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 | #include <openssl/bn.h> |
| 58 | |
Kenny Root | b849459 | 2015-09-25 02:29:14 +0000 | [diff] [blame] | 59 | #include <assert.h> |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 60 | #include <ctype.h> |
Kenny Root | b849459 | 2015-09-25 02:29:14 +0000 | [diff] [blame] | 61 | #include <limits.h> |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 62 | #include <stdio.h> |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 63 | |
| 64 | #include <openssl/bio.h> |
Adam Langley | 4139edb | 2016-01-13 15:00:54 -0800 | [diff] [blame] | 65 | #include <openssl/bytestring.h> |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 66 | #include <openssl/err.h> |
| 67 | #include <openssl/mem.h> |
| 68 | |
Robert Sloan | 8ff0355 | 2017-06-14 12:40:58 -0700 | [diff] [blame^] | 69 | #include "../fipsmodule/bn/internal.h" |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 70 | |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 71 | |
Adam Langley | 4139edb | 2016-01-13 15:00:54 -0800 | [diff] [blame] | 72 | int BN_bn2cbb_padded(CBB *out, size_t len, const BIGNUM *in) { |
| 73 | uint8_t *ptr; |
| 74 | return CBB_add_space(out, &ptr, len) && BN_bn2bin_padded(ptr, len, in); |
| 75 | } |
| 76 | |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 77 | static const char hextable[] = "0123456789abcdef"; |
| 78 | |
| 79 | char *BN_bn2hex(const BIGNUM *bn) { |
David Benjamin | c895d6b | 2016-08-11 13:26:41 -0400 | [diff] [blame] | 80 | char *buf = OPENSSL_malloc(1 /* leading '-' */ + 1 /* zero is non-empty */ + |
| 81 | bn->top * BN_BYTES * 2 + 1 /* trailing NUL */); |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 82 | if (buf == NULL) { |
Kenny Root | b849459 | 2015-09-25 02:29:14 +0000 | [diff] [blame] | 83 | OPENSSL_PUT_ERROR(BN, ERR_R_MALLOC_FAILURE); |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 84 | return NULL; |
| 85 | } |
| 86 | |
David Benjamin | c895d6b | 2016-08-11 13:26:41 -0400 | [diff] [blame] | 87 | char *p = buf; |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 88 | if (bn->neg) { |
| 89 | *(p++) = '-'; |
| 90 | } |
| 91 | |
| 92 | if (BN_is_zero(bn)) { |
| 93 | *(p++) = '0'; |
| 94 | } |
| 95 | |
David Benjamin | c895d6b | 2016-08-11 13:26:41 -0400 | [diff] [blame] | 96 | int z = 0; |
| 97 | for (int i = bn->top - 1; i >= 0; i--) { |
| 98 | for (int j = BN_BITS2 - 8; j >= 0; j -= 8) { |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 99 | /* strip leading zeros */ |
David Benjamin | c895d6b | 2016-08-11 13:26:41 -0400 | [diff] [blame] | 100 | int v = ((int)(bn->d[i] >> (long)j)) & 0xff; |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 101 | if (z || v != 0) { |
| 102 | *(p++) = hextable[v >> 4]; |
| 103 | *(p++) = hextable[v & 0x0f]; |
| 104 | z = 1; |
| 105 | } |
| 106 | } |
| 107 | } |
| 108 | *p = '\0'; |
| 109 | |
| 110 | return buf; |
| 111 | } |
| 112 | |
Kenny Root | b849459 | 2015-09-25 02:29:14 +0000 | [diff] [blame] | 113 | /* decode_hex decodes |in_len| bytes of hex data from |in| and updates |bn|. */ |
| 114 | static int decode_hex(BIGNUM *bn, const char *in, int in_len) { |
| 115 | if (in_len > INT_MAX/4) { |
| 116 | OPENSSL_PUT_ERROR(BN, BN_R_BIGNUM_TOO_LONG); |
