Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 1 | /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) |
| 2 | * All rights reserved. |
| 3 | * |
| 4 | * This package is an SSL implementation written |
| 5 | * by Eric Young (eay@cryptsoft.com). |
| 6 | * The implementation was written so as to conform with Netscapes SSL. |
| 7 | * |
| 8 | * This library is free for commercial and non-commercial use as long as |
| 9 | * the following conditions are aheared to. The following conditions |
| 10 | * apply to all code found in this distribution, be it the RC4, RSA, |
| 11 | * lhash, DES, etc., code; not just the SSL code. The SSL documentation |
| 12 | * included with this distribution is covered by the same copyright terms |
| 13 | * except that the holder is Tim Hudson (tjh@cryptsoft.com). |
| 14 | * |
| 15 | * Copyright remains Eric Young's, and as such any Copyright notices in |
| 16 | * the code are not to be removed. |
| 17 | * If this package is used in a product, Eric Young should be given attribution |
| 18 | * as the author of the parts of the library used. |
| 19 | * This can be in the form of a textual message at program startup or |
| 20 | * in documentation (online or textual) provided with the package. |
| 21 | * |
| 22 | * Redistribution and use in source and binary forms, with or without |
| 23 | * modification, are permitted provided that the following conditions |
| 24 | * are met: |
| 25 | * 1. Redistributions of source code must retain the copyright |
| 26 | * notice, this list of conditions and the following disclaimer. |
| 27 | * 2. Redistributions in binary form must reproduce the above copyright |
| 28 | * notice, this list of conditions and the following disclaimer in the |
| 29 | * documentation and/or other materials provided with the distribution. |
| 30 | * 3. All advertising materials mentioning features or use of this software |
| 31 | * must display the following acknowledgement: |
| 32 | * "This product includes cryptographic software written by |
| 33 | * Eric Young (eay@cryptsoft.com)" |
| 34 | * The word 'cryptographic' can be left out if the rouines from the library |
| 35 | * being used are not cryptographic related :-). |
| 36 | * 4. If you include any Windows specific code (or a derivative thereof) from |
| 37 | * the apps directory (application code) you must include an acknowledgement: |
| 38 | * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" |
| 39 | * |
| 40 | * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND |
| 41 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 42 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 43 | * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE |
| 44 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 45 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| 46 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 47 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| 48 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| 49 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 50 | * SUCH DAMAGE. |
| 51 | * |
| 52 | * The licence and distribution terms for any publically available version or |
| 53 | * derivative of this code cannot be changed. i.e. this code cannot simply be |
| 54 | * copied and put under another distribution licence |
| 55 | * [including the GNU Public Licence.] |
| 56 | */ |
| 57 | /* ==================================================================== |
| 58 | * Copyright (c) 1998-2001 The OpenSSL Project. All rights reserved. |
| 59 | * |
| 60 | * Redistribution and use in source and binary forms, with or without |
| 61 | * modification, are permitted provided that the following conditions |
| 62 | * are met: |
| 63 | * |
| 64 | * 1. Redistributions of source code must retain the above copyright |
