diff --git a/src/kernel/linux/v4.14/certs/.gitignore b/src/kernel/linux/v4.14/certs/.gitignore
new file mode 100644
index 0000000..f51aea4
--- /dev/null
+++ b/src/kernel/linux/v4.14/certs/.gitignore
@@ -0,0 +1,4 @@
+#
+# Generated files
+#
+x509_certificate_list
diff --git a/src/kernel/linux/v4.14/certs/Kconfig b/src/kernel/linux/v4.14/certs/Kconfig
new file mode 100644
index 0000000..5f7663d
--- /dev/null
+++ b/src/kernel/linux/v4.14/certs/Kconfig
@@ -0,0 +1,86 @@
+# SPDX-License-Identifier: GPL-2.0
+menu "Certificates for signature checking"
+
+config MODULE_SIG_KEY
+	string "File name or PKCS#11 URI of module signing key"
+	default "certs/signing_key.pem"
+	depends on MODULE_SIG
+	help
+         Provide the file name of a private key/certificate in PEM format,
+         or a PKCS#11 URI according to RFC7512. The file should contain, or
+         the URI should identify, both the certificate and its corresponding
+         private key.
+
+         If this option is unchanged from its default "certs/signing_key.pem",
+         then the kernel will automatically generate the private key and
+         certificate as described in Documentation/module-signing.txt
+
+config SYSTEM_TRUSTED_KEYRING
+	bool "Provide system-wide ring of trusted keys"
+	depends on KEYS
+	depends on ASYMMETRIC_KEY_TYPE
+	help
+	  Provide a system keyring to which trusted keys can be added.  Keys in
+	  the keyring are considered to be trusted.  Keys may be added at will
+	  by the kernel from compiled-in data and from hardware key stores, but
+	  userspace may only add extra keys if those keys can be verified by
+	  keys already in the keyring.
+
+	  Keys in this keyring are used by module signature checking.
+
+config SYSTEM_TRUSTED_KEYS
+	string "Additional X.509 keys for default system keyring"
+	depends on SYSTEM_TRUSTED_KEYRING
+	help
+	  If set, this option should be the filename of a PEM-formatted file
+	  containing trusted X.509 certificates to be included in the default
+	  system keyring. Any certificate used for module signing is implicitly
+	  also trusted.
+
+	  NOTE: If you previously provided keys for the system keyring in the
+	  form of DER-encoded *.x509 files in the top-level build directory,
+	  those are no longer used. You will need to set this option instead.
+
+config SYSTEM_EXTRA_CERTIFICATE
+	bool "Reserve area for inserting a certificate without recompiling"
+	depends on SYSTEM_TRUSTED_KEYRING
+	help
+	  If set, space for an extra certificate will be reserved in the kernel
+	  image. This allows introducing a trusted certificate to the default
+	  system keyring without recompiling the kernel.
+
+config SYSTEM_EXTRA_CERTIFICATE_SIZE
+	int "Number of bytes to reserve for the extra certificate"
+	depends on SYSTEM_EXTRA_CERTIFICATE
+	default 4096
+	help
+	  This is the number of bytes reserved in the kernel image for a
+	  certificate to be inserted.
+
+config SECONDARY_TRUSTED_KEYRING
+	bool "Provide a keyring to which extra trustable keys may be added"
+	depends on SYSTEM_TRUSTED_KEYRING
+	help
+	  If set, provide a keyring to which extra keys may be added, provided
+	  those keys are not blacklisted and are vouched for by a key built
+	  into the kernel or already in the secondary trusted keyring.
+
+config SYSTEM_BLACKLIST_KEYRING
+	bool "Provide system-wide ring of blacklisted keys"
+	depends on KEYS
+	help
+	  Provide a system keyring to which blacklisted keys can be added.
+	  Keys in the keyring are considered entirely untrusted.  Keys in this
+	  keyring are used by the module signature checking to reject loading
+	  of modules signed with a blacklisted key.
