Linux-EFI Archive on lore.kernel.org
 help / color / Atom feed
From: Nayna Jain <nayna@linux.ibm.com>
To: linuxppc-dev@ozlabs.org, linux-efi@vger.kernel.org,
	linux-integrity@vger.kernel.org
Cc: linux-kernel@vger.kernel.org,
	Michael Ellerman <mpe@ellerman.id.au>,
	Benjamin Herrenschmidt <benh@kernel.crashing.org>,
	Paul Mackerras <paulus@samba.org>,
	Ard Biesheuvel <ard.biesheuvel@linaro.org>,
	Jeremy Kerr <jk@ozlabs.org>,
	Matthew Garret <matthew.garret@nebula.com>,
	Mimi Zohar <zohar@linux.ibm.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	George Wilson <gcwilson@linux.ibm.com>,
	Claudio Carvalho <cclaudio@linux.ibm.com>,
	Elaine Palmer <erpalmer@us.ibm.com>,
	Eric Ricther <erichte@linux.ibm.com>,
	"Oliver O'Halloran" <oohall@gmail.com>,
	Nayna Jain <nayna@linux.ibm.com>
Subject: [PATCH v9 4/4] powerpc: load firmware trusted keys/hashes into kernel keyring
Date: Sun, 10 Nov 2019 21:10:36 -0600
Message-ID: <1573441836-3632-5-git-send-email-nayna@linux.ibm.com> (raw)
In-Reply-To: <1573441836-3632-1-git-send-email-nayna@linux.ibm.com>

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 <nayna@linux.ibm.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Eric Richter <erichte@linux.ibm.com>
---
 security/integrity/Kconfig                       |  9 +++
 security/integrity/Makefile                      |  4 +-
 security/integrity/platform_certs/load_powerpc.c | 99 ++++++++++++++++++++++++
 3 files changed, 111 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..9b2596e838ac
--- /dev/null
+++ b/security/integrity/platform_certs/load_powerpc.c
@@ -0,0 +1,99 @@
+// 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 <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/cred.h>
+#include <linux/err.h>
+#include <linux/slab.h>
+#include <linux/of.h>
+#include <asm/secure_boot.h>
+#include <asm/secvar.h>
+#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.
+	 * Return early if it is not set.
+	 */
+
+	node = of_find_compatible_node(NULL, NULL, "ibm,secvar-backend");
+	rc = of_property_match_string(node, "format", "ibm,edk2-compat-v1");
+	if (rc)
+		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);
-- 
2.13.6


  parent reply index

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-11-11  3:10 [PATCH v9 0/4] powerpc: expose secure variables to the kernel and userspace Nayna Jain
2019-11-11  3:10 ` [PATCH v9 1/4] powerpc/powernv: Add OPAL API interface to access secure variable Nayna Jain
2019-11-14  9:08   ` Michael Ellerman
2019-11-11  3:10 ` [PATCH v9 2/4] powerpc: expose secure variables to userspace via sysfs Nayna Jain
2019-11-11  3:10 ` [PATCH v9 3/4] x86/efi: move common keyring handler functions to new file Nayna Jain
2019-11-11  3:10 ` Nayna Jain [this message]
2019-11-11 22:37 ` [PATCH v9 0/4] powerpc: expose secure variables to the kernel and userspace Lakshmi Ramasubramanian
2019-11-12  1:21   ` Michael Ellerman

Reply instructions:

You may reply publically to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=1573441836-3632-5-git-send-email-nayna@linux.ibm.com \
    --to=nayna@linux.ibm.com \
    --cc=ard.biesheuvel@linaro.org \
    --cc=benh@kernel.crashing.org \
    --cc=cclaudio@linux.ibm.com \
    --cc=erichte@linux.ibm.com \
    --cc=erpalmer@us.ibm.com \
    --cc=gcwilson@linux.ibm.com \
    --cc=gregkh@linuxfoundation.org \
    --cc=jk@ozlabs.org \
    --cc=linux-efi@vger.kernel.org \
    --cc=linux-integrity@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linuxppc-dev@ozlabs.org \
    --cc=matthew.garret@nebula.com \
    --cc=mpe@ellerman.id.au \
    --cc=oohall@gmail.com \
    --cc=paulus@samba.org \
    --cc=zohar@linux.ibm.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

Linux-EFI Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/linux-efi/0 linux-efi/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 linux-efi linux-efi/ https://lore.kernel.org/linux-efi \
		linux-efi@vger.kernel.org
	public-inbox-index linux-efi

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-efi


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git