X-Git-Url: https://tinc-vpn.org/git/browse?p=tinc;a=blobdiff_plain;f=src%2Fprotocol.c;h=97b51b4321b4196d6a50a62b7bcddc7d8ae642d1;hp=1a791a717316ba82503997c4b0dca8c635ae2ffe;hb=d2a54597e029f9d4f7bd29837be1be33909d78b1;hpb=a07602c4fddfca9894f1d738959ae359695f5bf9 diff --git a/src/protocol.c b/src/protocol.c index 1a791a71..97b51b43 100644 --- a/src/protocol.c +++ b/src/protocol.c @@ -1,7 +1,7 @@ /* protocol.c -- handle the meta-protocol - Copyright (C) 1999,2000 Ivo Timmermans , - 2000 Guus Sliepen + Copyright (C) 1999-2001 Ivo Timmermans , + 2000,2001 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 @@ -17,7 +17,7 @@ along with this program; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. - $Id: protocol.c,v 1.28.4.64 2000/11/22 19:55:50 guus Exp $ + $Id: protocol.c,v 1.28.4.84 2001/03/02 11:25:56 guus Exp $ */ #include "config.h" @@ -31,9 +31,12 @@ #include #include #include +#include #include #include +#include +#include #include @@ -72,11 +75,12 @@ int check_id(char *id) for (i = 0; i < strlen(id); i++) if(!isalnum(id[i]) && id[i] != '_') return -1; - + return 0; } -/* Generic request routines - takes care of logging and error detection as well */ +/* Generic request routines - takes care of logging and error + detection as well */ int send_request(connection_t *cl, const char *format, ...) { @@ -85,8 +89,9 @@ int send_request(connection_t *cl, const char *format, ...) int len, request; cp - /* Use vsnprintf instead of vasprintf: faster, no memory fragmentation, cleanup is automatic, - and there is a limit on the input buffer anyway */ + /* Use vsnprintf instead of vasprintf: faster, no memory + fragmentation, cleanup is automatic, and there is a limit on the + input buffer anyway */ va_start(args, format); len = vsnprintf(buffer, MAXBUFSIZE, format, args); @@ -174,15 +179,14 @@ cp (H) SHA1, (E) Encrypted with symmetric cipher. - Part of the challenge is directly used to set the symmetric cipher key and the initial vector. - Since a man-in-the-middle cannot decrypt the RSA challenges, this means that he cannot get or - forge the key for the symmetric cipher. + Part of the challenge is directly used to set the symmetric cipher + key and the initial vector. Since a man-in-the-middle cannot + decrypt the RSA challenges, this means that he cannot get or forge + the key for the symmetric cipher. */ int send_id(connection_t *cl) { -cp - cl->allow_request = CHALLENGE; cp return send_request(cl, "%d %s %d %lx %hd", ID, myself->name, myself->protocol_version, myself->options, myself->port); } @@ -190,10 +194,11 @@ cp int id_h(connection_t *cl) { connection_t *old; - config_t const *cfg; + unsigned short int port; char name[MAX_STRING_SIZE]; + avl_node_t *node; cp - if(sscanf(cl->buffer, "%*d "MAX_STRING" %d %lx %hd", name, &cl->protocol_version, &cl->options, &cl->port) != 4) + if(sscanf(cl->buffer, "%*d "MAX_STRING" %d %lx %hd", name, &cl->protocol_version, &cl->options, &port) != 4) { syslog(LOG_ERR, _("Got bad ID from %s"), cl->hostname); return -1; @@ -250,21 +255,102 @@ cp id_add(cl); - /* Read in the public key, so that we can send a challenge */ + /* And uhr... cl->port just changed so we have to unlink it from the connection tree and re-insert... */ + + node = avl_unlink(connection_tree, cl); + cl->port = port; + avl_insert_node(connection_tree, node); + + /* Read in the public key, so that we can send a metakey */ - if((cfg = get_config_val(cl->config, config_publickey))) + if(read_rsa_public_key(cl)) + return -1; + + cl->allow_request = METAKEY; +cp + return send_metakey(cl); +} + +int ack_h(connection_t *cl) +{ + config_t const *cfg; + connection_t *old, *p; + subnet_t *subnet; + avl_node_t *node, *node2; +cp + /* Okay, before we active the connection, we check if there is another entry + in the connection list with the same name. If so, it presumably is an + old connection that has timed out but we don't know it yet. + */ + + while((old = lookup_id(cl->name))) { - cl->rsa_key = RSA_new(); - BN_hex2bn(&cl->rsa_key->n, cfg->data.ptr); - BN_hex2bn(&cl->rsa_key->e, "FFFF"); + if(debug_lvl >= DEBUG_CONNECTIONS) + syslog(LOG_NOTICE, _("Removing old entry for %s at %s in favour of new connection from %s"), + cl->name, old->hostname, cl->hostname); + + terminate_connection(old); } - else + + /* Activate this connection */ + + cl->allow_request = ALL; + cl->status.active = 1; + cl->nexthop = cl; + cl->cipher_pkttype = EVP_bf_cbc(); + cl->cipher_pktkeylength = cl->cipher_pkttype->key_len + cl->cipher_pkttype->iv_len; + + if(debug_lvl >= DEBUG_CONNECTIONS) + syslog(LOG_NOTICE, _("Connection with %s (%s) activated"), cl->name, cl->hostname); + +cp + /* Check some options */ + + if((cfg = get_config_val(cl->config, config_indirectdata))) { - syslog(LOG_ERR, _("No public key known for %s (%s)"), cl->name, cl->hostname); - return -1; + if(cfg->data.val == stupid_true) + cl->options |= OPTION_INDIRECT; } + + if((cfg = get_config_val(cl->config, config_tcponly))) + { + if(cfg->data.val == stupid_true) + cl->options |= OPTION_TCPONLY; + } + + /* Send him our subnets */ + + for(node = myself->subnet_tree->head; node; node = node->next) + { + subnet = (subnet_t *)node->data; + send_add_subnet(cl, subnet); + } + /* And send him all the hosts and their subnets we know... */ + + for(node = connection_tree->head; node; node = node->next) + { + p = (connection_t *)node->data; + + if(p != cl && p->status.active) + { + /* Notify others of this connection */ + + if(p->status.meta) + send_add_host(p, cl); + + /* Notify new connection of everything we know */ + + send_add_host(cl, p); + + for(node2 = p->subnet_tree->head; node2; node2 = node2->next) + { + subnet = (subnet_t *)node2->data; + send_add_subnet(cl, subnet); + } + } + } cp - return send_challenge(cl); + return 0; } int send_challenge(connection_t *cl) @@ -272,6 +358,8 @@ int send_challenge(connection_t *cl) char *buffer; int len, x; cp + /* CHECKME: what is most reasonable value for len? */ + len = RSA_size(cl->rsa_key); /* Allocate buffers for the challenge */ @@ -287,32 +375,15 @@ cp RAND_bytes(cl->hischallenge, len); - cl->hischallenge[0] &= 0x7F; /* Somehow if the first byte is more than 0xD0 or something like that, decryption fails... */ - - if(debug_lvl >= DEBUG_SCARY_THINGS) - { - bin2hex(cl->hischallenge, buffer, len); - buffer[len*2] = '\0'; - syslog(LOG_DEBUG, _("Generated random challenge (unencrypted): %s"), buffer); - } - - /* Encrypt the random data */ - - if(RSA_public_encrypt(len, cl->hischallenge, buffer, cl->rsa_key, RSA_NO_PADDING) != len) /* NO_PADDING because the message size equals the RSA key size and it is totally random */ - { - syslog(LOG_ERR, _("Error during encryption of challenge for %s (%s)"), cl->name, cl->hostname); - free(buffer); - return -1; - } cp - /* Convert the encrypted random data to a hexadecimal formatted string */ + /* Convert to hex */ - bin2hex(buffer, buffer, len); + bin2hex(cl->hischallenge, buffer, len); buffer[len*2] = '\0'; +cp /* Send the challenge */ - cl->allow_request = CHAL_REPLY; x = send_request(cl, "%d %s", CHALLENGE, buffer); free(buffer); cp @@ -347,22 +418,9 @@ cp /* Convert the challenge from hexadecimal back to binary */ - hex2bin(buffer,buffer,len); - - /* Decrypt the challenge */ - - if(RSA_private_decrypt(len, buffer, cl->mychallenge, myself->rsa_key, RSA_NO_PADDING) != len) /* See challenge() */ - { - syslog(LOG_ERR, _("Error during encryption of challenge for %s (%s)"), cl->name, cl->hostname); - return -1; - } + hex2bin(buffer,cl->mychallenge,len); - if(debug_lvl >= DEBUG_SCARY_THINGS) - { - bin2hex(cl->mychallenge, buffer, len); - buffer[len*2] = '\0'; - syslog(LOG_DEBUG, _("Received random challenge (unencrypted): %s"), buffer); - } + cl->allow_request = CHAL_REPLY; /* Rest is done by send_chal_reply() */ cp @@ -390,11 +448,6 @@ cp /* Send the reply */ - if(cl->status.outgoing) - cl->allow_request = ID; - else - cl->allow_request = METAKEY; - cp return send_request(cl, "%d %s", CHAL_REPLY, hash); } @@ -440,16 +493,11 @@ cp return -1; } - /* Identity has now been positively verified. - If we are accepting this new connection, then send our identity, - if we are making this connecting, acknowledge. + ack_h() handles the rest from now on. */ cp - if(cl->status.outgoing) - return send_metakey(cl); - else - return send_id(cl); + return ack_h(cl); } int send_metakey(connection_t *cl) @@ -473,8 +521,18 @@ cp RAND_bytes(cl->cipher_outkey, len); - cl->cipher_outkey[0] &= 0x7F; /* FIXME: Somehow if the first byte is more than 0xD0 or something like that, decryption fails... */ - + /* The message we send must be smaller than the modulus of the RSA key. + By definition, for a key of k bits, the following formula holds: + + 2^(k-1) <= modulus < 2^(k) + + Where ^ means "to the power of", not "xor". + This means that to be sure, we must choose our message < 2^(k-1). + This can be done by setting the most significant bit to zero. + */ + + cl->cipher_outkey[0] &= 0x7F; + if(debug_lvl >= DEBUG_SCARY_THINGS) { bin2hex(cl->cipher_outkey, buffer, len); @@ -482,9 +540,14 @@ cp syslog(LOG_DEBUG, _("Generated random meta key (unencrypted): %s"), buffer); } - /* Encrypt the random data */ + /* Encrypt the random data + + We do not use one of the PKCS padding schemes here. + This is allowed, because we encrypt a totally random string + with a length equal to that of the modulus of the RSA key. + */ - if(RSA_public_encrypt(len, cl->cipher_outkey, buffer, cl->rsa_key, RSA_NO_PADDING) != len) /* NO_PADDING because the message size equals the RSA key size and it is totally random */ + if(RSA_public_encrypt(len, cl->cipher_outkey, buffer, cl->rsa_key, RSA_NO_PADDING) != len) { syslog(LOG_ERR, _("Error during encryption of meta key for %s (%s)"), cl->name, cl->hostname); free(buffer); @@ -498,15 +561,16 @@ cp /* Send the meta key */ - if(cl->status.outgoing) - cl->allow_request = METAKEY; - else - cl->allow_request = ACK; - x = send_request(cl, "%d %s", METAKEY, buffer); free(buffer); - EVP_EncryptInit(cl->cipher_outctx, EVP_bf_cfb(), cl->cipher_outkey, cl->cipher_outkey + EVP_bf_cfb()->key_len); + /* Further outgoing requests are encrypted with the key we just generated */ + + EVP_EncryptInit(cl->cipher_outctx, EVP_bf_cfb(), + cl->cipher_outkey + len - EVP_bf_cfb()->key_len, + cl->cipher_outkey + len - EVP_bf_cfb()->key_len - EVP_bf_cfb()->iv_len); + + cl->status.encryptout = 1; cp return x; } @@ -559,99 +623,17 @@ cp syslog(LOG_DEBUG, _("Received random meta key (unencrypted): %s"), buffer); } - EVP_DecryptInit(cl->cipher_inctx, EVP_bf_cfb(), cl->cipher_inkey, cl->cipher_inkey + EVP_bf_cfb()->key_len); - -cp - if(cl->status.outgoing) - return send_ack(cl); - else - return send_metakey(cl); -} - -int send_ack(connection_t *cl) -{ - int x; -cp - if(cl->status.outgoing) - cl->allow_request = ACK; - - setup_vpn_connection(cl); - - x = send_request(cl, "%d", ACK); - cl->status.encryptout = 1; -cp - return x; -} - -int ack_h(connection_t *cl) -{ - connection_t *old, *p; - subnet_t *subnet; - rbl_t *rbl, *rbl2; -cp - /* Okay, before we active the connection, we check if there is another entry - in the connection list with the same name. If so, it presumably is an - old connection that has timed out but we don't know it yet. - */ - - while((old = lookup_id(cl->name))) - { - if(debug_lvl >= DEBUG_CONNECTIONS) - syslog(LOG_NOTICE, _("Removing old entry for %s at %s in favour of new connection from %s"), - cl->name, old->hostname, cl->hostname); - - terminate_connection(old); - } - - /* Activate this connection */ + /* All incoming requests will now be encrypted. */ - cl->allow_request = ALL; - cl->status.active = 1; - cl->status.decryptin = 1; - cl->nexthop = cl; - cl->cipher_pkttype = EVP_bf_cfb(); - cl->cipher_pktkeylength = cl->cipher_pkttype->key_len + cl->cipher_pkttype->iv_len; - - if(debug_lvl >= DEBUG_CONNECTIONS) - syslog(LOG_NOTICE, _("Connection with %s (%s) activated"), cl->name, cl->hostname); - -cp - if(!cl->status.outgoing) - send_ack(cl); - - /* Send him our subnets */ + EVP_DecryptInit(cl->cipher_inctx, EVP_bf_cfb(), + cl->cipher_inkey + len - EVP_bf_cfb()->key_len, + cl->cipher_inkey + len - EVP_bf_cfb()->key_len - EVP_bf_cfb()->iv_len); - RBL_FOREACH(myself->subnet_tree, rbl) - { - subnet = (subnet_t *)rbl->data; - send_add_subnet(cl, subnet); - } - /* And send him all the hosts and their subnets we know... */ - - RBL_FOREACH(connection_tree, rbl) - { - p = (connection_t *)rbl->data; - - if(p != cl && p->status.active) - { - /* Notify others of this connection */ - - if(p->status.meta) - send_add_host(p, cl); - - /* Notify new connection of everything we know */ - - send_add_host(cl, p); + cl->status.decryptin = 1; - RBL_FOREACH(p->subnet_tree, rbl2) - { - subnet = (subnet_t *)rbl2->data; - send_add_subnet(cl, subnet); - } - } - } + cl->allow_request = CHALLENGE; cp - return 0; + return send_challenge(cl); } /* Address and subnet information exchange */ @@ -660,9 +642,15 @@ int send_add_subnet(connection_t *cl, subnet_t *subnet) { int x; char *netstr; + char *owner; cp + if(cl->options & OPTION_INDIRECT) + owner = myself->name; + else + owner = subnet->owner->name; + x = send_request(cl, "%d %s %s", ADD_SUBNET, - subnet->owner->name, netstr = net2str(subnet)); + owner, netstr = net2str(subnet)); free(netstr); cp return x; @@ -674,7 +662,7 @@ int add_subnet_h(connection_t *cl) char name[MAX_STRING_SIZE]; connection_t *owner, *p; subnet_t *subnet; - rbl_t *rbl; + avl_node_t *node; cp if(sscanf(cl->buffer, "%*d "MAX_STRING" "MAX_STRING, name, subnetstr) != 2) { @@ -723,9 +711,9 @@ cp /* Tell the rest */ - RBL_FOREACH(connection_tree, rbl) + for(node = connection_tree->head; node; node = node->next) { - p = (connection_t *)rbl->data; + p = (connection_t *)node->data; if(p->status.meta && p->status.active && p!