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 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         for (token = key->payload.data[0]; token; token = token->next) {
  85                 sec = rxrpc_security_lookup(token->security_index);
  86                 if (sec)
  87                         goto found;
  88         }
  89         return -EKEYREJECTED;
  90
  91 found:
  92         conn->security = sec;
  93
  94         ret = conn->security->init_connection_security(conn, token);
  95         if (ret < 0) {
  96                 conn->security = &rxrpc_no_security;
  97                 return ret;
  98         }
  99
 100         _leave(" = 0");
 101         return 0;
 102 }
 103
 104 /*
 105  * Set the ops a server connection.
 106  */
 107 const struct rxrpc_security *rxrpc_get_incoming_security(struct rxrpc_sock *rx,
 108                                                          struct sk_buff *skb)
 109 {
 110         const struct rxrpc_security *sec;
 111         struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
 112
 113         _enter("");
 114
 115         sec = rxrpc_security_lookup(sp->hdr.securityIndex);
 116         if (!sec) {
 117                 trace_rxrpc_abort(0, "SVS",
 118                                   sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq,
 119                                   RX_INVALID_OPERATION, EKEYREJECTED);
 120                 skb->mark = RXRPC_SKB_MARK_REJECT_ABORT;
 121                 skb->priority = RX_INVALID_OPERATION;
 122                 return NULL;
 123         }
 124
 125         if (sp->hdr.securityIndex != RXRPC_SECURITY_NONE &&
 126             !rx->securities) {
 127                 trace_rxrpc_abort(0, "SVR",
 128                                   sp->hdr.cid, sp->hdr.callNumber, sp->hdr.seq,
 129                                   RX_INVALID_OPERATION, EKEYREJECTED);
 130                 skb->mark = RXRPC_SKB_MARK_REJECT_ABORT;
 131                 skb->priority = sec->no_key_abort;
 132                 return NULL;
 133         }
 134
 135         return sec;
 136 }
 137
 138 /*
 139  * Find the security key for a server connection.
 140  */
 141 struct key *rxrpc_look_up_server_security(struct rxrpc_connection *conn,
 142                                           struct sk_buff *skb,
 143                                           u32 kvno, u32 enctype)
 144 {
 145         struct rxrpc_skb_priv *sp = rxrpc_skb(skb);
 146         struct rxrpc_sock *rx;
 147         struct key *key = ERR_PTR(-EKEYREJECTED);
 148         key_ref_t kref = NULL;
 149         char kdesc[5 + 1 + 3 + 1 + 12 + 1 + 12 + 1];
 150         int ret;
 151
 152         _enter("");
 153
 154         if (enctype)
 155                 sprintf(kdesc, "%u:%u:%u:%u",
 156                         sp->hdr.serviceId, sp->hdr.securityIndex, kvno, enctype);
 157         else if (kvno)
 158                 sprintf(kdesc, "%u:%u:%u",
 159                         sp->hdr.serviceId, sp->hdr.securityIndex, kvno);
 160         else
 161                 sprintf(kdesc, "%u:%u",
 162                         sp->hdr.serviceId, sp->hdr.securityIndex);
 163
 164         rcu_read_lock();
 165
 166         rx = rcu_dereference(conn->params.local->service);
 167         if (!rx)
 168                 goto out;
 169
 170         /* look through the service's keyring */
 171         kref = keyring_search(make_key_ref(rx->securities, 1UL),
 172                               &key_type_rxrpc_s, kdesc, true);
 173         if (IS_ERR(kref)) {
 174                 key = ERR_CAST(kref);
 175                 goto out;
 176         }
 177
 178         key = key_ref_to_ptr(kref);
 179
 180         ret = key_validate(key);
 181         if (ret < 0) {
 182                 key_put(key);
 183                 key = ERR_PTR(ret);
 184                 goto out;
 185         }
 186
 187 out:
 188         rcu_read_unlock();
 189         return key;
 190 }