v4.19.13 snapshot.
diff --git a/security/integrity/digsig.c b/security/integrity/digsig.c
new file mode 100644
index 0000000..9bb0a7f
--- /dev/null
+++ b/security/integrity/digsig.c
@@ -0,0 +1,149 @@
+/*
+ * Copyright (C) 2011 Intel Corporation
+ *
+ * Author:
+ * Dmitry Kasatkin <dmitry.kasatkin@intel.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, version 2 of the License.
+ *
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/err.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/cred.h>
+#include <linux/key-type.h>
+#include <linux/digsig.h>
+#include <linux/vmalloc.h>
+#include <crypto/public_key.h>
+#include <keys/system_keyring.h>
+
+#include "integrity.h"
+
+static struct key *keyring[INTEGRITY_KEYRING_MAX];
+
+static const char *keyring_name[INTEGRITY_KEYRING_MAX] = {
+#ifndef CONFIG_INTEGRITY_TRUSTED_KEYRING
+ "_evm",
+ "_ima",
+#else
+ ".evm",
+ ".ima",
+#endif
+ "_module",
+};
+
+#ifdef CONFIG_INTEGRITY_TRUSTED_KEYRING
+static bool init_keyring __initdata = true;
+#else
+static bool init_keyring __initdata;
+#endif
+
+#ifdef CONFIG_IMA_KEYRINGS_PERMIT_SIGNED_BY_BUILTIN_OR_SECONDARY
+#define restrict_link_to_ima restrict_link_by_builtin_and_secondary_trusted
+#else
+#define restrict_link_to_ima restrict_link_by_builtin_trusted
+#endif
+
+int integrity_digsig_verify(const unsigned int id, const char *sig, int siglen,
+ const char *digest, int digestlen)
+{
+ if (id >= INTEGRITY_KEYRING_MAX || siglen < 2)
+ return -EINVAL;
+
+ if (!keyring[id]) {
+ keyring[id] =
+ request_key(&key_type_keyring, keyring_name[id], NULL);
+ if (IS_ERR(keyring[id])) {
+ int err = PTR_ERR(keyring[id]);
+ pr_err("no %s keyring: %d\n", keyring_name[id], err);
+ keyring[id] = NULL;
+ return err;
+ }
+ }
+
+ switch (sig[1]) {
+ case 1:
+ /* v1 API expect signature without xattr type */
+ return digsig_verify(keyring[id], sig + 1, siglen - 1,
+ digest, digestlen);
+ case 2:
+ return asymmetric_verify(keyring[id], sig, siglen,
+ digest, digestlen);
+ }
+
+ return -EOPNOTSUPP;
+}
+
+int __init integrity_init_keyring(const unsigned int id)
+{
+ const struct cred *cred = current_cred();
+ struct key_restriction *restriction;
+ int err = 0;
+
+ if (!init_keyring)
+ return 0;
+
+ restriction = kzalloc(sizeof(struct key_restriction), GFP_KERNEL);
+ if (!restriction)
+ return -ENOMEM;
+
+ restriction->check = restrict_link_to_ima;
+
+ keyring[id] = keyring_alloc(keyring_name[id], KUIDT_INIT(0),
+ KGIDT_INIT(0), cred,
+ ((KEY_POS_ALL & ~KEY_POS_SETATTR) |
+ KEY_USR_VIEW | KEY_USR_READ |
+ KEY_USR_WRITE | KEY_USR_SEARCH),
+ KEY_ALLOC_NOT_IN_QUOTA,
+ restriction, NULL);
+ if (IS_ERR(keyring[id])) {
+ err = PTR_ERR(keyring[id]);
+ pr_info("Can't allocate %s keyring (%d)\n",
+ keyring_name[id], err);
+ keyring[id] = NULL;
+ }
+ return err;
+}
+
+int __init integrity_load_x509(const unsigned int id, const char *path)
+{
+ key_ref_t key;
+ void *data;
+ loff_t size;
+ int rc;
+
+ if (!keyring[id])
+ return -EINVAL;
+
+ rc = kernel_read_file_from_path(path, &data, &size, 0,
+ READING_X509_CERTIFICATE);
+ if (rc < 0) {
+ pr_err("Unable to open file: %s (%d)", path, rc);
+ return rc;
+ }
+
+ key = key_create_or_update(make_key_ref(keyring[id], 1),
+ "asymmetric",
+ NULL,
+ data,
+ size,
+ ((KEY_POS_ALL & ~KEY_POS_SETATTR) |
+ KEY_USR_VIEW | KEY_USR_READ),
+ KEY_ALLOC_NOT_IN_QUOTA);
+ if (IS_ERR(key)) {
+ rc = PTR_ERR(key);
+ pr_err("Problem loading X.509 certificate (%d): %s\n",
+ rc, path);
+ } else {
+ pr_notice("Loaded X.509 cert '%s': %s\n",
+ key_ref_to_ptr(key)->description, path);
+ key_ref_put(key);
+ }
+ vfree(data);
+ return 0;
+}