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Diffstat (limited to 'crypto/bn/bn_rand.c')
| -rw-r--r-- | crypto/bn/bn_rand.c | 305 |
1 files changed, 305 insertions, 0 deletions
diff --git a/crypto/bn/bn_rand.c b/crypto/bn/bn_rand.c new file mode 100644 index 000000000000..f51830b12ba8 --- /dev/null +++ b/crypto/bn/bn_rand.c @@ -0,0 +1,305 @@ +/* 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 */ + time(&tim); + RAND_add(&tim,sizeof(tim),0.0); + + 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, 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, BIGNUM *range) + { + return bn_rand_range(0, r, range); + } + +int BN_pseudo_rand_range(BIGNUM *r, BIGNUM *range) + { + return bn_rand_range(1, r, range); + } |