1 /*
2 * Copyright 2002-2024 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 <string.h> /* strlen */
11 #include <openssl/crypto.h>
12 #include "internal/cryptlib.h"
13 #include "ec_local.h"
14
15 /* the return value must be freed (using OPENSSL_free()) */
EC_POINT_point2hex(const EC_GROUP * group,const EC_POINT * point,point_conversion_form_t form,BN_CTX * ctx)16 char *EC_POINT_point2hex(const EC_GROUP *group,
17 const EC_POINT *point,
18 point_conversion_form_t form, BN_CTX *ctx)
19 {
20 char *ret, *p;
21 size_t buf_len, i;
22 unsigned char *buf = NULL;
23
24 buf_len = EC_POINT_point2buf(group, point, form, &buf, ctx);
25
26 if (buf_len == 0)
27 return NULL;
28
29 ret = OPENSSL_malloc(buf_len * 2 + 2);
30 if (ret == NULL)
31 goto err;
32
33 p = ret;
34 for (i = 0; i < buf_len; ++i)
35 p += ossl_to_hex(p, buf[i]);
36 *p = '\0';
37
38 err:
39 OPENSSL_free(buf);
40 return ret;
41 }
42
EC_POINT_hex2point(const EC_GROUP * group,const char * hex,EC_POINT * point,BN_CTX * ctx)43 EC_POINT *EC_POINT_hex2point(const EC_GROUP *group,
44 const char *hex, EC_POINT *point, BN_CTX *ctx)
45 {
46 int ok = 0;
47 unsigned char *oct_buf = NULL;
48 size_t len, oct_buf_len = 0;
49 EC_POINT *pt = NULL;
50
51 if (group == NULL || hex == NULL)
52 return NULL;
53
54 if (point == NULL) {
55 pt = EC_POINT_new(group);
56 if (pt == NULL)
57 goto err;
58 } else {
59 pt = point;
60 }
61
62 len = strlen(hex) / 2;
63 oct_buf = OPENSSL_malloc(len);
64 if (oct_buf == NULL)
65 goto err;
66
67 if (!OPENSSL_hexstr2buf_ex(oct_buf, len, &oct_buf_len, hex, '\0')
68 || !EC_POINT_oct2point(group, pt, oct_buf, oct_buf_len, ctx))
69 goto err;
70 ok = 1;
71 err:
72 OPENSSL_clear_free(oct_buf, oct_buf_len);
73 if (!ok) {
74 if (pt != point)
75 EC_POINT_clear_free(pt);
76 pt = NULL;
77 }
78 return pt;
79 }
80
