ata: libata-scsi: fix ata_dsm_trim_pages() kernel-docgrafted

make htmldocs fails with:

  Documentation/driver-api/libata:604: ./drivers/ata/libata-scsi.c:2301:
  ERROR: Unexpected indentation. [docutils]

The Return: section of ata_dsm_trim_pages() ends its first sentence with
a colon and continues with an indented bullet list. reStructuredText
requires a blank line before an indented block, so docutils chokes on
the list.

Simply adding the missing blank line does not work either: Return: is a
kernel-doc "special section", which is terminated by the first blank
line, so the bullet list would end up in the Description section,
detached from the sentence introducing it.

Spell the two bounds out as prose instead, so that the Return: section
stays self-contained. Documentation-only change.

Fixes: e64e6b5dc867 ("ata: libata-scsi: scale DSM TRIM payload by MAX PAGES PER DSM COMMAND")
Reported-by: Thomas Huth <thuth@redhat.com>
Closes: https://lore.kernel.org/linux-ide/b0a0b8e8-cc4f-4c7b-8bc5-fee0712d405a@redhat.com/
Reviewed-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Link: https://lore.kernel.org/r/20260916130031.29990-2-cassel@kernel.org
Signed-off-by: Niklas Cassel <cassel@kernel.org>

12 files changed, 1413 insertions, 0 deletions

diff --git a/certs/.gitignore b/certs/.gitignore
new file mode 100644
index 000000000..cec5465f3
--- /dev/null
+++ b/certs/.gitignore
@@ -0,0 +1,5 @@
+# SPDX-License-Identifier: GPL-2.0-only
+/blacklist_hash_list
+/extract-cert
+/x509_certificate_list
+/x509_revocation_list
diff --git a/certs/Kconfig b/certs/Kconfig
new file mode 100644
index 000000000..9d2bf7fb5
--- /dev/null
+++ b/certs/Kconfig
@@ -0,0 +1,197 @@
+# 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 || (IMA_APPRAISE_MODSIG && MODULES)
+	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/admin-guide/module-signing.rst
+
+choice
+	prompt "Type of module signing key to be generated"
+	depends on MODULE_SIG || (IMA_APPRAISE_MODSIG && MODULES)
+	help
+	 The type of module signing key type to generate. This option
+	 does not apply if a #PKCS11 URI is used.
+
+config MODULE_SIG_KEY_TYPE_RSA
+	bool "RSA"
+	help
+	 Use an RSA key for module signing.
+
+config MODULE_SIG_KEY_TYPE_ECDSA
+	bool "ECDSA"
+	select CRYPTO_ECDSA
+	depends on !(MODULE_SIG_SHA256 || MODULE_SIG_SHA3_256)
+	help
+	 Use an elliptic curve key (NIST P384) for module signing. Use
+	 a strong hash of same or higher bit length, i.e. sha384 or
+	 sha512 for hashing modules.
+
+	 Note: Remove all ECDSA signing keys, e.g. certs/signing_key.pem,
+	 when falling back to building Linux 5.14 and older kernels.
+
+config MODULE_SIG_KEY_TYPE_MLDSA_44
+	bool "ML-DSA-44"
+	select CRYPTO_MLDSA
+	depends on OPENSSL_SUPPORTS_ML_DSA
+	help
+	  Use an ML-DSA-44 key (NIST FIPS 204) for module signing.  ML-DSA
+	  support requires OpenSSL-3.5 minimum; preferably OpenSSL-4+.  With
+	  the latter, the entire module body will be signed; with the former,
+	  signedAttrs will be used as it lacks support for CMS_NOATTR with
+	  ML-DSA.
+
+config MODULE_SIG_KEY_TYPE_MLDSA_65
+	bool "ML-DSA-65"
+	select CRYPTO_MLDSA
+	depends on OPENSSL_SUPPORTS_ML_DSA
+	help
+	  Use an ML-DSA-65 key (NIST FIPS 204) for module signing.  ML-DSA
+	  support requires OpenSSL-3.5 minimum; preferably OpenSSL-4+.  With
+	  the latter, the entire module body will be signed; with the former,
+	  signedAttrs will be used as it lacks support for CMS_NOATTR with
+	  ML-DSA.
+
+config MODULE_SIG_KEY_TYPE_MLDSA_87
+	bool "ML-DSA-87"
+	select CRYPTO_MLDSA
+	depends on OPENSSL_SUPPORTS_ML_DSA
+	help
+	  Use an ML-DSA-87 key (NIST FIPS 204) for module signing.  ML-DSA
+	  support requires OpenSSL-3.5 minimum; preferably OpenSSL-4+.  With
+	  the latter, the entire module body will be signed; with the former,
+	  signedAttrs will be used as it lacks support for CMS_NOATTR with
+	  ML-DSA.
+
+endchoice
+
+config SYSTEM_TRUSTED_KEYRING
+	bool "Provide system-wide ring of trusted keys"
+	depends on KEYS
+	depends on ASYMMETRIC_KEY_TYPE
+	depends on X509_CERTIFICATE_PARSER = y
+	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, machine keyring (if configured), or already in the
+	  secondary trusted keyring.
+
+config SECONDARY_TRUSTED_KEYRING_SIGNED_BY_BUILTIN
+	bool "Only allow additional certs signed by keys on the builtin trusted keyring"
+	depends on SECONDARY_TRUSTED_KEYRING
+	help
+	  If set, only certificates signed by keys on the builtin trusted
+	  keyring may be loaded onto the secondary trusted keyring.
+
+	  Note: The machine keyring, if configured, will be linked to the
+	  secondary keyring.  When enabling this option, it is recommended
+	  to also configure INTEGRITY_CA_MACHINE_KEYRING_MAX to prevent
+	  linking code signing keys with imputed trust to 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> must be a
+	  string starting with a prefix ("tbs" or "bin"), then a colon (":"), and
+	  finally an even number of hexadecimal lowercase characters (up to 128).
