1 files changed, 274 insertions, 0 deletions
diff --git a/crypto/asymmetric_keys/asymmetric_type.c b/crypto/asymmetric_keys/asymmetric_type.c
new file mode 100644
index 0000000..cf80765
--- /dev/null
+++ b/crypto/asymmetric_keys/asymmetric_type.c
@@ -0,0 +1,274 @@
+/* Asymmetric public-key cryptography key type
+ *
+ * See Documentation/security/asymmetric-keys.txt
+ *
+ * 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 <keys/asymmetric-subtype.h>
+#include <keys/asymmetric-parser.h>
+#include <linux/seq_file.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include "asymmetric_keys.h"
+
+MODULE_LICENSE("GPL");
+
+static LIST_HEAD(asymmetric_key_parsers);
+static DECLARE_RWSEM(asymmetric_key_parsers_sem);
+
+/*
+ * Match asymmetric keys on (part of) their name
+ * We have some shorthand methods for matching keys.  We allow:
+ *
+ *	"<desc>"	- request a key by description
+ *	"id:<id>"	- request a key matching the ID
+ *	"<subtype>:<id>" - request a key of a subtype
+ */
+static int asymmetric_key_match(const struct key *key, const void *description)
+{
+	const struct asymmetric_key_subtype *subtype = asymmetric_key_subtype(key);
+	const char *spec = description;
+	const char *id, *kid;
+	ptrdiff_t speclen;
+	size_t idlen, kidlen;
+
+	if (!subtype || !spec || !*spec)
+		return 0;
+
+	/* See if the full key description matches as is */
+	if (key->description && strcmp(key->description, description) == 0)
+		return 1;
+
+	/* All tests from here on break the criterion description into a
+	 * specifier, a colon and then an identifier.
+	 */
+	id = strchr(spec, ':');
+	if (!id)
+		return 0;
+
+	speclen = id - spec;
+	id++;
+
+	/* Anything after here requires a partial match on the ID string */
+	kid = asymmetric_key_id(key);
+	if (!kid)
+		return 0;
+
+	idlen = strlen(id);
+	kidlen = strlen(kid);
+	if (idlen > kidlen)
+		return 0;
+
+	kid += kidlen - idlen;
+	if (strcasecmp(id, kid) != 0)
+		return 0;
+
+	if (speclen == 2 &&
+	    memcmp(spec, "id", 2) == 0)
+		return 1;
+
+	if (speclen == subtype->name_len &&
+	    memcmp(spec, subtype->name, speclen) == 0)
+		return 1;
+
+	return 0;
+}
+
+/*
+ * Describe the asymmetric key
+ */
+static void asymmetric_key_describe(const struct key *key, struct seq_file *m)
+{
+	const struct asymmetric_key_subtype *subtype = asymmetric_key_subtype(key);
+	const char *kid = asymmetric_key_id(key);
+	size_t n;
+
+	seq_puts(m, key->description);
+
+	if (subtype) {
+		seq_puts(m, ": ");
+		subtype->describe(key, m);
+
+		if (kid) {
+			seq_putc(m, ' ');
+			n = strlen(kid);
+			if (n <= 8)
+				seq_puts(m, kid);
+			else
+				seq_puts(m, kid + n - 8);
+		}
+
+		seq_puts(m, " [");
+		/* put something here to indicate the key's capabilities */
+		seq_putc(m, ']');
+	}
+}
+
+/*
+ * Preparse a asymmetric payload to get format the contents appropriately for the
+ * internal payload to cut down on the number of scans of the data performed.
+ *
+ * We also generate a proposed description from the contents of the key that
+ * can be used to name the key if the user doesn't want to provide one.
