From 8220e22d11a05049aab9693839ab82e5e177ccde Mon Sep 17 00:00:00 2001 From: Nayna Jain Date: Sun, 10 Nov 2019 21:10:36 -0600 Subject: [PATCH] powerpc: Load firmware trusted keys/hashes into kernel keyring The keys used to verify the Host OS kernel are managed by firmware as secure variables. This patch loads the verification keys into the .platform keyring and revocation hashes into .blacklist keyring. This enables verification and loading of the kernels signed by the boot time keys which are trusted by firmware. Signed-off-by: Nayna Jain Reviewed-by: Mimi Zohar Signed-off-by: Eric Richter [mpe: Search by compatible in load_powerpc_certs(), not using format] Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/1573441836-3632-5-git-send-email-nayna@linux.ibm.com --- security/integrity/Kconfig | 9 ++ security/integrity/Makefile | 4 +- .../integrity/platform_certs/load_powerpc.c | 96 +++++++++++++++++++ 3 files changed, 108 insertions(+), 1 deletion(-) create mode 100644 security/integrity/platform_certs/load_powerpc.c diff --git a/security/integrity/Kconfig b/security/integrity/Kconfig index 0bae6adb63a9..71f0177e8716 100644 --- a/security/integrity/Kconfig +++ b/security/integrity/Kconfig @@ -72,6 +72,15 @@ config LOAD_IPL_KEYS depends on S390 def_bool y +config LOAD_PPC_KEYS + bool "Enable loading of platform and blacklisted keys for POWER" + depends on INTEGRITY_PLATFORM_KEYRING + depends on PPC_SECURE_BOOT + default y + help + Enable loading of keys to the .platform keyring and blacklisted + hashes to the .blacklist keyring for powerpc based platforms. + config INTEGRITY_AUDIT bool "Enables integrity auditing support " depends on AUDIT diff --git a/security/integrity/Makefile b/security/integrity/Makefile index 351c9662994b..7ee39d66cf16 100644 --- a/security/integrity/Makefile +++ b/security/integrity/Makefile @@ -14,6 +14,8 @@ integrity-$(CONFIG_LOAD_UEFI_KEYS) += platform_certs/efi_parser.o \ platform_certs/load_uefi.o \ platform_certs/keyring_handler.o integrity-$(CONFIG_LOAD_IPL_KEYS) += platform_certs/load_ipl_s390.o - +integrity-$(CONFIG_LOAD_PPC_KEYS) += platform_certs/efi_parser.o \ + platform_certs/load_powerpc.o \ + platform_certs/keyring_handler.o obj-$(CONFIG_IMA) += ima/ obj-$(CONFIG_EVM) += evm/ diff --git a/security/integrity/platform_certs/load_powerpc.c b/security/integrity/platform_certs/load_powerpc.c new file mode 100644 index 000000000000..a2900cb85357 --- /dev/null +++ b/security/integrity/platform_certs/load_powerpc.c @@ -0,0 +1,96 @@ +// 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 +#include +#include +#include +#include +#include +#include +#include +#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); -- 2.30.2