+
+config SYSTEM_BLACKLIST_HASH_LIST
+	string "Hashes to be preloaded into the system blacklist keyring"
+	depends on SYSTEM_BLACKLIST_KEYRING
+	help
+	  If set, this option should be the filename of a list of hashes in the
+	  form "<hash>", "<hash>", ... .  This will be included into a C
+	  wrapper to incorporate the list into the kernel.  Each <hash> should
+	  be a string of hex digits.
+
+endmenu
diff --git a/src/kernel/linux/v4.14/certs/Makefile b/src/kernel/linux/v4.14/certs/Makefile
new file mode 100644
index 0000000..5d0999b
--- /dev/null
+++ b/src/kernel/linux/v4.14/certs/Makefile
@@ -0,0 +1,106 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for the linux kernel signature checking certificates.
+#
+
+obj-$(CONFIG_SYSTEM_TRUSTED_KEYRING) += system_keyring.o system_certificates.o
+obj-$(CONFIG_SYSTEM_BLACKLIST_KEYRING) += blacklist.o
+ifneq ($(CONFIG_SYSTEM_BLACKLIST_HASH_LIST),"")
+obj-$(CONFIG_SYSTEM_BLACKLIST_KEYRING) += blacklist_hashes.o
+else
+obj-$(CONFIG_SYSTEM_BLACKLIST_KEYRING) += blacklist_nohashes.o
+endif
+
+ifeq ($(CONFIG_SYSTEM_TRUSTED_KEYRING),y)
+
+$(eval $(call config_filename,SYSTEM_TRUSTED_KEYS))
+
+# GCC doesn't include .incbin files in -MD generated dependencies (PR#66871)
+$(obj)/system_certificates.o: $(obj)/x509_certificate_list
+
+# Cope with signing_key.x509 existing in $(srctree) not $(objtree)
+AFLAGS_system_certificates.o := -I$(srctree)
+
+quiet_cmd_extract_certs  = EXTRACT_CERTS   $(patsubst "%",%,$(2))
+      cmd_extract_certs  = scripts/extract-cert $(2) $@ || ( rm $@; exit 1)
+
+targets += x509_certificate_list
+$(obj)/x509_certificate_list: scripts/extract-cert $(SYSTEM_TRUSTED_KEYS_SRCPREFIX)$(SYSTEM_TRUSTED_KEYS_FILENAME) FORCE
+	$(call if_changed,extract_certs,$(SYSTEM_TRUSTED_KEYS_SRCPREFIX)$(CONFIG_SYSTEM_TRUSTED_KEYS))
+endif # CONFIG_SYSTEM_TRUSTED_KEYRING
+
+clean-files := x509_certificate_list .x509.list
+
+ifeq ($(CONFIG_MODULE_SIG),y)
+###############################################################################
+#
+# If module signing is requested, say by allyesconfig, but a key has not been
+# supplied, then one will need to be generated to make sure the build does not
+# fail and that the kernel may be used afterwards.
+#
+###############################################################################
+ifndef CONFIG_MODULE_SIG_HASH
+$(error Could not determine digest type to use from kernel config)
+endif
+
+redirect_openssl	= 2>&1
+quiet_redirect_openssl	= 2>&1
+silent_redirect_openssl = 2>/dev/null
+
+# We do it this way rather than having a boolean option for enabling an
+# external private key, because 'make randconfig' might enable such a
+# boolean option and we unfortunately can't make it depend on !RANDCONFIG.
+ifeq ($(CONFIG_MODULE_SIG_KEY),"certs/signing_key.pem")
+$(obj)/signing_key.pem: $(obj)/x509.genkey
+	@$(kecho) "###"
+	@$(kecho) "### Now generating an X.509 key pair to be used for signing modules."