| 117 | return 0; |
| 118 | } |
| 119 | /* |in_len| is the number of hex digits. */ |
Robert Sloan | 9254e68 | 2017-04-24 09:42:06 -0700 | [diff] [blame] | 120 | if (!bn_expand(bn, in_len * 4)) { |
Kenny Root | b849459 | 2015-09-25 02:29:14 +0000 | [diff] [blame] | 121 | return 0; |
Adam Langley | 1e4884f | 2015-09-24 10:57:52 -0700 | [diff] [blame] | 122 | } |
Kenny Root | a04d78d | 2015-09-25 00:26:37 +0000 | [diff] [blame] | 123 | |
Kenny Root | b849459 | 2015-09-25 02:29:14 +0000 | [diff] [blame] | 124 | int i = 0; |
| 125 | while (in_len > 0) { |
| 126 | /* Decode one |BN_ULONG| at a time. */ |
| 127 | int todo = BN_BYTES * 2; |
| 128 | if (todo > in_len) { |
| 129 | todo = in_len; |
| 130 | } |
| 131 | |
| 132 | BN_ULONG word = 0; |
| 133 | int j; |
| 134 | for (j = todo; j > 0; j--) { |
| 135 | char c = in[in_len - j]; |
| 136 | |
| 137 | BN_ULONG hex; |
| 138 | if (c >= '0' && c <= '9') { |
| 139 | hex = c - '0'; |
| 140 | } else if (c >= 'a' && c <= 'f') { |
| 141 | hex = c - 'a' + 10; |
| 142 | } else if (c >= 'A' && c <= 'F') { |
| 143 | hex = c - 'A' + 10; |
| 144 | } else { |
| 145 | hex = 0; |
| 146 | /* This shouldn't happen. The caller checks |isxdigit|. */ |
| 147 | assert(0); |
| 148 | } |
| 149 | word = (word << 4) | hex; |
| 150 | } |
| 151 | |
| 152 | bn->d[i++] = word; |
| 153 | in_len -= todo; |
| 154 | } |
| 155 | assert(i <= bn->dmax); |
| 156 | bn->top = i; |
| 157 | return 1; |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 158 | } |
| 159 | |
Adam Langley | d82ab38 | 2015-04-23 13:54:37 -0700 | [diff] [blame] | 160 | /* decode_dec decodes |in_len| bytes of decimal data from |in| and updates |bn|. */ |
Kenny Root | b849459 | 2015-09-25 02:29:14 +0000 | [diff] [blame] | 161 | static int decode_dec(BIGNUM *bn, const char *in, int in_len) { |
Adam Langley | d82ab38 | 2015-04-23 13:54:37 -0700 | [diff] [blame] | 162 | int i, j; |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 163 | BN_ULONG l = 0; |
| 164 | |
Kenny Root | b849459 | 2015-09-25 02:29:14 +0000 | [diff] [blame] | 165 | /* Decode |BN_DEC_NUM| digits at a time. */ |
Adam Langley | d82ab38 | 2015-04-23 13:54:37 -0700 | [diff] [blame] | 166 | j = BN_DEC_NUM - (in_len % BN_DEC_NUM); |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 167 | if (j == BN_DEC_NUM) { |
| 168 | j = 0; |
| 169 | } |
| 170 | l = 0; |
Adam Langley | d82ab38 | 2015-04-23 13:54:37 -0700 | [diff] [blame] | 171 | for (i = 0; i < in_len; i++) { |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 172 | l *= 10; |
Adam Langley | d82ab38 | 2015-04-23 13:54:37 -0700 | [diff] [blame] | 173 | l += in[i] - '0'; |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 174 | if (++j == BN_DEC_NUM) { |
Kenny Root | b849459 | 2015-09-25 02:29:14 +0000 | [diff] [blame] | 175 | if (!BN_mul_word(bn, BN_DEC_CONV) || |
| 176 | !BN_add_word(bn, l)) { |
| 177 | return 0; |
| 178 | } |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 179 | l = 0; |
| 180 | j = 0; |
| 181 | } |
| 182 | } |
Kenny Root | b849459 | 2015-09-25 02:29:14 +0000 | [diff] [blame] | 183 | return 1; |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 184 | } |
| 185 | |
