1 files changed, 129 insertions, 0 deletions
diff --git a/crypto/asymmetric_keys/public_key.c b/crypto/asymmetric_keys/public_key.c
new file mode 100644
index 000000000..2f6e4fb1a
--- /dev/null
+++ b/crypto/asymmetric_keys/public_key.c
@@ -0,0 +1,129 @@
+/* In-software asymmetric public-key crypto subtype
+ *
+ * See Documentation/crypto/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.
+ */
+
+#define pr_fmt(fmt) "PKEY: "fmt
+#include <linux/module.h>
+#include <linux/export.h>
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/seq_file.h>
+#include <keys/asymmetric-subtype.h>
+#include "public_key.h"
+
+MODULE_LICENSE("GPL");
+
+const char *const pkey_algo_name[PKEY_ALGO__LAST] = {
+	[PKEY_ALGO_DSA]		= "DSA",
+	[PKEY_ALGO_RSA]		= "RSA",
+};
+EXPORT_SYMBOL_GPL(pkey_algo_name);
+
+const struct public_key_algorithm *pkey_algo[PKEY_ALGO__LAST] = {
+#if defined(CONFIG_PUBLIC_KEY_ALGO_RSA) || \
+	defined(CONFIG_PUBLIC_KEY_ALGO_RSA_MODULE)
+	[PKEY_ALGO_RSA]		= &RSA_public_key_algorithm,
+#endif
+};
+EXPORT_SYMBOL_GPL(pkey_algo);
+
+const char *const pkey_id_type_name[PKEY_ID_TYPE__LAST] = {
+	[PKEY_ID_PGP]		= "PGP",
+	[PKEY_ID_X509]		= "X509",
+};
+EXPORT_SYMBOL_GPL(pkey_id_type_name);
+
+/*
+ * Provide a part of a description of the key for /proc/keys.
+ */
+static void public_key_describe(const struct key *asymmetric_key,
+				struct seq_file *m)
+{
+	struct public_key *key = asymmetric_key->payload.data;
+
+	if (key)
+		seq_printf(m, "%s.%s",
+			   pkey_id_type_name[key->id_type], key->algo->name);
+}
+
+/*
+ * Destroy a public key algorithm key.
+ */
+void public_key_destroy(void *payload)
+{
+	struct public_key *key = payload;
+	int i;
+
+	if (key) {
+		for (i = 0; i < ARRAY_SIZE(key->mpi); i++)
+			mpi_free(key->mpi[i]);
+		kfree(key);
+	}
+}
+EXPORT_SYMBOL_GPL(public_key_destroy);
+
+/*
+ * Verify a signature using a public key.
+ */
+int public_key_verify_signature(const struct public_key *pk,
+				const struct public_key_signature *sig)
+{
+	const struct public_key_algorithm *algo;
+
+	BUG_ON(!pk);
+	BUG_ON(!pk->mpi[0]);
+	BUG_ON(!pk->mpi[1]);
+	BUG_ON(!sig);
+	BUG_ON(!sig->digest);
+	BUG_ON(!sig->mpi[0]);
+
+	algo = pk->algo;
+	if (!algo) {
+		if (pk->pkey_algo >= PKEY_ALGO__LAST)
+			return -ENOPKG;
+		algo = pkey_algo[pk->pkey_algo];
+		if (!algo)
+			return -ENOPKG;
+	}
+
+	if (!algo->verify_signature)
+		return -ENOTSUPP;
+
+	if (sig->nr_mpi != algo->n_sig_mpi) {
+		pr_debug("Signature has %u MPI not %u\n",
+			 sig->nr_mpi, algo->n_sig_mpi);
+		return -EINVAL;
+	}
+
+	return algo->verify_signature(pk, sig);
+}
+EXPORT_SYMBOL_GPL(public_key_verify_signature);
+
+static int public_key_verify_signature_2(const struct key *key,
+					 const struct public_key_signature *sig)
+{
+	const struct public_key *pk = key->payload.data;
+	return public_key_verify_signature(pk, sig);
+}
+
+/*
+ * Public key algorithm asymmetric key subtype
+ */
+struct asymmetric_key_subtype public_key_subtype = {
+	.owner			= THIS_MODULE,
+	.name			= "public_key",
+	.name_len		= sizeof("public_key") - 1,
+	.describe		= public_key_describe,
+	.destroy		= public_key_destroy,
+	.verify_signature	= public_key_verify_signature_2,
+};
+EXPORT_SYMBOL_GPL(public_key_subtype);