+	  Certificate hashes can be generated with
+	  tools/certs/print-cert-tbs-hash.sh .
+
+config SYSTEM_REVOCATION_LIST
+	bool "Provide system-wide ring of revocation certificates"
+	depends on SYSTEM_BLACKLIST_KEYRING
+	depends on PKCS7_MESSAGE_PARSER=y
+	help
+	  If set, this allows revocation certificates to be stored in the
+	  blacklist keyring and implements a hook whereby a PKCS#7 message can
+	  be checked to see if it matches such a certificate.
+
+config SYSTEM_REVOCATION_KEYS
+	string "X.509 certificates to be preloaded into the system blacklist keyring"
+	depends on SYSTEM_REVOCATION_LIST
+	help
+	  If set, this option should be the filename of a PEM-formatted file
+	  containing X.509 certificates to be included in the default blacklist
+	  keyring.
+
+config SYSTEM_BLACKLIST_AUTH_UPDATE
+	bool "Allow root to add signed blacklist keys"
+	depends on SYSTEM_BLACKLIST_KEYRING
+	depends on SYSTEM_DATA_VERIFICATION
+	help
+	  If set, provide the ability to load new blacklist keys at run time if
+	  they are signed and vouched by a certificate from the builtin trusted
+	  keyring.  The PKCS#7 signature of the description is set in the key
+	  payload.  Blacklist keys cannot be removed.
+
+config OPENSSL_SUPPORTS_ML_DSA
+	def_bool $(success, openssl list -key-managers | grep -q ML-DSA-87)
+	help
+	  Support for ML-DSA-44/65/87 was added in openssl-3.5, so as long
+	  as older versions are supported, the key types may only be
+	  set after testing the installed binary for support.
+
+endmenu
diff --git a/certs/Makefile b/certs/Makefile
new file mode 100644
index 000000000..3ee1960f9
--- /dev/null
+++ b/certs/Makefile
@@ -0,0 +1,91 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for the linux kernel signature checking certificates.
+#
+
+obj-$(CONFIG_SYSTEM_TRUSTED_KEYRING) += system_keyring.o system_certificates.o
+obj-$(CONFIG_SYSTEM_BLACKLIST_KEYRING) += blacklist.o blacklist_hashes.o
+obj-$(CONFIG_SYSTEM_REVOCATION_LIST) += revocation_certificates.o
+
+$(obj)/blacklist_hashes.o: $(obj)/blacklist_hash_list
+CFLAGS_blacklist_hashes.o := -I $(obj)
+
+quiet_cmd_check_and_copy_blacklist_hash_list = GEN     $@
+      cmd_check_and_copy_blacklist_hash_list = \
+	$(if $(CONFIG_SYSTEM_BLACKLIST_HASH_LIST), \
+	$(AWK) -f $(src)/check-blacklist-hashes.awk $(CONFIG_SYSTEM_BLACKLIST_HASH_LIST) >&2; \
+	{ cat $(CONFIG_SYSTEM_BLACKLIST_HASH_LIST); echo $(comma) NULL; } > $@, \
+	echo NULL > $@)
+
+$(obj)/blacklist_hash_list: $(CONFIG_SYSTEM_BLACKLIST_HASH_LIST) FORCE
+	$(call if_changed,check_and_copy_blacklist_hash_list)
+
+targets += blacklist_hash_list
+
+quiet_cmd_extract_certs  = CERT    $@
+      cmd_extract_certs  = $(obj)/extract-cert "$(extract-cert-in)" $@
+extract-cert-in = $(filter-out $(obj)/extract-cert, $(real-prereqs))
+
+$(obj)/system_certificates.o: $(obj)/x509_certificate_list
+
+$(obj)/x509_certificate_list: $(CONFIG_SYSTEM_TRUSTED_KEYS) $(obj)/extract-cert FORCE
+	$(call if_changed,extract_certs)
+
+targets += x509_certificate_list
+
+# If module signing is requested, say by allyesconfig, but a key has not been
+# supplied, then one will need to be generated to make sure the build does not
+# fail and that the kernel may be used afterwards.
+#
+# We do it this way rather than having a boolean option for enabling an
+# external private key, because 'make randconfig' might enable such a
+# boolean option and we unfortunately can't make it depend on !RANDCONFIG.
+ifeq ($(CONFIG_MODULE_SIG_KEY),certs/signing_key.pem)
+
+keytype-$(CONFIG_MODULE_SIG_KEY_TYPE_ECDSA) := -newkey ec -pkeyopt ec_paramgen_curve:secp384r1
+keytype-$(CONFIG_MODULE_SIG_KEY_TYPE_MLDSA_44) := -newkey ml-dsa-44
+keytype-$(CONFIG_MODULE_SIG_KEY_TYPE_MLDSA_65) := -newkey ml-dsa-65
+keytype-$(CONFIG_MODULE_SIG_KEY_TYPE_MLDSA_87) := -newkey ml-dsa-87
+
+quiet_cmd_gen_key = GENKEY  $@
+      cmd_gen_key = openssl req -new -nodes -utf8 -$(CONFIG_MODULE_SIG_HASH) -days 36500 \
+		-batch -x509 -config $< \
+		-outform PEM -out $@ -keyout $@ $(keytype-y) 2>&1
+
+$(obj)/signing_key.pem: $(obj)/x509.genkey FORCE
+	$(call if_changed,gen_key)
+
+targets += signing_key.pem
+
+quiet_cmd_copy_x509_config = COPY    $@
+      cmd_copy_x509_config = cat $(src)/default_x509.genkey > $@
+
+# You can provide your own config file. If not present, copy the default one.
