| /* crypto/bn/bn_rand.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. |
| * |
| * 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 <stdio.h> |
| #include <time.h> |
| #include "cryptlib.h" |
| #include "bn_lcl.h" |
| #include <openssl/rand.h> |
| |
| static int bnrand(int pseudorand, BIGNUM *rnd, int bits, int top, int bottom) |
| { |
| unsigned char *buf = NULL; |
| int ret = 0, bit, bytes, mask; |
| time_t tim; |
| |
| if (bits == 0) { |
| BN_zero(rnd); |
| return 1; |
| } |
| |
| bytes = (bits + 7) / 8; |
| bit = (bits - 1) % 8; |
| mask = 0xff << (bit + 1); |
| |
| buf = (unsigned char *)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 */ |
| #ifndef NO_TIME_BN_RAND |
| time(&tim); |
| RAND_add(&tim, sizeof(tim), 0.0); |
| #endif /* NO_TIME_BN_RAND */ |
| |
| if (pseudorand) { |
| if (RAND_pseudo_bytes(buf, bytes) == -1) |
| goto err; |
| } else { |
| if (RAND_bytes(buf, bytes) <= 0) |
| goto err; |
| } |
| |
| #if 1 |
| if (pseudorand == 2) { |
| /* |
| * generate patterns that are more likely to trigger BN library bugs |
| */ |
| int i; |
| unsigned char c; |
| |
| for (i = 0; i < bytes; i++) { |
| RAND_pseudo_bytes(&c, 1); |
| if (c >= 128 && i > 0) |
| buf[i] = buf[i - 1]; |
| else if (c < 42) |
| buf[i] = 0; |
| else if (c < 84) |
| buf[i] = 255; |
| } |
| } |
| #endif |
| |
| if (top != -1) { |
| 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: |
| if (buf != NULL) { |
| OPENSSL_cleanse(buf, bytes); |
| OPENSSL_free(buf); |
| } |
| bn_check_top(rnd); |
| return (ret); |
| } |
| |
| int BN_rand(BIGNUM *rnd, int bits, int top, int bottom) |
| { |
| return bnrand(0, rnd, bits, top, bottom); |
| } |
| |
| int BN_pseudo_rand(BIGNUM *rnd, int bits, int top, int bottom) |
| { |
| return bnrand(1, rnd, bits, top, bottom); |
| } |
| |
| #if 1 |
| int BN_bntest_rand(BIGNUM *rnd, int bits, int top, int bottom) |
| { |
| return bnrand(2, rnd, bits, top, bottom); |
| } |
| #endif |
| |
| /* random number r: 0 <= r < range */ |
| static int bn_rand_range(int pseudo, BIGNUM *r, const BIGNUM *range) |
| { |
| int (*bn_rand) (BIGNUM *, int, int, int) = |
| pseudo ? BN_pseudo_rand : BN_rand; |
| int n; |
| int count = 100; |
| |
| if (range->neg || BN_is_zero(range)) { |
| BNerr(BN_F_BN_RAND_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 (!bn_rand(r, n + 1, -1, 0)) |
| 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_BN_RAND_RANGE, 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) { |
| BNerr(BN_F_BN_RAND_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 bn_rand_range(0, r, range); |
| } |
| |
| int BN_pseudo_rand_range(BIGNUM *r, const BIGNUM *range) |
| { |
| return bn_rand_range(1, r, range); |
| } |
