crypto/bn/bn_print.c

   1 /* crypto/bn/bn_print.c */
   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 <stdio.h>
  60 #include <ctype.h>
  61 #include "cryptlib.h"
  62 #include <openssl/buffer.h>
  63 #include "bn_lcl.h"
  64
  65 static const char Hex[] = "0123456789ABCDEF";
  66
  67 /* Must 'OPENSSL_free' the returned data */
  68 char *BN_bn2hex(const BIGNUM *a)
  69 {
  70     int i, j, v, z = 0;
  71     char *buf;
  72     char *p;
  73
  74     buf = (char *)OPENSSL_malloc(a->top * BN_BYTES * 2 + 2);
  75     if (buf == NULL) {
  76         BNerr(BN_F_BN_BN2HEX, ERR_R_MALLOC_FAILURE);
  77         goto err;
  78     }
  79     p = buf;
  80     if (a->neg)
  81         *(p++) = '-';
  82     if (BN_is_zero(a))
  83         *(p++) = '0';
  84     for (i = a->top - 1; i >= 0; i--) {
  85         for (j = BN_BITS2 - 8; j >= 0; j -= 8) {
  86             /* strip leading zeros */
  87             v = ((int)(a->d[i] >> (long)j)) & 0xff;
  88             if (z || (v != 0)) {
  89                 *(p++) = Hex[v >> 4];
  90                 *(p++) = Hex[v & 0x0f];
  91                 z = 1;
  92             }
  93         }
  94     }
  95     *p = '\0';
  96  err:
  97     return (buf);
  98 }
  99
 100 /* Must 'OPENSSL_free' the returned data */
 101 char *BN_bn2dec(const BIGNUM *a)
 102 {
 103     int i = 0, num, ok = 0;
 104     char *buf = NULL;
 105     char *p;
 106     BIGNUM *t = NULL;
 107     BN_ULONG *bn_data = NULL, *lp;
 108
 109         /*-
 110          * get an upper bound for the length of the decimal integer
 111          * num <= (BN_num_bits(a) + 1) * log(2)
 112          *     <= 3 * BN_num_bits(a) * 0.1001 + log(2) + 1     (rounding error)
 113          *     <= BN_num_bits(a)/10 + BN_num_bits/1000 + 1 + 1
 114          */
 115     i = BN_num_bits(a) * 3;
 116     num = (i / 10 + i / 1000 + 1) + 1;
 117     bn_data =
 118         (BN_ULONG *)OPENSSL_malloc((num / BN_DEC_NUM + 1) * sizeof(BN_ULONG));
 119     buf = (char *)OPENSSL_malloc(num + 3);
 120     if ((buf == NULL) || (bn_data == NULL)) {
 121         BNerr(BN_F_BN_BN2DEC, ERR_R_MALLOC_FAILURE);
 122         goto err;
 123     }
 124     if ((t = BN_dup(a)) == NULL)
 125         goto err;
 126
 127 #define BUF_REMAIN (num+3 - (size_t)(p - buf))
 128     p = buf;
 129     lp = bn_data;
 130     if (BN_is_zero(t)) {
 131         *(p++) = '0';
 132         *(p++) = '\0';
 133     } else {
 134         if (BN_is_negative(t))
 135             *p++ = '-';
 136
 137         i = 0;
 138         while (!BN_is_zero(t)) {
 139             *lp = BN_div_word(t, BN_DEC_CONV);
 140             lp++;
 141         }
 142         lp--;
 143         /*
 144          * We now have a series of blocks, BN_DEC_NUM chars in length, where
 145          * the last one needs truncation. The blocks need to be reversed in
 146          * order.
 147          */
 148         BIO_snprintf(p, BUF_REMAIN, BN_DEC_FMT1, *lp);
 149         while (*p)
 150             p++;
 151         while (lp != bn_data) {
 152             lp--;
 153             BIO_snprintf(p, BUF_REMAIN, BN_DEC_FMT2, *lp);
 154             while (*p)
 155                 p++;
 156         }
 157     }
 158     ok = 1;
 159  err:
 160     if (bn_data != NULL)
 161         OPENSSL_free(bn_data);
 162     if (t != NULL)
 163         BN_free(t);
 164     if (!ok && buf) {
 165         OPENSSL_free(buf);
 166         buf = NULL;
 167     }
 168
 169     return (buf);
 170 }
 171
 172 int BN_hex2bn(BIGNUM **bn, const char *a)
 173 {
 174     BIGNUM *ret = NULL;
 175     BN_ULONG l = 0;
 176     int neg = 0, h, m, i, j, k, c;
 177     int num;
 178
 179     if ((a == NULL) || (*a == '\0'))
 180         return (0);
 181
 182     if (*a == '-') {
 183         neg = 1;
 184         a++;
 185     }
 186
 187     for (i = 0; isxdigit((unsigned char)a[i]); i++) ;
 188
 189     num = i + neg;
 190     if (bn == NULL)
 191         return (num);
 192
 193     /* a is the start of the hex digits, and it is 'i' long */
 194     if (*bn == NULL) {
 195         if ((ret = BN_new()) == NULL)
 196             return (0);
 197     } else {
 198         ret = *bn;
 199         BN_zero(ret);
 200     }
 201
 202     /* i is the number of hex digests; */
 203     if (bn_expand(ret, i * 4) == NULL)
 204         goto err;
 205
 206     j = i;                      /* least significant 'hex' */