+$(obj)/x509.genkey:
+	$(call cmd,copy_x509_config)
+
+endif # CONFIG_MODULE_SIG_KEY
+
+$(obj)/system_certificates.o: $(obj)/signing_key.x509
+
+PKCS11_URI := $(filter pkcs11:%, $(CONFIG_MODULE_SIG_KEY))
+ifdef PKCS11_URI
+$(obj)/signing_key.x509: extract-cert-in := $(PKCS11_URI)
+endif
+
+$(obj)/signing_key.x509: $(filter-out $(PKCS11_URI),$(CONFIG_MODULE_SIG_KEY)) $(obj)/extract-cert FORCE
+	$(call if_changed,extract_certs)
+
+targets += signing_key.x509
+
+$(obj)/revocation_certificates.o: $(obj)/x509_revocation_list
+
+$(obj)/x509_revocation_list: $(CONFIG_SYSTEM_REVOCATION_KEYS) $(obj)/extract-cert FORCE
+	$(call if_changed,extract_certs)
+
+targets += x509_revocation_list
+
+hostprogs := extract-cert
+
+HOSTCFLAGS_extract-cert.o = $(shell $(HOSTPKG_CONFIG) --cflags libcrypto 2> /dev/null) -I$(srctree)/scripts
+HOSTLDLIBS_extract-cert = $(shell $(HOSTPKG_CONFIG) --libs libcrypto 2> /dev/null || echo -lcrypto)
diff --git a/certs/blacklist.c b/certs/blacklist.c
new file mode 100644
index 000000000..fa561c12e
--- /dev/null
+++ b/certs/blacklist.c
@@ -0,0 +1,376 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* System hash blacklist.
+ *
+ * Copyright (C) 2016 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#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/hex.h>
+#include <linux/seq_file.h>
+#include <linux/uidgid.h>
+#include <keys/asymmetric-type.h>
+#include <keys/system_keyring.h>
+#include "blacklist.h"
+
+/*
+ * According to crypto/asymmetric_keys/x509_cert_parser.c:x509_note_pkey_algo(),
+ * the size of the currently longest supported hash algorithm is 512 bits,
+ * which translates into 128 hex characters.
+ */
+#define MAX_HASH_LEN	128
+
+#define BLACKLIST_KEY_PERM (KEY_POS_SEARCH | KEY_POS_VIEW | \
+			    KEY_USR_SEARCH | KEY_USR_VIEW)
+
+static const char tbs_prefix[] = "tbs";
+static const char bin_prefix[] = "bin";
+
+static struct key *blacklist_keyring;
+
+#ifdef CONFIG_SYSTEM_REVOCATION_LIST
+extern __initconst const u8 revocation_certificate_list[];
+extern __initconst const unsigned long revocation_certificate_list_size;
+#endif
+
+/*
+ * 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 i, prefix_len, tbs_step = 0, bin_step = 0;
+
+	/* The following algorithm only works if prefix lengths match. */
+	BUILD_BUG_ON(sizeof(tbs_prefix) != sizeof(bin_prefix));
+	prefix_len = sizeof(tbs_prefix) - 1;
+	for (i = 0; *desc; desc++, i++) {
+		if (*desc == ':') {
+			if (tbs_step == prefix_len)
+				goto found_colon;
+			if (bin_step == prefix_len)
+				goto found_colon;
+			return -EINVAL;
+		}
+		if (i >= prefix_len)
+			return -EINVAL;
+		if (*desc == tbs_prefix[i])
+			tbs_step++;
+		if (*desc == bin_prefix[i])
+			bin_step++;
+	}
+	return -EINVAL;
+
+found_colon:
+	desc++;
+	for (i = 0; *desc && i < MAX_HASH_LEN; desc++, i++) {
+		if (!isxdigit(*desc) || isupper(*desc))
+			return -EINVAL;
+	}
+	if (*desc)
+		/* The hash is greater than MAX_HASH_LEN. */
+		return -ENOPKG;
+
+	/* Checks for an even number of hexadecimal characters. */
+	if (i == 0 || i & 1)
+		return -EINVAL;
+	return 0;
+}
+
+static int blacklist_key_instantiate(struct key *key,
+		struct key_preparsed_payload *prep)
+{
+#ifdef CONFIG_SYSTEM_BLACKLIST_AUTH_UPDATE
+	int err;
+#endif
+
+	/* Sets safe default permissions for keys loaded by user space. */
+	key->perm = BLACKLIST_KEY_PERM;
+
+	/*
+	 * Skips the authentication step for builtin hashes, they are not
+	 * signed but still trusted.
+	 */
+	if (key->flags & (1 << KEY_FLAG_BUILTIN))
+		goto out;
+
+#ifdef CONFIG_SYSTEM_BLACKLIST_AUTH_UPDATE
+	/*
+	 * Verifies the description's PKCS#7 signature against the builtin
+	 * trusted keyring.
+	 */
+	err = verify_pkcs7_signature(key->description,
+			strlen(key->description), prep->data, prep->datalen,
+			NULL, VERIFYING_UNSPECIFIED_SIGNATURE, NULL, NULL);
+	if (err)
+		return err;
+#else
+	/*
+	 * It should not be possible to come here because the keyring doesn't
+	 * have KEY_USR_WRITE and the only other way to call this function is
+	 * for builtin hashes.
