rxrpc: Split the server key type (rxrpc_s) into its own file

Split the server private key type (rxrpc_s) out into its own file rather
than mingling it with the authentication/client key type (rxrpc) since they
don't really bear any relation.

Signed-off-by: David Howells <dhowells@redhat.com>

1 files changed, 141 insertions, 0 deletions

diff --git a/net/rxrpc/server_key.c b/net/rxrpc/server_key.c
new file mode 100644
index 000000000000..b75bda05120d
--- /dev/null
+++ b/net/rxrpc/server_key.c
@@ -0,0 +1,141 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/* RxRPC key management
+ *
+ * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
+ * Written by David Howells (dhowells@redhat.com)
+ *
+ * RxRPC keys should have a description of describing their purpose:
+ *	"afs@CAMBRIDGE.REDHAT.COM>
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <crypto/skcipher.h>
+#include <linux/module.h>
+#include <linux/net.h>
+#include <linux/skbuff.h>
+#include <linux/key-type.h>
+#include <linux/ctype.h>
+#include <linux/slab.h>
+#include <net/sock.h>
+#include <net/af_rxrpc.h>
+#include <keys/rxrpc-type.h>
+#include <keys/user-type.h>
+#include "ar-internal.h"
+
+static int rxrpc_vet_description_s(const char *);
+static int rxrpc_preparse_s(struct key_preparsed_payload *);
+static void rxrpc_free_preparse_s(struct key_preparsed_payload *);
+static void rxrpc_destroy_s(struct key *);
+static void rxrpc_describe_s(const struct key *, struct seq_file *);
+
+/*
+ * rxrpc server defined keys take "<serviceId>:<securityIndex>" as the
+ * description and an 8-byte decryption key as the payload
+ */
+struct key_type key_type_rxrpc_s = {
+	.name		= "rxrpc_s",
+	.flags		= KEY_TYPE_NET_DOMAIN,
+	.vet_description = rxrpc_vet_description_s,
+	.preparse	= rxrpc_preparse_s,
+	.free_preparse	= rxrpc_free_preparse_s,
+	.instantiate	= generic_key_instantiate,
+	.destroy	= rxrpc_destroy_s,
+	.describe	= rxrpc_describe_s,
+};
+
+/*
+ * Vet the description for an RxRPC server key
+ */
+static int rxrpc_vet_description_s(const char *desc)
+{
+	unsigned long num;
+	char *p;
+
+	num = simple_strtoul(desc, &p, 10);
+	if (*p != ':' || num > 65535)
+		return -EINVAL;
+	num = simple_strtoul(p + 1, &p, 10);
+	if (*p || num < 1 || num > 255)
+		return -EINVAL;
+	return 0;
+}
+
+/*
+ * Preparse a server secret key.
+ *
+ * The data should be the 8-byte secret key.
+ */
+static int rxrpc_preparse_s(struct key_preparsed_payload *prep)
+{
+	struct crypto_skcipher *ci;
+
+	_enter("%zu", prep->datalen);
+
+	if (prep->datalen != 8)
+		return -EINVAL;
+
+	memcpy(&prep->payload.data[2], prep->data, 8);
+
+	ci = crypto_alloc_skcipher("pcbc(des)", 0, CRYPTO_ALG_ASYNC);
+	if (IS_ERR(ci)) {
+		_leave(" = %ld", PTR_ERR(ci));
+		return PTR_ERR(ci);
+	}
+
+	if (crypto_skcipher_setkey(ci, prep->data, 8) < 0)
+		BUG();
+
+	prep->payload.data[0] = ci;
+	_leave(" = 0");
+	return 0;
+}
+
+static void rxrpc_free_preparse_s(struct key_preparsed_payload *prep)
+{
+	if (prep->payload.data[0])
+		crypto_free_skcipher(prep->payload.data[0]);
+}
+
+static void rxrpc_destroy_s(struct key *key)
+{
+	if (key->payload.data[0]) {
+		crypto_free_skcipher(key->payload.data[0]);
+		key->payload.data[0] = NULL;
+	}
+}
+
+static void rxrpc_describe_s(const struct key *key, struct seq_file *m)
+{
+	seq_puts(m, key->description);
+}
+
+/*
+ * grab the security keyring for a server socket
+ */
+int rxrpc_server_keyring(struct rxrpc_sock *rx, sockptr_t optval, int optlen)
+{
+	struct key *key;
+	char *description;
+
+	_enter("");
+
+	if (optlen <= 0 || optlen > PAGE_SIZE - 1)
+		return -EINVAL;
+
+	description = memdup_sockptr_nul(optval, optlen);
+	if (IS_ERR(description))
+		return PTR_ERR(description);
+
+	key = request_key(&key_type_keyring, description, NULL);
+	if (IS_ERR(key)) {
+		kfree(description);
+		_leave(" = %ld", PTR_ERR(key));
+		return PTR_ERR(key);
+	}
+
+	rx->securities = key;
+	kfree(description);
+	_leave(" = 0 [key %x]", key->serial);
+	return 0;
+}