 207     m = 0;
 208     h = 0;
 209     while (j > 0) {
 210         m = ((BN_BYTES * 2) <= j) ? (BN_BYTES * 2) : j;
 211         l = 0;
 212         for (;;) {
 213             c = a[j - m];
 214             if ((c >= '0') && (c <= '9'))
 215                 k = c - '0';
 216             else if ((c >= 'a') && (c <= 'f'))
 217                 k = c - 'a' + 10;
 218             else if ((c >= 'A') && (c <= 'F'))
 219                 k = c - 'A' + 10;
 220             else
 221                 k = 0;          /* paranoia */
 222             l = (l << 4) | k;
 223
 224             if (--m <= 0) {
 225                 ret->d[h++] = l;
 226                 break;
 227             }
 228         }
 229         j -= (BN_BYTES * 2);
 230     }
 231     ret->top = h;
 232     bn_correct_top(ret);
 233     ret->neg = neg;
 234
 235     *bn = ret;
 236     bn_check_top(ret);
 237     return (num);
 238  err:
 239     if (*bn == NULL)
 240         BN_free(ret);
 241     return (0);
 242 }
 243
 244 int BN_dec2bn(BIGNUM **bn, const char *a)
 245 {
 246     BIGNUM *ret = NULL;
 247     BN_ULONG l = 0;
 248     int neg = 0, i, j;
 249     int num;
 250
 251     if ((a == NULL) || (*a == '\0'))
 252         return (0);
 253     if (*a == '-') {
 254         neg = 1;
 255         a++;
 256     }
 257
 258     for (i = 0; isdigit((unsigned char)a[i]); i++) ;
 259
 260     num = i + neg;
 261     if (bn == NULL)
 262         return (num);
 263
 264     /*
 265      * a is the start of the digits, and it is 'i' long. We chop it into
 266      * BN_DEC_NUM digits at a time
 267      */
 268     if (*bn == NULL) {
 269         if ((ret = BN_new()) == NULL)
 270             return (0);
 271     } else {
 272         ret = *bn;
 273         BN_zero(ret);
 274     }
 275
 276     /* i is the number of digests, a bit of an over expand; */
 277     if (bn_expand(ret, i * 4) == NULL)
 278         goto err;
 279
 280     j = BN_DEC_NUM - (i % BN_DEC_NUM);
 281     if (j == BN_DEC_NUM)
 282         j = 0;
 283     l = 0;
 284     while (*a) {
 285         l *= 10;
 286         l += *a - '0';
 287         a++;
 288         if (++j == BN_DEC_NUM) {
 289             BN_mul_word(ret, BN_DEC_CONV);
 290             BN_add_word(ret, l);
 291             l = 0;
 292             j = 0;
 293         }
 294     }
 295     ret->neg = neg;
 296
 297     bn_correct_top(ret);
 298     *bn = ret;
 299     bn_check_top(ret);
 300     return (num);
 301  err:
 302     if (*bn == NULL)
 303         BN_free(ret);
 304     return (0);
 305 }
 306
 307 int BN_asc2bn(BIGNUM **bn, const char *a)
 308 {
 309     const char *p = a;
 310     if (*p == '-')
 311         p++;
 312
 313     if (p[0] == '0' && (p[1] == 'X' || p[1] == 'x')) {
 314         if (!BN_hex2bn(bn, p + 2))
 315             return 0;
 316     } else {
 317         if (!BN_dec2bn(bn, p))
 318             return 0;
 319     }
 320     if (*a == '-')
 321         (*bn)->neg = 1;
 322     return 1;
 323 }
 324
 325 #ifndef OPENSSL_NO_BIO
 326 # ifndef OPENSSL_NO_FP_API
 327 int BN_print_fp(FILE *fp, const BIGNUM *a)
 328 {
 329     BIO *b;
 330     int ret;
 331
 332     if ((b = BIO_new(BIO_s_file())) == NULL)
 333         return (0);
 334     BIO_set_fp(b, fp, BIO_NOCLOSE);
 335     ret = BN_print(b, a);
 336     BIO_free(b);
 337     return (ret);
 338 }
 339 # endif
 340
 341 int BN_print(BIO *bp, const BIGNUM *a)
 342 {
 343     int i, j, v, z = 0;
 344     int ret = 0;
 345
 346     if ((a->neg) && (BIO_write(bp, "-", 1) != 1))
 347         goto end;
 348     if (BN_is_zero(a) && (BIO_write(bp, "0", 1) != 1))
 349         goto end;
 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, &(Hex[v]), 1) != 1)
 356                     goto end;
 357                 z = 1;
 358             }
 359         }
 360     }
 361     ret = 1;
 362  end:
 363     return (ret);
 364 }
 365 #endif
 366
 367 char *BN_options(void)
 368 {
 369     static int init = 0;
 370     static char data[16];
 371
 372     if (!init) {
 373         init++;
 374 #ifdef BN_LLONG
 375         BIO_snprintf(data, sizeof data, "bn(%d,%d)",
 376                      (int)sizeof(BN_ULLONG) * 8, (int)sizeof(BN_ULONG) * 8);
 377 #else
 378         BIO_snprintf(data, sizeof data, "bn(%d,%d)",
 379                      (int)sizeof(BN_ULONG) * 8, (int)sizeof(BN_ULONG) * 8);
 380 #endif
 381     }
 382     return (data);
 383 }