+	 */
+	WARN_ON_ONCE(1);
+	return -EPERM;
+#endif
+
+out:
+	return generic_key_instantiate(key, prep);
+}
+
+static int blacklist_key_update(struct key *key,
+		struct key_preparsed_payload *prep)
+{
+	return -EPERM;
+}
+
+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,
+	.instantiate		= blacklist_key_instantiate,
+	.update			= blacklist_key_update,
+	.describe		= blacklist_describe,
+};
+
+static char *get_raw_hash(const u8 *hash, size_t hash_len,
+		enum blacklist_hash_type hash_type)
+{
+	size_t type_len;
+	const char *type_prefix;
+	char *buffer, *p;
+
+	switch (hash_type) {
+	case BLACKLIST_HASH_X509_TBS:
+		type_len = sizeof(tbs_prefix) - 1;
+		type_prefix = tbs_prefix;
+		break;
+	case BLACKLIST_HASH_BINARY:
+		type_len = sizeof(bin_prefix) - 1;
+		type_prefix = bin_prefix;
+		break;
+	default:
+		WARN_ON_ONCE(1);
+		return ERR_PTR(-EINVAL);
+	}
+	buffer = kmalloc(type_len + 1 + hash_len * 2 + 1, GFP_KERNEL);
+	if (!buffer)
+		return ERR_PTR(-ENOMEM);
+	p = memcpy(buffer, type_prefix, type_len);
+	p += type_len;
+	*p++ = ':';
+	bin2hex(p, hash, hash_len);
+	p += hash_len * 2;
+	*p = '\0';
+	return buffer;
+}
+
+/**
+ * mark_raw_hash_blacklisted - Add a hash to the system blacklist
+ * @hash: The hash as a hex string with a type prefix (eg. "tbs:23aa429783")
+ */
+static int mark_raw_hash_blacklisted(const char *hash)
+{
+	key_ref_t key;
+
+	key = key_create(make_key_ref(blacklist_keyring, true),
+			 "blacklist",
+			 hash,
+			 NULL,
+			 0,
+			 BLACKLIST_KEY_PERM,
+			 KEY_ALLOC_NOT_IN_QUOTA |
+			 KEY_ALLOC_BUILT_IN);
+	if (IS_ERR(key)) {
+		if (PTR_ERR(key) == -EEXIST)
+			pr_warn("Duplicate blacklisted hash %s\n", hash);
+		else
+			pr_err("Problem blacklisting hash %s: %pe\n", hash, key);
+		return PTR_ERR(key);
+	}
+	return 0;
+}
+
+int mark_hash_blacklisted(const u8 *hash, size_t hash_len,
+		enum blacklist_hash_type hash_type)
+{
+	const char *buffer;
+	int err;
+
+	buffer = get_raw_hash(hash, hash_len, hash_type);
+	if (IS_ERR(buffer))
+		return PTR_ERR(buffer);
+	err = mark_raw_hash_blacklisted(buffer);
+	kfree(buffer);
+	return err;
+}
+
+/**
+ * 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
+ * @hash_type: Type of hash
+ */
+int is_hash_blacklisted(const u8 *hash, size_t hash_len,
+		enum blacklist_hash_type hash_type)
+{
+	key_ref_t kref;
+	const char *buffer;
+	int ret = 0;
+
+	buffer = get_raw_hash(hash, hash_len, hash_type);
+	if (IS_ERR(buffer))
+		return PTR_ERR(buffer);
+	kref = keyring_search(make_key_ref(blacklist_keyring, true),
+			      &key_type_blacklist, buffer, false);
+	if (!IS_ERR(kref)) {
+		key_ref_put(kref);
+		ret = -EKEYREJECTED;
+	}
+
+	kfree(buffer);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(is_hash_blacklisted);
+
+int is_binary_blacklisted(const u8 *hash, size_t hash_len)
+{
+	if (is_hash_blacklisted(hash, hash_len, BLACKLIST_HASH_BINARY) ==
+			-EKEYREJECTED)
+		return -EPERM;
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(is_binary_blacklisted);
+
+#ifdef CONFIG_SYSTEM_REVOCATION_LIST
+/**
+ * add_key_to_revocation_list - Add a revocation certificate to the blacklist
+ * @data: The data blob containing the certificate
+ * @size: The size of data blob
+ */
+int add_key_to_revocation_list(const char *data, size_t size)
+{
+	key_ref_t key;
+
+	key = key_create_or_update(make_key_ref(blacklist_keyring, true),
+				   "asymmetric",
+				   NULL,
+				   data,
+				   size,
+				   KEY_POS_VIEW | KEY_POS_READ | KEY_POS_SEARCH
+				   | KEY_USR_VIEW,
+				   KEY_ALLOC_NOT_IN_QUOTA | KEY_ALLOC_BUILT_IN
+				   | KEY_ALLOC_BYPASS_RESTRICTION);
+
+	if (IS_ERR(key)) {
+		pr_err("Problem with revocation key (%ld)\n", PTR_ERR(key));
+		return PTR_ERR(key);
+	}
+
+	return 0;
+}
+
+/**
+ * is_key_on_revocation_list - Determine if the key for a PKCS#7 message is revoked
+ * @pkcs7: The PKCS#7 message to check
+ */
+int is_key_on_revocation_list(struct pkcs7_message *pkcs7)
+{
+	int ret;
+
+	ret = pkcs7_validate_trust(pkcs7, blacklist_keyring);
+
+	if (ret == 0)
+		return -EKEYREJECTED;
+
+	return -ENOKEY;
+}
+#endif
+
+static int restrict_link_for_blacklist(struct key *dest_keyring,
+		const struct key_type *type, const union key_payload *payload,
+		struct key *restrict_key)
+{
+	if (type == &key_type_blacklist)
+		return 0;
+	return -EOPNOTSUPP;
+}
+
+/*
+ * Initialise the blacklist
+ *
+ * The blacklist_init() function is registered as an initcall via
+ * device_initcall().  As a result if the blacklist_init() function fails for
+ * any reason the kernel continues to execute.  While cleanly returning -ENODEV
+ * could be acceptable for some non-critical kernel parts, if the blacklist
+ * keyring fails to load it defeats the certificate/key based deny list for
+ * signed modules.  If a critical piece of security functionality that users
+ * expect to be present fails to initialize, panic()ing is likely the right
+ * thing to do.
