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
14BIGNUM *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
34EC_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 buf_len = 1;
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_bn2binpad(bn, buf, buf_len)) {
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
72static const char *HEX_DIGITS = "0123456789ABCDEF";
73
74/* the return value must be freed (using OPENSSL_free()) */
75char *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
107EC_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}
122