X-Git-Url: https://tinc-vpn.org/git/browse?p=tinc;a=blobdiff_plain;f=src%2Fprotocol.c;h=29282a1c4f47a60c2aca51ec8d51505b9795a4b4;hp=b19e572596c40a2d8b25c73730c04e918416e3cd;hb=37ed4265fa73d4c06c74362514d78c92029b2f05;hpb=52b842f8076d507d3a6ea07045d085ae21d1aa10 diff --git a/src/protocol.c b/src/protocol.c index b19e5725..29282a1c 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 1.28.4.44 2000/10/21 11:52:07 guus Exp $ + $Id: protocol.c,v 1.28.4.101 2001/07/20 13:54:19 guus Exp $ */ #include "config.h" @@ -30,23 +30,35 @@ #include #include #include +#include +#include #include #include +#include +#include #include #include +#include +#include + +#ifndef HAVE_RAND_PSEUDO_BYTES +#define RAND_pseudo_bytes RAND_bytes +#endif #include "conf.h" -#include "encr.h" #include "net.h" #include "netutl.h" #include "protocol.h" #include "meta.h" +#include "connection.h" #include "system.h" +int mykeyused = 0; + int check_id(char *id) { int i; @@ -54,21 +66,23 @@ 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(conn_list_t *cl, const char *format, ...) +int send_request(connection_t *cl, const char *format, ...) { va_list args; char buffer[MAXBUFSIZE]; 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); @@ -81,33 +95,55 @@ cp return -1; } - len++; - if(debug_lvl >= DEBUG_PROTOCOL) - syslog(LOG_DEBUG, _("Sending %s to %s (%s)"), request_name[request], cl->name, cl->hostname); + { + if(debug_lvl >= DEBUG_META) + syslog(LOG_DEBUG, _("Sending %s to %s (%s): %s"), request_name[request], cl->name, cl->hostname, buffer); + else + syslog(LOG_DEBUG, _("Sending %s to %s (%s)"), request_name[request], cl->name, cl->hostname); + } + buffer[len++] = '\n'; cp return send_meta(cl, buffer, len); } -int receive_request(conn_list_t *cl) +int receive_request(connection_t *cl) { int request; -cp +cp if(sscanf(cl->buffer, "%d", &request) == 1) { - if((request < 0) || (request > 255) || (request_handlers[request] == NULL)) + if((request < 0) || (request >= LAST) || (request_handlers[request] == NULL)) { - syslog(LOG_ERR, _("Unknown request from %s (%s)"), - cl->name, cl->hostname); + if(debug_lvl >= DEBUG_META) + syslog(LOG_DEBUG, _("Unknown request from %s (%s): %s"), + cl->name, cl->hostname, cl->buffer); + else + syslog(LOG_ERR, _("Unknown request from %s (%s)"), + cl->name, cl->hostname); + return -1; } else { if(debug_lvl >= DEBUG_PROTOCOL) - syslog(LOG_DEBUG, _("Got %s from %s (%s)"), - request_name[request], cl->name, cl->hostname); + { + if(debug_lvl >= DEBUG_META) + syslog(LOG_DEBUG, _("Got %s from %s (%s): %s"), + request_name[request], cl->name, cl->hostname, cl->buffer); + else + syslog(LOG_DEBUG, _("Got %s from %s (%s)"), + request_name[request], cl->name, cl->hostname); + } } + + if((cl->allow_request != ALL) && (cl->allow_request != request)) + { + syslog(LOG_ERR, _("Unauthorized request from %s (%s)"), cl->name, cl->hostname); + return -1; + } + if(request_handlers[request](cl)) /* Something went wrong. Probably scriptkiddies. Terminate. */ { @@ -122,50 +158,24 @@ cp cl->name, cl->hostname); return -1; } +cp + return 0; } -/* Connection protocol: - - Client Server - send_id(u) - send_challenge(R) - send_chal_reply(H) - send_id(u) - send_challenge(R) - send_chal_reply(H) - --------------------------------------- - Any negotations about the meta protocol - encryption go here(u). - --------------------------------------- - send_ack(u) - send_ack(u) - --------------------------------------- - Other requests(E)... - - (u) Unencrypted, - (R) RSA, - (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. -*/ +/* The authentication protocol is described in detail in doc/SECURITY2, + the rest will be described in doc/PROTOCOL. */ -int send_id(conn_list_t *cl) +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); } -int id_h(conn_list_t *cl) +int id_h(connection_t *cl) { - conn_list_t *old; - config_t *cfg; + char name[MAX_STRING_SIZE]; cp - if(sscanf(cl->buffer, "%*d %as %d %lx %hd", &cl->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, &cl->port) != 4) { syslog(LOG_ERR, _("Got bad ID from %s"), cl->hostname); return -1; @@ -182,60 +192,150 @@ cp /* Check if identity is a valid name */ - if(check_id(cl->name)) + if(check_id(name)) { syslog(LOG_ERR, _("Peer %s uses invalid identity name"), cl->hostname); return -1; } + + /* Copy string to cl */ + + if(cl->name) + free(cl->name); + + cl->name = xstrdup(name); /* Load information about peer */ -cp + if(read_host_config(cl)) { syslog(LOG_ERR, _("Peer %s had unknown identity (%s)"), cl->hostname, cl->name); return -1; } - /* First check if the host we connected to is already in our - connection list. If so, we are probably making a loop, which - is not desirable. - */ + /* Read in the public key, so that we can send a metakey */ + + if(read_rsa_public_key(cl)) + return -1; + + cl->allow_request = METAKEY; cp - if(cl->status.outgoing) + 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. + */ + + if((old = lookup_id(cl->name))) { - if((old = lookup_id(cl->name))) + if(debug_lvl >= DEBUG_CONNECTIONS) + syslog(LOG_NOTICE, _("Removing old connection for %s at %s in favour of new connection from %s"), + cl->name, old->hostname, cl->hostname); + if(old->status.outgoing) { - if(debug_lvl >= DEBUG_CONNECTIONS) - syslog(LOG_NOTICE, _("Uplink %s (%s) is already in our connection list"), cl->name, cl->hostname); - cl->status.outgoing = 0; - old->status.outgoing = 1; - terminate_connection(cl); - return 0; + cl->status.outgoing = 1; + old->status.outgoing = 0; } + terminate_connection(old); + return 0; } -cp - if(!(cfg = get_config_val(cl->config, publickey))) + + /* Now we can add the name to the id tree */ + + id_add(cl); + + /* Also check if no other tinc daemon uses the same IP and port for UDP traffic */ + + old = avl_search(active_tree, cl); + if(old) + { + syslog(LOG_ERR, _("%s is listening on %s:%hd, which is already in use by %s!"), + cl->name, cl->hostname, cl->port, old->name); + return -1; + } + + /* 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; + + active_add(cl); + + if(debug_lvl >= DEBUG_CONNECTIONS) + syslog(LOG_NOTICE, _("Connection with %s (%s) activated"), cl->name, cl->hostname); + + if(cl->status.outgoing) + seconds_till_retry = 5; /* Reset retry timeout */ +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; } - else + + if((cfg = get_config_val(cl->config, config_tcponly))) { -cp - cl->rsa_key = RSA_new(); - BN_hex2bn(&cl->rsa_key->n, cfg->data.ptr); - BN_hex2bn(&cl->rsa_key->e, "FFFF"); + 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 = active_tree->head; node; node = node->next) + { + p = (connection_t *)node->data; + + if(p != cl) + { + /* 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(conn_list_t *cl) +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 */ @@ -247,52 +347,31 @@ cp cl->hischallenge = xmalloc(len); cp - /* Seed the PRNG with urandom (can't afford to block) */ - - RAND_load_file("/dev/urandom", 1024); - /* Copy random data to the buffer */ 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 return x; } -int challenge_h(conn_list_t *cl) +int challenge_h(connection_t *cl) { - char *buffer; + char buffer[MAX_STRING_SIZE]; int len; cp - if(sscanf(cl->buffer, "%*d %as", &buffer) != 1) + if(sscanf(cl->buffer, "%*d "MAX_STRING, buffer) != 1) { syslog(LOG_ERR, _("Got bad CHALLENGE from %s (%s)"), cl->name, cl->hostname); return -1; @@ -305,7 +384,6 @@ cp if(strlen(buffer) != len*2) { syslog(LOG_ERR, _("Intruder: wrong challenge length from %s (%s)"), cl->name, cl->hostname); - free(buffer); return -1; } @@ -316,32 +394,16 @@ 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); - free(buffer); - 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; - free(buffer); - /* Rest is done by send_chal_reply() */ cp return send_chal_reply(cl); } -int send_chal_reply(conn_list_t *cl) +int send_chal_reply(connection_t *cl) { char hash[SHA_DIGEST_LENGTH*2+1]; cp @@ -362,24 +424,18 @@ cp /* Send the reply */ - if(cl->status.outgoing) - cl->allow_request = ID; - else - cl->allow_request = ACK; - cp return send_request(cl, "%d %s", CHAL_REPLY, hash); } -int chal_reply_h(conn_list_t *cl) +int chal_reply_h(connection_t *cl) { - char *hishash; + char hishash[MAX_STRING_SIZE]; char myhash[SHA_DIGEST_LENGTH]; cp - if(sscanf(cl->buffer, "%*d %as", &hishash) != 1) + if(sscanf(cl->buffer, "%*d "MAX_STRING, hishash) != 1) { syslog(LOG_ERR, _("Got bad CHAL_REPLY from %s (%s)"), cl->name, cl->hostname); - free(hishash); return -1; } @@ -388,7 +444,6 @@ cp if(strlen(hishash) != SHA_DIGEST_LENGTH*2) { syslog(LOG_ERR, _("Intruder: wrong challenge reply length from %s (%s)"), cl->name, cl->hostname); - free(hishash); return -1; } @@ -411,98 +466,183 @@ cp hishash[SHA_DIGEST_LENGTH*2] = '\0'; syslog(LOG_DEBUG, _("Expected challenge reply: %s"), hishash); } - free(hishash); return -1; } - - free(hishash); - /* 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_ack(cl); - else - return send_id(cl); + return ack_h(cl); } -int send_ack(conn_list_t *cl) +int send_metakey(connection_t *cl) { + char *buffer; + int len, x; +cp + len = RSA_size(cl->rsa_key); + + /* Allocate buffers for the meta key */ + + buffer = xmalloc(len*2+1); + + if(!cl->cipher_outkey) + cl->cipher_outkey = xmalloc(len); + + if(!cl->cipher_outctx) + cl->cipher_outctx = xmalloc(sizeof(*cl->cipher_outctx)); +cp + /* Copy random data to the buffer */ + + RAND_bytes(cl->cipher_outkey, len); + + /* 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); + buffer[len*2] = '\0'; + syslog(LOG_DEBUG, _("Generated random meta key (unencrypted): %s"), buffer); + } + + /* 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) + { + syslog(LOG_ERR, _("Error during encryption of meta key for %s (%s)"), cl->name, cl->hostname); + free(buffer); + return -1; + } cp - cl->allow_request = ACK; + /* Convert the encrypted random data to a hexadecimal formatted string */ + + bin2hex(buffer, buffer, len); + buffer[len*2] = '\0'; + + /* Send the meta key */ + + x = send_request(cl, "%d %s", METAKEY, buffer); + free(buffer); + + /* 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 send_request(cl, "%d", ACK); + return x; } -int ack_h(conn_list_t *cl) +int metakey_h(connection_t *cl) { - conn_list_t *old; + char buffer[MAX_STRING_SIZE]; + int len; 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. - */ + if(sscanf(cl->buffer, "%*d "MAX_STRING, buffer) != 1) + { + syslog(LOG_ERR, _("Got bad METAKEY from %s (%s)"), cl->name, cl->hostname); + return -1; + } + + len = RSA_size(myself->rsa_key); + + /* Check if the length of the meta key is all right */ - while((old = lookup_id(cl->name))) + if(strlen(buffer) != len*2) { - 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); - old->status.active = 0; - terminate_connection(old); + syslog(LOG_ERR, _("Intruder: wrong meta key length from %s (%s)"), cl->name, cl->hostname); + return -1; } - /* Activate this connection */ + /* Allocate buffers for the meta key */ - cl->allow_request = ALL; - cl->status.active = 1; + if(!cl->cipher_inkey) + cl->cipher_inkey = xmalloc(len); - if(debug_lvl >= DEBUG_CONNECTIONS) - syslog(LOG_NOTICE, _("Connection with %s (%s) activated"), cl->name, cl->hostname); + if(!cl->cipher_inctx) + cl->cipher_inctx = xmalloc(sizeof(*cl->cipher_inctx)); + + /* Convert the challenge from hexadecimal back to binary */ - /* Exchange information about other tinc daemons */ + hex2bin(buffer,buffer,len); -/* FIXME: reprogram this. - notify_others(cl, NULL, send_add_host); - notify_one(cl); -*/ - upstreamindex = 0; + /* Decrypt the meta key */ + + if(RSA_private_decrypt(len, buffer, cl->cipher_inkey, myself->rsa_key, RSA_NO_PADDING) != len) /* See challenge() */ + { + syslog(LOG_ERR, _("Error during encryption of meta key for %s (%s)"), cl->name, cl->hostname); + return -1; + } + + if(debug_lvl >= DEBUG_SCARY_THINGS) + { + bin2hex(cl->cipher_inkey, buffer, len); + buffer[len*2] = '\0'; + syslog(LOG_DEBUG, _("Received random meta key (unencrypted): %s"), buffer); + } + + /* All incoming requests will now be encrypted. */ + + 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); + + cl->status.decryptin = 1; + cl->allow_request = CHALLENGE; cp - if(cl->status.outgoing) - return 0; - else - return send_ack(cl); + return send_challenge(cl); } /* Address and subnet information exchange */ -int send_add_subnet(conn_list_t *cl, conn_list_t *other, subnet_t *subnet) +int send_add_subnet(connection_t *cl, subnet_t *subnet) { int x; char *netstr; + char *owner; cp + if((cl->options | myself->options | subnet->owner->options) & OPTION_INDIRECT) + owner = myself->name; + else + owner = subnet->owner->name; + x = send_request(cl, "%d %s %s", ADD_SUBNET, - other->name, netstr = net2str(subnet)); + owner, netstr = net2str(subnet)); free(netstr); cp return x; } -int add_subnet_h(conn_list_t *cl) +int add_subnet_h(connection_t *cl) { - char *subnetstr; - char *name; - conn_list_t *owner; - subnet_t *subnet, *old; + char subnetstr[MAX_STRING_SIZE]; + char name[MAX_STRING_SIZE]; + connection_t *owner, *p; + subnet_t *subnet; + avl_node_t *node; cp - if(sscanf(cl->buffer, "%*d %as %as", &name, &subnetstr) != 3) + if(sscanf(cl->buffer, "%*d "MAX_STRING" "MAX_STRING, name, subnetstr) != 2) { syslog(LOG_ERR, _("Got bad ADD_SUBNET from %s (%s)"), cl->name, cl->hostname); - free(name); free(subnetstr); return -1; } @@ -511,7 +651,6 @@ cp if(check_id(name)) { syslog(LOG_ERR, _("Got bad ADD_SUBNET from %s (%s): invalid identity name"), cl->name, cl->hostname); - free(name); free(subnetstr); return -1; } @@ -520,19 +659,15 @@ cp if(!(subnet = str2net(subnetstr))) { syslog(LOG_ERR, _("Got bad ADD_SUBNET from %s (%s): invalid subnet string"), cl->name, cl->hostname); - free(name); free(subnetstr); return -1; } - free(subnetstr); - /* Check if somebody tries to add a subnet of ourself */ if(!strcmp(name, myself->name)) { syslog(LOG_ERR, _("Warning: got ADD_SUBNET from %s (%s) for ourself, restarting"), cl->name, cl->hostname); - free(name); sighup = 1; return 0; } @@ -543,34 +678,53 @@ cp { syslog(LOG_ERR, _("Got ADD_SUBNET for %s from %s (%s) which is not in our connection list"), name, cl->name, cl->hostname); - free(name); return -1; } /* If everything is correct, add the subnet to the list of the owner */ subnet_add(owner, subnet); + + /* Tell the rest */ + + for(node = connection_tree->head; node; node = node->next) + { + p = (connection_t *)node->data; + if(p->status.active && p!= cl) + send_add_subnet(p, subnet); + } cp return 0; } -int send_del_subnet(conn_list_t *cl, conn_list_t *other, subnet_t *subnet) +int send_del_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", DEL_SUBNET, owner, netstr = net2str(subnet)); + free(netstr); cp - return send_request(cl, "%d %s %s", DEL_SUBNET, other->name, net2str(subnet)); + return x; } -int del_subnet_h(conn_list_t *cl) +int del_subnet_h(connection_t *cl) { - char *subnetstr; - char *name; - conn_list_t *owner; - subnet_t *subnet, *old; + char subnetstr[MAX_STRING_SIZE]; + char name[MAX_STRING_SIZE]; + connection_t *owner, *p; + subnet_t *subnet; + avl_node_t *node; cp - if(sscanf(cl->buffer, "%*d %as %as", &name, &subnetstr) != 3) + if(sscanf(cl->buffer, "%*d "MAX_STRING" "MAX_STRING, name, subnetstr) != 3) { syslog(LOG_ERR, _("Got bad DEL_SUBNET from %s (%s)"), cl->name, cl->hostname); - free(name); free(subnetstr); return -1; } @@ -579,7 +733,6 @@ cp if(check_id(name)) { syslog(LOG_ERR, _("Got bad DEL_SUBNET from %s (%s): invalid identity name"), cl->name, cl->hostname); - free(name); free(subnetstr); return -1; } @@ -588,7 +741,6 @@ cp if(!