crypto/ec/ec_print.c

   1 /*
   2  * Copyright 2002-2018 The OpenSSL Project Authors. All Rights Reserved.
   3  *
   4  * Licensed under the Apache License 2.0 (the "License").  You may not use
   5  * this file except in compliance with the License.  You can obtain a copy
   6  * in the file LICENSE in the source distribution or at
   7  * https://www.openssl.org/source/license.html
   8  */
   9
  10 #include <openssl/crypto.h>
  11 #include <openssl/err.h>
  12 #include "ec_local.h"
  13
  14 BIGNUM *EC_POINT_point2bn(const EC_GROUP *group,
  15                           const EC_POINT *point,
  16                           point_conversion_form_t form,
  17                           BIGNUM *ret, BN_CTX *ctx)
  18 {
  19     size_t buf_len = 0;
  20     unsigned char *buf;
  21
  22     buf_len = EC_POINT_point2buf(group, point, form, &buf, ctx);
  23
  24     if (buf_len == 0)
  25         return NULL;
  26
  27     ret = BN_bin2bn(buf, buf_len, ret);
  28
  29     OPENSSL_free(buf);
  30
  31     return ret;
  32 }
  33
  34 EC_POINT *EC_POINT_bn2point(const EC_GROUP *group,
  35                             const BIGNUM *bn, EC_POINT *point, BN_CTX *ctx)
  36 {
  37     size_t buf_len = 0;
  38     unsigned char *buf;
  39     EC_POINT *ret;
  40
  41     if ((buf_len = BN_num_bytes(bn)) == 0)
  42         return NULL;
  43     if ((buf = OPENSSL_malloc(buf_len)) == NULL) {
  44         ECerr(EC_F_EC_POINT_BN2POINT, ERR_R_MALLOC_FAILURE);
  45         return NULL;
  46     }
  47
  48     if (!BN_bn2bin(bn, buf)) {
  49         OPENSSL_free(buf);
  50         return NULL;
  51     }
  52
  53     if (point == NULL) {
  54         if ((ret = EC_POINT_new(group)) == NULL) {
  55             OPENSSL_free(buf);
  56             return NULL;
  57         }
  58     } else
  59         ret = point;
  60
  61     if (!EC_POINT_oct2point(group, ret, buf, buf_len, ctx)) {
  62         if (ret != point)
  63             EC_POINT_clear_free(ret);
  64         OPENSSL_free(buf);
  65         return NULL;
  66     }
  67
  68     OPENSSL_free(buf);
  69     return ret;
  70 }
  71
  72 static const char *HEX_DIGITS = "0123456789ABCDEF";
  73
  74 /* the return value must be freed (using OPENSSL_free()) */
  75 char *EC_POINT_point2hex(const EC_GROUP *group,
  76                          const EC_POINT *point,
  77                          point_conversion_form_t form, BN_CTX *ctx)
  78 {
  79     char *ret, *p;
  80     size_t buf_len = 0, i;
  81     unsigned char *buf = NULL, *pbuf;
  82
  83     buf_len = EC_POINT_point2buf(group, point, form, &buf, ctx);
  84
  85     if (buf_len == 0)
  86         return NULL;
  87
  88     ret = OPENSSL_malloc(buf_len * 2 + 2);
  89     if (ret == NULL) {
  90         OPENSSL_free(buf);
  91         return NULL;
  92     }
  93     p = ret;
  94     pbuf = buf;
  95     for (i = buf_len; i > 0; i--) {
  96         int v = (int)*(pbuf++);
  97         *(p++) = HEX_DIGITS[v >> 4];
  98         *(p++) = HEX_DIGITS[v & 0x0F];
  99     }
 100     *p = '\0';
 101
 102     OPENSSL_free(buf);
 103
 104     return ret;
 105 }
 106
 107 EC_POINT *EC_POINT_hex2point(const EC_GROUP *group,
 108                              const char *buf, EC_POINT *point, BN_CTX *ctx)
 109 {
 110     EC_POINT *ret = NULL;
 111     BIGNUM *tmp_bn = NULL;
 112
 113     if (!BN_hex2bn(&tmp_bn, buf))
 114         return NULL;
 115
 116     ret = EC_POINT_bn2point(group, tmp_bn, point, ctx);
 117
 118     BN_clear_free(tmp_bn);
 119
 120     return ret;
 121 }