2 * Copyright 2007-2021 The OpenSSL Project Authors. All Rights Reserved.
4 * Licensed under the OpenSSL license (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
11 #include "internal/cryptlib.h"
12 #include <openssl/evp.h>
13 #include "crypto/asn1.h"
14 #include "crypto/evp.h"
17 * HMAC "ASN1" method. This is just here to indicate the maximum HMAC output
18 * length and to free up an HMAC key.
21 static int hmac_size(const EVP_PKEY *pkey)
23 return EVP_MAX_MD_SIZE;
26 static void hmac_key_free(EVP_PKEY *pkey)
28 ASN1_OCTET_STRING *os = EVP_PKEY_get0(pkey);
31 OPENSSL_cleanse(os->data, os->length);
32 ASN1_OCTET_STRING_free(os);
36 static int hmac_pkey_ctrl(EVP_PKEY *pkey, int op, long arg1, void *arg2)
39 case ASN1_PKEY_CTRL_DEFAULT_MD_NID:
40 *(int *)arg2 = NID_sha256;
48 static int hmac_pkey_public_cmp(const EVP_PKEY *a, const EVP_PKEY *b)
50 /* the ameth pub_cmp must return 1 on match, 0 on mismatch */
51 return ASN1_OCTET_STRING_cmp(EVP_PKEY_get0(a), EVP_PKEY_get0(b)) == 0;
54 static int hmac_set_priv_key(EVP_PKEY *pkey, const unsigned char *priv,
57 ASN1_OCTET_STRING *os;
59 if (pkey->pkey.ptr != NULL)
62 os = ASN1_OCTET_STRING_new();
67 if (!ASN1_OCTET_STRING_set(os, priv, len)) {
68 ASN1_OCTET_STRING_free(os);
76 static int hmac_get_priv_key(const EVP_PKEY *pkey, unsigned char *priv,
79 ASN1_OCTET_STRING *os = (ASN1_OCTET_STRING *)pkey->pkey.ptr;
82 *len = ASN1_STRING_length(os);
86 if (os == NULL || *len < (size_t)ASN1_STRING_length(os))
89 *len = ASN1_STRING_length(os);
90 memcpy(priv, ASN1_STRING_get0_data(os), *len);
95 const EVP_PKEY_ASN1_METHOD hmac_asn1_meth = {
101 "OpenSSL HMAC method",
103 0, 0, hmac_pkey_public_cmp, 0,