/* protocol_key.c -- handle the meta-protocol, key exchange Copyright (C) 1999-2005 Ivo Timmermans, 2000-2006 Guus Sliepen This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. $Id$ */ #include "system.h" #include "splay_tree.h" #include "cipher.h" #include "connection.h" #include "logger.h" #include "net.h" #include "netutl.h" #include "node.h" #include "protocol.h" #include "utils.h" #include "xalloc.h" static bool mykeyused = false; bool send_key_changed(connection_t *c, const node_t *n) { cp(); /* Only send this message if some other daemon requested our key previously. This reduces unnecessary key_changed broadcasts. */ if(n == myself && !mykeyused) return true; return send_request(c, "%d %lx %s", KEY_CHANGED, random(), n->name); } bool key_changed_h(connection_t *c, char *request) { char name[MAX_STRING_SIZE]; node_t *n; cp(); if(sscanf(request, "%*d %*x " MAX_STRING, name) != 1) { logger(LOG_ERR, _("Got bad %s from %s (%s)"), "KEY_CHANGED", c->name, c->hostname); return false; } if(seen_request(request)) return true; n = lookup_node(name); if(!n) { logger(LOG_ERR, _("Got %s from %s (%s) origin %s which does not exist"), "KEY_CHANGED", c->name, c->hostname, name); return false; } n->status.validkey = false; n->status.waitingforkey = false; /* Tell the others */ if(!tunnelserver) forward_request(c, request); return true; } bool send_req_key(connection_t *c, const node_t *from, const node_t *to) { cp(); return send_request(c, "%d %s %s", REQ_KEY, from->name, to->name); } bool req_key_h(connection_t *c, char *request) { char from_name[MAX_STRING_SIZE]; char to_name[MAX_STRING_SIZE]; node_t *from, *to; cp(); if(sscanf(request, "%*d " MAX_STRING " " MAX_STRING, from_name, to_name) != 2) { logger(LOG_ERR, _("Got bad %s from %s (%s)"), "REQ_KEY", c->name, c->hostname); return false; } from = lookup_node(from_name); if(!from) { logger(LOG_ERR, _("Got %s from %s (%s) origin %s which does not exist in our connection list"), "REQ_KEY", c->name, c->hostname, from_name); return false; } to = lookup_node(to_name); if(!to) { logger(LOG_ERR, _("Got %s from %s (%s) destination %s which does not exist in our connection list"), "REQ_KEY", c->name, c->hostname, to_name); return false; } /* Check if this key request is for us */ if(to == myself) { /* Yes, send our own key back */ mykeyused = true; from->received_seqno = 0; memset(from->late, 0, sizeof(from->late)); send_ans_key(c, myself, from); } else { if(tunnelserver) return false; send_req_key(to->nexthop->connection, from, to); } return true; } bool send_ans_key(connection_t *c, const node_t *from, const node_t *to) { size_t keylen = cipher_keylength(&from->cipher); char key[keylen * 2 + 1]; cp(); cipher_get_key(&from->cipher, key); bin2hex(key, key, keylen); key[keylen * 2] = '\0'; return send_request(c, "%d %s %s %s %d %d %d %d", ANS_KEY, from->name, to->name, key, cipher_get_nid(&from->cipher), digest_get_nid(&from->digest), from->maclength, from->compression); } bool ans_key_h(connection_t *c, char *request) { char from_name[MAX_STRING_SIZE]; char to_name[MAX_STRING_SIZE]; char key[MAX_STRING_SIZE]; int cipher, digest, maclength, compression; node_t *from, *to; cp(); if(sscanf(request, "%*d "MAX_STRING" "MAX_STRING" "MAX_STRING" %d %d %d %d", from_name, to_name, key, &cipher, &digest, &maclength, &compression) != 7) { logger(LOG_ERR, _("Got bad %s from %s (%s)"), "ANS_KEY", c->name, c->hostname); return false; } from = lookup_node(from_name); if(!from) { logger(LOG_ERR, _("Got %s from %s (%s) origin %s which does not exist in our connection list"), "ANS_KEY", c->name, c->hostname, from_name); return false; } to = lookup_node(to_name); if(!to) { logger(LOG_ERR, _("Got %s from %s (%s) destination %s which does not exist in our connection list"), "ANS_KEY", c->name, c->hostname, to_name); return false; } /* Forward it if necessary */ if(to != myself) { if(tunnelserver) return false; return send_request(to->nexthop->connection, "%s", request); } /* Check and lookup cipher and digest algorithms */ if(!cipher_open_by_nid(&from->cipher, cipher)) { logger(LOG_ERR, _("Node %s (%s) uses unknown cipher!"), from->name, from->hostname); return false; } if(strlen(key) / 2 != cipher_keylength(&from->cipher)) { logger(LOG_ERR, _("Node %s (%s) uses wrong keylength!"), from->name, from->hostname); return false; } from->maclength = maclength; if(!digest_open_by_nid(&from->digest, digest)) { logger(LOG_ERR, _("Node %s (%s) uses unknown digest!"), from->name, from->hostname); return false; } if(from->maclength > digest_length(&from->digest) || from->maclength < 0) { logger(LOG_ERR, _("Node %s (%s) uses bogus MAC length!"), from->name, from->hostname); return false; } if(compression < 0 || compression > 11) { logger(LOG_ERR, _("Node %s (%s) uses bogus compression level!"), from->name, from->hostname); return false; } from->compression = compression; /* Update our copy of the origin's packet key */ hex2bin(key, key, cipher_keylength(&from->cipher)); cipher_set_key(&from->cipher, key, false); from->status.validkey = true; from->status.waitingforkey = false; from->sent_seqno = 0; if(from->options & OPTION_PMTU_DISCOVERY && !from->mtuprobes) send_mtu_probe(from); flush_queue(from); return true; }