/* $OpenBSD: ec_print.c,v 1.7 2014/12/03 19:53:20 deraadt Exp $ */

/* ====================================================================

 * Copyright (c) 1998-2002 The OpenSSL Project.  All rights reserved.

 *

 * 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 above 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 acknowledgment:

 *    "This product includes software developed by the OpenSSL Project

 *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"

 *

 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to

 *    endorse or promote products derived from this software without

 *    prior written permission. For written permission, please contact

 *    openssl-core@openssl.org.

 *

 * 5. Products derived from this software may not be called "OpenSSL"

 *    nor may "OpenSSL" appear in their names without prior written

 *    permission of the OpenSSL Project.

 *

 * 6. Redistributions of any form whatsoever must retain the following

 *    acknowledgment:

 *    "This product includes software developed by the OpenSSL Project

 *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"

 *

 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY

 * EXPRESSED 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 OpenSSL PROJECT OR

 * ITS 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.

 * ====================================================================

 *

 * This product includes cryptographic software written by Eric Young

 * (eay@cryptsoft.com).  This product includes software written by Tim

 * Hudson (tjh@cryptsoft.com).

 *

 */

#include <openssl/crypto.h>

#include "ec_lcl.h"

BIGNUM *

EC_POINT_point2bn(const EC_GROUP * group, const EC_POINT * point,

    point_conversion_form_t form, BIGNUM * ret, BN_CTX * ctx)

{

  size_t buf_len = 0;

  unsigned char *buf;

  buf_len = EC_POINT_point2oct(group, point, form,

      NULL, 0, ctx);

  if (buf_len == 0)

    return NULL;

  if ((buf = malloc(buf_len)) == NULL)

    return NULL;

  if (!EC_POINT_point2oct(group, point, form, buf, buf_len, ctx)) {

    free(buf);

    return NULL;

  }

  ret = BN_bin2bn(buf, buf_len, ret);

  free(buf);

  return ret;

}

EC_POINT *

EC_POINT_bn2point(const EC_GROUP * group,

    const BIGNUM * bn, EC_POINT * point, BN_CTX * ctx)

{

  size_t buf_len = 0;

  unsigned char *buf;

  EC_POINT *ret;

  if ((buf_len = BN_num_bytes(bn)) == 0)

    return NULL;

  buf = malloc(buf_len);

  if (buf == NULL)

    return NULL;

  if (!BN_bn2bin(bn, buf)) {

    free(buf);

    return NULL;

  }

  if (point == NULL) {

    if ((ret = EC_POINT_new(group)) == NULL) {

      free(buf);

      return NULL;

    }

  } else

    ret = point;

  if (!EC_POINT_oct2point(group, ret, buf, buf_len, ctx)) {

    if (point == NULL)

      EC_POINT_clear_free(ret);

    free(buf);

    return NULL;

  }

  free(buf);

  return ret;

}

static const char *HEX_DIGITS = "0123456789ABCDEF";

/* the return value must be freed (using free()) */

char *

EC_POINT_point2hex(const EC_GROUP * group, const EC_POINT * point,

    point_conversion_form_t form, BN_CTX * ctx)

{

  char *ret, *p;

  size_t buf_len = 0, i;

  unsigned char *buf, *pbuf;

  buf_len = EC_POINT_point2oct(group, point, form,

      NULL, 0, ctx);

  if (buf_len == 0 || buf_len + 1 == 0)

    return NULL;

  if ((buf = malloc(buf_len)) == NULL)

    return NULL;

  if (!EC_POINT_point2oct(group, point, form, buf, buf_len, ctx)) {

    free(buf);

    return NULL;

  }

  ret = reallocarray(NULL, buf_len + 1, 2);

  if (ret == NULL) {

    free(buf);

    return NULL;

  }

  p = ret;

  pbuf = buf;

  for (i = buf_len; i > 0; i--) {

    int v = (int) *(pbuf++);

    *(p++) = HEX_DIGITS[v >> 4];

    *(p++) = HEX_DIGITS[v & 0x0F];

  }

  *p = '\0';

  free(buf);

  return ret;

}

EC_POINT *

EC_POINT_hex2point(const EC_GROUP * group, const char *buf,

    EC_POINT * point, BN_CTX * ctx)

{

  EC_POINT *ret = NULL;

  BIGNUM *tmp_bn = NULL;

  if (!BN_hex2bn(&tmp_bn, buf))

    return NULL;

  ret = EC_POINT_bn2point(group, tmp_bn, point, ctx);

  BN_clear_free(tmp_bn);

  return ret;

}