+	@$(kecho) "###"
+	@$(kecho) "### If this takes a long time, you might wish to run rngd in the"
+	@$(kecho) "### background to keep the supply of entropy topped up.  It"
+	@$(kecho) "### needs to be run as root, and uses a hardware random"
+	@$(kecho) "### number generator if one is available."
+	@$(kecho) "###"
+	$(Q)openssl req -new -nodes -utf8 -$(CONFIG_MODULE_SIG_HASH) -days 36500 \
+		-batch -x509 -config $(obj)/x509.genkey \
+		-outform PEM -out $(obj)/signing_key.pem \
+		-keyout $(obj)/signing_key.pem \
+		$($(quiet)redirect_openssl)
+	@$(kecho) "###"
+	@$(kecho) "### Key pair generated."
+	@$(kecho) "###"
+
+$(obj)/x509.genkey:
+	@$(kecho) Generating X.509 key generation config
+	@echo  >$@ "[ req ]"
+	@echo >>$@ "default_bits = 4096"
+	@echo >>$@ "distinguished_name = req_distinguished_name"
+	@echo >>$@ "prompt = no"
+	@echo >>$@ "string_mask = utf8only"
+	@echo >>$@ "x509_extensions = myexts"
+	@echo >>$@
+	@echo >>$@ "[ req_distinguished_name ]"
+	@echo >>$@ "#O = Unspecified company"
+	@echo >>$@ "CN = Build time autogenerated kernel key"
+	@echo >>$@ "#emailAddress = unspecified.user@unspecified.company"
+	@echo >>$@
+	@echo >>$@ "[ myexts ]"
+	@echo >>$@ "basicConstraints=critical,CA:FALSE"
+	@echo >>$@ "keyUsage=digitalSignature"
+	@echo >>$@ "subjectKeyIdentifier=hash"
+	@echo >>$@ "authorityKeyIdentifier=keyid"
+endif # CONFIG_MODULE_SIG_KEY
+
+$(eval $(call config_filename,MODULE_SIG_KEY))
+
+# If CONFIG_MODULE_SIG_KEY isn't a PKCS#11 URI, depend on it
+ifeq ($(patsubst pkcs11:%,%,$(firstword $(MODULE_SIG_KEY_FILENAME))),$(firstword $(MODULE_SIG_KEY_FILENAME)))
+X509_DEP := $(MODULE_SIG_KEY_SRCPREFIX)$(MODULE_SIG_KEY_FILENAME)
+endif
+
+# GCC PR#66871 again.
+$(obj)/system_certificates.o: $(obj)/signing_key.x509
+
+targets += signing_key.x509
+$(obj)/signing_key.x509: scripts/extract-cert $(X509_DEP) FORCE
+	$(call if_changed,extract_certs,$(MODULE_SIG_KEY_SRCPREFIX)$(CONFIG_MODULE_SIG_KEY))
+endif # CONFIG_MODULE_SIG
diff --git a/src/kernel/linux/v4.14/certs/blacklist.c b/src/kernel/linux/v4.14/certs/blacklist.c
new file mode 100644
index 0000000..3a507b9
--- /dev/null
+++ b/src/kernel/linux/v4.14/certs/blacklist.c
@@ -0,0 +1,174 @@
+/* System hash blacklist.
+ *
+ * Copyright (C) 2016 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public Licence
+ * as published by the Free Software Foundation; either version
+ * 2 of the Licence, or (at your option) any later version.
+ */
+
+#define pr_fmt(fmt) "blacklist: "fmt
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/key.h>
+#include <linux/key-type.h>
+#include <linux/sched.h>
+#include <linux/ctype.h>
+#include <linux/err.h>
+#include <linux/seq_file.h>
+#include <keys/system_keyring.h>
+#include "blacklist.h"
+
+static struct key *blacklist_keyring;
+
+/*
+ * The description must be a type prefix, a colon and then an even number of
+ * hex digits.  The hash is kept in the description.