Kenny Root | b849459 | 2015-09-25 02:29:14 +0000 | [diff] [blame] | 186 | typedef int (*decode_func) (BIGNUM *bn, const char *in, int in_len); |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 187 | typedef int (*char_test_func) (int c); |
| 188 | |
| 189 | static int bn_x2bn(BIGNUM **outp, const char *in, decode_func decode, char_test_func want_char) { |
| 190 | BIGNUM *ret = NULL; |
| 191 | int neg = 0, i; |
| 192 | int num; |
| 193 | |
| 194 | if (in == NULL || *in == 0) { |
| 195 | return 0; |
| 196 | } |
| 197 | |
| 198 | if (*in == '-') { |
| 199 | neg = 1; |
| 200 | in++; |
| 201 | } |
| 202 | |
Kenny Root | b849459 | 2015-09-25 02:29:14 +0000 | [diff] [blame] | 203 | for (i = 0; want_char((unsigned char)in[i]) && i + neg < INT_MAX; i++) {} |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 204 | |
| 205 | num = i + neg; |
| 206 | if (outp == NULL) { |
| 207 | return num; |
| 208 | } |
| 209 | |
| 210 | /* in is the start of the hex digits, and it is 'i' long */ |
| 211 | if (*outp == NULL) { |
| 212 | ret = BN_new(); |
| 213 | if (ret == NULL) { |
| 214 | return 0; |
| 215 | } |
| 216 | } else { |
| 217 | ret = *outp; |
| 218 | BN_zero(ret); |
| 219 | } |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 220 | |
Kenny Root | b849459 | 2015-09-25 02:29:14 +0000 | [diff] [blame] | 221 | if (!decode(ret, in, i)) { |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 222 | goto err; |
| 223 | } |
| 224 | |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 225 | bn_correct_top(ret); |
Adam Langley | d82ab38 | 2015-04-23 13:54:37 -0700 | [diff] [blame] | 226 | if (!BN_is_zero(ret)) { |
| 227 | ret->neg = neg; |
| 228 | } |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 229 | |
| 230 | *outp = ret; |
| 231 | return num; |
| 232 | |
| 233 | err: |
| 234 | if (*outp == NULL) { |
| 235 | BN_free(ret); |
| 236 | } |
| 237 | |
| 238 | return 0; |
| 239 | } |
| 240 | |
| 241 | int BN_hex2bn(BIGNUM **outp, const char *in) { |
| 242 | return bn_x2bn(outp, in, decode_hex, isxdigit); |
| 243 | } |
| 244 | |
| 245 | char *BN_bn2dec(const BIGNUM *a) { |
David Benjamin | f0c4a6c | 2016-08-11 13:26:41 -0400 | [diff] [blame] | 246 | /* It is easier to print strings little-endian, so we assemble it in reverse |
| 247 | * and fix at the end. */ |
| 248 | BIGNUM *copy = NULL; |
| 249 | CBB cbb; |
| 250 | if (!CBB_init(&cbb, 16) || |
| 251 | !CBB_add_u8(&cbb, 0 /* trailing NUL */)) { |
| 252 | goto cbb_err; |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 253 | } |
| 254 | |
David Benjamin | f0c4a6c | 2016-08-11 13:26:41 -0400 | [diff] [blame] | 255 | if (BN_is_zero(a)) { |
| 256 | if (!CBB_add_u8(&cbb, '0')) { |
| 257 | goto cbb_err; |
| 258 | } |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 259 | } else { |
David Benjamin | f0c4a6c | 2016-08-11 13:26:41 -0400 | [diff] [blame] | 260 | copy = BN_dup(a); |
| 261 | if (copy == NULL) { |
| 262 | goto err; |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 263 | } |
David Benjamin | f0c4a6c | 2016-08-11 13:26:41 -0400 | [diff] [blame] | 264 | |
| 265 | while (!BN_is_zero(copy)) { |
| 266 | BN_ULONG word = BN_div_word(copy, BN_DEC_CONV); |
| 267 | if (word == (BN_ULONG)-1) { |
| 268 | goto err; |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 269 | } |