| 65 | * notice, this list of conditions and the following disclaimer. |
| 66 | * |
| 67 | * 2. Redistributions in binary form must reproduce the above copyright |
| 68 | * notice, this list of conditions and the following disclaimer in |
| 69 | * the documentation and/or other materials provided with the |
| 70 | * distribution. |
| 71 | * |
| 72 | * 3. All advertising materials mentioning features or use of this |
| 73 | * software must display the following acknowledgment: |
| 74 | * "This product includes software developed by the OpenSSL Project |
| 75 | * for use in the OpenSSL Toolkit. (http://www.openssl.org/)" |
| 76 | * |
| 77 | * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to |
| 78 | * endorse or promote products derived from this software without |
| 79 | * prior written permission. For written permission, please contact |
| 80 | * openssl-core@openssl.org. |
| 81 | * |
| 82 | * 5. Products derived from this software may not be called "OpenSSL" |
| 83 | * nor may "OpenSSL" appear in their names without prior written |
| 84 | * permission of the OpenSSL Project. |
| 85 | * |
| 86 | * 6. Redistributions of any form whatsoever must retain the following |
| 87 | * acknowledgment: |
| 88 | * "This product includes software developed by the OpenSSL Project |
| 89 | * for use in the OpenSSL Toolkit (http://www.openssl.org/)" |
| 90 | * |
| 91 | * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY |
| 92 | * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 93 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR |
| 94 | * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR |
| 95 | * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| 96 | * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT |
| 97 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; |
| 98 | * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 99 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, |
| 100 | * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| 101 | * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED |
| 102 | * OF THE POSSIBILITY OF SUCH DAMAGE. |
| 103 | * ==================================================================== |
| 104 | * |
| 105 | * This product includes cryptographic software written by Eric Young |
| 106 | * (eay@cryptsoft.com). This product includes software written by Tim |
| 107 | * Hudson (tjh@cryptsoft.com). */ |
| 108 | |
| 109 | #include <openssl/bn.h> |
| 110 | |
| 111 | #include <string.h> |
| 112 | |
| 113 | #include <openssl/err.h> |
| 114 | #include <openssl/mem.h> |
| 115 | #include <openssl/rand.h> |
| 116 | #include <openssl/sha.h> |
Robert Sloan | 572a4e2 | 2017-04-17 10:52:19 -0700 | [diff] [blame] | 117 | #include <openssl/type_check.h> |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 118 | |
Robert Sloan | 69939df | 2017-01-09 10:53:07 -0800 | [diff] [blame] | 119 | #include "../internal.h" |
Robert Sloan | 9254e68 | 2017-04-24 09:42:06 -0700 | [diff] [blame] | 120 | #include "../fipsmodule/rand/internal.h" |
Robert Sloan | 69939df | 2017-01-09 10:53:07 -0800 | [diff] [blame] | 121 | |
| 122 | |
Robert Sloan | 572a4e2 | 2017-04-17 10:52:19 -0700 | [diff] [blame] | 123 | static const uint8_t kZeroAdditionalData[32] = {0}; |
| 124 | |
| 125 | static int bn_rand_with_additional_data(BIGNUM *rnd, int bits, int top, |
| 126 | int bottom, |
| 127 | const uint8_t additional_data[32]) { |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 128 | uint8_t *buf = NULL; |
| 129 | int ret = 0, bit, bytes, mask; |
| 130 | |
| 131 | if (rnd == NULL) { |
| 132 | return 0; |
| 133 | } |
| 134 | |
David Benjamin | f0c4a6c | 2016-08-11 13:26:41 -0400 | [diff] [blame] | 135 | if (top != BN_RAND_TOP_ANY && top != BN_RAND_TOP_ONE && |
| 136 | top != BN_RAND_TOP_TWO) { |