+ */
+static int blacklist_vet_description(const char *desc)
+{
+	int n = 0;
+
+	if (*desc == ':')
+		return -EINVAL;
+	for (; *desc; desc++)
+		if (*desc == ':')
+			goto found_colon;
+	return -EINVAL;
+
+found_colon:
+	desc++;
+	for (; *desc; desc++) {
+		if (!isxdigit(*desc))
+			return -EINVAL;
+		n++;
+	}
+
+	if (n == 0 || n & 1)
+		return -EINVAL;
+	return 0;
+}
+
+/*
+ * The hash to be blacklisted is expected to be in the description.  There will
+ * be no payload.
+ */
+static int blacklist_preparse(struct key_preparsed_payload *prep)
+{
+	if (prep->datalen > 0)
+		return -EINVAL;
+	return 0;
+}
+
+static void blacklist_free_preparse(struct key_preparsed_payload *prep)
+{
+}
+
+static void blacklist_describe(const struct key *key, struct seq_file *m)
+{
+	seq_puts(m, key->description);
+}
+
+static struct key_type key_type_blacklist = {
+	.name			= "blacklist",
+	.vet_description	= blacklist_vet_description,
+	.preparse		= blacklist_preparse,
+	.free_preparse		= blacklist_free_preparse,
+	.instantiate		= generic_key_instantiate,
+	.describe		= blacklist_describe,
+};
+
+/**
+ * mark_hash_blacklisted - Add a hash to the system blacklist
+ * @hash - The hash as a hex string with a type prefix (eg. "tbs:23aa429783")
+ */
+int mark_hash_blacklisted(const char *hash)
+{
+	key_ref_t key;
+
+	key = key_create_or_update(make_key_ref(blacklist_keyring, true),
+				   "blacklist",
+				   hash,
+				   NULL,
+				   0,
+				   ((KEY_POS_ALL & ~KEY_POS_SETATTR) |
+				    KEY_USR_VIEW),
+				   KEY_ALLOC_NOT_IN_QUOTA |
+				   KEY_ALLOC_BUILT_IN);
+	if (IS_ERR(key)) {
+		pr_err("Problem blacklisting hash (%ld)\n", PTR_ERR(key));
+		return PTR_ERR(key);
+	}
+	return 0;
+}
+
+/**
+ * is_hash_blacklisted - Determine if a hash is blacklisted
+ * @hash: The hash to be checked as a binary blob
+ * @hash_len: The length of the binary hash
+ * @type: Type of hash
+ */
+int is_hash_blacklisted(const u8 *hash, size_t hash_len, const char *type)
+{
+	key_ref_t kref;
+	size_t type_len = strlen(type);
+	char *buffer, *p;
+	int ret = 0;
+
+	buffer = kmalloc(type_len + 1 + hash_len * 2 + 1, GFP_KERNEL);
+	if (!buffer)
+		return -ENOMEM;
+	p = memcpy(buffer, type, type_len);
+	p += type_len;
+	*p++ = ':';
+	bin2hex(p, hash, hash_len);
+	p += hash_len * 2;
+	*p = 0;
+
+	kref = keyring_search(make_key_ref(blacklist_keyring, true),
+			      &key_type_blacklist, buffer);
+	if (!IS_ERR(kref)) {
+		key_ref_put(kref);
+		ret = -EKEYREJECTED;
+	}
+
+	kfree(buffer);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(is_hash_blacklisted);
+
+/*
+ * Initialise the blacklist
+ */
+static int __init blacklist_init(void)
+{
+	const char *const *bl;
+
+	if (register_key_type(&key_type_blacklist) < 0)
+		panic("Can't allocate system blacklist key type\n");
+
+	blacklist_keyring =
+		keyring_alloc(".blacklist",
+			      KUIDT_INIT(0), KGIDT_INIT(0),
+			      current_cred(),
+			      (KEY_POS_ALL & ~KEY_POS_SETATTR) |
+			      KEY_USR_VIEW | KEY_USR_READ |
+			      KEY_USR_SEARCH,
+			      KEY_ALLOC_NOT_IN_QUOTA |
+			      KEY_FLAG_KEEP,
+			      NULL, NULL);
+	if (IS_ERR(blacklist_keyring))
+		panic("Can't allocate system blacklist keyring\n");
+
+	for (bl = blacklist_hashes; *bl; bl++)
+		if (mark_hash_blacklisted(*bl) < 0)
+			pr_err("- blacklisting failed\n");
+	return 0;
+}
+
+/*
+ * Must be initialised before we try and load the keys into the keyring.