= cl) send_add_subnet(p, subnet); } @@ -737,9 +725,14 @@ int send_del_subnet(connection_t *cl, subnet_t *subnet) { int x; char *netstr; + char *owner; cp - netstr = net2str(subnet); - x = send_request(cl, "%d %s %s", DEL_SUBNET, subnet->owner->name, netstr); + if(cl->options & OPTION_INDIRECT) + owner = myself->name; + else + owner = subnet->owner->name; + + x = send_request(cl, "%d %s %s", DEL_SUBNET, owner, netstr = net2str(subnet)); free(netstr); cp return x; @@ -751,7 +744,7 @@ int del_subnet_h(connection_t *cl) char name[MAX_STRING_SIZE]; connection_t *owner, *p; subnet_t *subnet; - rbl_t *rbl; + avl_node_t *node; cp if(sscanf(cl->buffer, "%*d "MAX_STRING" "MAX_STRING, name, subnetstr) != 3) { @@ -802,9 +795,9 @@ cp /* Tell the rest */ - RBL_FOREACH(connection_tree, rbl) + for(node = connection_tree->head; node; node = node->next) { - p = (connection_t *)rbl->data; + p = (connection_t *)node->data; if(p->status.meta && p->status.active && p!= cl) send_del_subnet(p, subnet); } @@ -817,19 +810,22 @@ cp int send_add_host(connection_t *cl, connection_t *other) { cp - return send_request(cl, "%d %s %lx:%d %lx", ADD_HOST, + if(!(cl->options & OPTION_INDIRECT)) + return send_request(cl, "%d %s %lx:%d %lx", ADD_HOST, other->name, other->address, other->port, other->options); + else + return 0; } int add_host_h(connection_t *cl) { connection_t *old, *new, *p; char name[MAX_STRING_SIZE]; - rbl_t *rbl; + avl_node_t *node; cp new = new_connection(); - if(sscanf(cl->buffer, "%*d "MAX_STRING" %lx:%d %lx", name, &new->address, &new->port, &new->options) != 4) + if(sscanf(cl->buffer, "%*d "MAX_STRING" %lx:%hd %lx", name, &new->address, &new->port, &new->options) != 4) { syslog(LOG_ERR, _("Got bad ADD_HOST from %s (%s)"), cl->name, cl->hostname); return -1; @@ -846,7 +842,7 @@ cp /* Check if somebody tries to add ourself */ - if(!strcmp(new->name, myself->name)) + if(!strcmp(name, myself->name)) { syslog(LOG_ERR, _("Warning: got ADD_HOST from %s (%s) for ourself, restarting"), cl->name, cl->hostname); sighup = 1; @@ -888,9 +884,9 @@ cp /* Tell the rest about the new host */ - RBL_FOREACH(connection_tree, rbl) + for(node = connection_tree->head; node; node = node->next) { - p = (connection_t *)rbl->data; + p = (connection_t *)node->data; if(p->status.meta && p->status.active && p!=cl) send_add_host(p, new); } @@ -899,14 +895,8 @@ cp new->nexthop = cl; new->status.active = 1; - new->cipher_pkttype = EVP_bf_cfb(); + new->cipher_pkttype = EVP_bf_cbc(); new->cipher_pktkeylength = cl->cipher_pkttype->key_len + cl->cipher_pkttype->iv_len; - - /* Okay this is a bit ugly... it would be better to setup UDP sockets dynamically, or - * perhaps just one UDP socket... but then again, this has benefits too... - */ - - setup_vpn_connection(new); cp return 0; } @@ -914,8 +904,11 @@ cp int send_del_host(connection_t *cl, connection_t *other) { cp - return send_request(cl, "%d %s %lx:%d %lx", DEL_HOST, + if(!(cl->options & OPTION_INDIRECT)) + return send_request(cl, "%d %s %lx:%d %lx", DEL_HOST, other->name, other->address, other->port, other->options); + else + return 0; } int del_host_h(connection_t *cl) @@ -925,9 +918,9 @@ int del_host_h(connection_t *cl) port_t port; long int options; connection_t *old, *p; - rbl_t *rbl; + avl_node_t *node; cp - if(sscanf(cl->buffer, "%*d "MAX_STRING" %lx:%d %lx", name, &address, &port, &options) != 4) + if(sscanf(cl->buffer, "%*d "MAX_STRING" %lx:%hd %lx", name, &address, &port, &options) != 4) { syslog(LOG_ERR, _("Got bad DEL_HOST from %s (%s)"), cl->name, cl->hostname); @@ -976,9 +969,9 @@ cp /* Tell the rest about the new host */ - RBL_FOREACH(connection_tree, rbl) + for(node = connection_tree->head; node; node = node->next) { - p = (connection_t *)rbl->data; + p = (connection_t *)node->data; if(p->status.meta && p->status.active && p!