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From: Eric Snowberg <eric.snowberg@oracle.com>
To: keyrings@vger.kernel.org, linux-integrity@vger.kernel.org,
	zohar@linux.ibm.com, dhowells@redhat.com, dwmw2@infradead.org,
	herbert@gondor.apana.org.au, davem@davemloft.net,
	jarkko@kernel.org, jmorris@namei.org, serge@hallyn.com
Cc: eric.snowberg@oracle.com, keescook@chromium.org,
	gregkh@linuxfoundation.org, torvalds@linux-foundation.org,
	scott.branden@broadcom.com, weiyongjun1@huawei.com,
	nayna@linux.ibm.com, ebiggers@google.com, ardb@kernel.org,
	nramas@linux.microsoft.com, lszubowi@redhat.com,
	linux-kernel@vger.kernel.org, linux-crypto@vger.kernel.org,
	linux-security-module@vger.kernel.org,
	James.Bottomley@HansenPartnership.com, pjones@redhat.com,
	konrad.wilk@oracle.com
Subject: [PATCH v5 01/12] integrity: Introduce a Linux keyring called machine
Date: Tue,  7 Sep 2021 12:00:59 -0400	[thread overview]
Message-ID: <20210907160110.2699645-2-eric.snowberg@oracle.com> (raw)
In-Reply-To: <20210907160110.2699645-1-eric.snowberg@oracle.com>

Many UEFI Linux distributions boot using shim.  The UEFI shim provides
what is called Machine Owner Keys (MOK). Shim uses both the UEFI Secure
Boot DB and MOK keys to validate the next step in the boot chain.  The
MOK facility can be used to import user generated keys.  These keys can
be used to sign an end-users development kernel build.  When Linux
boots, both UEFI Secure Boot DB and MOK keys get loaded in the Linux
.platform keyring.

Add a new Linux keyring called machine.  This keyring shall contain just
MOK CA keys and not the remaining keys in the platform keyring. This new
machine keyring will be used in follow on patches.  Unlike keys in the
platform keyring, keys contained in the machine keyring will be trusted
within the kernel if the end-user has chosen to do so.

Signed-off-by: Eric Snowberg <eric.snowberg@oracle.com>
---
v1: Initial version
v2: Removed destory keyring code
v3: Unmodified from v2
v4: Add Kconfig, merged in "integrity: add add_to_mok_keyring" 
v5: Rename to machine keyring
---
 security/integrity/Kconfig                    | 11 +++++
 security/integrity/Makefile                   |  1 +
 security/integrity/digsig.c                   |  1 +
 security/integrity/integrity.h                | 12 +++++-
 .../platform_certs/machine_keyring.c          | 42 +++++++++++++++++++
 5 files changed, 66 insertions(+), 1 deletion(-)
 create mode 100644 security/integrity/platform_certs/machine_keyring.c

diff --git a/security/integrity/Kconfig b/security/integrity/Kconfig
index 71f0177e8716..52193b86768a 100644
--- a/security/integrity/Kconfig
+++ b/security/integrity/Kconfig
@@ -62,6 +62,17 @@ 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 CA Machine Owner Keys may be added"
+	depends on SECONDARY_TRUSTED_KEYRING
+	depends on INTEGRITY_ASYMMETRIC_KEYS
+	depends on SYSTEM_BLACKLIST_KEYRING
+	help
+	 If set, provide a keyring to which CA Machine Owner Keys (MOK) may
+	 be added. This keyring shall contain just CA 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..8c315be8ad99 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
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..948ec6c738c8
--- /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)
+		rc = integrity_load_cert(INTEGRITY_KEYRING_PLATFORM, source,
+					 data, len, perm);
+
+	if (rc)
+		pr_info("Error adding keys to machine keyring %s\n", source);
+}
-- 
2.18.4


  reply	other threads:[~2021-09-07 16:03 UTC|newest]

Thread overview: 31+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-09-07 16:00 [PATCH v5 00/12] Enroll kernel keys thru MOK Eric Snowberg
2021-09-07 16:00 ` Eric Snowberg [this message]
2021-09-09 13:55   ` [PATCH v5 01/12] integrity: Introduce a Linux keyring called machine Jarkko Sakkinen
2021-09-09 15:19   ` Mimi Zohar
2021-09-09 17:32     ` Eric Snowberg
2021-09-07 16:01 ` [PATCH v5 02/12] integrity: Do not allow machine keyring updates following init Eric Snowberg
2021-09-09 13:43   ` Jarkko Sakkinen
2021-09-07 16:01 ` [PATCH v5 03/12] KEYS: CA link restriction Eric Snowberg
2021-09-07 16:01 ` [PATCH v5 04/12] integrity: restrict INTEGRITY_KEYRING_MACHINE to restrict_link_by_ca Eric Snowberg
2021-09-09 13:49   ` Jarkko Sakkinen
2021-09-09 17:25   ` Mimi Zohar
2021-09-09 17:53     ` Eric Snowberg
2021-09-09 18:19       ` Mimi Zohar
2021-09-07 16:01 ` [PATCH v5 05/12] integrity: add new keyring handler for mok keys Eric Snowberg
2021-09-07 16:01 ` [PATCH v5 06/12] KEYS: add a reference to machine keyring Eric Snowberg
2021-09-07 16:01 ` [PATCH v5 07/12] KEYS: Introduce link restriction to include builtin, secondary and machine keys Eric Snowberg
2021-09-09 17:26   ` Mimi Zohar
2021-09-09 18:03     ` Eric Snowberg
2021-09-09 18:19       ` Mimi Zohar
2021-09-07 16:01 ` [PATCH v5 08/12] KEYS: integrity: change link restriction to trust the machine keyring Eric Snowberg
2021-09-09 17:27   ` Mimi Zohar
2021-09-07 16:01 ` [PATCH v5 09/12] KEYS: link secondary_trusted_keys to machine trusted keys Eric Snowberg
2021-09-07 16:01 ` [PATCH v5 10/12] integrity: store reference to machine keyring Eric Snowberg
2021-09-07 16:01 ` [PATCH v5 11/12] integrity: Trust MOK keys if MokListTrustedRT found Eric Snowberg
2021-09-07 16:01 ` [PATCH v5 12/12] integrity: Only use machine keyring when uefi_check_trust_mok_keys is true Eric Snowberg
2021-09-09 13:58   ` Jarkko Sakkinen
2021-09-08 16:03 ` [PATCH v5 00/12] Enroll kernel keys thru MOK Jarkko Sakkinen
2021-09-08 16:49   ` Jarkko Sakkinen
2021-09-08 22:25     ` Eric Snowberg
2021-09-09 13:02       ` Mimi Zohar
2021-09-08 17:09   ` Eric Snowberg

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