/* protocol_key.c -- handle the meta-protocol, key exchange Copyright (C) 1999-2003 Ivo Timmermans , 2000-2003 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: protocol_key.c,v 1.1.4.21 2003/07/23 22:17:31 guus Exp $ */ #include "system.h" #include "avl_tree.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" bool mykeyused = false; bool send_key_changed(connection_t *c, 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 name[MAX_STRING_SIZE]; node_t *n; cp(); if(sscanf(c->buffer, "%*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(c->buffer)) 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 */ forward_request(c); return true; } bool send_req_key(connection_t *c, node_t *from, 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 from_name[MAX_STRING_SIZE]; char to_name[MAX_STRING_SIZE]; node_t *from, *to; cp(); if(sscanf(c->buffer, "%*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 { send_req_key(to->nexthop->connection, from, to); } return true; } bool send_ans_key(connection_t *c, node_t *from, node_t *to) { char key[MAX_STRING_SIZE]; cp(); bin2hex(from->key, key, from->keylength); key[from->keylength * 2] = '\0'; return send_request(c, "%d %s %s %s %d %d %d %d", ANS_KEY, from->name, to->name, key, from->cipher ? from->cipher->nid : 0, from->digest ? from->digest->type : 0, from->maclength, from->compression); } bool ans_key_h(connection_t *c) { 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(c->buffer, "%*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) { return send_request(to->nexthop->connection, "%s", c->buffer); } /* Update our copy of the origin's packet key */ if(from->key) free(from->key); from->key = xstrdup(key); from->keylength = strlen(key) / 2; hex2bin(from->key, from->key, from->keylength); from->key[from->keylength] = '\0'; from->status.validkey = true; from->status.waitingforkey = false; from->sent_seqno = 0; /* Check and lookup cipher and digest algorithms */ if(cipher) { from->cipher = EVP_get_cipherbynid(cipher); if(!from->cipher) { logger(LOG_ERR, _("Node %s (%s) uses unknown cipher!"), from->name, from->hostname); return false; } if(from->keylength != from->cipher->key_len + from->cipher->iv_len) { logger(LOG_ERR, _("Node %s (%s) uses wrong keylength!"), from->name, from->hostname); return false; } } else { from->cipher = NULL; } from->maclength = maclength; if(digest) { from->digest = EVP_get_digestbynid(digest); if(!from->digest) { logger(LOG_ERR, _("Node %s (%s) uses unknown digest!"), from->name, from->hostname); return false; } if(from->maclength > from->digest->md_size || from->maclength < 0) { logger(LOG_ERR, _("Node %s (%s) uses bogus MAC length!"), from->name, from->hostname); return false; } } else { from->digest = NULL; } if(compression < 0 || compression > 11) { logger(LOG_ERR, _("Node %s (%s) uses bogus compression level!"), from->name, from->hostname); return false; } from->compression = compression; if(from->cipher) EVP_EncryptInit_ex(&from->packet_ctx, from->cipher, NULL, from->key, from->key + from->cipher->key_len); flush_queue(from); return true; }