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