diff options
| -rw-r--r-- | security/integrity/Kconfig | 13 | ||||
| -rw-r--r-- | security/integrity/Makefile | 1 | ||||
| -rw-r--r-- | security/integrity/digsig.c | 13 | ||||
| -rw-r--r-- | security/integrity/integrity.h | 12 | ||||
| -rw-r--r-- | security/integrity/platform_certs/machine_keyring.c | 42 |
5 files changed, 78 insertions, 3 deletions
diff --git a/security/integrity/Kconfig b/security/integrity/Kconfig index 71f0177e8716..599429f99f99 100644 --- a/security/integrity/Kconfig +++ b/security/integrity/Kconfig @@ -62,6 +62,19 @@ config INTEGRITY_PLATFORM_KEYRING provided by the platform for verifying the kexec'ed kerned image and, possibly, the initramfs signature. +config INTEGRITY_MACHINE_KEYRING + bool "Provide a keyring to which Machine Owner Keys may be added" + depends on SECONDARY_TRUSTED_KEYRING + depends on INTEGRITY_ASYMMETRIC_KEYS + depends on SYSTEM_BLACKLIST_KEYRING + depends on LOAD_UEFI_KEYS + depends on !IMA_KEYRINGS_PERMIT_SIGNED_BY_BUILTIN_OR_SECONDARY + help + If set, provide a keyring to which Machine Owner Keys (MOK) may + be added. This keyring shall contain just MOK keys. Unlike keys + in the platform keyring, keys contained in the .machine keyring will + be trusted within the kernel. + config LOAD_UEFI_KEYS depends on INTEGRITY_PLATFORM_KEYRING depends on EFI diff --git a/security/integrity/Makefile b/security/integrity/Makefile index 7ee39d66cf16..d0ffe37dc1d6 100644 --- a/security/integrity/Makefile +++ b/security/integrity/Makefile @@ -10,6 +10,7 @@ integrity-$(CONFIG_INTEGRITY_AUDIT) += integrity_audit.o integrity-$(CONFIG_INTEGRITY_SIGNATURE) += digsig.o integrity-$(CONFIG_INTEGRITY_ASYMMETRIC_KEYS) += digsig_asymmetric.o integrity-$(CONFIG_INTEGRITY_PLATFORM_KEYRING) += platform_certs/platform_keyring.o +integrity-$(CONFIG_INTEGRITY_MACHINE_KEYRING) += platform_certs/machine_keyring.o integrity-$(CONFIG_LOAD_UEFI_KEYS) += platform_certs/efi_parser.o \ platform_certs/load_uefi.o \ platform_certs/keyring_handler.o diff --git a/security/integrity/digsig.c b/security/integrity/digsig.c index 3b06a01bd0fd..2b7fa85613c0 100644 --- a/security/integrity/digsig.c +++ b/security/integrity/digsig.c @@ -30,6 +30,7 @@ static const char * const keyring_name[INTEGRITY_KEYRING_MAX] = { ".ima", #endif ".platform", + ".machine", }; #ifdef CONFIG_IMA_KEYRINGS_PERMIT_SIGNED_BY_BUILTIN_OR_SECONDARY @@ -126,7 +127,8 @@ int __init integrity_init_keyring(const unsigned int id) perm = (KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_VIEW | KEY_USR_READ | KEY_USR_SEARCH; - if (id == INTEGRITY_KEYRING_PLATFORM) { + if (id == INTEGRITY_KEYRING_PLATFORM || + id == INTEGRITY_KEYRING_MACHINE) { restriction = NULL; goto out; } @@ -139,7 +141,14 @@ int __init integrity_init_keyring(const unsigned int id) return -ENOMEM; restriction->check = restrict_link_to_ima; - perm |= KEY_USR_WRITE; + + /* + * MOK keys can only be added through a read-only runtime services + * UEFI variable during boot. No additional keys shall be allowed to + * load into the machine keyring following init from userspace. + */ + if (id != INTEGRITY_KEYRING_MACHINE) + perm |= KEY_USR_WRITE; out: return __integrity_init_keyring(id, perm, restriction); diff --git a/security/integrity/integrity.h b/security/integrity/integrity.h index 547425c20e11..730771eececd 100644 --- a/security/integrity/integrity.h +++ b/security/integrity/integrity.h @@ -151,7 +151,8 @@ int integrity_kernel_read(struct file *file, loff_t offset, #define INTEGRITY_KEYRING_EVM 0 #define INTEGRITY_KEYRING_IMA 1 #define INTEGRITY_KEYRING_PLATFORM 2 -#define INTEGRITY_KEYRING_MAX 3 +#define INTEGRITY_KEYRING_MACHINE 3 +#define INTEGRITY_KEYRING_MAX 4 extern struct dentry *integrity_dir; @@ -283,3 +284,12 @@ static inline void __init add_to_platform_keyring(const char *source, { } #endif + +#ifdef CONFIG_INTEGRITY_MACHINE_KEYRING +void __init add_to_machine_keyring(const char *source, const void *data, size_t len); +#else +static inline void __init add_to_machine_keyring(const char *source, + const void *data, size_t len) +{ +} +#endif diff --git a/security/integrity/platform_certs/machine_keyring.c b/security/integrity/platform_certs/machine_keyring.c new file mode 100644 index 000000000000..ea2ac2f9f2b5 --- /dev/null +++ b/security/integrity/platform_certs/machine_keyring.c @@ -0,0 +1,42 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Machine keyring routines. + * + * Copyright (c) 2021, Oracle and/or its affiliates. + */ + +#include "../integrity.h" + +static __init int machine_keyring_init(void) +{ + int rc; + + rc = integrity_init_keyring(INTEGRITY_KEYRING_MACHINE); + if (rc) + return rc; + + pr_notice("Machine keyring initialized\n"); + return 0; +} +device_initcall(machine_keyring_init); + +void __init add_to_machine_keyring(const char *source, const void *data, size_t len) +{ + key_perm_t perm; + int rc; + + perm = (KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_VIEW; + rc = integrity_load_cert(INTEGRITY_KEYRING_MACHINE, source, data, len, perm); + + /* + * Some MOKList keys may not pass the machine keyring restrictions. + * If the restriction check does not pass and the platform keyring + * is configured, try to add it into that keyring instead. + */ + if (rc && IS_ENABLED(CONFIG_INTEGRITY_PLATFORM_KEYRING)) + rc = integrity_load_cert(INTEGRITY_KEYRING_PLATFORM, source, + data, len, perm); + + if (rc) + pr_info("Error adding keys to machine keyring %s\n", source); +} |