| 137 | OPENSSL_PUT_ERROR(BN, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); |
| 138 | return 0; |
| 139 | } |
| 140 | |
| 141 | if (bottom != BN_RAND_BOTTOM_ANY && bottom != BN_RAND_BOTTOM_ODD) { |
| 142 | OPENSSL_PUT_ERROR(BN, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED); |
| 143 | return 0; |
| 144 | } |
| 145 | |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 146 | if (bits == 0) { |
| 147 | BN_zero(rnd); |
| 148 | return 1; |
| 149 | } |
| 150 | |
| 151 | bytes = (bits + 7) / 8; |
| 152 | bit = (bits - 1) % 8; |
| 153 | mask = 0xff << (bit + 1); |
| 154 | |
| 155 | buf = OPENSSL_malloc(bytes); |
| 156 | if (buf == NULL) { |
Kenny Root | b849459 | 2015-09-25 02:29:14 +0000 | [diff] [blame] | 157 | OPENSSL_PUT_ERROR(BN, ERR_R_MALLOC_FAILURE); |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 158 | goto err; |
| 159 | } |
| 160 | |
| 161 | /* Make a random number and set the top and bottom bits. */ |
Robert Sloan | 572a4e2 | 2017-04-17 10:52:19 -0700 | [diff] [blame] | 162 | RAND_bytes_with_additional_data(buf, bytes, additional_data); |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 163 | |
David Benjamin | f0c4a6c | 2016-08-11 13:26:41 -0400 | [diff] [blame] | 164 | if (top != BN_RAND_TOP_ANY) { |
| 165 | if (top == BN_RAND_TOP_TWO && bits > 1) { |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 166 | if (bit == 0) { |
| 167 | buf[0] = 1; |
| 168 | buf[1] |= 0x80; |
| 169 | } else { |
| 170 | buf[0] |= (3 << (bit - 1)); |
| 171 | } |
| 172 | } else { |
| 173 | buf[0] |= (1 << bit); |
| 174 | } |
| 175 | } |
| 176 | |
| 177 | buf[0] &= ~mask; |
| 178 | |
David Benjamin | f0c4a6c | 2016-08-11 13:26:41 -0400 | [diff] [blame] | 179 | /* Set the bottom bit if requested, */ |
| 180 | if (bottom == BN_RAND_BOTTOM_ODD) { |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 181 | buf[bytes - 1] |= 1; |
| 182 | } |
| 183 | |
| 184 | if (!BN_bin2bn(buf, bytes, rnd)) { |
| 185 | goto err; |
| 186 | } |
| 187 | |
| 188 | ret = 1; |
| 189 | |
| 190 | err: |
| 191 | if (buf != NULL) { |
| 192 | OPENSSL_cleanse(buf, bytes); |
| 193 | OPENSSL_free(buf); |
| 194 | } |
| 195 | return (ret); |
| 196 | } |
| 197 | |
Robert Sloan | 572a4e2 | 2017-04-17 10:52:19 -0700 | [diff] [blame] | 198 | int BN_rand(BIGNUM *rnd, int bits, int top, int bottom) { |
| 199 | return bn_rand_with_additional_data(rnd, bits, top, bottom, |
| 200 | kZeroAdditionalData); |
| 201 | } |
| 202 | |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 203 | int BN_pseudo_rand(BIGNUM *rnd, int bits, int top, int bottom) { |
| 204 | return BN_rand(rnd, bits, top, bottom); |
| 205 | } |
| 206 | |
Robert Sloan | 572a4e2 | 2017-04-17 10:52:19 -0700 | [diff] [blame] | 207 | static int bn_rand_range_with_additional_data( |
| 208 | BIGNUM *r, BN_ULONG min_inclusive, const BIGNUM *max_exclusive, |
| 209 | const uint8_t additional_data[32]) { |
David Benjamin | c895d6b | 2016-08-11 13:26:41 -0400 | [diff] [blame] | 210 | if (BN_cmp_word(max_exclusive, min_inclusive) <= 0) { |
Kenny Root | b849459 | 2015-09-25 02:29:14 +0000 | [diff] [blame] | 211 | OPENSSL_PUT_ERROR(BN, BN_R_INVALID_RANGE); |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 212 | return 0; |
| 213 | } |
| 214 | |
Robert Sloan | 572a4e2 | 2017-04-17 10:52:19 -0700 | [diff] [blame] | 215 | /* This function is used to implement steps 4 through 7 of FIPS 186-4 |
| 216 | * appendices B.4.2 and B.5.2. When called in those contexts, |max_exclusive| |
| 217 | * is n and |min_inclusive| is one. */ |
| 218 | unsigned count = 100; |
| 219 | unsigned n = BN_num_bits(max_exclusive); /* n > 0 */ |
David Benjamin | c895d6b | 2016-08-11 13:26:41 -0400 | [diff] [blame] | 220 | do { |
| 221 | if (!--count) { |
| 222 | OPENSSL_PUT_ERROR(BN, BN_R_TOO_MANY_ITERATIONS); |
| 223 | return 0; |
| 224 | } |
| 225 | |
