1 /* $OpenBSD: bn_print.c,v 1.31 2017/01/29 17:49:22 beck 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 BNerror(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, bn_data_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 BNerror(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_num = num / BN_DEC_NUM + 1; 140 bn_data = reallocarray(NULL, bn_data_num, sizeof(BN_ULONG)); 141 buf = malloc(num + 3); 142 if ((buf == NULL) || (bn_data == NULL)) { 143 BNerror(ERR_R_MALLOC_FAILURE); 144 goto err; 145 } 146 if ((t = BN_dup(a)) == NULL) 147 goto err; 148 149 #define BUF_REMAIN (num+3 - (size_t)(p - buf)) 150 p = buf; 151 lp = bn_data; 152 if (BN_is_negative(t)) 153 *p++ = '-'; 154 155 while (!BN_is_zero(t)) { 156 if (lp - bn_data >= bn_data_num) 157 goto err; 158 *lp = BN_div_word(t, BN_DEC_CONV); 159 if (*lp == (BN_ULONG)-1) 160 goto err; 161 lp++; 162 } 163 lp--; 164 /* We now have a series of blocks, BN_DEC_NUM chars 165 * in length, where the last one needs truncation. 166 * The blocks need to be reversed in order. */ 167 snprintf(p, BUF_REMAIN, BN_DEC_FMT1, *lp); 168 while (*p) 169 p++; 170 while (lp != bn_data) { 171 lp--; 172 snprintf(p, BUF_REMAIN, BN_DEC_FMT2, *lp); 173 while (*p) 174 p++; 175 } 176 ok = 1; 177 178 err: 179 free(bn_data); 180 BN_free(t); 181 if (!ok && buf) { 182 free(buf); 183 buf = NULL; 184 } 185 186 return (buf); 187 } 188 189 int 190 BN_hex2bn(BIGNUM **bn, const char *a) 191 { 192 BIGNUM *ret = NULL; 193 BN_ULONG l = 0; 194 int neg = 0, h, m, i,j, k, c; 195 int num; 196 197 if ((a == NULL) || (*a == '\0')) 198 return (0); 199 200 if (*a == '-') { 201 neg = 1; 202 a++; 203 } 204 205 for (i = 0; i <= (INT_MAX / 4) && isxdigit((unsigned char)a[i]); i++) 206 ; 207 if (i > INT_MAX / 4) 208 goto err; 209 210 num = i + neg; 211 if (bn == NULL) 212 return (num); 213 214 /* a is the start of the hex digits, and it is 'i' long */ 215 if (*bn == NULL) { 216 if ((ret = BN_new()) == NULL) 217 return (0); 218 } else { 219 ret= *bn; 220 BN_zero(ret); 221 } 222 223 /* i is the number of hex digits */ 224 if (bn_expand(ret, i * 4) == NULL) 225 goto err; 226 227 j = i; /* least significant 'hex' */ 228 m = 0; 229 h = 0; 230 while (j > 0) { 231 m = ((BN_BYTES*2) <= j) ? (BN_BYTES * 2) : j; 232 l = 0; 233 for (;;) { 234 c = a[j - m]; 235 if ((c >= '0') && (c <= '9')) 236 k = c - '0'; 237 else if ((c >= 'a') && (c <= 'f')) 238 k = c - 'a' + 10; 239 else if ((c >= 'A') && (c <= 'F')) 240 k = c - 'A' + 10; 241 else 242 k = 0; /* paranoia */ 243 l = (l << 4) | k; 244 245 if (--m <= 0) { 246 ret->d[h++] = l; 247 break; 248 } 249 } 250 j -= (BN_BYTES * 2); 251 } 252 ret->top = h; 253 bn_correct_top(ret); 254 ret->neg = neg; 255 256 *bn = ret; 257 bn_check_top(ret); 258 return (num); 259 260 err: 261 if (*bn == NULL) 262 BN_free(ret); 263 return (0); 264 } 