/* $OpenBSD: bn_print.c,v 1.33 2022/01/20 10:53:33 inoguchi Exp $ */

/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)

 * All rights reserved.

 *

 * This package is an SSL implementation written

 * by Eric Young (eay@cryptsoft.com).

 * The implementation was written so as to conform with Netscapes SSL.

 *

 * This library is free for commercial and non-commercial use as long as

 * the following conditions are aheared to.  The following conditions

 * apply to all code found in this distribution, be it the RC4, RSA,

 * lhash, DES, etc., code; not just the SSL code.  The SSL documentation

 * included with this distribution is covered by the same copyright terms

 * except that the holder is Tim Hudson (tjh@cryptsoft.com).

 *

 * Copyright remains Eric Young's, and as such any Copyright notices in

 * the code are not to be removed.

 * If this package is used in a product, Eric Young should be given attribution

 * as the author of the parts of the library used.

 * This can be in the form of a textual message at program startup or

 * in documentation (online or textual) provided with the package.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 * 1. Redistributions of source code must retain the copyright

 *    notice, this list of conditions and the following disclaimer.

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in the

 *    documentation and/or other materials provided with the distribution.

 * 3. All advertising materials mentioning features or use of this software

 *    must display the following acknowledgement:

 *    "This product includes cryptographic software written by

 *     Eric Young (eay@cryptsoft.com)"

 *    The word 'cryptographic' can be left out if the rouines from the library

 *    being used are not cryptographic related :-).

 * 4. If you include any Windows specific code (or a derivative thereof) from

 *    the apps directory (application code) you must include an acknowledgement:

 *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"

 *

 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND

 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE

 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL

 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS

 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)

 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT

 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY

 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF

 * SUCH DAMAGE.

 *

 * The licence and distribution terms for any publically available version or

 * derivative of this code cannot be changed.  i.e. this code cannot simply be

 * copied and put under another distribution licence

 * [including the GNU Public Licence.]

 */

#include <ctype.h>

#include <limits.h>

#include <stdio.h>

#include <openssl/opensslconf.h>

#include <openssl/bio.h>

#include <openssl/buffer.h>

#include <openssl/err.h>

#include "bn_lcl.h"

static const char Hex[]="0123456789ABCDEF";

/* Must 'free' the returned data */

char *

BN_bn2hex(const BIGNUM *a)

{

  int i, j, v, z = 0;

  char *buf;

  char *p;

  buf = malloc(BN_is_negative(a) + a->top * BN_BYTES * 2 + 2);

  if (buf == NULL) {

    BNerror(ERR_R_MALLOC_FAILURE);

    goto err;

  }

  p = buf;

  if (BN_is_negative(a))

    *p++ = '-';

  if (BN_is_zero(a))

    *p++ = '0';

  for (i = a->top - 1; i >=0; i--) {

    for (j = BN_BITS2 - 8; j >= 0; j -= 8) {

      /* strip leading zeros */

      v = ((int)(a->d[i] >> (long)j)) & 0xff;

      if (z || (v != 0)) {

        *p++ = Hex[v >> 4];

        *p++ = Hex[v & 0x0f];

        z = 1;

      }

    }

  }

  *p = '\0';

err:

  return (buf);

}

/* Must 'free' the returned data */

char *

BN_bn2dec(const BIGNUM *a)

{

  int i = 0, num, bn_data_num, ok = 0;

  char *buf = NULL;

  char *p;

  BIGNUM *t = NULL;

  BN_ULONG *bn_data = NULL, *lp;

  if (BN_is_zero(a)) {

    buf = malloc(BN_is_negative(a) + 2);

    if (buf == NULL) {

      BNerror(ERR_R_MALLOC_FAILURE);

      goto err;

    }

    p = buf;

    if (BN_is_negative(a))

      *p++ = '-';

    *p++ = '0';

    *p++ = '\0';

    return (buf);

  }

  /* get an upper bound for the length of the decimal integer

   * num <= (BN_num_bits(a) + 1) * log(2)

   *     <= 3 * BN_num_bits(a) * 0.1001 + log(2) + 1     (rounding error)

   *     <= BN_num_bits(a)/10 + BN_num_bits/1000 + 1 + 1

   */

  i = BN_num_bits(a) * 3;

  num = (i / 10 + i / 1000 + 1) + 1;

  bn_data_num = num / BN_DEC_NUM + 1;

  bn_data = reallocarray(NULL, bn_data_num, sizeof(BN_ULONG));

  buf = malloc(num + 3);

  if ((buf == NULL) || (bn_data == NULL)) {

    BNerror(ERR_R_MALLOC_FAILURE);

    goto err;

  }

  if ((t = BN_dup(a)) == NULL)

    goto err;

#define BUF_REMAIN (num+3 - (size_t)(p - buf))

  p = buf;

  lp = bn_data;

  if (BN_is_negative(t))

    *p++ = '-';

  while (!BN_is_zero(t)) {

    if (lp - bn_data >= bn_data_num)

      goto err;

    *lp = BN_div_word(t, BN_DEC_CONV);

    if (*lp == (BN_ULONG)-1)

      goto err;

    lp++;

  }

  lp--;

  /* We now have a series of blocks, BN_DEC_NUM chars

   * in length, where the last one needs truncation.