+ */
+device_initcall(blacklist_init);
diff --git a/src/kernel/linux/v4.14/certs/blacklist.h b/src/kernel/linux/v4.14/certs/blacklist.h
new file mode 100644
index 0000000..150d82d
--- /dev/null
+++ b/src/kernel/linux/v4.14/certs/blacklist.h
@@ -0,0 +1,3 @@
+#include <linux/kernel.h>
+
+extern const char __initdata *const blacklist_hashes[];
diff --git a/src/kernel/linux/v4.14/certs/blacklist_hashes.c b/src/kernel/linux/v4.14/certs/blacklist_hashes.c
new file mode 100644
index 0000000..3448923
--- /dev/null
+++ b/src/kernel/linux/v4.14/certs/blacklist_hashes.c
@@ -0,0 +1,7 @@
+// SPDX-License-Identifier: GPL-2.0
+#include "blacklist.h"
+
+const char __initdata *const blacklist_hashes[] = {
+#include CONFIG_SYSTEM_BLACKLIST_HASH_LIST
+	, NULL
+};
diff --git a/src/kernel/linux/v4.14/certs/blacklist_nohashes.c b/src/kernel/linux/v4.14/certs/blacklist_nohashes.c
new file mode 100644
index 0000000..73fd990
--- /dev/null
+++ b/src/kernel/linux/v4.14/certs/blacklist_nohashes.c
@@ -0,0 +1,6 @@
+// SPDX-License-Identifier: GPL-2.0
+#include "blacklist.h"
+
+const char __initdata *const blacklist_hashes[] = {
+	NULL
+};
diff --git a/src/kernel/linux/v4.14/certs/system_certificates.S b/src/kernel/linux/v4.14/certs/system_certificates.S
new file mode 100644
index 0000000..3918ff7
--- /dev/null
+++ b/src/kernel/linux/v4.14/certs/system_certificates.S
@@ -0,0 +1,37 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#include <linux/export.h>
+#include <linux/init.h>
+
+	__INITRODATA
+
+	.align 8
+	.globl VMLINUX_SYMBOL(system_certificate_list)
+VMLINUX_SYMBOL(system_certificate_list):
+__cert_list_start:
+#ifdef CONFIG_MODULE_SIG
+	.incbin "certs/signing_key.x509"
+#endif
+	.incbin "certs/x509_certificate_list"
+__cert_list_end:
+
+#ifdef CONFIG_SYSTEM_EXTRA_CERTIFICATE
+	.globl VMLINUX_SYMBOL(system_extra_cert)
+	.size system_extra_cert, CONFIG_SYSTEM_EXTRA_CERTIFICATE_SIZE
+VMLINUX_SYMBOL(system_extra_cert):
+	.fill CONFIG_SYSTEM_EXTRA_CERTIFICATE_SIZE, 1, 0
+
+	.align 4
+	.globl VMLINUX_SYMBOL(system_extra_cert_used)
+VMLINUX_SYMBOL(system_extra_cert_used):
+	.int 0
+
+#endif /* CONFIG_SYSTEM_EXTRA_CERTIFICATE */
+
+	.align 8
+	.globl VMLINUX_SYMBOL(system_certificate_list_size)
+VMLINUX_SYMBOL(system_certificate_list_size):
+#ifdef CONFIG_64BIT
+	.quad __cert_list_end - __cert_list_start
+#else
+	.long __cert_list_end - __cert_list_start
+#endif
diff --git a/src/kernel/linux/v4.14/certs/system_keyring.c b/src/kernel/linux/v4.14/certs/system_keyring.c
new file mode 100644
index 0000000..4ba922f
--- /dev/null
+++ b/src/kernel/linux/v4.14/certs/system_keyring.c
@@ -0,0 +1,309 @@
+/* System trusted keyring for trusted public keys
+ *
+ * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public Licence
+ * as published by the Free Software Foundation; either version
+ * 2 of the Licence, or (at your option) any later version.
