/* 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 #include #include #include #include #include #include #include "../internal.h" #include "../rand/internal.h" static const uint8_t kZeroAdditionalData[32] = {0}; static int bn_rand_with_additional_data(BIGNUM *rnd, int bits, int top, int bottom, const uint8_t additional_data[32]) { uint8_t *buf = NULL; int ret = 0, bit, bytes, mask; if (rnd == NULL) { return 0; } if (top != BN_RAND_TOP_ANY && top != BN_RAND_TOP_ONE && top != BN_RAND_TOP_TWO) { OPENSSL_PUT_ERROR(BN, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); return 0; } if (bottom != BN_RAND_BOTTOM_ANY && bottom != BN_RAND_BOTTOM_ODD) { OPENSSL_PUT_ERROR(BN, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); 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, ERR_R_MALLOC_FAILURE); goto err; } /* Make a random number and set the top and bottom bits. */ RAND_bytes_with_additional_data(buf, bytes, additional_data); if (top != BN_RAND_TOP_ANY) { if (top == BN_RAND_TOP_TWO && bits > 1) { if (bit == 0) { buf[0] = 1; buf[1] |= 0x80; } else { buf[0] |= (3 << (bit - 1)); } } else { buf[0] |= (1 << bit); } } buf[0] &= ~mask; /* Set the bottom bit if requested, */ if (bottom == BN_RAND_BOTTOM_ODD) { 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_rand(BIGNUM *rnd, int bits, int top, int bottom) { return bn_rand_with_additional_data(rnd, bits, top, bottom, kZeroAdditionalData); } int BN_pseudo_rand(BIGNUM *rnd, int bits, int top, int bottom) { return BN_rand(rnd, bits, top, bottom); } static int bn_rand_range_with_additional_data( BIGNUM *r, BN_ULONG min_inclusive, const BIGNUM *max_exclusive, const uint8_t additional_data[32]) { if (BN_cmp_word(max_exclusive, min_inclusive) <= 0) { OPENSSL_PUT_ERROR(BN, BN_R_INVALID_RANGE); return 0; } /* This function is used to implement steps 4 through 7 of FIPS 186-4 * appendices B.4.2 and B.5.2. When called in those contexts, |max_exclusive| * is n and |min_inclusive| is one. */ unsigned count = 100; unsigned n = BN_num_bits(max_exclusive); /* n > 0 */ do { if (!--count) { OPENSSL_PUT_ERROR(BN, BN_R_TOO_MANY_ITERATIONS); return 0; } if (/* steps 4 and 5 */ !bn_rand_with_additional_data(r, n, BN_RAND_TOP_ANY, BN_RAND_BOTTOM_ANY, additional_data) || /* step 7 */ !BN_add_word(r, min_inclusive)) { return 0; } /* Step 6. This loops if |r| >= |max_exclusive|. This is identical to * checking |r| > |max_exclusive| - 1 or |r| - 1 > |max_exclusive| - 2, the * formulation stated in FIPS 186-4. */ } while (BN_cmp(r, max_exclusive) >= 0); return 1; } int BN_rand_range_ex(BIGNUM *r, BN_ULONG min_inclusive, const BIGNUM *max_exclusive) { return bn_rand_range_with_additional_data(r, min_inclusive, max_exclusive, kZeroAdditionalData); } int BN_rand_range(BIGNUM *r, const BIGNUM *range) { return BN_rand_range_ex(r, 0, range); } 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) { /* We copy |priv| into a local buffer to avoid furthur exposing its * length. */ uint8_t private_bytes[96]; size_t 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_R_PRIVATE_KEY_TOO_LARGE); return 0; } OPENSSL_memcpy(private_bytes, priv->d, todo); OPENSSL_memset(private_bytes + todo, 0, sizeof(private_bytes) - todo); /* Pass a SHA256 hash of the private key and message as additional data into * the RBG. This is a hardening measure against entropy failure. */ OPENSSL_COMPILE_ASSERT(SHA256_DIGEST_LENGTH == 32, additional_data_is_different_size_from_sha256); SHA256_CTX sha; uint8_t digest[SHA256_DIGEST_LENGTH]; SHA256_Init(&sha); SHA256_Update(&sha, private_bytes, sizeof(private_bytes)); SHA256_Update(&sha, message, message_len); SHA256_Final(digest, &sha); /* Select a value k from [1, range-1], following FIPS 186-4 appendix B.5.2. */ return bn_rand_range_with_additional_data(out, 1, range, digest); }