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Diffstat (limited to 'src/crypto/bn/random.c')
| -rw-r--r-- | src/crypto/bn/random.c | 328 |
1 files changed, 328 insertions, 0 deletions
diff --git a/src/crypto/bn/random.c b/src/crypto/bn/random.c new file mode 100644 index 0000000..285bf26 --- /dev/null +++ b/src/crypto/bn/random.c @@ -0,0 +1,328 @@ +/* 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, BN_rand, 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) { + 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_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 /* 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_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) { + OPENSSL_PUT_ERROR(BN, BN_rand_range, 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_generate_dsa_nonce, BN_R_DIV_BY_ZERO); + goto err; + } + + k_bytes = OPENSSL_malloc(num_k_bytes); + if (!k_bytes) { + OPENSSL_PUT_ERROR(BN, BN_generate_dsa_nonce, 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_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 (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: + if (k_bytes) { + OPENSSL_free(k_bytes); + } + return ret; +} |