265 266 int 267 BN_dec2bn(BIGNUM **bn, const char *a) 268 { 269 BIGNUM *ret = NULL; 270 BN_ULONG l = 0; 271 int neg = 0, i, j; 272 int num; 273 274 if ((a == NULL) || (*a == '\0')) 275 return (0); 276 if (*a == '-') { 277 neg = 1; 278 a++; 279 } 280 281 for (i = 0; i <= (INT_MAX / 4) && isdigit((unsigned char)a[i]); i++) 282 ; 283 if (i > INT_MAX / 4) 284 goto err; 285 286 num = i + neg; 287 if (bn == NULL) 288 return (num); 289 290 /* a is the start of the digits, and it is 'i' long. 291 * We chop it into BN_DEC_NUM digits at a time */ 292 if (*bn == NULL) { 293 if ((ret = BN_new()) == NULL) 294 return (0); 295 } else { 296 ret = *bn; 297 BN_zero(ret); 298 } 299 300 /* i is the number of digits, a bit of an over expand */ 301 if (bn_expand(ret, i * 4) == NULL) 302 goto err; 303 304 j = BN_DEC_NUM - (i % BN_DEC_NUM); 305 if (j == BN_DEC_NUM) 306 j = 0; 307 l = 0; 308 while (*a) { 309 l *= 10; 310 l += *a - '0'; 311 a++; 312 if (++j == BN_DEC_NUM) { 313 BN_mul_word(ret, BN_DEC_CONV); 314 BN_add_word(ret, l); 315 l = 0; 316 j = 0; 317 } 318 } 319 ret->neg = neg; 320 321 bn_correct_top(ret); 322 *bn = ret; 323 bn_check_top(ret); 324 return (num); 325 326 err: 327 if (*bn == NULL) 328 BN_free(ret); 329 return (0); 330 } 331 332 int 333 BN_asc2bn(BIGNUM **bn, const char *a) 334 { 335 const char *p = a; 336 if (*p == '-') 337 p++; 338 339 if (p[0] == '0' && (p[1] == 'X' || p[1] == 'x')) { 340 if (!BN_hex2bn(bn, p + 2)) 341 return 0; 342 } else { 343 if (!BN_dec2bn(bn, p)) 344 return 0; 345 } 346 if (*a == '-') 347 (*bn)->neg = 1; 348 return 1; 349 } 350 351 #ifndef OPENSSL_NO_BIO 352 int 353 BN_print_fp(FILE *fp, const BIGNUM *a) 354 { 355 BIO *b; 356 int ret; 357 358 if ((b = BIO_new(BIO_s_file())) == NULL) 359 return (0); 360 BIO_set_fp(b, fp, BIO_NOCLOSE); 361 ret = BN_print(b, a); 362 BIO_free(b); 363 return (ret); 364 } 365 366 int 367 BN_print(BIO *bp, const BIGNUM *a) 368 { 369 int i, j, v, z = 0; 370 int ret = 0; 371 372 if ((a->neg) && (BIO_write(bp, "-", 1) != 1)) 373 goto end; 374 if (BN_is_zero(a) && (BIO_write(bp, "0", 1) != 1)) 375 goto end; 376 for (i = a->top - 1; i >= 0; i--) { 377 for (j = BN_BITS2 - 4; j >= 0; j -= 4) { 378 /* strip leading zeros */ 379 v = ((int)(a->d[i] >> (long)j)) & 0x0f; 380 if (z || (v != 0)) { 381 if (BIO_write(bp, &(Hex[v]), 1) != 1) 382 goto end; 383 z = 1; 384 } 385 } 386 } 387 ret = 1; 388 389 end: 390 return (ret); 391 } 392 #endif 393 394 char * 395 BN_options(void) 396 { 397 static int init = 0; 398 static char data[16]; 399 400 if (!init) { 401 init++; 402 #ifdef BN_LLONG 403 snprintf(data,sizeof data, "bn(%d,%d)", 404 (int)sizeof(BN_ULLONG) * 8, (int)sizeof(BN_ULONG) * 8); 405 #else 406 snprintf(data,sizeof data, "bn(%d,%d)", 407 (int)sizeof(BN_ULONG) * 8, (int)sizeof(BN_ULONG) * 8); 408 #endif 409 } 410 return (data); 411 } 412