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
rxrpc_init_security(void)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
rxrpc_exit_security(void)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 */
rxrpc_security_lookup(u8 security_index)58 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 call.
67 */
rxrpc_init_client_call_security(struct rxrpc_call * call)68 int rxrpc_init_client_call_security(struct rxrpc_call *call)
69 {
70 const struct rxrpc_security *sec = &rxrpc_no_security;
71 struct rxrpc_key_token *token;
72 struct key *key = call->key;
73 int ret;
74
75 if (!key)
76 goto found;
77
78 ret = key_validate(key);
79 if (ret < 0)
80 return ret;
81
82 for (token = key->payload.data[0]; token; token = token->next) {
83 sec = rxrpc_security_lookup(token->security_index);
84 if (sec)
85 goto found;
86 }
87 return -EKEYREJECTED;
88
89 found:
90 call->security = sec;
91 call->security_ix = sec->security_index;
92 return 0;
93 }
94
95 /*
96 * initialise the security on a client connection
97 */
rxrpc_init_client_conn_security(struct rxrpc_connection * conn)98 int rxrpc_init_client_conn_security(struct rxrpc_connection *conn)
99 {
100 struct rxrpc_key_token *token;
101 struct key *key = conn->key;
102 int ret = 0;
103
104 _enter("{%d},{%x}", conn->debug_id, key_serial(key));
105
106 for (token = key->payload.data[0]; token; token = token->next) {
107 if (token->security_index == conn->security->security_index)
108 goto found;
109 }
110 return -EKEYREJECTED;
111
112 found:
113 mutex_lock(&conn->security_lock);
114 if (conn->state == RXRPC_CONN_CLIENT_UNSECURED) {
115 ret = conn->security->init_connection_security(conn, token);
116 if (ret == 0) {
117 spin_lock(&conn->state_lock);
118 if (conn->state == RXRPC_CONN_CLIENT_UNSECURED)
119 conn->state = RXRPC_CONN_CLIENT;
120 spin_unlock(&conn->state_lock);
121 }
122 }
123 mutex_unlock(&conn->security_lock);
124 return ret;
125 }
126
127 /*
128 * Set the ops a server connection.
129 */
rxrpc_get_incoming_security(struct rxrpc_sock * rx,struct sk_buff * skb)130 const struct rxrpc_security *rxrpc_get_incoming_security(struct rxrpc_sock *rx,
131 struct sk_buff *skb)
132 {
133 const struct rxrpc_security *sec;
134 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
135
136 _enter("");
137
138 sec = rxrpc_security_lookup(sp->hdr.securityIndex);
139 if (!sec) {
140 rxrpc_direct_abort(skb, rxrpc_abort_unsupported_security,
141 RX_INVALID_OPERATION, -EKEYREJECTED);
142 return NULL;
143 }
144
145 if (sp->hdr.securityIndex != RXRPC_SECURITY_NONE &&
146 !rx->securities) {
147 rxrpc_direct_abort(skb, rxrpc_abort_no_service_key,
148 sec->no_key_abort, -EKEYREJECTED);
149 return NULL;
150 }
151
152 return sec;
153 }
154
155 /*
156 * Find the security key for a server connection.
157 */
rxrpc_look_up_server_security(struct rxrpc_connection * conn,struct sk_buff * skb,u32 kvno,u32 enctype)158 struct key *rxrpc_look_up_server_security(struct rxrpc_connection *conn,
159 struct sk_buff *skb,
160 u32 kvno, u32 enctype)
161 {
162 struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
163 struct rxrpc_sock *rx;
164 struct key *key = ERR_PTR(-EKEYREJECTED);
165 key_ref_t kref = NULL;
166 char kdesc[5 + 1 + 3 + 1 + 12 + 1 + 12 + 1];
167 int ret;
168
169 _enter("");
170
171 if (enctype)
172 sprintf(kdesc, "%u:%u:%u:%u",
173 sp->hdr.serviceId, sp->hdr.securityIndex, kvno, enctype);
174 else if (kvno)
175 sprintf(kdesc, "%u:%u:%u",
176 sp->hdr.serviceId, sp->hdr.securityIndex, kvno);
177 else
178 sprintf(kdesc, "%u:%u",
179 sp->hdr.serviceId, sp->hdr.securityIndex);
180
181 read_lock(&conn->local->services_lock);
182
183 rx = conn->local->service;
184 if (!rx)
185 goto out;
186
187 /* look through the service's keyring */
188 kref = keyring_search(make_key_ref(rx->securities, 1UL),
189 &key_type_rxrpc_s, kdesc, true);
190 if (IS_ERR(kref)) {
191 key = ERR_CAST(kref);
192 goto out;
193 }
194
195 key = key_ref_to_ptr(kref);
196
197 ret = key_validate(key);
198 if (ret < 0) {
199 key_put(key);
200 key = ERR_PTR(ret);
201 goto out;
202 }
203
204 out:
205 read_unlock(&conn->local->services_lock);
206 return key;
207 }
208