+ */
+static int __init blacklist_init(void)
+{
+	const char *const *bl;
+	struct key_restriction *restriction;
+
+	if (register_key_type(&key_type_blacklist) < 0)
+		panic("Can't allocate system blacklist key type\n");
+
+	restriction = kzalloc_obj(*restriction);
+	if (!restriction)
+		panic("Can't allocate blacklist keyring restriction\n");
+	restriction->check = restrict_link_for_blacklist;
+
+	blacklist_keyring =
+		keyring_alloc(".blacklist",
+			      GLOBAL_ROOT_UID, GLOBAL_ROOT_GID, current_cred(),
+			      KEY_POS_VIEW | KEY_POS_READ | KEY_POS_SEARCH |
+			      KEY_POS_WRITE |
+			      KEY_USR_VIEW | KEY_USR_READ | KEY_USR_SEARCH
+#ifdef CONFIG_SYSTEM_BLACKLIST_AUTH_UPDATE
+			      | KEY_USR_WRITE
+#endif
+			      , KEY_ALLOC_NOT_IN_QUOTA |
+			      KEY_ALLOC_SET_KEEP,
+			      restriction, NULL);
+	if (IS_ERR(blacklist_keyring))
+		panic("Can't allocate system blacklist keyring\n");
+
+	for (bl = blacklist_hashes; *bl; bl++)
+		if (mark_raw_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);
+
+#ifdef CONFIG_SYSTEM_REVOCATION_LIST
+/*
+ * Load the compiled-in list of revocation X.509 certificates.
+ */
+static __init int load_revocation_certificate_list(void)
+{
+	if (revocation_certificate_list_size)
+		pr_notice("Loading compiled-in revocation X.509 certificates\n");
+
+	return x509_load_certificate_list(revocation_certificate_list,
+					  revocation_certificate_list_size,
+					  blacklist_keyring);
+}
+late_initcall(load_revocation_certificate_list);
+#endif
diff --git a/certs/blacklist.h b/certs/blacklist.h
new file mode 100644
index 000000000..51b320cf8
--- /dev/null
+++ b/certs/blacklist.h
@@ -0,0 +1,5 @@
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <crypto/pkcs7.h>
+
+extern const char __initconst *const blacklist_hashes[];
diff --git a/certs/blacklist_hashes.c b/certs/blacklist_hashes.c
new file mode 100644
index 000000000..0c5476abe
--- /dev/null
+++ b/certs/blacklist_hashes.c
@@ -0,0 +1,6 @@
+// SPDX-License-Identifier: GPL-2.0
+#include "blacklist.h"
+
+const char __initconst *const blacklist_hashes[] = {
+#include "blacklist_hash_list"
+};
diff --git a/certs/check-blacklist-hashes.awk b/certs/check-blacklist-hashes.awk
new file mode 100755
index 000000000..107c1d320
--- /dev/null
+++ b/certs/check-blacklist-hashes.awk
@@ -0,0 +1,37 @@
+#!/usr/bin/awk -f
+# SPDX-License-Identifier: GPL-2.0
+#
+# Copyright © 2020, Microsoft Corporation. All rights reserved.
+#
+# Author: Mickaël Salaün <mic@linux.microsoft.com>
+#
+# Check that a CONFIG_SYSTEM_BLACKLIST_HASH_LIST file contains a valid array of
+# hash strings.  Such string must start with a prefix ("tbs" or "bin"), then a
+# colon (":"), and finally an even number of hexadecimal lowercase characters
+# (up to 128).
+
+BEGIN {
+	RS = ","
+}
+{
+	if (!match($0, "^[ \t\n\r]*\"([^\"]*)\"[ \t\n\r]*$", part1)) {
+		print "Not a string (item " NR "):", $0;
+		exit 1;
+	}
+	if (!match(part1[1], "^(tbs|bin):(.*)$", part2)) {
+		print "Unknown prefix (item " NR "):", part1[1];
+		exit 1;
+	}
+	if (!match(part2[2], "^([0-9a-f]+)$", part3)) {
+		print "Not a lowercase hexadecimal string (item " NR "):", part2[2];
+		exit 1;
+	}
+	if (length(part3[1]) > 128) {
+		print "Hash string too long (item " NR "):", part3[1];
+		exit 1;
+	}
+	if (length(part3[1]) % 2 == 1) {
+		print "Not an even number of hexadecimal characters (item " NR "):", part3[1];
+		exit 1;
+	}
+}
diff --git a/certs/default_x509.genkey b/certs/default_x509.genkey
new file mode 100644
index 000000000..d4c6628cb
--- /dev/null
+++ b/certs/default_x509.genkey
@@ -0,0 +1,17 @@
+[ req ]
+default_bits = 4096
+distinguished_name = req_distinguished_name
+prompt = no
+string_mask = utf8only
+x509_extensions = myexts
+
+[ req_distinguished_name ]
+#O = Unspecified company
+CN = Build time autogenerated kernel key
+#emailAddress = unspecified.user@unspecified.company
+
+[ myexts ]
+basicConstraints=critical,CA:FALSE
+keyUsage=digitalSignature
+subjectKeyIdentifier=hash
+authorityKeyIdentifier=keyid
diff --git a/certs/extract-cert.c b/certs/extract-cert.c
new file mode 100644
index 000000000..f3eb2c492
--- /dev/null
+++ b/certs/extract-cert.c
@@ -0,0 +1,184 @@
+/* Extract X.509 certificate in DER form from PKCS#11 or PEM.
+ *
+ * Copyright © 2014-2015 Red Hat, Inc. All Rights Reserved.
+ * Copyright © 2015      Intel Corporation.
+ *
+ * Authors: David Howells <dhowells@redhat.com>
+ *          David Woodhouse <dwmw2@infradead.org>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public License
+ * as published by the Free Software Foundation; either version 2.1
+ * of the licence, or (at your option) any later version.
