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 = 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 = OPENSSL_malloc((num / BN_DEC_NUM + 1) * sizeof(BN_ULONG));
 118     buf = OPENSSL_malloc(num + 3);
 119     if ((buf == NULL) || (bn_data == NULL)) {
 120         BNerr(BN_F_BN_BN2DEC, ERR_R_MALLOC_FAILURE);
 121         goto err;
 122     }
 123     if ((t = BN_dup(a)) == NULL)
 124         goto err;
 125
 126 #define BUF_REMAIN (num+3 - (size_t)(p - buf))
 127     p = buf;
 128     lp = bn_data;
 129     if (BN_is_zero(t)) {
 130         *(p++) = '0';
 131         *(p++) = '\0';
 132     } else {
 133         if (BN_is_negative(t))
 134             *p++ = '-';
 135
 136         i = 0;
 137         while (!BN_is_zero(t)) {
 138             *lp = BN_div_word(t, BN_DEC_CONV);
 139             lp++;
 140         }
 141         lp--;
 142         /*
 143          * We now have a series of blocks, BN_DEC_NUM chars in length, where
 144          * the last one needs truncation. The blocks need to be reversed in
 145          * order.
 146          */
 147         BIO_snprintf(p, BUF_REMAIN, BN_DEC_FMT1, *lp);
 148         while (*p)
 149             p++;
 150         while (lp != bn_data) {
 151             lp--;
 152             BIO_snprintf(p, BUF_REMAIN, BN_DEC_FMT2, *lp);
 153             while (*p)
 154                 p++;
 155         }
 156     }
 157     ok = 1;
 158  err:
 159     if (bn_data != NULL)
 160         OPENSSL_free(bn_data);
 161     BN_free(t);
 162     if (!ok && buf) {
 163         OPENSSL_free(buf);
 164         buf = NULL;
 165     }
 166
 167     return (buf);
 168 }
 169
 170 int BN_hex2bn(BIGNUM **bn, const char *a)
 171 {
 172     BIGNUM *ret = NULL;
 173     BN_ULONG l = 0;
 174     int neg = 0, h, m, i, j, k, c;
 175     int num;
 176
 177     if ((a == NULL) || (*a == '\0'))
 178         return (0);
 179
 180     if (*a == '-') {
 181         neg = 1;
 182         a++;
 183     }
 184
 185     for (i = 0; isxdigit((unsigned char)a[i]); i++) ;
 186
 187     num = i + neg;
 188     if (bn == NULL)
 189         return (num);
 190
 191     /* a is the start of the hex digits, and it is 'i' long */
 192     if (*bn == NULL) {
 193         if ((ret = BN_new()) == NULL)
 194             return (0);
 195     } else {
 196         ret = *bn;
 197         BN_zero(ret);
 198     }
 199
 200     /* i is the number of hex digests; */
 201     if (bn_expand(ret, i * 4) == NULL)
 202         goto err;
 203
 204     j = i;                      /* least significant 'hex' */
 205     m = 0;
 206     h = 0;
 207     while (j > 0) {
 208         m = ((BN_BYTES * 2) <= j) ? (BN_BYTES * 2) : j;
 209         l = 0;
 210         for (;;) {
 211             c = a[j - m];
 212             if ((c >= '0') && (c <= '9'))
 213                 k = c - '0';
 214             else if ((c >= 'a') && (c <= 'f'))
 215                 k = c - 'a' + 10;
 216             else if ((c >= 'A') && (c <= 'F'))
 217                 k = c - 'A' + 10;
 218             else
 219                 k = 0;          /* paranoia */
 220             l = (l << 4) | k;
 221
 222             if (--m <= 0) {
 223                 ret->d[h++] = l;
 224                 break;
 225             }
 226         }
 227         j -= (BN_BYTES * 2);
 228     }
 229     ret->top = h;
 230     bn_correct_top(ret);
 231     ret->neg = neg;
 232
 233     *bn = ret;
 234     bn_check_top(ret);
 235     return (num);
 236  err:
 237     if (*bn == NULL)
 238         BN_free(ret);
 239     return (0);
 240 }
 241
