/* crypto/bn/bn_print.c */

/* 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 <stdio.h>

#include <ctype.h>

#include <limits.h>

#include "cryptlib.h"

#include <openssl/buffer.h>

#include "bn_lcl.h"

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

/* Must 'OPENSSL_free' the returned data */

char *BN_bn2hex(const BIGNUM *a)

{

    int i, j, v, z = 0;

    char *buf;

    char *p;

    if (BN_is_zero(a))

        return OPENSSL_strdup("0");

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

    if (buf == NULL) {

        BNerr(BN_F_BN_BN2HEX, ERR_R_MALLOC_FAILURE);

        goto err;

    }

    p = buf;

    if (a->neg)

        *(p++) = '-';

    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 'OPENSSL_free' the returned data */

char *BN_bn2dec(const BIGNUM *a)

{

    int i = 0, num, ok = 0;

    char *buf = NULL;

    char *p;

    BIGNUM *t = NULL;

    BN_ULONG *bn_data = NULL, *lp;

    int bn_data_num;

    /*-

     * 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 = OPENSSL_malloc(bn_data_num * sizeof(BN_ULONG));

    buf = OPENSSL_malloc(num + 3);

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

        BNerr(BN_F_BN_BN2DEC, 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_zero(t)) {

        *(p++) = '0';

        *(p++) = '\0';

    } else {

        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.

         */

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

        while (*p)

            p++;

        while (lp != bn_data) {

            lp--;

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

            while (*p)

                p++;

        }

    }

    ok = 1;

 err:

    if (bn_data != NULL)

        OPENSSL_free(bn_data);

    if (t != NULL)

        BN_free(t);

    if (!ok && buf) {

        OPENSSL_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++)

        continue;

    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);

    *bn = ret;

    bn_check_top(ret);

    /* Don't set the negative flag if it's zero. */

    if (ret->top != 0)

        ret->neg = neg;

    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++)

        continue;

    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 (--i >= 0) {

        l *= 10;

        l += *a - '0';

        a++;

        if (++j == BN_DEC_NUM) {

            BN_mul_word(ret, BN_DEC_CONV);

            BN_add_word(ret, l);

            l = 0;

            j = 0;

        }

    }

    bn_correct_top(ret);

    *bn = ret;

    bn_check_top(ret);

    /* Don't set the negative flag if it's zero. */

    if (ret->top != 0)

        ret->neg = neg;

    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;

    }

    /* Don't set the negative flag if it's zero. */

    if (*a == '-' && (*bn)->top != 0)

        (*bn)->neg = 1;

    return 1;

}

#ifndef OPENSSL_NO_BIO

# ifndef OPENSSL_NO_FP_API

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);

}

# endif

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

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

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

#else

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

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

#endif

    }

    return (data);

}