David Benjamin | f0c4a6c | 2016-08-11 13:26:41 -0400 | [diff] [blame] | 270 | |
| 271 | const int add_leading_zeros = !BN_is_zero(copy); |
| 272 | for (int i = 0; i < BN_DEC_NUM && (add_leading_zeros || word != 0); i++) { |
| 273 | if (!CBB_add_u8(&cbb, '0' + word % 10)) { |
| 274 | goto cbb_err; |
| 275 | } |
| 276 | word /= 10; |
| 277 | } |
| 278 | assert(word == 0); |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 279 | } |
| 280 | } |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 281 | |
David Benjamin | f0c4a6c | 2016-08-11 13:26:41 -0400 | [diff] [blame] | 282 | if (BN_is_negative(a) && |
| 283 | !CBB_add_u8(&cbb, '-')) { |
| 284 | goto cbb_err; |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 285 | } |
| 286 | |
David Benjamin | f0c4a6c | 2016-08-11 13:26:41 -0400 | [diff] [blame] | 287 | uint8_t *data; |
| 288 | size_t len; |
| 289 | if (!CBB_finish(&cbb, &data, &len)) { |
| 290 | goto cbb_err; |
| 291 | } |
| 292 | |
| 293 | /* Reverse the buffer. */ |
| 294 | for (size_t i = 0; i < len/2; i++) { |
| 295 | uint8_t tmp = data[i]; |
| 296 | data[i] = data[len - 1 - i]; |
| 297 | data[len - 1 - i] = tmp; |
| 298 | } |
| 299 | |
| 300 | BN_free(copy); |
| 301 | return (char *)data; |
| 302 | |
| 303 | cbb_err: |
| 304 | OPENSSL_PUT_ERROR(BN, ERR_R_MALLOC_FAILURE); |
| 305 | err: |
| 306 | BN_free(copy); |
| 307 | CBB_cleanup(&cbb); |
| 308 | return NULL; |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 309 | } |
| 310 | |
| 311 | int BN_dec2bn(BIGNUM **outp, const char *in) { |
| 312 | return bn_x2bn(outp, in, decode_dec, isdigit); |
| 313 | } |
| 314 | |
| 315 | int BN_asc2bn(BIGNUM **outp, const char *in) { |
| 316 | const char *const orig_in = in; |
| 317 | if (*in == '-') { |
| 318 | in++; |
| 319 | } |
| 320 | |
| 321 | if (in[0] == '0' && (in[1] == 'X' || in[1] == 'x')) { |
| 322 | if (!BN_hex2bn(outp, in+2)) { |
| 323 | return 0; |
| 324 | } |
| 325 | } else { |
| 326 | if (!BN_dec2bn(outp, in)) { |
| 327 | return 0; |
| 328 | } |
| 329 | } |
| 330 | |
Adam Langley | d82ab38 | 2015-04-23 13:54:37 -0700 | [diff] [blame] | 331 | if (*orig_in == '-' && !BN_is_zero(*outp)) { |
Adam Langley | d9e397b | 2015-01-22 14:27:53 -0800 | [diff] [blame] | 332 | (*outp)->neg = 1; |
| 333 | } |
| 334 | |
| 335 | return 1; |
| 336 | } |
| 337 | |
| 338 | int BN_print(BIO *bp, const BIGNUM *a) { |
| 339 | int i, j, v, z = 0; |
| 340 | int ret = 0; |
| 341 | |
| 342 | if (a->neg && BIO_write(bp, "-", 1) != 1) { |
| 343 | goto end; |
| 344 | } |
| 345 | |
| 346 | if (BN_is_zero(a) && BIO_write(bp, "0", 1) != 1) { |
| 347 | goto end; |
| 348 | } |
| 349 | |
| 350 | for (i = a->top - 1; i >= 0; i--) { |
| 351 | for (j = BN_BITS2 - 4; j >= 0; j -= 4) { |
| 352 | /* strip leading zeros */ |
| 353 | v = ((int)(a->d[i] >> (long)j)) & 0x0f; |
| 354 | if (z || v != 0) { |
| 355 | if (BIO_write(bp, &hextable[v], 1) != 1) { |
| 356 | goto end; |
| 357 | } |
| 358 | z = 1; |
| 359 | } |
| 360 | } |
| 361 | } |
| 362 | ret = 1; |
| 363 | |
| 364 | end: |
| 365 | return ret; |
| 366 | } |
| 367 | |
| 368 | int BN_print_fp(FILE *fp, const BIGNUM *a) { |
| 369 | BIO *b; |
| 370 | int ret; |
| 371 | |
| 372 | b = BIO_new(BIO_s_file()); |
| 373 | if (b == NULL) { |