+ */
+#define _GNU_SOURCE
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <stdbool.h>
+#include <string.h>
+#include <err.h>
+#include <openssl/bio.h>
+#include <openssl/pem.h>
+#include <openssl/err.h>
+#if OPENSSL_VERSION_MAJOR >= 3
+# define USE_PKCS11_PROVIDER
+# include <openssl/provider.h>
+# include <openssl/store.h>
+#else
+# if !defined(OPENSSL_NO_ENGINE) && !defined(OPENSSL_NO_DEPRECATED_3_0)
+#  define USE_PKCS11_ENGINE
+#  include <openssl/engine.h>
+# endif
+#endif
+#include "ssl-common.h"
+
+static __attribute__((noreturn))
+void format(void)
+{
+	fprintf(stderr,
+		"Usage: extract-cert <source> <dest>\n");
+	exit(2);
+}
+
+#ifdef USE_PKCS11_ENGINE
+static const char *key_pass;
+#endif
+static BIO *wb;
+static char *cert_dst;
+static bool verbose;
+
+static void write_cert(X509 *x509)
+{
+	char buf[200];
+
+	if (!wb) {
+		wb = BIO_new_file(cert_dst, "wb");
+		ERR(!wb, "%s", cert_dst);
+	}
+	X509_NAME_oneline(X509_get_subject_name(x509), buf, sizeof(buf));
+	ERR(!i2d_X509_bio(wb, x509), "%s", cert_dst);
+	if (verbose)
+		fprintf(stderr, "Extracted cert: %s\n", buf);
+}
+
+static X509 *load_cert_pkcs11(const char *cert_src)
+{
+	X509 *cert = NULL;
+#ifdef USE_PKCS11_PROVIDER
+	OSSL_STORE_CTX *store;
+
+	if (!OSSL_PROVIDER_try_load(NULL, "pkcs11", true))
+		ERR(1, "OSSL_PROVIDER_try_load(pkcs11)");
+	if (!OSSL_PROVIDER_try_load(NULL, "default", true))
+		ERR(1, "OSSL_PROVIDER_try_load(default)");
+
+	store = OSSL_STORE_open(cert_src, NULL, NULL, NULL, NULL);
+	ERR(!store, "OSSL_STORE_open");
+
+	while (!OSSL_STORE_eof(store)) {
+		OSSL_STORE_INFO *info = OSSL_STORE_load(store);
+
+		if (!info) {
+			drain_openssl_errors(__LINE__, 0);
+			continue;
+		}
+		if (OSSL_STORE_INFO_get_type(info) == OSSL_STORE_INFO_CERT) {
+			cert = OSSL_STORE_INFO_get1_CERT(info);
+			ERR(!cert, "OSSL_STORE_INFO_get1_CERT");
+		}
+		OSSL_STORE_INFO_free(info);
+		if (cert)
+			break;
+	}
+	OSSL_STORE_close(store);
+#elif defined(USE_PKCS11_ENGINE)
+		ENGINE *e;
+		struct {
+			const char *cert_id;
+			X509 *cert;
+		} parms;
+
+		parms.cert_id = cert_src;
+		parms.cert = NULL;
+
+		ENGINE_load_builtin_engines();
+		drain_openssl_errors(__LINE__, 1);
+		e = ENGINE_by_id("pkcs11");
+		ERR(!e, "Load PKCS#11 ENGINE");
+		if (ENGINE_init(e))
+			drain_openssl_errors(__LINE__, 1);
+		else
+			ERR(1, "ENGINE_init");
+		if (key_pass)
+			ERR(!ENGINE_ctrl_cmd_string(e, "PIN", key_pass, 0), "Set PKCS#11 PIN");
+		ENGINE_ctrl_cmd(e, "LOAD_CERT_CTRL", 0, &parms, NULL, 1);
+		ERR(!parms.cert, "Get X.509 from PKCS#11");
+		cert = parms.cert;
+#else
+		fprintf(stderr, "no pkcs11 engine/provider available\n");
+		exit(1);
+#endif
+	return cert;
+}
+
+int main(int argc, char **argv)
+{
+	char *cert_src;
+	char *verbose_env;
+
+	OpenSSL_add_all_algorithms();
+	ERR_load_crypto_strings();
+	ERR_clear_error();
+
+	verbose_env = getenv("KBUILD_VERBOSE");
+	if (verbose_env && strchr(verbose_env, '1'))
+		verbose = true;
+
+#ifdef USE_PKCS11_ENGINE
+	key_pass = getenv("KBUILD_SIGN_PIN");
+#endif
+
+	if (argc != 3)
+		format();
+
+	cert_src = argv[1];
+	cert_dst = argv[2];
+
+	if (!cert_src[0]) {
+		/* Invoked with no input; create empty file */
+		FILE *f = fopen(cert_dst, "wb");
+		ERR(!f, "%s", cert_dst);
+		fclose(f);
+		exit(0);
+	} else if (!strncmp(cert_src, "pkcs11:", 7)) {
+		X509 *cert = load_cert_pkcs11(cert_src);
+
+		ERR(!cert, "load_cert_pkcs11 failed");
+		write_cert(cert);
+	} else {
+		BIO *b;
+		X509 *x509;
+
+		b = BIO_new_file(cert_src, "rb");
+		ERR(!b, "%s", cert_src);
+
+		while (1) {
+			x509 = PEM_read_bio_X509(b, NULL, NULL, NULL);
+			if (wb && !x509) {
+				unsigned long err = ERR_peek_last_error();
+				if (ERR_GET_LIB(err) == ERR_LIB_PEM &&
+				    ERR_GET_REASON(err) == PEM_R_NO_START_LINE) {
+					ERR_clear_error();
+					break;
+				}
+			}
+			ERR(!x509, "%s", cert_src);
+			write_cert(x509);
+		}
+	}
+
+	BIO_free(wb);
+
+	return 0;
+}
diff --git a/certs/revocation_certificates.S b/certs/revocation_certificates.S
new file mode 100644
index 000000000..f21aae8a8
--- /dev/null
+++ b/certs/revocation_certificates.S
@@ -0,0 +1,21 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#include <linux/export.h>
+#include <linux/init.h>
+
+	__INITRODATA
+
+	.align 8
+	.globl revocation_certificate_list
+revocation_certificate_list:
+__revocation_list_start:
+	.incbin "certs/x509_revocation_list"
+__revocation_list_end:
+
+	.align 8
+	.globl revocation_certificate_list_size
+revocation_certificate_list_size:
+#ifdef CONFIG_64BIT
+	.quad __revocation_list_end - __revocation_list_start
+#else
+	.long __revocation_list_end - __revocation_list_start
+#endif
