Commit ad723674 authored by Nayna Jain's avatar Nayna Jain Committed by Michael Ellerman
Browse files

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: default avatarNayna Jain <nayna@linux.ibm.com>
Acked-by: default avatarMimi Zohar <zohar@linux.ibm.com>
Signed-off-by: default avatarEric Richter <erichte@linux.ibm.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1573441836-3632-4-git-send-email-nayna@linux.ibm.com
parent bd5d9c74

security/integrity/Makefile

+2 −1
Original line number Diff line number Diff line
@@ -11,7 +11,8 @@ integrity-$(CONFIG_INTEGRITY_SIGNATURE) += digsig.o 
integrity-$(CONFIG_INTEGRITY_ASYMMETRIC_KEYS) += digsig_asymmetric.o

integrity-$(CONFIG_INTEGRITY_PLATFORM_KEYRING) += platform_certs/platform_keyring.o

integrity-$(CONFIG_LOAD_UEFI_KEYS) += platform_certs/efi_parser.o \

					platform_certs/load_uefi.o

				      platform_certs/load_uefi.o \

				      platform_certs/keyring_handler.o

integrity-$(CONFIG_LOAD_IPL_KEYS) += platform_certs/load_ipl_s390.o



obj-$(CONFIG_IMA)			+= ima/

security/integrity/platform_certs/keyring_handler.c

0 → 100644
+80 −0
Original line number Diff line number Diff line 
// 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;

}

security/integrity/platform_certs/keyring_handler.h

0 → 100644
+32 −0
Original line number Diff line number Diff line 
/* SPDX-License-Identifier: GPL-2.0 */



#ifndef PLATFORM_CERTS_INTERNAL_H

#define PLATFORM_CERTS_INTERNAL_H



#include <linux/efi.h>



void blacklist_hash(const char *source, const void *data,

		    size_t len, const char *type,

		    size_t type_len);



/*

 * Blacklist an X509 TBS hash.

 */

void blacklist_x509_tbs(const char *source, const void *data, size_t len);



/*

 * Blacklist the hash of an executable.

 */

void blacklist_binary(const char *source, const void *data, size_t len);



/*

 * Return the handler for particular signature list types found in the db.

 */

efi_element_handler_t get_handler_for_db(const efi_guid_t *sig_type);



/*

 * Return the handler for particular signature list types found in the dbx.

 */

efi_element_handler_t get_handler_for_dbx(const efi_guid_t *sig_type);



#endif

security/integrity/platform_certs/load_uefi.c

+1 −66
Original line number Diff line number Diff line
@@ -9,6 +9,7 @@ 
#include <keys/asymmetric-type.h>

#include <keys/system_keyring.h>

#include "../integrity.h"

#include "keyring_handler.h"



static efi_guid_t efi_cert_x509_guid __initdata = EFI_CERT_X509_GUID;

static efi_guid_t efi_cert_x509_sha256_guid __initdata =
@@ -67,72 +68,6 @@ static __init void *get_cert_list(efi_char16_t *name, efi_guid_t *guid, 
	return db;

}



/*

 * 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.

 */

static __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.

 */

static __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;

}



/*

 * Load the certs contained in the UEFI databases into the platform trusted

 * keyring and the UEFI blacklisted X.509 cert SHA256 hashes into the blacklist

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