host/lib/host_key.c

/* Copyright (c) 2011 The Chromium OS Authors. All rights reserved.
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 *
 * Host functions for keys.
 */

/* TODO: change all 'return 0', 'return 1' into meaningful return codes */

#include <openssl/pem.h>

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>

#include "2sysincludes.h"
#include "2common.h"
#include "2rsa.h"
#include "2sha.h"
#include "cryptolib.h"
#include "host_common.h"
#include "host_key.h"
#include "host_misc.h"
#include "vb2_common.h"
#include "vboot_common.h"

int packed_key_looks_ok(const struct vb2_packed_key *key, uint32_t size)
{
	struct vb2_public_key pubkey;
	if (VB2_SUCCESS != vb2_unpack_key(&pubkey, (const uint8_t *)key, size))
		return 0;

	if (key->key_version > VB2_MAX_KEY_VERSION) {
		/* Currently, TPM only supports 16-bit version */
		VB2_DEBUG("%s() - packed key invalid version\n", __func__);
		return 0;
	}

	/* Success */
	return 1;
}

/* TODO: the host code just uses this to check the embedded key length in
 * uint32_t's.  It should get folded into packed_key_looks_ok. */

RSAPublicKey *vb2_packed_key_to_rsa(const struct vb2_packed_key *key)
{
	RSAPublicKey *rsa;

	if (!packed_key_looks_ok(key, key->key_size))
	    return NULL;

	rsa = RSAPublicKeyFromBuf(vb2_packed_key_data(key), key->key_size);
	if (!rsa)
		return NULL;

	rsa->algorithm = (unsigned int)key->algorithm;
	return rsa;
}