANY, BN_RAND_BOTTOM_ANY))
+ return 0;
+
+ if (!--count) {
+ BNerr(BN_F_BNRAND_RANGE, BN_R_TOO_MANY_ITERATIONS);
+ return 0;
+ }
+ }
+ while (BN_cmp(r, range) >= 0);
+ }
+
+ bn_check_top(r);
+ return 1;
+}
+
+int BN_rand_range(BIGNUM *r, const BIGNUM *range)
+{
+ return bnrand_range(NORMAL, r, range);
+}
+
+int BN_priv_rand_range(BIGNUM *r, const BIGNUM *range)
+{
+ return bnrand_range(PRIVATE, r, range);
+}
+
+int BN_pseudo_rand(BIGNUM *rnd, int bits, int top, int bottom)
+{
+ return BN_rand(rnd, bits, top, bottom);
+}
+
+int BN_pseudo_rand_range(BIGNUM *r, const BIGNUM *range)
+{
+ return BN_rand_range(r, range);
+}
+
+/*
+ * BN_generate_dsa_nonce generates a random number 0 <= out < range. Unlike
+ * BN_rand_range, it also includes the contents of |priv| and |message| in
+ * the generation so that an RNG failure isn't fatal as long as |priv|
+ * remains secret. This is intended for use in DSA and ECDSA where an RNG
+ * weakness leads directly to private key exposure unless this function is
+ * used.
+ */
+int BN_generate_dsa_nonce(BIGNUM *out, const BIGNUM *range,
+ const BIGNUM *priv, const unsigned char *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.
+ */
+ unsigned char random_bytes[64];
+ unsigned char digest[SHA512_DIGEST_LENGTH];
+ unsigned done, todo;
+ /* We generate |range|+8 bytes of random output. */
+ const unsigned num_k_bytes = BN_num_bytes(range) + 8;
+ unsigned char private_bytes[96];
+ unsigned char *k_bytes;
+ int ret = 0;
+
+ k_bytes = OPENSSL_malloc(num_k_bytes);
+ if (k_bytes == NULL)
+ goto err;
+
+ /* We copy |priv| into a local buffer to avoid 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.
+ */
+ BNerr(BN_F_BN_GENERATE_DSA_NONCE, BN_R_PRIVATE_KEY_TOO_LARGE);
+ goto err;
+ }
+ memcpy(private_bytes, priv->d, todo);
+ memset(private_bytes + todo, 0, sizeof(private_bytes) - todo);
+
+ for (done = 0; done < num_k_bytes;) {
+ if (RAND_priv_bytes(random_bytes, sizeof(random_bytes)) != 1)
+ goto err;
+ SHA512_Init(&sha);
+ 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;
+ }
+
+ if (!BN_bin2bn(k_bytes, num_k_bytes, out))
+ goto err;
+ if (BN_mod(out, out, range, ctx) != 1)
+ goto err;
+ ret = 1;
+
+ err:
+ OPENSSL_free(k_bytes);
+ OPENSSL_cleanse(private_bytes, sizeof(private_bytes));
+ return ret;
+}
projects / openssl.git / blobdiff