5d2787cf0b
Add KEY_ALLOC_BUILT_IN to convey that a key should have KEY_FLAG_BUILTIN set rather than setting it after the fact. Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
157 lines
4 KiB
C
157 lines
4 KiB
C
/* System trusted keyring for trusted public keys
|
|
*
|
|
* Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
|
|
* Written by David Howells (dhowells@redhat.com)
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public Licence
|
|
* as published by the Free Software Foundation; either version
|
|
* 2 of the Licence, or (at your option) any later version.
|
|
*/
|
|
|
|
#include <linux/export.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/cred.h>
|
|
#include <linux/err.h>
|
|
#include <keys/asymmetric-type.h>
|
|
#include <keys/system_keyring.h>
|
|
#include <crypto/pkcs7.h>
|
|
|
|
struct key *system_trusted_keyring;
|
|
EXPORT_SYMBOL_GPL(system_trusted_keyring);
|
|
|
|
extern __initconst const u8 system_certificate_list[];
|
|
extern __initconst const unsigned long system_certificate_list_size;
|
|
|
|
/*
|
|
* Load the compiled-in keys
|
|
*/
|
|
static __init int system_trusted_keyring_init(void)
|
|
{
|
|
pr_notice("Initialise system trusted keyring\n");
|
|
|
|
system_trusted_keyring =
|
|
keyring_alloc(".system_keyring",
|
|
KUIDT_INIT(0), KGIDT_INIT(0), current_cred(),
|
|
((KEY_POS_ALL & ~KEY_POS_SETATTR) |
|
|
KEY_USR_VIEW | KEY_USR_READ | KEY_USR_SEARCH),
|
|
KEY_ALLOC_NOT_IN_QUOTA, NULL);
|
|
if (IS_ERR(system_trusted_keyring))
|
|
panic("Can't allocate system trusted keyring\n");
|
|
|
|
set_bit(KEY_FLAG_TRUSTED_ONLY, &system_trusted_keyring->flags);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Must be initialised before we try and load the keys into the keyring.
|
|
*/
|
|
device_initcall(system_trusted_keyring_init);
|
|
|
|
/*
|
|
* Load the compiled-in list of X.509 certificates.
|
|
*/
|
|
static __init int load_system_certificate_list(void)
|
|
{
|
|
key_ref_t key;
|
|
const u8 *p, *end;
|
|
size_t plen;
|
|
|
|
pr_notice("Loading compiled-in X.509 certificates\n");
|
|
|
|
p = system_certificate_list;
|
|
end = p + system_certificate_list_size;
|
|
while (p < end) {
|
|
/* Each cert begins with an ASN.1 SEQUENCE tag and must be more
|
|
* than 256 bytes in size.
|
|
*/
|
|
if (end - p < 4)
|
|
goto dodgy_cert;
|
|
if (p[0] != 0x30 &&
|
|
p[1] != 0x82)
|
|
goto dodgy_cert;
|
|
plen = (p[2] << 8) | p[3];
|
|
plen += 4;
|
|
if (plen > end - p)
|
|
goto dodgy_cert;
|
|
|
|
key = key_create_or_update(make_key_ref(system_trusted_keyring, 1),
|
|
"asymmetric",
|
|
NULL,
|
|
p,
|
|
plen,
|
|
((KEY_POS_ALL & ~KEY_POS_SETATTR) |
|
|
KEY_USR_VIEW | KEY_USR_READ),
|
|
KEY_ALLOC_NOT_IN_QUOTA |
|
|
KEY_ALLOC_TRUSTED |
|
|
KEY_ALLOC_BUILT_IN);
|
|
if (IS_ERR(key)) {
|
|
pr_err("Problem loading in-kernel X.509 certificate (%ld)\n",
|
|
PTR_ERR(key));
|
|
} else {
|
|
pr_notice("Loaded X.509 cert '%s'\n",
|
|
key_ref_to_ptr(key)->description);
|
|
key_ref_put(key);
|
|
}
|
|
p += plen;
|
|
}
|
|
|
|
return 0;
|
|
|
|
dodgy_cert:
|
|
pr_err("Problem parsing in-kernel X.509 certificate list\n");
|
|
return 0;
|
|
}
|
|
late_initcall(load_system_certificate_list);
|
|
|
|
#ifdef CONFIG_SYSTEM_DATA_VERIFICATION
|
|
|
|
/**
|
|
* Verify a PKCS#7-based signature on system data.
|
|
* @data: The data to be verified.
|
|
* @len: Size of @data.
|
|
* @raw_pkcs7: The PKCS#7 message that is the signature.
|
|
* @pkcs7_len: The size of @raw_pkcs7.
|
|
* @usage: The use to which the key is being put.
|
|
*/
|
|
int system_verify_data(const void *data, unsigned long len,
|
|
const void *raw_pkcs7, size_t pkcs7_len,
|
|
enum key_being_used_for usage)
|
|
{
|
|
struct pkcs7_message *pkcs7;
|
|
bool trusted;
|
|
int ret;
|
|
|
|
pkcs7 = pkcs7_parse_message(raw_pkcs7, pkcs7_len);
|
|
if (IS_ERR(pkcs7))
|
|
return PTR_ERR(pkcs7);
|
|
|
|
/* The data should be detached - so we need to supply it. */
|
|
if (pkcs7_supply_detached_data(pkcs7, data, len) < 0) {
|
|
pr_err("PKCS#7 signature with non-detached data\n");
|
|
ret = -EBADMSG;
|
|
goto error;
|
|
}
|
|
|
|
ret = pkcs7_verify(pkcs7, usage);
|
|
if (ret < 0)
|
|
goto error;
|
|
|
|
ret = pkcs7_validate_trust(pkcs7, system_trusted_keyring, &trusted);
|
|
if (ret < 0)
|
|
goto error;
|
|
|
|
if (!trusted) {
|
|
pr_err("PKCS#7 signature not signed with a trusted key\n");
|
|
ret = -ENOKEY;
|
|
}
|
|
|
|
error:
|
|
pkcs7_free_message(pkcs7);
|
|
pr_devel("<==%s() = %d\n", __func__, ret);
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(system_verify_data);
|
|
|
|
#endif /* CONFIG_SYSTEM_DATA_VERIFICATION */
|