+ */
+static int asymmetric_key_preparse(struct key_preparsed_payload *prep)
+{
+	struct asymmetric_key_parser *parser;
+	int ret;
+
+	pr_devel("==>%s()\n", __func__);
+
+	if (prep->datalen == 0)
+		return -EINVAL;
+
+	down_read(&asymmetric_key_parsers_sem);
+
+	ret = -EBADMSG;
+	list_for_each_entry(parser, &asymmetric_key_parsers, link) {
+		pr_debug("Trying parser '%s'\n", parser->name);
+
+		ret = parser->parse(prep);
+		if (ret != -EBADMSG) {
+			pr_debug("Parser recognised the format (ret %d)\n",
+				 ret);
+			break;
+		}
+	}
+
+	up_read(&asymmetric_key_parsers_sem);
+	pr_devel("<==%s() = %d\n", __func__, ret);
+	return ret;
+}
+
+/*
+ * Clean up the preparse data
+ */
+static void asymmetric_key_free_preparse(struct key_preparsed_payload *prep)
+{
+	struct asymmetric_key_subtype *subtype = prep->type_data[0];
+
+	pr_devel("==>%s()\n", __func__);
+
+	if (subtype) {
+		subtype->destroy(prep->payload);
+		module_put(subtype->owner);
+	}
+	kfree(prep->type_data[1]);
+	kfree(prep->description);
+}
+
+/*
+ * Instantiate a asymmetric_key defined key.  The key was preparsed, so we just
+ * have to transfer the data here.
+ */
+static int asymmetric_key_instantiate(struct key *key, struct key_preparsed_payload *prep)
+{
+	int ret;
+
+	pr_devel("==>%s()\n", __func__);
+
+	ret = key_payload_reserve(key, prep->quotalen);
+	if (ret == 0) {
+		key->type_data.p[0] = prep->type_data[0];
+		key->type_data.p[1] = prep->type_data[1];
+		key->payload.data = prep->payload;
+		prep->type_data[0] = NULL;
+		prep->type_data[1] = NULL;
+		prep->payload = NULL;
+	}
+	pr_devel("<==%s() = %d\n", __func__, ret);
+	return ret;
+}
+
+/*
+ * dispose of the data dangling from the corpse of a asymmetric key
+ */
+static void asymmetric_key_destroy(struct key *key)
+{
+	struct asymmetric_key_subtype *subtype = asymmetric_key_subtype(key);
+	if (subtype) {
+		subtype->destroy(key->payload.data);
+		module_put(subtype->owner);
+		key->type_data.p[0] = NULL;
+	}
+	kfree(key->type_data.p[1]);
+	key->type_data.p[1] = NULL;
+}
+
+struct key_type key_type_asymmetric = {
+	.name		= "asymmetric",
+	.preparse	= asymmetric_key_preparse,
+	.free_preparse	= asymmetric_key_free_preparse,
+	.instantiate	= asymmetric_key_instantiate,
+	.match		= asymmetric_key_match,
+	.destroy	= asymmetric_key_destroy,
+	.describe	= asymmetric_key_describe,
+};
+EXPORT_SYMBOL_GPL(key_type_asymmetric);
+
+/**
+ * register_asymmetric_key_parser - Register a asymmetric key blob parser
+ * @parser: The parser to register
+ */
+int register_asymmetric_key_parser(struct asymmetric_key_parser *parser)
+{
+	struct asymmetric_key_parser *cursor;
+	int ret;
+
+	down_write(&asymmetric_key_parsers_sem);
+
+	list_for_each_entry(cursor, &asymmetric_key_parsers, link) {
+		if (strcmp(cursor->name, parser->name) == 0) {
+			pr_err("Asymmetric key parser '%s' already registered\n",
+			       parser->name);
+			ret = -EEXIST;
+			goto out;
+		}
+	}
+
+	list_add_tail(&parser->link, &asymmetric_key_parsers);
+
+	pr_notice("Asymmetric key parser '%s' registered\n", parser->name);
+	ret = 0;
+
+out:
+	up_write(&asymmetric_key_parsers_sem);
+	return ret;
+}
+EXPORT_SYMBOL_GPL(register_asymmetric_key_parser);
+
+/**
+ * unregister_asymmetric_key_parser - Unregister a asymmetric key blob parser
+ * @parser: The parser to unregister
+ */
+void unregister_asymmetric_key_parser(struct asymmetric_key_parser *parser)
+{
+	down_write(&asymmetric_key_parsers_sem);
+	list_del(&parser->link);
+	up_write(&asymmetric_key_parsers_sem);
+
+	pr_notice("Asymmetric key parser '%s' unregistered\n", parser->name);
+}
+EXPORT_SYMBOL_GPL(unregister_asymmetric_key_parser);
+
+/*
+ * Module stuff
+ */
+static int __init asymmetric_key_init(void)
+{
+	return register_key_type(&key_type_asymmetric);
+}
+
+static void __exit asymmetric_key_cleanup(void)
+{
+	unregister_key_type(&key_type_asymmetric);
+}
+
+module_init(asymmetric_key_init);
+module_exit(asymmetric_key_cleanup);