(subnet = str2net(subnetstr))) { syslog(LOG_ERR, _("Got bad DEL_SUBNET from %s (%s): invalid subnet string"), cl->name, cl->hostname); - free(name); free(subnetstr); return -1; } @@ -600,7 +752,6 @@ cp { syslog(LOG_ERR, _("Warning: got DEL_SUBNET from %s (%s) for ourself, restarting"), cl->name, cl->hostname); - free(name); sighup = 1; return 0; } @@ -611,34 +762,46 @@ cp { syslog(LOG_ERR, _("Got DEL_SUBNET for %s from %s (%s) which is not in our connection list"), name, cl->name, cl->hostname); - free(name); return -1; } /* If everything is correct, delete the subnet from the list of the owner */ subnet_del(subnet); + + /* Tell the rest */ + + for(node = connection_tree->head; node; node = node->next) + { + p = (connection_t *)node->data; + if(p->status.active && p!= cl) + send_del_subnet(p, subnet); + } cp return 0; } /* New and closed connections notification */ -int send_add_host(conn_list_t *cl, conn_list_t *other) +int send_add_host(connection_t *cl, connection_t *other) { cp - return send_request(cl, "%d %s %s %lx:%d %lx", ADD_HOST, - myself->name, other->name, other->address, other->port, other->options); + if(!((cl->options | myself->options | other->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(conn_list_t *cl) +int add_host_h(connection_t *cl) { - char *sender; - conn_list_t *old, *new, *hisuplink; + connection_t *old, *new, *p; + char name[MAX_STRING_SIZE]; + avl_node_t *node; cp - new = new_conn_list(); + new = new_connection(); - if(sscanf(cl->buffer, "%*d %as %as %lx:%d %lx", &sender, &new->name, &new->address, &new->port, &new->options) != 5) + 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; @@ -646,105 +809,94 @@ cp /* Check if identity is a valid name */ - if(check_id(new->name) || check_id(sender)) + if(check_id(name)) { syslog(LOG_ERR, _("Got bad ADD_HOST from %s (%s): invalid identity name"), cl->name, cl->hostname); - free(sender); + free_connection(new); return -1; } /* 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; - free(sender); + free_connection(new); return 0; } - - /* We got an ADD_HOST from ourself!? */ - - if(!strcmp(sender, myself->name)) - { - syslog(LOG_ERR, _("Warning: got ADD_HOST from %s (%s) from ourself, restarting"), cl->name, cl->hostname); - sighup = 1; - free(sender); - return 0; - } - - /* Lookup his uplink */ - - if(!(new->hisuplink = lookup_id(sender))) - { - syslog(LOG_ERR, _("Got ADD_HOST from %s (%s) with origin %s which is not in our connection list"), - sender, cl->name, cl->hostname); - free(sender); - return -1; - } - free(sender); - - /* Fill in more of the new conn_list structure */ + /* Fill in more of the new connection structure */ new->hostname = hostlookup(htonl(new->address)); /* Check if the new host already exists in the connnection list */ - if((old = lookup_id(new->name))) + if((old = lookup_id(name))) { if((new->address == old->address) && (new->port == old->port)) { if(debug_lvl >= DEBUG_CONNECTIONS) syslog(LOG_NOTICE, _("Got duplicate ADD_HOST for %s (%s) from %s (%s)"), - old->name, old->hostname, new->name, new->hostname); + old->name, old->hostname, cl->name, cl->hostname); + free_connection(new); return 0; } else { if(debug_lvl >= DEBUG_CONNECTIONS) - syslog(LOG_NOTICE, _("Removing old entry for %s (%s)"), + syslog(LOG_NOTICE, _("Removing old entry for %s (%s) in favour of new connection"), old->name, old->hostname); - old->status.active = 0; + terminate_connection(old); } } - /* Fill in rest of conn_list structure */ + /* Hook it up into the active tree */ - new->myuplink = cl; - new->status.active = 1; + new->name = xstrdup(name); + active_add(new); + id_add(new); + + /* Tell the rest about the new host */ - /* Hook it up into the conn_list */ + for(node = connection_tree->head; node; node = node->next) + { + p = (connection_t *)node->data; + if(p->status.active && p!