+ */
+
+#include <linux/export.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/cred.h>
+#include <linux/err.h>
+#include <linux/slab.h>
+#include <linux/verification.h>
+#include <keys/asymmetric-type.h>
+#include <keys/system_keyring.h>
+#include <crypto/pkcs7.h>
+
+static struct key *builtin_trusted_keys;
+#ifdef CONFIG_SECONDARY_TRUSTED_KEYRING
+static struct key *secondary_trusted_keys;
+#endif
+
+extern __initconst const u8 system_certificate_list[];
+extern __initconst const unsigned long system_certificate_list_size;
+
+/**
+ * restrict_link_to_builtin_trusted - Restrict keyring addition by built in CA
+ *
+ * Restrict the addition of keys into a keyring based on the key-to-be-added
+ * being vouched for by a key in the built in system keyring.
+ */
+int restrict_link_by_builtin_trusted(struct key *dest_keyring,
+				     const struct key_type *type,
+				     const union key_payload *payload,
+				     struct key *restriction_key)
+{
+	return restrict_link_by_signature(dest_keyring, type, payload,
+					  builtin_trusted_keys);
+}
+
+#ifdef CONFIG_SECONDARY_TRUSTED_KEYRING
+/**
+ * restrict_link_by_builtin_and_secondary_trusted - Restrict keyring
+ *   addition by both builtin and secondary keyrings
+ *
+ * Restrict the addition of keys into a keyring based on the key-to-be-added
+ * being vouched for by a key in either the built-in or the secondary system
+ * keyrings.
+ */
+int restrict_link_by_builtin_and_secondary_trusted(
+	struct key *dest_keyring,
+	const struct key_type *type,
+	const union key_payload *payload,
+	struct key *restrict_key)
+{
+	/* If we have a secondary trusted keyring, then that contains a link
+	 * through to the builtin keyring and the search will follow that link.
+	 */
+	if (type == &key_type_keyring &&
+	    dest_keyring == secondary_trusted_keys &&
+	    payload == &builtin_trusted_keys->payload)
+		/* Allow the builtin keyring to be added to the secondary */
+		return 0;
+
+	return restrict_link_by_signature(dest_keyring, type, payload,
+					  secondary_trusted_keys);
+}
+
+/**
+ * Allocate a struct key_restriction for the "builtin and secondary trust"
+ * keyring. Only for use in system_trusted_keyring_init().
