1 /*
2 * Copyright 2015-2021 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 /*
11 * ECDH low level APIs are deprecated for public use, but still ok for
12 * internal use.
13 */
14 #include "internal/deprecated.h"
15
16 #include <string.h>
17 #include <openssl/core_names.h>
18 #include <openssl/ec.h>
19 #include <openssl/evp.h>
20 #include <openssl/kdf.h>
21 #include "ec_local.h"
22
23 /* Key derivation function from X9.63/SECG */
ossl_ecdh_kdf_X9_63(unsigned char * out,size_t outlen,const unsigned char * Z,size_t Zlen,const unsigned char * sinfo,size_t sinfolen,const EVP_MD * md,OSSL_LIB_CTX * libctx,const char * propq)24 int ossl_ecdh_kdf_X9_63(unsigned char *out, size_t outlen,
25 const unsigned char *Z, size_t Zlen,
26 const unsigned char *sinfo, size_t sinfolen,
27 const EVP_MD *md,
28 OSSL_LIB_CTX *libctx, const char *propq)
29 {
30 int ret = 0;
31 EVP_KDF_CTX *kctx = NULL;
32 OSSL_PARAM params[4], *p = params;
33 const char *mdname = EVP_MD_get0_name(md);
34 EVP_KDF *kdf = EVP_KDF_fetch(libctx, OSSL_KDF_NAME_X963KDF, propq);
35
36 if ((kctx = EVP_KDF_CTX_new(kdf)) != NULL) {
37 *p++ = OSSL_PARAM_construct_utf8_string(OSSL_KDF_PARAM_DIGEST,
38 (char *)mdname, 0);
39 *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_KEY,
40 (void *)Z, Zlen);
41 *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_INFO,
42 (void *)sinfo, sinfolen);
43 *p = OSSL_PARAM_construct_end();
44
45 ret = EVP_KDF_derive(kctx, out, outlen, params) > 0;
46 EVP_KDF_CTX_free(kctx);
47 }
48 EVP_KDF_free(kdf);
49 return ret;
50 }
51
52 /*-
53 * The old name for ecdh_KDF_X9_63
54 * Retained for ABI compatibility
55 */
56 #ifndef OPENSSL_NO_DEPRECATED_3_0
ECDH_KDF_X9_62(unsigned char * out,size_t outlen,const unsigned char * Z,size_t Zlen,const unsigned char * sinfo,size_t sinfolen,const EVP_MD * md)57 int ECDH_KDF_X9_62(unsigned char *out, size_t outlen,
58 const unsigned char *Z, size_t Zlen,
59 const unsigned char *sinfo, size_t sinfolen,
60 const EVP_MD *md)
61 {
62 return ossl_ecdh_kdf_X9_63(out, outlen, Z, Zlen, sinfo, sinfolen, md, NULL,
63 NULL);
64 }
65 #endif
66