xref: /openbmc/linux/net/rxrpc/security.c (revision 37744fee)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* RxRPC security handling
3  *
4  * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
5  * Written by David Howells (dhowells@redhat.com)
6  */
7 
8 #include <linux/module.h>
9 #include <linux/net.h>
10 #include <linux/skbuff.h>
11 #include <linux/udp.h>
12 #include <linux/crypto.h>
13 #include <net/sock.h>
14 #include <net/af_rxrpc.h>
15 #include <keys/rxrpc-type.h>
16 #include "ar-internal.h"
17 
18 static const struct rxrpc_security *rxrpc_security_types[] = {
19 	[RXRPC_SECURITY_NONE]	= &rxrpc_no_security,
20 #ifdef CONFIG_RXKAD
21 	[RXRPC_SECURITY_RXKAD]	= &rxkad,
22 #endif
23 };
24 
25 int __init rxrpc_init_security(void)
26 {
27 	int i, ret;
28 
29 	for (i = 0; i < ARRAY_SIZE(rxrpc_security_types); i++) {
30 		if (rxrpc_security_types[i]) {
31 			ret = rxrpc_security_types[i]->init();
32 			if (ret < 0)
33 				goto failed;
34 		}
35 	}
36 
37 	return 0;
38 
39 failed:
40 	for (i--; i >= 0; i--)
41 		if (rxrpc_security_types[i])
42 			rxrpc_security_types[i]->exit();
43 	return ret;
44 }
45 
46 void rxrpc_exit_security(void)
47 {
48 	int i;
49 
50 	for (i = 0; i < ARRAY_SIZE(rxrpc_security_types); i++)
51 		if (rxrpc_security_types[i])
52 			rxrpc_security_types[i]->exit();
53 }
54 
55 /*
56  * look up an rxrpc security module
57  */
58 static const struct rxrpc_security *rxrpc_security_lookup(u8 security_index)
59 {
60 	if (security_index >= ARRAY_SIZE(rxrpc_security_types))
61 		return NULL;
62 	return rxrpc_security_types[security_index];
63 }
64 
65 /*
66  * initialise the security on a client connection
67  */
68 int rxrpc_init_client_conn_security(struct rxrpc_connection *conn)
69 {
70 	const struct rxrpc_security *sec;
71 	struct rxrpc_key_token *token;
72 	struct key *key = conn->params.key;
73 	int ret;
74 
75 	_enter("{%d},{%x}", conn->debug_id, key_serial(key));
76 
77 	if (!key)
78 		return 0;
79 
80 	ret = key_validate(key);
81 	if (ret < 0)
82 		return ret;
83 
84 	token = key->payload.data[0];
85 	if (!token)
86 		return -EKEYREJECTED;
87 
88 	sec = rxrpc_security_lookup(token->security_index);
89 	if (!sec)
90 		return -EKEYREJECTED;
91 	conn->security = sec;
92 
93 	ret = conn->security->init_connection_security(conn);
94 	if (ret < 0) {
95 		conn->security = &rxrpc_no_security;
96 		return ret;
97 	}
98 
99 	_leave(" = 0");
100 	return 0;
101 }
102 
103 /*
104  * Find the security key for a server connection.
105  */
106 bool rxrpc_look_up_server_security(struct rxrpc_local *local, struct rxrpc_sock *rx,
107 				   const struct rxrpc_security **_sec,
108 				   struct key **_key,
109 				   struct sk_buff *skb)
110 {
111 	const struct rxrpc_security *sec;
112 	struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
113 	key_ref_t kref = NULL;
114 	char kdesc[5 + 1 + 3 + 1];
115 
116 	_enter("");
117 
118 	sprintf(kdesc, "%u:%u", sp->hdr.serviceId, sp->hdr.securityIndex);
119 
120 	sec = rxrpc_security_lookup(sp->hdr.securityIndex);
121 	if (!sec) {
122 		trace_rxrpc_abort(0, "SVS",
123 				  sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq,
124 				  RX_INVALID_OPERATION, EKEYREJECTED);
125 		skb->mark = RXRPC_SKB_MARK_REJECT_ABORT;
126 		skb->priority = RX_INVALID_OPERATION;
127 		return false;
128 	}
129 
130 	if (sp->hdr.securityIndex == RXRPC_SECURITY_NONE)
131 		goto out;
132 
133 	if (!rx->securities) {
134 		trace_rxrpc_abort(0, "SVR",
135 				  sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq,
136 				  RX_INVALID_OPERATION, EKEYREJECTED);
137 		skb->mark = RXRPC_SKB_MARK_REJECT_ABORT;
138 		skb->priority = RX_INVALID_OPERATION;
139 		return false;
140 	}
141 
142 	/* look through the service's keyring */
143 	kref = keyring_search(make_key_ref(rx->securities, 1UL),
144 			      &key_type_rxrpc_s, kdesc, true);
145 	if (IS_ERR(kref)) {
146 		trace_rxrpc_abort(0, "SVK",
147 				  sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq,
148 				  sec->no_key_abort, EKEYREJECTED);
149 		skb->mark = RXRPC_SKB_MARK_REJECT_ABORT;
150 		skb->priority = sec->no_key_abort;
151 		return false;
152 	}
153 
154 out:
155 	*_sec = sec;
156 	*_key = key_ref_to_ptr(kref);
157 	return true;
158 }
159