+ */
+static __init struct key_restriction *get_builtin_and_secondary_restriction(void)
+{
+	struct key_restriction *restriction;
+
+	restriction = kzalloc(sizeof(struct key_restriction), GFP_KERNEL);
+
+	if (!restriction)
+		panic("Can't allocate secondary trusted keyring restriction\n");
+
+	restriction->check = restrict_link_by_builtin_and_secondary_trusted;
+
+	return restriction;
+}
+#endif
+
+/*
+ * Create the trusted keyrings
+ */
+static __init int system_trusted_keyring_init(void)
+{
+	pr_notice("Initialise system trusted keyrings\n");
+
+	builtin_trusted_keys =
+		keyring_alloc(".builtin_trusted_keys",
+			      KUIDT_INIT(0), KGIDT_INIT(0), current_cred(),
+			      ((KEY_POS_ALL & ~KEY_POS_SETATTR) |
+			      KEY_USR_VIEW | KEY_USR_READ | KEY_USR_SEARCH),
+			      KEY_ALLOC_NOT_IN_QUOTA,
+			      NULL, NULL);
+	if (IS_ERR(builtin_trusted_keys))
+		panic("Can't allocate builtin trusted keyring\n");
+
+#ifdef CONFIG_SECONDARY_TRUSTED_KEYRING
+	secondary_trusted_keys =
+		keyring_alloc(".secondary_trusted_keys",
+			      KUIDT_INIT(0), KGIDT_INIT(0), current_cred(),
+			      ((KEY_POS_ALL & ~KEY_POS_SETATTR) |
+			       KEY_USR_VIEW | KEY_USR_READ | KEY_USR_SEARCH |
+			       KEY_USR_WRITE),
+			      KEY_ALLOC_NOT_IN_QUOTA,
+			      get_builtin_and_secondary_restriction(),
+			      NULL);
+	if (IS_ERR(secondary_trusted_keys))
+		panic("Can't allocate secondary trusted keyring\n");
+
+	if (key_link(secondary_trusted_keys, builtin_trusted_keys) < 0)
+		panic("Can't link trusted keyrings\n");
+#endif
+
+	return 0;
+}
+
+/*
+ * Must be initialised before we try and load the keys into the keyring.
+ */
+device_initcall(system_trusted_keyring_init);
+
+/*
+ * Load the compiled-in list of X.509 certificates.
+ */
+static __init int load_system_certificate_list(void)
+{
+	key_ref_t key;
+	const u8 *p, *end;
+	size_t plen;
+
+	pr_notice("Loading compiled-in X.509 certificates\n");
+
+	p = system_certificate_list;
+	end = p + system_certificate_list_size;
+	while (p < end) {
+		/* Each cert begins with an ASN.1 SEQUENCE tag and must be more
+		 * than 256 bytes in size.
+		 */
+		if (end - p < 4)
+			goto dodgy_cert;
+		if (p[0] != 0x30 &&
+		    p[1] != 0x82)
+			goto dodgy_cert;
+		plen = (p[2] << 8) | p[3];
+		plen += 4;
+		if (plen > end - p)
+			goto dodgy_cert;
+
+		key = key_create_or_update(make_key_ref(builtin_trusted_keys, 1),
+					   "asymmetric",
+					   NULL,
+					   p,
+					   plen,
+					   ((KEY_POS_ALL & ~KEY_POS_SETATTR) |
+					   KEY_USR_VIEW | KEY_USR_READ),
+					   KEY_ALLOC_NOT_IN_QUOTA |
+					   KEY_ALLOC_BUILT_IN |
+					   KEY_ALLOC_BYPASS_RESTRICTION);
+		if (IS_ERR(key)) {
+			pr_err("Problem loading in-kernel X.509 certificate (%ld)\n",
+			       PTR_ERR(key));
+		} else {
+			pr_notice("Loaded X.509 cert '%s'\n",
+				  key_ref_to_ptr(key)->description);
+			key_ref_put(key);
+		}
+		p += plen;
+	}
+
+	return 0;
+
+dodgy_cert:
+	pr_err("Problem parsing in-kernel X.509 certificate list\n");
+	return 0;
+}
+late_initcall(load_system_certificate_list);
+
+#ifdef CONFIG_SYSTEM_DATA_VERIFICATION
+
+/**
+ * verify_pkcs7_signature - Verify a PKCS#7-based signature on system data.
+ * @data: The data to be verified (NULL if expecting internal data).
+ * @len: Size of @data.
+ * @raw_pkcs7: The PKCS#7 message that is the signature.
+ * @pkcs7_len: The size of @raw_pkcs7.
+ * @trusted_keys: Trusted keys to use (NULL for builtin trusted keys only,
+ *					(void *)1UL for all trusted keys).
