1 /* $OpenBSD: bn_print.c,v 1.28 2015/09/28 18:58:33 deraadt Exp $ */ 2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) 3 * All rights reserved. 4 * 5 * This package is an SSL implementation written 6 * by Eric Young (eay@cryptsoft.com). 7 * The implementation was written so as to conform with Netscapes SSL. 8 * 9 * This library is free for commercial and non-commercial use as long as 10 * the following conditions are aheared to. The following conditions 11 * apply to all code found in this distribution, be it the RC4, RSA, 12 * lhash, DES, etc., code; not just the SSL code. The SSL documentation 13 * included with this distribution is covered by the same copyright terms 14 * except that the holder is Tim Hudson (tjh@cryptsoft.com). 15 * 16 * Copyright remains Eric Young's, and as such any Copyright notices in 17 * the code are not to be removed. 18 * If this package is used in a product, Eric Young should be given attribution 19 * as the author of the parts of the library used. 20 * This can be in the form of a textual message at program startup or 21 * in documentation (online or textual) provided with the package. 22 * 23 * Redistribution and use in source and binary forms, with or without 24 * modification, are permitted provided that the following conditions 25 * are met: 26 * 1. Redistributions of source code must retain the copyright 27 * notice, this list of conditions and the following disclaimer. 28 * 2. Redistributions in binary form must reproduce the above copyright 29 * notice, this list of conditions and the following disclaimer in the 30 * documentation and/or other materials provided with the distribution. 31 * 3. All advertising materials mentioning features or use of this software 32 * must display the following acknowledgement: 33 * "This product includes cryptographic software written by 34 * Eric Young (eay@cryptsoft.com)" 35 * The word 'cryptographic' can be left out if the rouines from the library 36 * being used are not cryptographic related :-). 37 * 4. If you include any Windows specific code (or a derivative thereof) from 38 * the apps directory (application code) you must include an acknowledgement: 39 * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" 40 * 41 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND 42 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 43 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 44 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 45 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 46 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 47 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 49 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 50 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 51 * SUCH DAMAGE. 52 * 53 * The licence and distribution terms for any publically available version or 54 * derivative of this code cannot be changed. i.e. this code cannot simply be 55 * copied and put under another distribution licence 56 * [including the GNU Public Licence.] 