digsig.c

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/*
 * Copyright (C) 2011 Intel Corporation
 *
 * Author:
 * Dmitry Kasatkin <[email protected]>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, version 2 of the License.
 *
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/err.h>
#include <linux/rbtree.h>
#include <linux/key-type.h>
#include <linux/digsig.h>

#include "integrity.h"

static struct key *keyring[INTEGRITY_KEYRING_MAX];

static const char *keyring_name[INTEGRITY_KEYRING_MAX] = {
    "_evm",
    "_module",
    "_ima",
};

int integrity_digsig_verify(const unsigned int id, const char *sig, int siglen,
                    const char *digest, int digestlen)
{
    if (id >= INTEGRITY_KEYRING_MAX)
        return -EINVAL;

    if (!keyring[id]) {
        keyring[id] =
            request_key(&key_type_keyring, keyring_name[id], NULL);
        if (IS_ERR(keyring[id])) {
            int err = PTR_ERR(keyring[id]);
            pr_err("no %s keyring: %d\n", keyring_name[id], err);
            keyring[id] = NULL;
            return err;
        }
    }

    return digsig_verify(keyring[id], sig, siglen, digest, digestlen);
}