linux/net/rxrpc/server_key.c
David Howells d5953f6543 rxrpc: Allow security classes to give more info on server keys
Allow a security class to give more information on an rxrpc_s-type key when
it is viewed in /proc/keys.  This will allow the upcoming RxGK security
class to show the enctype name here.

Signed-off-by: David Howells <dhowells@redhat.com>
2020-11-23 18:09:29 +00:00

144 lines
3.4 KiB
C

// 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 keys take "<serviceId>:<securityIndex>[:<sec-specific>]" as the
* description and the key material 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 service, sec_class;
char *p;
service = simple_strtoul(desc, &p, 10);
if (*p != ':' || service > 65535)
return -EINVAL;
sec_class = simple_strtoul(p + 1, &p, 10);
if ((*p && *p != ':') || sec_class < 1 || sec_class > 255)
return -EINVAL;
return 0;
}
/*
* Preparse a server secret key.
*/
static int rxrpc_preparse_s(struct key_preparsed_payload *prep)
{
const struct rxrpc_security *sec;
unsigned int service, sec_class;
int n;
_enter("%zu", prep->datalen);
if (!prep->orig_description)
return -EINVAL;
if (sscanf(prep->orig_description, "%u:%u%n", &service, &sec_class, &n) != 2)
return -EINVAL;
sec = rxrpc_security_lookup(sec_class);
if (!sec)
return -ENOPKG;
prep->payload.data[1] = (struct rxrpc_security *)sec;
return sec->preparse_server_key(prep);
}
static void rxrpc_free_preparse_s(struct key_preparsed_payload *prep)
{
const struct rxrpc_security *sec = prep->payload.data[1];
if (sec)
sec->free_preparse_server_key(prep);
}
static void rxrpc_destroy_s(struct key *key)
{
const struct rxrpc_security *sec = key->payload.data[1];
if (sec)
sec->destroy_server_key(key);
}
static void rxrpc_describe_s(const struct key *key, struct seq_file *m)
{
const struct rxrpc_security *sec = key->payload.data[1];
seq_puts(m, key->description);
if (sec && sec->describe_server_key)
sec->describe_server_key(key, m);
}
/*
* 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;
}