=cl) + send_add_host(p, new); + } - conn_list_add(conn_list, new); + /* Fill in rest of connection structure */ - /* Tell the rest about the new host */ -/* FIXME: reprogram this. - notify_others(new, cl, send_add_host); -*/ + new->nexthop = cl; + new->status.active = 1; + new->cipher_pkttype = EVP_bf_cbc(); + new->cipher_pktkeylength = cl->cipher_pkttype->key_len + cl->cipher_pkttype->iv_len; cp return 0; } -int send_del_host(conn_list_t *cl, conn_list_t *other) +int send_del_host(connection_t *cl, connection_t *other) { cp - return send_request(cl, "%d %s %s %lx:%d %lx", DEL_HOST, - myself->name, other->name, other->address, other->port, other->options); + if(!((cl->options | myself->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(conn_list_t *cl) +int del_host_h(connection_t *cl) { - char *name; - char *sender; - ip_t address; + char name[MAX_STRING_SIZE]; + ipv4_t address; port_t port; - int options; - conn_list_t *old, *hisuplink; - + long int options; + connection_t *old, *p; + avl_node_t *node; cp - if(sscanf(cl->buffer, "%*d %as %as %lx:%d %lx", &sender, &name, &address, &port, &options) != 5) + 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); @@ -753,10 +905,9 @@ cp /* Check if identity is a valid name */ - if(check_id(name) || check_id(sender)) + if(check_id(name)) { syslog(LOG_ERR, _("Got bad DEL_HOST from %s (%s): invalid identity name"), cl->name, cl->hostname); - free(name); free(sender); return -1; } @@ -766,46 +917,22 @@ cp { syslog(LOG_ERR, _("Warning: got DEL_HOST from %s (%s) for ourself, restarting"), cl->name, cl->hostname); - free(name); free(sender); sighup = 1; return 0; } - /* We got an ADD_HOST from ourself!? */ - - if(!strcmp(sender, myself->name)) - { - syslog(LOG_ERR, _("Warning: got DEL_HOST from %s (%s) from ourself, restarting"), cl->name, cl->hostname); - sighup = 1; - free(name); free(sender); - return 0; - } - - /* Lookup his uplink */ - - if(!(hisuplink = lookup_id(sender))) - { - syslog(LOG_ERR, _("Got DEL_HOST from %s (%s) with origin %s which is not in our connection list"), - cl->name, cl->hostname, sender); - free(name); free(sender); - return -1; - } - - free(sender); - /* Check if the new host already exists in the connnection list */ if(!(old = lookup_id(name))) { syslog(LOG_ERR, _("Got DEL_HOST from %s (%s) for %s which is not in our connection list"), - name, cl->name, cl->hostname); - free(name); + cl->name, cl->hostname, name); return -1; } /* Check if the rest matches */ - if(address!=old->address || port!=old->port || options!=old->options || hisuplink!=old->hisuplink || cl!=old->myuplink) + if(address!=old->address || port!=old->port || options!=old->options || cl!=old->nexthop) { syslog(LOG_WARNING, _("Got DEL_HOST from %s (%s) for %s which doesn't match"), cl->name, cl->hostname, old->name); return 0; @@ -813,17 +940,24 @@ cp /* Ok, since EVERYTHING seems to check out all right, delete it */ - old->status.termreq = 1; old->status.active = 0; - terminate_connection(old); + + /* Tell the rest about the new host */ + + for(node = connection_tree->head; node; node = node->next) + { + p = (connection_t *)node->data; + if(p->status.active && p!=cl) + send_del_host(p, old); + } cp return 0; } /* Status and error notification routines */ -int send_status(conn_list_t *cl, int statusno, char *statusstring) +int send_status(connection_t *cl, int statusno, char *statusstring) { cp if(!statusstring) @@ -832,12 +966,12 @@ cp return send_request(cl, "%d %d %s", STATUS, statusno, statusstring); } -int status_h(conn_list_t *cl) +int status_h(connection_t *cl) { int statusno; - char *statusstring; + char statusstring[MAX_STRING_SIZE]; cp - if(sscanf(cl->buffer, "%*d %d %as", &statusno, &statusstring) != 2) + if(sscanf(cl->buffer, "%*d %d "MAX_STRING, &statusno, statusstring) != 2) { syslog(LOG_ERR, _("Got bad STATUS from %s (%s)"), cl->name, cl->hostname); @@ -851,24 +985,23 @@ cp } cp - free(statusstring); return 0; } -int send_error(conn_list_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(conn_list_t *cl) +int error_h(connection_t *cl) { - int errno; - char *errorstring; + int err; + char errorstring[MAX_STRING_SIZE]; cp - if(sscanf(cl->buffer, "%*d %d %as", &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); @@ -878,82 +1011,97 @@ 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); } - free(errorstring); - cl->status.termreq = 1; terminate_connection(cl); cp return 0; } -int send_termreq(conn_list_t *cl) +int send_termreq(connection_t *cl) { cp return send_request(cl, "%d", TERMREQ); } -int termreq_h(conn_list_t *cl) +int termreq_h(connection_t *cl) { cp - cl->status.termreq = 1; terminate_connection(cl); cp return 0; } -/* Keepalive routines - FIXME: needs a closer look */ - -int send_ping(conn_list_t *cl) +int send_ping(connection_t *cl) { + char salt[SALTLEN*2+1]; +cp cl->status.pinged = 1; + cl->last_ping_time = time(NULL); + RAND_pseudo_bytes(salt, SALTLEN); + bin2hex(salt, salt, SALTLEN); + salt[SALTLEN*2] = '\0'; cp - return send_request(cl, "%d", PING); + return send_request(cl, "%d %s", PING, salt); } -int ping_h(conn_list_t *cl) +int ping_h(connection_t *cl) { cp return send_pong(cl); } -int send_pong(conn_list_t *cl) +int send_pong(connection_t *cl) { + char salt[SALTLEN*2+1]; +cp + RAND_pseudo_bytes(salt, SALTLEN); + bin2hex(salt, salt, SALTLEN); + salt[SALTLEN*2] = '\0'; cp - return send_request(cl, "%d", PONG); + return send_request(cl, "%d %s", PONG, salt); } -int pong_h(conn_list_t *cl) +int pong_h(connection_t *cl) { cp - cl->status.got_pong = 1; + cl->status.pinged = 0; cp return 0; } /* Key exchange */ -int send_key_changed(conn_list_t *from, conn_list_t *cl) +int send_key_changed(connection_t *from, connection_t *cl) { - conn_list_t *p; + connection_t *p; + avl_node_t *node; cp - for(p = conn_list; p != NULL; p = p->next) + /* Only send this message if some other daemon requested our key previously. + This reduces unnecessary key_changed broadcasts. + */ + + if(from==myself && !mykeyused) + return 0; + + for(node = connection_tree->head; node; node = node->next) { - if(p!=cl && p->status.meta && p->status.active) - send_request(p, "%d %s", KEY_CHANGED, - from->name); + p = (connection_t *)node->data; + if(p != cl && p->status.active) + if(!(p->options & OPTION_INDIRECT) || from == myself) + send_request(p, "%d %s", KEY_CHANGED, from->name); } cp return 0; } -int key_changed_h(conn_list_t *cl) +int key_changed_h(connection_t *cl) { - char *from_id; - conn_list_t *from; + char from_id[MAX_STRING_SIZE]; + connection_t *from; cp - if(sscanf(cl->buffer, "%*d %as", &from_id) != 1) + if(sscanf(cl->buffer, "%*d "MAX_STRING, from_id) != 1) { syslog(LOG_ERR, _("Got bad KEY_CHANGED from %s (%s)"), cl->name, cl->hostname); @@ -964,33 +1112,33 @@ cp { syslog(LOG_ERR, _("Got KEY_CHANGED from %s (%s) origin %s which does not exist in our connection list"), cl->name, cl->hostname, from_id); - free(from_id); return -1; } - free(from_id); - from->status.validkey = 0; from->status.waitingforkey = 0; - send_key_changed(from, cl); + if(!(from->options | cl->options | myself->options) & OPTION_INDIRECT) + send_key_changed(from, cl); cp return 0; } -int send_req_key(conn_list_t *from, conn_list_t *to) +int send_req_key(connection_t *from, connection_t *to) { cp return send_request(to->nexthop, "%d %s %s", REQ_KEY, from->name, to->name); } -int req_key_h(conn_list_t *cl) +int req_key_h(connection_t *cl) { - char *from_id, *to_id; - conn_list_t *from, *to; + char from_id[MAX_STRING_SIZE]; + char to_id[MAX_STRING_SIZE]; + connection_t *from, *to; + char pktkey[129]; cp - if(sscanf(cl->buffer, "%*d %as %as", &from_id, &to_id) != 2) + if(sscanf(cl->buffer, "%*d "MAX_STRING" "MAX_STRING, from_id, to_id) != 2) { syslog(LOG_ERR, _("Got bad REQ_KEY from %s (%s)"), cl->name, cl->hostname); @@ -1001,15 +1149,17 @@ cp { syslog(LOG_ERR, _("Got REQ_KEY from %s (%s) origin %s which does not exist in our connection list"), cl->name, cl->hostname, from_id); - free(from_id); free(to_id); return -1; } /* Check if this key request is for us */ - if(!strcmp(to_id, myself->name)) + if(!strcmp(to_id, myself->name)) /* Yes, send