openssl/crypto/hmac/hm_ameth.c

129 lines
2.6 KiB
C

/*
* Copyright 2007-2021 The OpenSSL Project Authors. All Rights Reserved.
*
* Licensed under the OpenSSL license (the "License"). You may not use
* this file except in compliance with the License. You can obtain a copy
* in the file LICENSE in the source distribution or at
* https://www.openssl.org/source/license.html
*/
#include <stdio.h>
#include "internal/cryptlib.h"
#include <openssl/evp.h>
#include "crypto/asn1.h"
#include "crypto/evp.h"
/*
* HMAC "ASN1" method. This is just here to indicate the maximum HMAC output
* length and to free up an HMAC key.
*/
static int hmac_size(const EVP_PKEY *pkey)
{
return EVP_MAX_MD_SIZE;
}
static void hmac_key_free(EVP_PKEY *pkey)
{
ASN1_OCTET_STRING *os = EVP_PKEY_get0(pkey);
if (os) {
if (os->data)
OPENSSL_cleanse(os->data, os->length);
ASN1_OCTET_STRING_free(os);
}
}
static int hmac_pkey_ctrl(EVP_PKEY *pkey, int op, long arg1, void *arg2)
{
switch (op) {
case ASN1_PKEY_CTRL_DEFAULT_MD_NID:
*(int *)arg2 = NID_sha256;
return 1;
default:
return -2;
}
}
static int hmac_pkey_public_cmp(const EVP_PKEY *a, const EVP_PKEY *b)
{
/* the ameth pub_cmp must return 1 on match, 0 on mismatch */
return ASN1_OCTET_STRING_cmp(EVP_PKEY_get0(a), EVP_PKEY_get0(b)) == 0;
}
static int hmac_set_priv_key(EVP_PKEY *pkey, const unsigned char *priv,
size_t len)
{
ASN1_OCTET_STRING *os;
if (pkey->pkey.ptr != NULL)
return 0;
os = ASN1_OCTET_STRING_new();
if (os == NULL)
return 0;
if (!ASN1_OCTET_STRING_set(os, priv, len)) {
ASN1_OCTET_STRING_free(os);
return 0;
}
pkey->pkey.ptr = os;
return 1;
}
static int hmac_get_priv_key(const EVP_PKEY *pkey, unsigned char *priv,
size_t *len)
{
ASN1_OCTET_STRING *os = (ASN1_OCTET_STRING *)pkey->pkey.ptr;
if (priv == NULL) {
*len = ASN1_STRING_length(os);
return 1;
}
if (os == NULL || *len < (size_t)ASN1_STRING_length(os))
return 0;
*len = ASN1_STRING_length(os);
memcpy(priv, ASN1_STRING_get0_data(os), *len);
return 1;
}
const EVP_PKEY_ASN1_METHOD hmac_asn1_meth = {
EVP_PKEY_HMAC,
EVP_PKEY_HMAC,
0,
"HMAC",
"OpenSSL HMAC method",
0, 0, hmac_pkey_public_cmp, 0,
0, 0, 0,
hmac_size,
0, 0,
0, 0, 0, 0, 0, 0, 0,
hmac_key_free,
hmac_pkey_ctrl,
NULL,
NULL,
NULL,
NULL,
NULL,
NULL,
NULL,
NULL,
hmac_set_priv_key,
NULL,
hmac_get_priv_key,
NULL,
};