+ * @usage: The use to which the key is being put.
+ * @view_content: Callback to gain access to content.
+ * @ctx: Context for callback.
+ */
+int verify_pkcs7_signature(const void *data, size_t len,
+			   const void *raw_pkcs7, size_t pkcs7_len,
+			   struct key *trusted_keys,
+			   enum key_being_used_for usage,
+			   int (*view_content)(void *ctx,
+					       const void *data, size_t len,
+					       size_t asn1hdrlen),
+			   void *ctx)
+{
+	struct pkcs7_message *pkcs7;
+	int ret;
+
+	pkcs7 = pkcs7_parse_message(raw_pkcs7, pkcs7_len);
+	if (IS_ERR(pkcs7))
+		return PTR_ERR(pkcs7);
+
+	/* The data should be detached - so we need to supply it. */
+	if (data && pkcs7_supply_detached_data(pkcs7, data, len) < 0) {
+		pr_err("PKCS#7 signature with non-detached data\n");
+		ret = -EBADMSG;
+		goto error;
+	}
+
+	ret = pkcs7_verify(pkcs7, usage);
+	if (ret < 0)
+		goto error;
+
+	if (!trusted_keys) {
+		trusted_keys = builtin_trusted_keys;
+	} else if (trusted_keys == VERIFY_USE_SECONDARY_KEYRING) {
+#ifdef CONFIG_SECONDARY_TRUSTED_KEYRING
+		trusted_keys = secondary_trusted_keys;
+#else
+		trusted_keys = builtin_trusted_keys;
+#endif
+	}
+	ret = pkcs7_validate_trust(pkcs7, trusted_keys);
+	if (ret < 0) {
+		if (ret == -ENOKEY)
+			pr_err("PKCS#7 signature not signed with a trusted key\n");
+		goto error;
+	}
+
+	if (view_content) {
+		size_t asn1hdrlen;
+
+		ret = pkcs7_get_content_data(pkcs7, &data, &len, &asn1hdrlen);
+		if (ret < 0) {
+			if (ret == -ENODATA)
+				pr_devel("PKCS#7 message does not contain data\n");
+			goto error;
+		}
+
+		ret = view_content(ctx, data, len, asn1hdrlen);
+	}
+
+error:
+	pkcs7_free_message(pkcs7);
+	pr_devel("<==%s() = %d\n", __func__, ret);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(verify_pkcs7_signature);
+#endif /* CONFIG_SYSTEM_DATA_VERIFICATION */
+
+/**
+ * verify_signature_one - Verify a signature with keys from given keyring
+ * @sig: The signature to be verified
+ * @trusted_keys: Trusted keys to use (NULL for builtin trusted keys only,
+ *					(void *)1UL for all trusted keys).
+ * @keyid: key description (not partial)
+ */
+int verify_signature_one(const struct public_key_signature *sig,
+			   struct key *trusted_keys, const char *keyid)
+{
+	key_ref_t ref;
+	struct key *key;
+	int ret;
+
+	if (!sig)
+		return -EBADMSG;
+	if (!trusted_keys) {
+		trusted_keys = builtin_trusted_keys;
+	} else if (trusted_keys == (void *)1UL) {
+#ifdef CONFIG_SECONDARY_TRUSTED_KEYRING
+		trusted_keys = secondary_trusted_keys;
+#else
+		trusted_keys = builtin_trusted_keys;
+#endif
+	}
+
+	ref = keyring_search(make_key_ref(trusted_keys, 1),
+				&key_type_asymmetric, keyid);
+	if (IS_ERR(ref)) {
+		pr_err("Asymmetric key (%s) not found in keyring(%s)\n",
+				keyid, trusted_keys->description);
+		return -ENOKEY;
+	}
+
+	key = key_ref_to_ptr(ref);
+	ret = verify_signature(key, sig);
+	key_put(key);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(verify_signature_one);
+