57 */ 58 59 #include <ctype.h> 60 #include <limits.h> 61 #include <stdio.h> 62 63 #include <openssl/opensslconf.h> 64 65 #include <openssl/bio.h> 66 #include <openssl/buffer.h> 67 #include <openssl/err.h> 68 69 #include "bn_lcl.h" 70 71 static const char Hex[]="0123456789ABCDEF"; 72 73 /* Must 'free' the returned data */ 74 char * 75 BN_bn2hex(const BIGNUM *a) 76 { 77 int i, j, v, z = 0; 78 char *buf; 79 char *p; 80 81 buf = malloc(BN_is_negative(a) + a->top * BN_BYTES * 2 + 2); 82 if (buf == NULL) { 83 BNerr(BN_F_BN_BN2HEX, ERR_R_MALLOC_FAILURE); 84 goto err; 85 } 86 p = buf; 87 if (BN_is_negative(a)) 88 *p++ = '-'; 89 if (BN_is_zero(a)) 90 *p++ = '0'; 91 for (i = a->top - 1; i >=0; i--) { 92 for (j = BN_BITS2 - 8; j >= 0; j -= 8) { 93 /* strip leading zeros */ 94 v = ((int)(a->d[i] >> (long)j)) & 0xff; 95 if (z || (v != 0)) { 96 *p++ = Hex[v >> 4]; 97 *p++ = Hex[v & 0x0f]; 98 z = 1; 99 } 100 } 101 } 102 *p = '\0'; 103 104 err: 105 return (buf); 106 } 107 108 /* Must 'free' the returned data */ 109 char * 110 BN_bn2dec(const BIGNUM *a) 111 { 112 int i = 0, num, ok = 0; 113 char *buf = NULL; 114 char *p; 115 BIGNUM *t = NULL; 116 BN_ULONG *bn_data = NULL, *lp; 117 118 if (BN_is_zero(a)) { 119 buf = malloc(BN_is_negative(a) + 2); 120 if (buf == NULL) { 121 BNerr(BN_F_BN_BN2DEC, ERR_R_MALLOC_FAILURE); 122 goto err; 123 } 124 p = buf; 125 if (BN_is_negative(a)) 126 *p++ = '-'; 127 *p++ = '0'; 128 *p++ = '\0'; 129 return (buf); 130 } 131 132 /* get an upper bound for the length of the decimal integer 133 * num <= (BN_num_bits(a) + 1) * log(2) 134 * <= 3 * BN_num_bits(a) * 0.1001 + log(2) + 1 (rounding error) 135 * <= BN_num_bits(a)/10 + BN_num_bits/1000 + 1 + 1 136 */ 137 i = BN_num_bits(a) * 3; 138 num = (i / 10 + i / 1000 + 1) + 1; 139 bn_data = reallocarray(NULL, num / BN_DEC_NUM + 1, sizeof(BN_ULONG)); 140 buf = malloc(num + 3); 141 if ((buf == NULL) || (bn_data == NULL)) { 142 BNerr(BN_F_BN_BN2DEC, ERR_R_MALLOC_FAILURE); 143 goto err; 144 } 145 if ((t = BN_dup(a)) == NULL) 146 goto err; 147 148 #define BUF_REMAIN (num+3 - (size_t)(p - buf)) 149 p = buf; 150 lp = bn_data; 151 if (BN_is_negative(t)) 152 *p++ = '-'; 153 154 i = 0; 155 while (!BN_is_zero(t)) { 156 *lp = BN_div_word(t, BN_DEC_CONV); 157 lp++; 158 } 159 lp--; 160 /* We now have a series of blocks, BN_DEC_NUM chars 161 * in length, where the last one needs truncation. 162 * The blocks need to be reversed in order. */ 163 snprintf(p, BUF_REMAIN, BN_DEC_FMT1, *lp); 164 while (*p) 165 p++; 166 while (lp != bn_data) { 167 lp--; 168 snprintf(p, BUF_REMAIN, BN_DEC_FMT2, *lp); 169 while (*p) 170 p++; 171 } 172 ok = 1; 173 174 err: 175 free(bn_data); 176 BN_free(t); 177 if (!ok && buf) { 178 free(buf); 179 buf = NULL; 180 } 181 182 return (buf); 183 } 184 185 int 186 BN_hex2bn(BIGNUM **bn, const char *a) 187 { 188 BIGNUM *ret = NULL; 189 BN_ULONG l = 0; 190 int neg = 0, h, m, i,j, k, c; 191 int num; 192 193 if ((a == NULL) || (*a == '\0')) 194 return (0); 195 196 if (*a == '-') { 197 neg = 1; 198 a++; 199 } 200 201 for (i = 0; i <= (INT_MAX / 4) && isxdigit((unsigned char)a[i]); i++) 202 ; 203 if (i > INT_MAX / 4) 204 goto err; 205 206 num = i + neg; 207 if (bn == NULL) 208 return (num); 209 210 /* a is the start of the hex digits, and it is 'i' long */ 211 if (*bn == NULL) { 212 if ((ret = BN_new()) == NULL) 213 return (0); 214 } else { 215 ret= *bn; 216 BN_zero(ret); 217 } 218 219 /* i is the number of hex digits */ 220 if (bn_expand(ret, i * 4) == NULL) 221 goto err; 222 223 j = i; /* least significant 'hex' */ 224 m = 0; 225 h = 0; 226 while (j > 0) { 227 m = ((BN_BYTES*2) <= j) ? (BN_BYTES * 2) : j; 228 l = 0; 229 for (;;) { 230 c = a[j - m]; 