| 374 | return 0; |
| 375 | } |
| 376 | BIO_set_fp(b, fp, BIO_NOCLOSE); |
| 377 | ret = BN_print(b, a); |
| 378 | BIO_free(b); |
| 379 | |
| 380 | return ret; |
| 381 | } |
| 382 | |
Robert Sloan | 69939df | 2017-01-09 10:53:07 -0800 | [diff] [blame] | 383 | |
Kenny Root | b849459 | 2015-09-25 02:29:14 +0000 | [diff] [blame] | 384 | size_t BN_bn2mpi(const BIGNUM *in, uint8_t *out) { |
| 385 | const size_t bits = BN_num_bits(in); |
| 386 | const size_t bytes = (bits + 7) / 8; |
| 387 | /* If the number of bits is a multiple of 8, i.e. if the MSB is set, |
| 388 | * prefix with a zero byte. */ |
| 389 | int extend = 0; |
| 390 | if (bytes != 0 && (bits & 0x07) == 0) { |
| 391 | extend = 1; |
| 392 | } |
| 393 | |
| 394 | const size_t len = bytes + extend; |
| 395 | if (len < bytes || |
| 396 | 4 + len < len || |
| 397 | (len & 0xffffffff) != len) { |
| 398 | /* If we cannot represent the number then we emit zero as the interface |
| 399 | * doesn't allow an error to be signalled. */ |
| 400 | if (out) { |
Robert Sloan | 69939df | 2017-01-09 10:53:07 -0800 | [diff] [blame] | 401 | OPENSSL_memset(out, 0, 4); |
Kenny Root | b849459 | 2015-09-25 02:29:14 +0000 | [diff] [blame] | 402 | } |
| 403 | return 4; |
| 404 | } |
| 405 | |
| 406 | if (out == NULL) { |
| 407 | return 4 + len; |
| 408 | } |
| 409 | |
| 410 | out[0] = len >> 24; |
| 411 | out[1] = len >> 16; |
| 412 | out[2] = len >> 8; |
| 413 | out[3] = len; |
| 414 | if (extend) { |
| 415 | out[4] = 0; |
| 416 | } |
| 417 | BN_bn2bin(in, out + 4 + extend); |
| 418 | if (in->neg && len > 0) { |
| 419 | out[4] |= 0x80; |
| 420 | } |
| 421 | return len + 4; |
| 422 | } |
| 423 | |
| 424 | BIGNUM *BN_mpi2bn(const uint8_t *in, size_t len, BIGNUM *out) { |
| 425 | if (len < 4) { |
| 426 | OPENSSL_PUT_ERROR(BN, BN_R_BAD_ENCODING); |
| 427 | return NULL; |
| 428 | } |
| 429 | const size_t in_len = ((size_t)in[0] << 24) | |
| 430 | ((size_t)in[1] << 16) | |
| 431 | ((size_t)in[2] << 8) | |
| 432 | ((size_t)in[3]); |
| 433 | if (in_len != len - 4) { |
| 434 | OPENSSL_PUT_ERROR(BN, BN_R_BAD_ENCODING); |
| 435 | return NULL; |
| 436 | } |
| 437 | |
David Benjamin | 4969cc9 | 2016-04-22 15:02:23 -0400 | [diff] [blame] | 438 | int out_is_alloced = 0; |
Kenny Root | b849459 | 2015-09-25 02:29:14 +0000 | [diff] [blame] | 439 | if (out == NULL) { |
| 440 | out = BN_new(); |
David Benjamin | 4969cc9 | 2016-04-22 15:02:23 -0400 | [diff] [blame] | 441 | if (out == NULL) { |
| 442 | OPENSSL_PUT_ERROR(BN, ERR_R_MALLOC_FAILURE); |
| 443 | return NULL; |
| 444 | } |
| 445 | out_is_alloced = 1; |
Kenny Root | b849459 | 2015-09-25 02:29:14 +0000 | [diff] [blame] | 446 | } |
| 447 | |
| 448 | if (in_len == 0) { |
| 449 | BN_zero(out); |
| 450 | return out; |
| 451 | } |
| 452 | |
| 453 | in += 4; |
| 454 | if (BN_bin2bn(in, in_len, out) == NULL) { |
David Benjamin | 4969cc9 | 2016-04-22 15:02:23 -0400 | [diff] [blame] | 455 | if (out_is_alloced) { |
| 456 | BN_free(out); |
| 457 | } |
Kenny Root | b849459 | 2015-09-25 02:29:14 +0000 | [diff] [blame] | 458 | return NULL; |
| 459 | } |
| 460 | out->neg = ((*in) & 0x80) != 0; |
| 461 | if (out->neg) { |
| 462 | BN_clear_bit(out, BN_num_bits(out) - 1); |
| 463 | } |
| 464 | return out; |
| 465 | } |