Robert Sloan | 572a4e2 | 2017-04-17 10:52:19 -0700 | [diff] [blame] | 226 | if (/* steps 4 and 5 */ |
| 227 | !bn_rand_with_additional_data(r, n, BN_RAND_TOP_ANY, BN_RAND_BOTTOM_ANY, |
| 228 | additional_data) || |
| 229 | /* step 7 */ |
| 230 | !BN_add_word(r, min_inclusive)) { |
| 231 | return 0; |
David Benjamin | c895d6b | 2016-08-11 13:26:41 -0400 | [diff] [blame] | 232 | } |
Robert Sloan | 572a4e2 | 2017-04-17 10:52:19 -0700 | [diff] [blame] | 233 | |
| 234 | /* Step 6. This loops if |r| >= |max_exclusive|. This is identical to |
| 235 | * checking |r| > |max_exclusive| - 1 or |r| - 1 > |max_exclusive| - 2, the |
| 236 | * formulation stated in FIPS 186-4. */ |
| 237 | } while (BN_cmp(r, max_exclusive) >= 0); |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 238 | |
| 239 | return 1; |
| 240 | } |
| 241 | |
Robert Sloan | 572a4e2 | 2017-04-17 10:52:19 -0700 | [diff] [blame] | 242 | int BN_rand_range_ex(BIGNUM *r, BN_ULONG min_inclusive, |
| 243 | const BIGNUM *max_exclusive) { |
| 244 | return bn_rand_range_with_additional_data(r, min_inclusive, max_exclusive, |
| 245 | kZeroAdditionalData); |
| 246 | } |
| 247 | |
David Benjamin | c895d6b | 2016-08-11 13:26:41 -0400 | [diff] [blame] | 248 | int BN_rand_range(BIGNUM *r, const BIGNUM *range) { |
| 249 | return BN_rand_range_ex(r, 0, range); |
| 250 | } |
| 251 | |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 252 | int BN_pseudo_rand_range(BIGNUM *r, const BIGNUM *range) { |
| 253 | return BN_rand_range(r, range); |
| 254 | } |
| 255 | |
| 256 | int BN_generate_dsa_nonce(BIGNUM *out, const BIGNUM *range, const BIGNUM *priv, |
| 257 | const uint8_t *message, size_t message_len, |
| 258 | BN_CTX *ctx) { |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 259 | /* We copy |priv| into a local buffer to avoid furthur exposing its |
| 260 | * length. */ |
Robert Sloan | 572a4e2 | 2017-04-17 10:52:19 -0700 | [diff] [blame] | 261 | uint8_t private_bytes[96]; |
| 262 | size_t todo = sizeof(priv->d[0]) * priv->top; |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 263 | if (todo > sizeof(private_bytes)) { |
| 264 | /* No reasonable DSA or ECDSA key should have a private key |
| 265 | * this large and we don't handle this case in order to avoid |
| 266 | * leaking the length of the private key. */ |
Kenny Root | b849459 | 2015-09-25 02:29:14 +0000 | [diff] [blame] | 267 | OPENSSL_PUT_ERROR(BN, BN_R_PRIVATE_KEY_TOO_LARGE); |
Robert Sloan | 572a4e2 | 2017-04-17 10:52:19 -0700 | [diff] [blame] | 268 | return 0; |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 269 | } |
Robert Sloan | 69939df | 2017-01-09 10:53:07 -0800 | [diff] [blame] | 270 | OPENSSL_memcpy(private_bytes, priv->d, todo); |
| 271 | OPENSSL_memset(private_bytes + todo, 0, sizeof(private_bytes) - todo); |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 272 | |
Robert Sloan | 572a4e2 | 2017-04-17 10:52:19 -0700 | [diff] [blame] | 273 | /* Pass a SHA256 hash of the private key and message as additional data into |
| 274 | * the RBG. This is a hardening measure against entropy failure. */ |
| 275 | OPENSSL_COMPILE_ASSERT(SHA256_DIGEST_LENGTH == 32, |
| 276 | additional_data_is_different_size_from_sha256); |
| 277 | SHA256_CTX sha; |
| 278 | uint8_t digest[SHA256_DIGEST_LENGTH]; |
| 279 | SHA256_Init(&sha); |
| 280 | SHA256_Update(&sha, private_bytes, sizeof(private_bytes)); |
| 281 | SHA256_Update(&sha, message, message_len); |
| 282 | SHA256_Final(digest, &sha); |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 283 | |
Robert Sloan | 572a4e2 | 2017-04-17 10:52:19 -0700 | [diff] [blame] | 284 | /* Select a value k from [1, range-1], following FIPS 186-4 appendix B.5.2. */ |
| 285 | return bn_rand_range_with_additional_data(out, 1, range, digest); |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 286 | } |