diff --git a/certs/system_certificates.S b/certs/system_certificates.S
new file mode 100644
index 000000000..003e25d4a
--- /dev/null
+++ b/certs/system_certificates.S
@@ -0,0 +1,46 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#include <linux/export.h>
+#include <linux/init.h>
+
+	__INITRODATA
+
+	.align 8
+	.globl system_certificate_list
+system_certificate_list:
+__cert_list_start:
+__module_cert_start:
+	.incbin "certs/signing_key.x509"
+__module_cert_end:
+	.incbin "certs/x509_certificate_list"
+__cert_list_end:
+
+#ifdef CONFIG_SYSTEM_EXTRA_CERTIFICATE
+	.globl system_extra_cert
+	.size system_extra_cert, CONFIG_SYSTEM_EXTRA_CERTIFICATE_SIZE
+system_extra_cert:
+	.fill CONFIG_SYSTEM_EXTRA_CERTIFICATE_SIZE, 1, 0
+
+	.align 4
+	.globl system_extra_cert_used
+system_extra_cert_used:
+	.int 0
+
+#endif /* CONFIG_SYSTEM_EXTRA_CERTIFICATE */
+
+	.align 8
+	.globl system_certificate_list_size
+system_certificate_list_size:
+#ifdef CONFIG_64BIT
+	.quad __cert_list_end - __cert_list_start
+#else
+	.long __cert_list_end - __cert_list_start
+#endif
+
+	.align 8
+	.globl module_cert_size
+module_cert_size:
+#ifdef CONFIG_64BIT
+	.quad __module_cert_end - __module_cert_start
+#else
+	.long __module_cert_end - __module_cert_start
+#endif
diff --git a/certs/system_keyring.c b/certs/system_keyring.c
new file mode 100644
index 000000000..e0761436e
--- /dev/null
+++ b/certs/system_keyring.c
@@ -0,0 +1,428 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* System trusted keyring for trusted public keys
+ *
+ * Copyright (C) 2012 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ */
+
+#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/uidgid.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
+#ifdef CONFIG_INTEGRITY_MACHINE_KEYRING
+static struct key *machine_trusted_keys;
+#endif
+#ifdef CONFIG_INTEGRITY_PLATFORM_KEYRING
+static struct key *platform_trusted_keys;
+#endif
+
+extern __initconst const u8 system_certificate_list[];
+extern __initconst const unsigned long system_certificate_list_size;
+extern __initconst const unsigned long module_cert_size;
+
+/**
+ * restrict_link_by_builtin_trusted - Restrict keyring addition by built-in CA
+ * @dest_keyring: Keyring being linked to.
+ * @type: The type of key being added.
+ * @payload: The payload of the new key.
+ * @restriction_key: A ring of keys that can be used to vouch for the new cert.
+ *
+ * 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);
+}
+
+/**
+ * restrict_link_by_digsig_builtin - Restrict digitalSignature key additions by the built-in keyring
+ * @dest_keyring: Keyring being linked to.
+ * @type: The type of key being added.
+ * @payload: The payload of the new key.
+ * @restriction_key: A ring of keys that can be used to vouch for the new cert.
+ *
+ * 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. The new key
+ * must have the digitalSignature usage field set.
+ */
+int restrict_link_by_digsig_builtin(struct key *dest_keyring,
+				    const struct key_type *type,
+				    const union key_payload *payload,
+				    struct key *restriction_key)
+{
+	return restrict_link_by_digsig(dest_keyring, type, payload,
+				       builtin_trusted_keys);
+}
+
+#ifdef CONFIG_SECONDARY_TRUSTED_KEYRING
+/**
+ * restrict_link_by_builtin_and_secondary_trusted - Restrict keyring
+ *   addition by both built-in and secondary keyrings.
+ * @dest_keyring: Keyring being linked to.
+ * @type: The type of key being added.
+ * @payload: The payload of the new key.
+ * @restrict_key: A ring of keys that can be used to vouch for the new cert.
+ *
+ * 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);
+}
+
+/**
+ * restrict_link_by_digsig_builtin_and_secondary - Restrict by digitalSignature.
+ * @dest_keyring: Keyring being linked to.
+ * @type: The type of key being added.
+ * @payload: The payload of the new key.
+ * @restrict_key: A ring of keys that can be used to vouch for the new cert.
+ *
+ * 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. The new key must have the digitalSignature usage field set.
+ */
+int restrict_link_by_digsig_builtin_and_secondary(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_digsig(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_obj(struct key_restriction);
+
+	if (!restriction)
+		panic("Can't allocate secondary trusted keyring restriction\n");
+
+	if (IS_ENABLED(CONFIG_INTEGRITY_MACHINE_KEYRING))
+		restriction->check = restrict_link_by_builtin_secondary_and_machine;
+	else
+		restriction->check = restrict_link_by_builtin_and_secondary_trusted;
+
+	return restriction;
+}
+
+/**
+ * add_to_secondary_keyring - Add to secondary keyring.