231 if ((c >= '0') && (c <= '9')) 232 k = c - '0'; 233 else if ((c >= 'a') && (c <= 'f')) 234 k = c - 'a' + 10; 235 else if ((c >= 'A') && (c <= 'F')) 236 k = c - 'A' + 10; 237 else 238 k = 0; /* paranoia */ 239 l = (l << 4) | k; 240 241 if (--m <= 0) { 242 ret->d[h++] = l; 243 break; 244 } 245 } 246 j -= (BN_BYTES * 2); 247 } 248 ret->top = h; 249 bn_correct_top(ret); 250 ret->neg = neg; 251 252 *bn = ret; 253 bn_check_top(ret); 254 return (num); 255 256 err: 257 if (*bn == NULL) 258 BN_free(ret); 259 return (0); 260 } 261 262 int 263 BN_dec2bn(BIGNUM **bn, const char *a) 264 { 265 BIGNUM *ret = NULL; 266 BN_ULONG l = 0; 267 int neg = 0, i, j; 268 int num; 269 270 if ((a == NULL) || (*a == '\0')) 271 return (0); 272 if (*a == '-') { 273 neg = 1; 274 a++; 275 } 276 277 for (i = 0; i <= (INT_MAX / 4) && isdigit((unsigned char)a[i]); i++) 278 ; 279 if (i > INT_MAX / 4) 280 goto err; 281 282 num = i + neg; 283 if (bn == NULL) 284 return (num); 285 286 /* a is the start of the digits, and it is 'i' long. 287 * We chop it into BN_DEC_NUM digits at a time */ 288 if (*bn == NULL) { 289 if ((ret = BN_new()) == NULL) 290 return (0); 291 } else { 292 ret = *bn; 293 BN_zero(ret); 294 } 295 296 /* i is the number of digits, a bit of an over expand */ 297 if (bn_expand(ret, i * 4) == NULL) 298 goto err; 299 300 j = BN_DEC_NUM - (i % BN_DEC_NUM); 301 if (j == BN_DEC_NUM) 302 j = 0; 303 l = 0; 304 while (*a) { 305 l *= 10; 306 l += *a - '0'; 307 a++; 308 if (++j == BN_DEC_NUM) { 309 BN_mul_word(ret, BN_DEC_CONV); 310 BN_add_word(ret, l); 311 l = 0; 312 j = 0; 313 } 314 } 315 ret->neg = neg; 316 317 bn_correct_top(ret); 318 *bn = ret; 319 bn_check_top(ret); 320 return (num); 321 322 err: 323 if (*bn == NULL) 324 BN_free(ret); 325 return (0); 326 } 327 328 int 329 BN_asc2bn(BIGNUM **bn, const char *a) 330 { 331 const char *p = a; 332 if (*p == '-') 333 p++; 334 335 if (p[0] == '0' && (p[1] == 'X' || p[1] == 'x')) { 336 if (!BN_hex2bn(bn, p + 2)) 337 return 0; 338 } else { 339 if (!BN_dec2bn(bn, p)) 340 return 0; 341 } 342 if (*a == '-') 343 (*bn)->neg = 1; 344 return 1; 345 } 346 347 #ifndef OPENSSL_NO_BIO 348 int 349 BN_print_fp(FILE *fp, const BIGNUM *a) 350 { 351 BIO *b; 352 int ret; 353 354 if ((b = BIO_new(BIO_s_file())) == NULL) 355 return (0); 356 BIO_set_fp(b, fp, BIO_NOCLOSE); 357 ret = BN_print(b, a); 358 BIO_free(b); 359 return (ret); 360 } 361 362 int 363 BN_print(BIO *bp, const BIGNUM *a) 364 { 365 int i, j, v, z = 0; 366 int ret = 0; 367 368 if ((a->neg) && (BIO_write(bp, "-", 1) != 1)) 369 goto end; 370 if (BN_is_zero(a) && (BIO_write(bp, "0", 1) != 1)) 371 goto end; 372 for (i = a->top - 1; i >= 0; i--) { 373 for (j = BN_BITS2 - 4; j >= 0; j -= 4) { 374 /* strip leading zeros */ 375 v = ((int)(a->d[i] >> (long)j)) & 0x0f; 376 if (z || (v != 0)) { 377 if (BIO_write(bp, &(Hex[v]), 1) != 1) 378 goto end; 379 z = 1; 380 } 381 } 382 } 383 ret = 1; 384 385 end: 386 return (ret); 387 } 388 #endif 389 390 char * 391 BN_options(void) 392 { 393 static int init = 0; 394 static char data[16]; 395 396 if (!init) { 397 init++; 398 #ifdef BN_LLONG 399 snprintf(data,sizeof data, "bn(%d,%d)", 400 (int)sizeof(BN_ULLONG) * 8, (int)sizeof(BN_ULONG) * 8); 401 #else 402 snprintf(data,sizeof data, "bn(%d,%d)", 403 (int)sizeof(BN_ULONG) * 8, (int)sizeof(BN_ULONG) * 8); 404 #endif 405 } 406 return (data); 407 } 408