linux/security/integrity/platform_certs/keyring_handler.c
Nayna Jain ad723674d6 x86/efi: move common keyring handler functions to new file
The handlers to add the keys to the .platform keyring and blacklisted
hashes to the .blacklist keyring is common for both the uefi and powerpc
mechanisms of loading the keys/hashes from the firmware.

This patch moves the common code from load_uefi.c to keyring_handler.c

Signed-off-by: Nayna Jain <nayna@linux.ibm.com>
Acked-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Eric Richter <erichte@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1573441836-3632-4-git-send-email-nayna@linux.ibm.com
2019-11-13 00:33:23 +11:00

81 lines
2.0 KiB
C

// SPDX-License-Identifier: GPL-2.0
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/cred.h>
#include <linux/err.h>
#include <linux/efi.h>
#include <linux/slab.h>
#include <keys/asymmetric-type.h>
#include <keys/system_keyring.h>
#include "../integrity.h"
static efi_guid_t efi_cert_x509_guid __initdata = EFI_CERT_X509_GUID;
static efi_guid_t efi_cert_x509_sha256_guid __initdata =
EFI_CERT_X509_SHA256_GUID;
static efi_guid_t efi_cert_sha256_guid __initdata = EFI_CERT_SHA256_GUID;
/*
* Blacklist a hash.
*/
static __init void uefi_blacklist_hash(const char *source, const void *data,
size_t len, const char *type,
size_t type_len)
{
char *hash, *p;
hash = kmalloc(type_len + len * 2 + 1, GFP_KERNEL);
if (!hash)
return;
p = memcpy(hash, type, type_len);
p += type_len;
bin2hex(p, data, len);
p += len * 2;
*p = 0;
mark_hash_blacklisted(hash);
kfree(hash);
}
/*
* Blacklist an X509 TBS hash.
*/
static __init void uefi_blacklist_x509_tbs(const char *source,
const void *data, size_t len)
{
uefi_blacklist_hash(source, data, len, "tbs:", 4);
}
/*
* Blacklist the hash of an executable.
*/
static __init void uefi_blacklist_binary(const char *source,
const void *data, size_t len)
{
uefi_blacklist_hash(source, data, len, "bin:", 4);
}
/*
* Return the appropriate handler for particular signature list types found in
* the UEFI db and MokListRT tables.
*/
__init efi_element_handler_t get_handler_for_db(const efi_guid_t *sig_type)
{
if (efi_guidcmp(*sig_type, efi_cert_x509_guid) == 0)
return add_to_platform_keyring;
return 0;
}
/*
* Return the appropriate handler for particular signature list types found in
* the UEFI dbx and MokListXRT tables.
*/
__init efi_element_handler_t get_handler_for_dbx(const efi_guid_t *sig_type)
{
if (efi_guidcmp(*sig_type, efi_cert_x509_sha256_guid) == 0)
return uefi_blacklist_x509_tbs;
if (efi_guidcmp(*sig_type, efi_cert_sha256_guid) == 0)
return uefi_blacklist_binary;
return 0;
}