+ * @source: Source of key
+ * @data: The blob holding the key
+ * @len: The length of the data blob
+ *
+ * Add a key to the secondary keyring. The key must be vouched for by a key in the builtin,
+ * machine or secondary keyring itself.
+ */
+void __init add_to_secondary_keyring(const char *source, const void *data, size_t len)
+{
+	key_ref_t key;
+	key_perm_t perm;
+
+	perm = (KEY_POS_ALL & ~KEY_POS_SETATTR) | KEY_USR_VIEW;
+
+	key = key_create_or_update(make_key_ref(secondary_trusted_keys, 1),
+				   "asymmetric",
+				   NULL, data, len, perm,
+				   KEY_ALLOC_NOT_IN_QUOTA);
+	if (IS_ERR(key)) {
+		pr_err("Problem loading X.509 certificate from %s to secondary keyring %ld\n",
+		       source, PTR_ERR(key));
+		return;
+	}
+
+	pr_notice("Loaded X.509 cert '%s'\n", key_ref_to_ptr(key)->description);
+	key_ref_put(key);
+}
+#endif
+#ifdef CONFIG_INTEGRITY_MACHINE_KEYRING
+void __init set_machine_trusted_keys(struct key *keyring)
+{
+	machine_trusted_keys = keyring;
+
+	if (key_link(secondary_trusted_keys, machine_trusted_keys) < 0)
+		panic("Can't link (machine) trusted keyrings\n");
+}
+
+/**
+ * restrict_link_by_builtin_secondary_and_machine - Restrict keyring addition.
+ * @dest_keyring: Keyring being linked to.
+ * @type: The type of key being added.
+ * @payload: The payload of the new key.
+ * @restrict_key: A ring of keys that can be used to vouch for the new cert.
+ *
+ * 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, the secondary, or
+ * the machine keyrings.
+ */
+int restrict_link_by_builtin_secondary_and_machine(
+	struct key *dest_keyring,
+	const struct key_type *type,
+	const union key_payload *payload,
+	struct key *restrict_key)
+{
+	if (machine_trusted_keys && type == &key_type_keyring &&
+	    dest_keyring == secondary_trusted_keys &&
+	    payload == &machine_trusted_keys->payload)
+		/* Allow the machine keyring to be added to the secondary */
+		return 0;
+
+	return restrict_link_by_builtin_and_secondary_trusted(dest_keyring, type,
+							      payload, restrict_key);
+}
+#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",
+			      GLOBAL_ROOT_UID, GLOBAL_ROOT_GID, 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",
+			      GLOBAL_ROOT_UID, GLOBAL_ROOT_GID, 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);
+
+__init int load_module_cert(struct key *keyring)
+{
+	if (!IS_ENABLED(CONFIG_IMA_APPRAISE_MODSIG))
+		return 0;
+
+	pr_notice("Loading compiled-in module X.509 certificates\n");
+
+	return x509_load_certificate_list(system_certificate_list,
+					  module_cert_size, keyring);
+}
+
+/*
+ * Load the compiled-in list of X.509 certificates.
+ */
+static __init int load_system_certificate_list(void)
+{
+	const u8 *p;
+	unsigned long size;
+
+	pr_notice("Loading compiled-in X.509 certificates\n");
+
+#ifdef CONFIG_MODULE_SIG
+	p = system_certificate_list;
+	size = system_certificate_list_size;
+#else
+	p = system_certificate_list + module_cert_size;
+	size = system_certificate_list_size - module_cert_size;
+#endif
+
+	return x509_load_certificate_list(p, size, builtin_trusted_keys);
+}
+late_initcall(load_system_certificate_list);
+
+#ifdef CONFIG_SYSTEM_DATA_VERIFICATION
+
+/**
+ * verify_pkcs7_message_sig - Verify a PKCS#7-based signature on system data.
+ * @data: The data to be verified (NULL if expecting internal data).
+ * @len: Size of @data.
+ * @pkcs7: The PKCS#7 message that is the signature.
+ * @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_message_sig(const void *data, size_t len,
+			     struct pkcs7_message *pkcs7,
+			     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)
+{
+	int ret;
+
+	/* 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;
+
+	ret = is_key_on_revocation_list(pkcs7);
+	if (ret != -ENOKEY) {
+		pr_devel("PKCS#7 key is on revocation list\n");
+		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
+	} else if (trusted_keys == VERIFY_USE_PLATFORM_KEYRING) {
+#ifdef CONFIG_INTEGRITY_PLATFORM_KEYRING
+		trusted_keys = platform_trusted_keys;
+#else
+		trusted_keys = NULL;
+#endif
+		if (!trusted_keys) {
+			ret = -ENOKEY;
+			pr_devel("PKCS#7 platform keyring is not available\n");
+			goto error;
+		}
+	}
+	ret = pkcs7_validate_trust(pkcs7, trusted_keys);
+	if (ret < 0) {
+		if (ret == -ENOKEY)
+			pr_devel("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:
+	pr_devel("<==%s() = %d\n", __func__, ret);
+	return ret;
+}
+
+/**
+ * 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);
+
+	ret = verify_pkcs7_message_sig(data, len, pkcs7, trusted_keys, usage,
+				       view_content, ctx);
+
+	pkcs7_free_message(pkcs7);
+	pr_devel("<==%s() = %d\n", __func__, ret);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(verify_pkcs7_signature);
+
+#endif /* CONFIG_SYSTEM_DATA_VERIFICATION */
+
+#ifdef CONFIG_INTEGRITY_PLATFORM_KEYRING
+void __init set_platform_trusted_keys(struct key *keyring)
+{
+	platform_trusted_keys = keyring;
+}
+#endif