 242 int BN_dec2bn(BIGNUM **bn, const char *a)
 243 {
 244     BIGNUM *ret = NULL;
 245     BN_ULONG l = 0;
 246     int neg = 0, i, j;
 247     int num;
 248
 249     if ((a == NULL) || (*a == '\0'))
 250         return (0);
 251     if (*a == '-') {
 252         neg = 1;
 253         a++;
 254     }
 255
 256     for (i = 0; isdigit((unsigned char)a[i]); i++) ;
 257
 258     num = i + neg;
 259     if (bn == NULL)
 260         return (num);
 261
 262     /*
 263      * a is the start of the digits, and it is 'i' long. We chop it into
 264      * BN_DEC_NUM digits at a time
 265      */
 266     if (*bn == NULL) {
 267         if ((ret = BN_new()) == NULL)
 268             return (0);
 269     } else {
 270         ret = *bn;
 271         BN_zero(ret);
 272     }
 273
 274     /* i is the number of digests, a bit of an over expand; */
 275     if (bn_expand(ret, i * 4) == NULL)
 276         goto err;
 277
 278     j = BN_DEC_NUM - (i % BN_DEC_NUM);
 279     if (j == BN_DEC_NUM)
 280         j = 0;
 281     l = 0;
 282     while (*a) {
 283         l *= 10;
 284         l += *a - '0';
 285         a++;
 286         if (++j == BN_DEC_NUM) {
 287             BN_mul_word(ret, BN_DEC_CONV);
 288             BN_add_word(ret, l);
 289             l = 0;
 290             j = 0;
 291         }
 292     }
 293     ret->neg = neg;
 294
 295     bn_correct_top(ret);
 296     *bn = ret;
 297     bn_check_top(ret);
 298     return (num);
 299  err:
 300     if (*bn == NULL)
 301         BN_free(ret);
 302     return (0);
 303 }
 304
 305 int BN_asc2bn(BIGNUM **bn, const char *a)
 306 {
 307     const char *p = a;
 308     if (*p == '-')
 309         p++;
 310
 311     if (p[0] == '0' && (p[1] == 'X' || p[1] == 'x')) {
 312         if (!BN_hex2bn(bn, p + 2))
 313             return 0;
 314     } else {
 315         if (!BN_dec2bn(bn, p))
 316             return 0;
 317     }
 318     if (*a == '-')
 319         (*bn)->neg = 1;
 320     return 1;
 321 }
 322
 323 # ifndef OPENSSL_NO_STDIO
 324 int BN_print_fp(FILE *fp, const BIGNUM *a)
 325 {
 326     BIO *b;
 327     int ret;
 328
 329     if ((b = BIO_new(BIO_s_file())) == NULL)
 330         return (0);
 331     BIO_set_fp(b, fp, BIO_NOCLOSE);
 332     ret = BN_print(b, a);
 333     BIO_free(b);
 334     return (ret);
 335 }
 336 # endif
 337
 338 int BN_print(BIO *bp, const BIGNUM *a)
 339 {
 340     int i, j, v, z = 0;
 341     int ret = 0;
 342
 343     if ((a->neg) && (BIO_write(bp, "-", 1) != 1))
 344         goto end;
 345     if (BN_is_zero(a) && (BIO_write(bp, "0", 1) != 1))
 346         goto end;
 347     for (i = a->top - 1; i >= 0; i--) {
 348         for (j = BN_BITS2 - 4; j >= 0; j -= 4) {
 349             /* strip leading zeros */
 350             v = ((int)(a->d[i] >> (long)j)) & 0x0f;
 351             if (z || (v != 0)) {
 352                 if (BIO_write(bp, &(Hex[v]), 1) != 1)
 353                     goto end;
 354                 z = 1;
 355             }
 356         }
 357     }
 358     ret = 1;
 359  end:
 360     return (ret);
 361 }
 362
 363 char *BN_options(void)
 364 {
 365     static int init = 0;
 366     static char data[16];
 367
 368     if (!init) {
 369         init++;
 370 #ifdef BN_LLONG
 371         BIO_snprintf(data, sizeof data, "bn(%d,%d)",
 372                      (int)sizeof(BN_ULLONG) * 8, (int)sizeof(BN_ULONG) * 8);
 373 #else
 374         BIO_snprintf(data, sizeof data, "bn(%d,%d)",
 375                      (int)sizeof(BN_ULONG) * 8, (int)sizeof(BN_ULONG) * 8);
 376 #endif
 377     }
 378     return (data);
 379 }