net/rxrpc/security.c

   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  * initialise the security on a server connection
 105  */
 106 int rxrpc_init_server_conn_security(struct rxrpc_connection *conn)
 107 {
 108         const struct rxrpc_security *sec;
 109         struct rxrpc_local *local = conn->params.local;
 110         struct rxrpc_sock *rx;
 111         struct key *key;
 112         key_ref_t kref;
 113         char kdesc[5 + 1 + 3 + 1];
 114
 115         _enter("");
 116
 117         sprintf(kdesc, "%u:%u", conn->service_id, conn->security_ix);
 118
 119         sec = rxrpc_security_lookup(conn->security_ix);
 120         if (!sec) {
 121                 _leave(" = -ENOKEY [lookup]");
 122                 return -ENOKEY;
 123         }
 124
 125         /* find the service */
 126         read_lock(&local->services_lock);
 127         rx = rcu_dereference_protected(local->service,
 128                                        lockdep_is_held(&local->services_lock));
 129         if (rx && (rx->srx.srx_service == conn->service_id ||
 130                    rx->second_service == conn->service_id))
 131                 goto found_service;
 132
 133         /* the service appears to have died */
 134         read_unlock(&local->services_lock);
 135         _leave(" = -ENOENT");
 136         return -ENOENT;
 137
 138 found_service:
 139         if (!rx->securities) {
 140                 read_unlock(&local->services_lock);
 141                 _leave(" = -ENOKEY");
 142                 return -ENOKEY;
 143         }
 144
 145         /* look through the service's keyring */
 146         kref = keyring_search(make_key_ref(rx->securities, 1UL),
 147                               &key_type_rxrpc_s, kdesc, true);
 148         if (IS_ERR(kref)) {
 149                 read_unlock(&local->services_lock);
 150                 _leave(" = %ld [search]", PTR_ERR(kref));
 151                 return PTR_ERR(kref);
 152         }
 153
 154         key = key_ref_to_ptr(kref);
 155         read_unlock(&local->services_lock);
 156
 157         conn->server_key = key;
 158         conn->security = sec;
 159
 160         _leave(" = 0");
 161         return 0;
 162 }