lib/libcrypto/ec/ec_print.c

   1 /* $OpenBSD: ec_print.c,v 1.7 2014/12/03 19:53:20 deraadt Exp $ */
   2 /* ====================================================================
   3  * Copyright (c) 1998-2002 The OpenSSL Project.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  *
   9  * 1. Redistributions of source code must retain the above copyright
  10  *    notice, this list of conditions and the following disclaimer.
  11  *
  12  * 2. Redistributions in binary form must reproduce the above copyright
  13  *    notice, this list of conditions and the following disclaimer in
  14  *    the documentation and/or other materials provided with the
  15  *    distribution.
  16  *
  17  * 3. All advertising materials mentioning features or use of this
  18  *    software must display the following acknowledgment:
  19  *    "This product includes software developed by the OpenSSL Project
  20  *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
  21  *
  22  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
  23  *    endorse or promote products derived from this software without
  24  *    prior written permission. For written permission, please contact
  25  *    openssl-core@openssl.org.
  26  *
  27  * 5. Products derived from this software may not be called "OpenSSL"
  28  *    nor may "OpenSSL" appear in their names without prior written
  29  *    permission of the OpenSSL Project.
  30  *
  31  * 6. Redistributions of any form whatsoever must retain the following
  32  *    acknowledgment:
  33  *    "This product includes software developed by the OpenSSL Project
  34  *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
  35  *
  36  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
  37  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  38  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  39  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
  40  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  41  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  42  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  43  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  44  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
  45  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  46  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
  47  * OF THE POSSIBILITY OF SUCH DAMAGE.
  48  * ====================================================================
  49  *
  50  * This product includes cryptographic software written by Eric Young
  51  * (eay@cryptsoft.com).  This product includes software written by Tim
  52  * Hudson (tjh@cryptsoft.com).
  53  *
  54  */
  55
  56 #include <openssl/crypto.h>
  57 #include "ec_lcl.h"
  58
  59 BIGNUM *
  60 EC_POINT_point2bn(const EC_GROUP * group, const EC_POINT * point,
  61     point_conversion_form_t form, BIGNUM * ret, BN_CTX * ctx)
  62 {
  63         size_t buf_len = 0;
  64         unsigned char *buf;
  65
  66         buf_len = EC_POINT_point2oct(group, point, form,
  67             NULL, 0, ctx);
  68         if (buf_len == 0)
  69                 return NULL;
  70
  71         if ((buf = malloc(buf_len)) == NULL)
  72                 return NULL;
  73
  74         if (!EC_POINT_point2oct(group, point, form, buf, buf_len, ctx)) {
  75                 free(buf);
  76                 return NULL;
  77         }
  78         ret = BN_bin2bn(buf, buf_len, ret);
  79
  80         free(buf);
  81
  82         return ret;
  83 }
  84
  85 EC_POINT *
  86 EC_POINT_bn2point(const EC_GROUP * group,
  87     const BIGNUM * bn, EC_POINT * point, BN_CTX * ctx)
  88 {
  89         size_t buf_len = 0;
  90         unsigned char *buf;
  91         EC_POINT *ret;
  92
  93         if ((buf_len = BN_num_bytes(bn)) == 0)
  94                 return NULL;
  95         buf = malloc(buf_len);
  96         if (buf == NULL)
  97                 return NULL;
  98
  99         if (!BN_bn2bin(bn, buf)) {
 100                 free(buf);
 101                 return NULL;
 102         }
 103         if (point == NULL) {
 104                 if ((ret = EC_POINT_new(group)) == NULL) {
 105                         free(buf);
 106                         return NULL;
 107                 }
 108         } else
 109                 ret = point;
 110
 111         if (!EC_POINT_oct2point(group, ret, buf, buf_len, ctx)) {
 112                 if (point == NULL)
 113                         EC_POINT_clear_free(ret);
 114                 free(buf);
 115                 return NULL;
 116         }
 117         free(buf);
 118         return ret;
 119 }
 120
 121 static const char *HEX_DIGITS = "0123456789ABCDEF";
 122
 123 /* the return value must be freed (using free()) */
 124 char *
 125 EC_POINT_point2hex(const EC_GROUP * group, const EC_POINT * point,
 126     point_conversion_form_t form, BN_CTX * ctx)
 127 {
 128         char *ret, *p;
 129         size_t buf_len = 0, i;
 130         unsigned char *buf, *pbuf;
 131
 132         buf_len = EC_POINT_point2oct(group, point, form,
 133             NULL, 0, ctx);
 134         if (buf_len == 0 || buf_len + 1 == 0)
 135                 return NULL;
 136
 137         if ((buf = malloc(buf_len)) == NULL)
 138                 return NULL;
 139
 140         if (!EC_POINT_point2oct(group, point, form, buf, buf_len, ctx)) {
 141                 free(buf);
 142                 return NULL;
 143         }
 144         ret = reallocarray(NULL, buf_len + 1, 2);
 145         if (ret == NULL) {
 146                 free(buf);
 147                 return NULL;
 148         }
 149         p = ret;
 150         pbuf = buf;
 151         for (i = buf_len; i > 0; i--) {
 152                 int v = (int) *(pbuf++);
 153                 *(p++) = HEX_DIGITS[v >> 4];
 154                 *(p++) = HEX_DIGITS[v & 0x0F];
 155         }
 156         *p = '\0';
 157
 158         free(buf);
 159
 160         return ret;
 161 }
 162
 163 EC_POINT *
 164 EC_POINT_hex2point(const EC_GROUP * group, const char *buf,
 165     EC_POINT * point, BN_CTX * ctx)
 166 {
 167         EC_POINT *ret = NULL;
 168         BIGNUM *tmp_bn = NULL;
 169
 170         if (!BN_hex2bn(&tmp_bn, buf))
 171                 return NULL;
 172
 173         ret = EC_POINT_bn2point(group, tmp_bn, point, ctx);
 174
 175         BN_clear_free(tmp_bn);
 176
 177         return ret;
 178 }