1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun * Copyright (C) 2019 IBM Corporation
4*4882a593Smuzhiyun * Author: Nayna Jain
5*4882a593Smuzhiyun *
6*4882a593Smuzhiyun * - loads keys and hashes stored and controlled by the firmware.
7*4882a593Smuzhiyun */
8*4882a593Smuzhiyun #include <linux/kernel.h>
9*4882a593Smuzhiyun #include <linux/sched.h>
10*4882a593Smuzhiyun #include <linux/cred.h>
11*4882a593Smuzhiyun #include <linux/err.h>
12*4882a593Smuzhiyun #include <linux/slab.h>
13*4882a593Smuzhiyun #include <linux/of.h>
14*4882a593Smuzhiyun #include <asm/secure_boot.h>
15*4882a593Smuzhiyun #include <asm/secvar.h>
16*4882a593Smuzhiyun #include "keyring_handler.h"
17*4882a593Smuzhiyun
18*4882a593Smuzhiyun /*
19*4882a593Smuzhiyun * Get a certificate list blob from the named secure variable.
20*4882a593Smuzhiyun */
get_cert_list(u8 * key,unsigned long keylen,uint64_t * size)21*4882a593Smuzhiyun static __init void *get_cert_list(u8 *key, unsigned long keylen, uint64_t *size)
22*4882a593Smuzhiyun {
23*4882a593Smuzhiyun int rc;
24*4882a593Smuzhiyun void *db;
25*4882a593Smuzhiyun
26*4882a593Smuzhiyun rc = secvar_ops->get(key, keylen, NULL, size);
27*4882a593Smuzhiyun if (rc) {
28*4882a593Smuzhiyun pr_err("Couldn't get size: %d\n", rc);
29*4882a593Smuzhiyun return NULL;
30*4882a593Smuzhiyun }
31*4882a593Smuzhiyun
32*4882a593Smuzhiyun db = kmalloc(*size, GFP_KERNEL);
33*4882a593Smuzhiyun if (!db)
34*4882a593Smuzhiyun return NULL;
35*4882a593Smuzhiyun
36*4882a593Smuzhiyun rc = secvar_ops->get(key, keylen, db, size);
37*4882a593Smuzhiyun if (rc) {
38*4882a593Smuzhiyun kfree(db);
39*4882a593Smuzhiyun pr_err("Error reading %s var: %d\n", key, rc);
40*4882a593Smuzhiyun return NULL;
41*4882a593Smuzhiyun }
42*4882a593Smuzhiyun
43*4882a593Smuzhiyun return db;
44*4882a593Smuzhiyun }
45*4882a593Smuzhiyun
46*4882a593Smuzhiyun /*
47*4882a593Smuzhiyun * Load the certs contained in the keys databases into the platform trusted
48*4882a593Smuzhiyun * keyring and the blacklisted X.509 cert SHA256 hashes into the blacklist
49*4882a593Smuzhiyun * keyring.
50*4882a593Smuzhiyun */
load_powerpc_certs(void)51*4882a593Smuzhiyun static int __init load_powerpc_certs(void)
52*4882a593Smuzhiyun {
53*4882a593Smuzhiyun void *db = NULL, *dbx = NULL;
54*4882a593Smuzhiyun uint64_t dbsize = 0, dbxsize = 0;
55*4882a593Smuzhiyun int rc = 0;
56*4882a593Smuzhiyun struct device_node *node;
57*4882a593Smuzhiyun
58*4882a593Smuzhiyun if (!secvar_ops)
59*4882a593Smuzhiyun return -ENODEV;
60*4882a593Smuzhiyun
61*4882a593Smuzhiyun /* The following only applies for the edk2-compat backend. */
62*4882a593Smuzhiyun node = of_find_compatible_node(NULL, NULL, "ibm,edk2-compat-v1");
63*4882a593Smuzhiyun if (!node)
64*4882a593Smuzhiyun return -ENODEV;
65*4882a593Smuzhiyun
66*4882a593Smuzhiyun /*
67*4882a593Smuzhiyun * Get db, and dbx. They might not exist, so it isn't an error if we
68*4882a593Smuzhiyun * can't get them.
69*4882a593Smuzhiyun */
70*4882a593Smuzhiyun db = get_cert_list("db", 3, &dbsize);
71*4882a593Smuzhiyun if (!db) {
72*4882a593Smuzhiyun pr_err("Couldn't get db list from firmware\n");
73*4882a593Smuzhiyun } else {
74*4882a593Smuzhiyun rc = parse_efi_signature_list("powerpc:db", db, dbsize,
75*4882a593Smuzhiyun get_handler_for_db);
76*4882a593Smuzhiyun if (rc)
77*4882a593Smuzhiyun pr_err("Couldn't parse db signatures: %d\n", rc);
78*4882a593Smuzhiyun kfree(db);
79*4882a593Smuzhiyun }
80*4882a593Smuzhiyun
81*4882a593Smuzhiyun dbx = get_cert_list("dbx", 4, &dbxsize);
82*4882a593Smuzhiyun if (!dbx) {
83*4882a593Smuzhiyun pr_info("Couldn't get dbx list from firmware\n");
84*4882a593Smuzhiyun } else {
85*4882a593Smuzhiyun rc = parse_efi_signature_list("powerpc:dbx", dbx, dbxsize,
86*4882a593Smuzhiyun get_handler_for_dbx);
87*4882a593Smuzhiyun if (rc)
88*4882a593Smuzhiyun pr_err("Couldn't parse dbx signatures: %d\n", rc);
89*4882a593Smuzhiyun kfree(dbx);
90*4882a593Smuzhiyun }
91*4882a593Smuzhiyun
92*4882a593Smuzhiyun of_node_put(node);
93*4882a593Smuzhiyun
94*4882a593Smuzhiyun return rc;
95*4882a593Smuzhiyun }
96*4882a593Smuzhiyun late_initcall(load_powerpc_certs);
97