   * The blocks need to be reversed in order. */

  snprintf(p, BUF_REMAIN, BN_DEC_FMT1, *lp);

  while (*p)

    p++;

  while (lp != bn_data) {

    lp--;

    snprintf(p, BUF_REMAIN, BN_DEC_FMT2, *lp);

    while (*p)

      p++;

  }

  ok = 1;

err:

  free(bn_data);

  BN_free(t);

  if (!ok && buf) {

    free(buf);

    buf = NULL;

  }

  return (buf);

}

int

BN_hex2bn(BIGNUM **bn, const char *a)

{

  BIGNUM *ret = NULL;

  BN_ULONG l = 0;

  int neg = 0, h, m, i,j, k, c;

  int num;

  if ((a == NULL) || (*a == '\0'))

    return (0);

  if (*a == '-') {

    neg = 1;

    a++;

  }

  for (i = 0; i <= (INT_MAX / 4) && isxdigit((unsigned char)a[i]); i++)

    ;

  if (i > INT_MAX / 4)

    goto err;

  num = i + neg;

  if (bn == NULL)

    return (num);

  /* a is the start of the hex digits, and it is 'i' long */

  if (*bn == NULL) {

    if ((ret = BN_new()) == NULL)

      return (0);

  } else {

    ret = *bn;

    BN_zero(ret);

  }

  /* i is the number of hex digits */

  if (bn_expand(ret, i * 4) == NULL)

    goto err;

  j = i; /* least significant 'hex' */

  m = 0;

  h = 0;

  while (j > 0) {

    m = ((BN_BYTES * 2) <= j) ? (BN_BYTES * 2) : j;

    l = 0;

    for (;;) {

      c = a[j - m];

      if ((c >= '0') && (c <= '9'))

        k = c - '0';

      else if ((c >= 'a') && (c <= 'f'))

        k = c - 'a' + 10;

      else if ((c >= 'A') && (c <= 'F'))

        k = c - 'A' + 10;

      else

        k = 0; /* paranoia */

      l = (l << 4) | k;

      if (--m <= 0) {

        ret->d[h++] = l;

        break;

      }

    }

    j -= (BN_BYTES * 2);

  }

  ret->top = h;

  bn_correct_top(ret);

  ret->neg = neg;

  *bn = ret;

  bn_check_top(ret);

  return (num);

err:

  if (*bn == NULL)

    BN_free(ret);

  return (0);

}

int

BN_dec2bn(BIGNUM **bn, const char *a)

{

  BIGNUM *ret = NULL;

  BN_ULONG l = 0;

  int neg = 0, i, j;

  int num;

  if ((a == NULL) || (*a == '\0'))

    return (0);

  if (*a == '-') {

    neg = 1;

    a++;

  }

  for (i = 0; i <= (INT_MAX / 4) && isdigit((unsigned char)a[i]); i++)

    ;

  if (i > INT_MAX / 4)

    goto err;

  num = i + neg;

  if (bn == NULL)

    return (num);

  /* a is the start of the digits, and it is 'i' long.

   * We chop it into BN_DEC_NUM digits at a time */

  if (*bn == NULL) {

    if ((ret = BN_new()) == NULL)

      return (0);

  } else {

    ret = *bn;

    BN_zero(ret);

  }

  /* i is the number of digits, a bit of an over expand */

  if (bn_expand(ret, i * 4) == NULL)

    goto err;

  j = BN_DEC_NUM - (i % BN_DEC_NUM);

  if (j == BN_DEC_NUM)

    j = 0;

  l = 0;

  while (*a) {

    l *= 10;

    l += *a - '0';

    a++;

    if (++j == BN_DEC_NUM) {

      if (!BN_mul_word(ret, BN_DEC_CONV))

        goto err;

      if (!BN_add_word(ret, l))

        goto err;

      l = 0;

      j = 0;

    }

  }

  ret->neg = neg;

  bn_correct_top(ret);

  *bn = ret;

  bn_check_top(ret);

  return (num);

err:

  if (*bn == NULL)

    BN_free(ret);

  return (0);

}

int

BN_asc2bn(BIGNUM **bn, const char *a)

{

  const char *p = a;

  if (*p == '-')

    p++;

  if (p[0] == '0' && (p[1] == 'X' || p[1] == 'x')) {

    if (!BN_hex2bn(bn, p + 2))

      return 0;

  } else {

    if (!BN_dec2bn(bn, p))

      return 0;

  }

  if (*a == '-')

    (*bn)->neg = 1;

  return 1;

}

#ifndef OPENSSL_NO_BIO

int

BN_print_fp(FILE *fp, const BIGNUM *a)

{

  BIO *b;

  int ret;

  if ((b = BIO_new(BIO_s_file())) == NULL)

    return (0);

  BIO_set_fp(b, fp, BIO_NOCLOSE);

  ret = BN_print(b, a);

  BIO_free(b);

  return (ret);

}

int

BN_print(BIO *bp, const BIGNUM *a)

{

  int i, j, v, z = 0;

  int ret = 0;

  if ((a->neg) && (BIO_write(bp, "-", 1) != 1))

    goto end;

  if (BN_is_zero(a) && (BIO_write(bp, "0", 1) != 1))

    goto end;

  for (i = a->top - 1; i >= 0; i--) {

    for (j = BN_BITS2 - 4; j >= 0; j -= 4) {

      /* strip leading zeros */

      v = ((int)(a->d[i] >> (long)j)) & 0x0f;

      if (z || (v != 0)) {

        if (BIO_write(bp, &(Hex[v]), 1) != 1)

          goto end;

        z = 1;

      }

    }

  }

  ret = 1;

end:

  return (ret);

}

#endif

char *

BN_options(void)

{

  static int init = 0;

  static char data[16];

  if (!init) {

    init++;

#ifdef BN_LLONG

    snprintf(data,sizeof data, "bn(%d,%d)",

        (int)sizeof(BN_ULLONG) * 8, (int)sizeof(BN_ULONG) * 8);

#else

    snprintf(data,sizeof data, "bn(%d,%d)",

        (int)sizeof(BN_ULONG) * 8, (int)sizeof(BN_ULONG) * 8);

#endif

  }

  return (data);

}