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/*
* Copyright (c) 2015, ARM Limited and Contributors. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
#include <assert.h>
#include <crypto_mod.h>
#include <debug.h>
/* Variable exported by the crypto library through REGISTER_CRYPTO_LIB() */
extern const crypto_lib_desc_t crypto_lib_desc;
/*
* The crypto module is responsible for verifying digital signatures and hashes.
* It relies on a crypto library to perform the cryptographic operations.
*
* The crypto module itself does not impose any specific format on signatures,
* signature algorithm, keys or hashes, but most cryptographic libraries will
* take the parameters as the following DER encoded ASN.1 structures:
*
* AlgorithmIdentifier ::= SEQUENCE {
* algorithm OBJECT IDENTIFIER,
* parameters ANY DEFINED BY algorithm OPTIONAL
* }
*
* DigestInfo ::= SEQUENCE {
* digestAlgorithm AlgorithmIdentifier,
* digest OCTET STRING
* }
*
* SubjectPublicKeyInfo ::= SEQUENCE {
* algorithm AlgorithmIdentifier,
* subjectPublicKey BIT STRING
* }
*
* SignatureAlgorithm ::= AlgorithmIdentifier
*
* SignatureValue ::= BIT STRING
*/
/*
* Perform some static checking and call the library initialization function
*/
void crypto_mod_init(void)
{
assert(crypto_lib_desc.name != NULL);
assert(crypto_lib_desc.init != NULL);
assert(crypto_lib_desc.verify_signature != NULL);
assert(crypto_lib_desc.verify_hash != NULL);
/* Initialize the cryptographic library */
crypto_lib_desc.init();
INFO("Using crypto library '%s'\n", crypto_lib_desc.name);
}
/*
* Function to verify a digital signature
*
* Parameters:
*
* data_ptr, data_len: signed data
* sig_ptr, sig_len: the digital signature
* sig_alg_ptr, sig_alg_len: the digital signature algorithm
* pk_ptr, pk_len: the public key
*/
int crypto_mod_verify_signature(void *data_ptr, unsigned int data_len,
void *sig_ptr, unsigned int sig_len,
void *sig_alg_ptr, unsigned int sig_alg_len,
void *pk_ptr, unsigned int pk_len)
{
assert(data_ptr != NULL);
assert(data_len != 0);
assert(sig_ptr != NULL);
assert(sig_len != 0);
assert(sig_alg_ptr != NULL);
assert(sig_alg_len != 0);
assert(pk_ptr != NULL);
assert(pk_len != 0);
return crypto_lib_desc.verify_signature(data_ptr, data_len,
sig_ptr, sig_len,
sig_alg_ptr, sig_alg_len,
pk_ptr, pk_len);
}
/*
* Verify a hash by comparison
*
* Parameters:
*
* data_ptr, data_len: data to be hashed
* digest_info_ptr, digest_info_len: hash to be compared
*/
int crypto_mod_verify_hash(void *data_ptr, unsigned int data_len,
void *digest_info_ptr, unsigned int digest_info_len)
{
assert(data_ptr != NULL);
assert(data_len != 0);
assert(digest_info_ptr != NULL);
assert(digest_info_len != 0);
return crypto_lib_desc.verify_hash(data_ptr, data_len,
digest_info_ptr, digest_info_len);
}
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