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Diffstat (limited to 'core/lib/libtomcrypt/src/math/rand_prime.c')
-rw-r--r-- | core/lib/libtomcrypt/src/math/rand_prime.c | 117 |
1 files changed, 117 insertions, 0 deletions
diff --git a/core/lib/libtomcrypt/src/math/rand_prime.c b/core/lib/libtomcrypt/src/math/rand_prime.c new file mode 100644 index 0000000..4b73142 --- /dev/null +++ b/core/lib/libtomcrypt/src/math/rand_prime.c @@ -0,0 +1,117 @@ +/* + * Copyright (c) 2001-2007, Tom St Denis + * 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. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "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 COPYRIGHT HOLDER 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. + */ + +/* LibTomCrypt, modular cryptographic library -- Tom St Denis + * + * LibTomCrypt is a library that provides various cryptographic + * algorithms in a highly modular and flexible manner. + * + * The library is free for all purposes without any express + * guarantee it works. + * + * Tom St Denis, tomstdenis@gmail.com, http://libtom.org + */ +#include "tomcrypt.h" + +#if !defined LTC_NO_MATH && !defined LTC_NO_PRNGS + +/** + @file rand_prime.c + Generate a random prime, Tom St Denis +*/ + +#define USE_BBS 1 + +int rand_prime(void *N, long len, prng_state *prng, int wprng) +{ + int err, res, type; + unsigned char *buf; + + LTC_ARGCHK(N != NULL); + + /* get type */ + if (len < 0) { + type = USE_BBS; + len = -len; + } else { + type = 0; + } + + /* allow sizes between 2 and 512 bytes for a prime size */ + if (len < 2 || len > 512) { + return CRYPT_INVALID_PRIME_SIZE; + } + + /* valid PRNG? Better be! */ + if ((err = prng_is_valid(wprng)) != CRYPT_OK) { + return err; + } + + /* allocate buffer to work with */ + buf = XCALLOC(1, len); + if (buf == NULL) { + return CRYPT_MEM; + } + + do { + /* generate value */ + if (prng_descriptor[wprng]->read(buf, len, prng) != (unsigned long)len) { + XFREE(buf); + return CRYPT_ERROR_READPRNG; + } + + /* munge bits */ + buf[0] |= 0x80 | 0x40; + buf[len-1] |= 0x01 | ((type & USE_BBS) ? 0x02 : 0x00); + + /* load value */ + if ((err = mp_read_unsigned_bin(N, buf, len)) != CRYPT_OK) { + XFREE(buf); + return err; + } + + /* test */ + if ((err = mp_prime_is_prime(N, 8, &res)) != CRYPT_OK) { + XFREE(buf); + return err; + } + } while (res == LTC_MP_NO); + +#ifdef LTC_CLEAN_STACK + zeromem(buf, len); +#endif + + XFREE(buf); + return CRYPT_OK; +} + +#endif /* LTC_NO_MATH */ + + +/* $Source: /cvs/libtom/libtomcrypt/src/math/rand_prime.c,v $ */ +/* $Revision: 1.7 $ */ +/* $Date: 2006/12/28 01:27:23 $ */ |