=cl) send_del_host(p, old); } @@ -1019,20 +1012,20 @@ cp return 0; } -int send_error(connection_t *cl, int errno, char *errstring) +int send_error(connection_t *cl, int err, char *errstring) { cp if(!errstring) - errstring = strerror(errno); - return send_request(cl, "%d %d %s", ERROR, errno, errstring); + errstring = strerror(err); + return send_request(cl, "%d %d %s", ERROR, err, errstring); } int error_h(connection_t *cl) { - int errno; + int err; char errorstring[MAX_STRING_SIZE]; cp - if(sscanf(cl->buffer, "%*d %d "MAX_STRING, &errno, errorstring) != 2) + if(sscanf(cl->buffer, "%*d %d "MAX_STRING, &err, errorstring) != 2) { syslog(LOG_ERR, _("Got bad ERROR from %s (%s)"), cl->name, cl->hostname); @@ -1042,7 +1035,7 @@ cp if(debug_lvl >= DEBUG_ERROR) { syslog(LOG_NOTICE, _("Error message from %s (%s): %s: %s"), - cl->name, cl->hostname, strerror(errno), errorstring); + cl->name, cl->hostname, strerror(err), errorstring); } terminate_connection(cl); @@ -1064,8 +1057,6 @@ cp return 0; } -/* Keepalive routines - FIXME: needs a closer look */ - int send_ping(connection_t *cl) { cp @@ -1100,13 +1091,14 @@ cp int send_key_changed(connection_t *from, connection_t *cl) { connection_t *p; - rbl_t *rbl; + avl_node_t *node; cp - RBL_FOREACH(connection_tree, rbl) + for(node = connection_tree->head; node; node = node->next) { - p = (connection_t *)rbl->data; + p = (connection_t *)node->data; if(p != cl && p->status.meta && p->status.active) - send_request(p, "%d %s", KEY_CHANGED, from->name); + if(!(p->options & OPTION_INDIRECT) || from == myself) + send_request(p, "%d %s", KEY_CHANGED, from->name); } cp return 0; @@ -1258,35 +1250,92 @@ cp from->cipher_pktkey = xstrdup(pktkey); keylength /= 2; - hex2bin(pktkey, pktkey, keylength); - pktkey[keylength] = '\0'; + hex2bin(from->cipher_pktkey, from->cipher_pktkey, keylength); + from->cipher_pktkey[keylength] = '\0'; from->status.validkey = 1; from->status.waitingforkey = 0; + + flush_queue(from); cp return 0; } +int send_tcppacket(connection_t *cl, vpn_packet_t *packet) +{ + int x; + + x = send_request(cl->nexthop, "%d %hd", PACKET, packet->len); + + if(x) + return x; + + return send_meta(cl->nexthop, packet->data, packet->len); +} + +int tcppacket_h(connection_t *cl) +{ + vpn_packet_t packet; + char *p; + int todo, x; + + if(sscanf(cl->buffer, "%*d %hd", packet.len) != 1) + { + syslog(LOG_ERR, _("Got bad PACKET from %s (%s)"), cl->name, cl->hostname); + return -1; + } + + /* Evil hack. */ + + p = packet.data; + todo = packet.len; + + while(todo) + { + x = read(cl->meta_socket, p, todo); + + if(x<=0) + { + if(x==0) + syslog(LOG_NOTICE, _("Connection closed by %s (%s)"), cl->name, cl->hostname); + else + if(errno==EINTR) + continue; + else + syslog(LOG_ERR, _("Error during reception of PACKET from %s (%s): %m"), cl->name, cl->hostname); + + return -1; + } + + todo -= x; + p += x; + } + + return receive_packet(cl, &packet); +} + /* Jumptable for the request handlers */ int (*request_handlers[])(connection_t*) = { - id_h, challenge_h, chal_reply_h, metakey_h, ack_h, + id_h, metakey_h, challenge_h, chal_reply_h, status_h, error_h, termreq_h, ping_h, pong_h, add_host_h, del_host_h, add_subnet_h, del_subnet_h, key_changed_h, req_key_h, ans_key_h, + tcppacket_h, }; /* Request names */ char (*request_name[]) = { - "ID", "CHALLENGE", "CHAL_REPLY", "METAKEY", "ACK", + "ID", "METAKEY", "CHALLENGE", "CHAL_REPLY", "STATUS", "ERROR", "TERMREQ", "PING", "PONG", "ADD_HOST", "DEL_HOST", "ADD_SUBNET", "DEL_SUBNET", "KEY_CHANGED", "REQ_KEY", "ANS_KEY", + "PACKET", }; /* Status strings */