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// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2019 IBM Corporation
* Author: Nayna Jain
*
* - loads keys and hashes stored and controlled by the firmware.
*/
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/cred.h>
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/of.h>
#include <asm/secure_boot.h>
#include <asm/secvar.h>
#include "keyring_handler.h"
/*
* Get a certificate list blob from the named secure variable.
*/
static __init void *get_cert_list(u8 *key, unsigned long keylen, uint64_t *size)
{
int rc;
void *db;
rc = secvar_ops->get(key, keylen, NULL, size);
if (rc) {
pr_err("Couldn't get size: %d\n", rc);
return NULL;
}
db = kmalloc(*size, GFP_KERNEL);
if (!db)
return NULL;
rc = secvar_ops->get(key, keylen, db, size);
if (rc) {
kfree(db);
pr_err("Error reading %s var: %d\n", key, rc);
return NULL;
}
return db;
}
/*
* Load the certs contained in the keys databases into the platform trusted
* keyring and the blacklisted X.509 cert SHA256 hashes into the blacklist
* keyring.
*/
static int __init load_powerpc_certs(void)
{
void *db = NULL, *dbx = NULL;
uint64_t dbsize = 0, dbxsize = 0;
int rc = 0;
struct device_node *node;
if (!secvar_ops)
return -ENODEV;
/* The following only applies for the edk2-compat backend. */
node = of_find_compatible_node(NULL, NULL, "ibm,edk2-compat-v1");
if (!node)
return -ENODEV;
/*
* Get db, and dbx. They might not exist, so it isn't an error if we
* can't get them.
*/
db = get_cert_list("db", 3, &dbsize);
if (!db) {
pr_err("Couldn't get db list from firmware\n");
} else {
rc = parse_efi_signature_list("powerpc:db", db, dbsize,
get_handler_for_db);
if (rc)
pr_err("Couldn't parse db signatures: %d\n", rc);
kfree(db);
}
dbx = get_cert_list("dbx", 4, &dbxsize);
if (!dbx) {
pr_info("Couldn't get dbx list from firmware\n");
} else {
rc = parse_efi_signature_list("powerpc:dbx", dbx, dbxsize,
get_handler_for_dbx);
if (rc)
pr_err("Couldn't parse dbx signatures: %d\n", rc);
kfree(dbx);
}
of_node_put(node);
return rc;
}
late_initcall(load_powerpc_certs);
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