our own key back */ { - send_ans_key(myself, from, myself->cipher_pktkey); + bin2hex(myself->cipher_pktkey, pktkey, myself->cipher_pktkeylength); + pktkey[myself->cipher_pktkeylength*2] = '\0'; + send_ans_key(myself, from, pktkey); + mykeyused = 1; } else { @@ -1017,31 +1167,39 @@ cp { syslog(LOG_ERR, _("Got REQ_KEY from %s (%s) destination %s which does not exist in our connection list"), cl->name, cl->hostname, to_id); - free(from_id); free(to_id); return -1; } - send_req_key(from, to); + + if(to->status.validkey) /* Proxy keys */ + { + bin2hex(to->cipher_pktkey, pktkey, to->cipher_pktkeylength); + pktkey[to->cipher_pktkeylength*2] = '\0'; + send_ans_key(to, from, pktkey); + } + else + send_req_key(from, to); } - free(from_id); free(to_id); cp return 0; } -int send_ans_key(conn_list_t *from, conn_list_t *to, char *pktkey) +int send_ans_key(connection_t *from, connection_t *to, char *pktkey) { cp return send_request(to->nexthop, "%d %s %s %s", ANS_KEY, from->name, to->name, pktkey); } -int ans_key_h(conn_list_t *cl) +int ans_key_h(connection_t *cl) { - char *from_id, *to_id, *pktkey; + char from_id[MAX_STRING_SIZE]; + char to_id[MAX_STRING_SIZE]; + char pktkey[MAX_STRING_SIZE]; int keylength; - conn_list_t *from, *to; + connection_t *from, *to; cp - if(sscanf(cl->buffer, "%*d %as %as %as", &from_id, &to_id, &pktkey) != 3) + if(sscanf(cl->buffer, "%*d "MAX_STRING" "MAX_STRING" "MAX_STRING, from_id, to_id, pktkey) != 3) { syslog(LOG_ERR, _("Got bad ANS_KEY from %s (%s)"), cl->name, cl->hostname); @@ -1052,66 +1210,104 @@ cp { syslog(LOG_ERR, _("Got ANS_KEY from %s (%s) origin %s which does not exist in our connection list"), cl->name, cl->hostname, from_id); - free(from_id); free(to_id); free(pktkey); return -1; } - /* Check if this key request is for us */ + /* Check correctness of packet key */ + + keylength = strlen(pktkey); - if(!strcmp(to_id, myself->name)) + if(keylength != from->cipher_pktkeylength*2) { - /* It is for us, convert it to binary and set the key with it. */ + syslog(LOG_ERR, _("Got bad ANS_KEY from %s (%s) origin %s: invalid key length"), + cl->name, cl->hostname, from->name); + return -1; + } - keylength = strlen(pktkey); + /* Forward it if necessary */ - if((keylength%2) || (keylength <= 0)) - { - syslog(LOG_ERR, _("Got bad ANS_KEY from %s (%s) origin %s: invalid key"), - cl->name, cl->hostname, from->name); - free(from_id); free(to_id); free(pktkey); - return -1; - } - keylength /= 2; - hex2bin(pktkey, pktkey, keylength); - BF_set_key(cl->cipher_pktkey, keylength, pktkey); - } - else + if(strcmp(to_id, myself->name)) { if(!(to = lookup_id(to_id))) { syslog(LOG_ERR, _("Got ANS_KEY from %s (%s) destination %s which does not exist in our connection list"), cl->name, cl->hostname, to_id); - free(from_id); free(to_id); free(pktkey); return -1; } send_ans_key(from, to, pktkey); } - free(from_id); free(to_id); free(pktkey); + /* Update our copy of the origin's packet key */ + + if(from->cipher_pktkey) + free(from->cipher_pktkey); + + from->cipher_pktkey = xstrdup(pktkey); + keylength /= 2; + 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; +cp + /* Evil hack. */ + + x = send_request(cl->nexthop, "%d %hd", PACKET, packet->len); + + if(x) + return x; +cp + return send_meta(cl, packet->data, packet->len); +} + +int tcppacket_h(connection_t *cl) +{ + short int len; +cp + if(sscanf(cl->buffer, "%*d %hd", &len) != 1) + { + syslog(LOG_ERR, _("Got bad PACKET from %s (%s)"), cl->name, cl->hostname); + return -1; + } + + /* Set reqlen to len, this will tell receive_meta() that a tcppacket is coming. */ + + cl->tcplen = len; cp return 0; } /* Jumptable for the request handlers */ -int (*request_handlers[])(conn_list_t*) = { - id_h, challenge_h, chal_reply_h, ack_h, +int (*request_handlers[])(connection_t*) = { + 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", "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 */