X-Git-Url: http://tinc-vpn.org/git/browse?a=blobdiff_plain;f=src%2Fprotocol_auth.c;h=497d43f7940d269c1ec9c1d1f4562303489b903a;hb=refs%2Fheads%2F1.0-gnutls;hp=1fad4b78e510d36318667d1c37b53ce236e6d845;hpb=5bf4b88666ecafe190e8ed71d6c14c9de8d16e1f;p=tinc diff --git a/src/protocol_auth.c b/src/protocol_auth.c index 1fad4b78..497d43f7 100644 --- a/src/protocol_auth.c +++ b/src/protocol_auth.c @@ -1,7 +1,7 @@ /* protocol_auth.c -- handle the meta-protocol, authentication - Copyright (C) 1999-2002 Ivo Timmermans , - 2000-2002 Guus Sliepen + 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 @@ -17,545 +17,246 @@ along with this program; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. - $Id: protocol_auth.c,v 1.1.4.1 2002/02/11 10:05:58 guus Exp $ + $Id: protocol_auth.c,v 1.1.4.34 2003/12/22 11:04:16 guus Exp $ */ -#include "config.h" - -#include -#include -#include -#include -#include -#include - -#include -#include -#include - -#include -#include -#include +#include "system.h" -#ifndef HAVE_RAND_PSEUDO_BYTES -#define RAND_pseudo_bytes RAND_bytes -#endif +#include +#include +#include "avl_tree.h" #include "conf.h" -#include "net.h" -#include "netutl.h" -#include "protocol.h" -#include "meta.h" #include "connection.h" -#include "node.h" #include "edge.h" #include "graph.h" +#include "logger.h" +#include "net.h" +#include "netutl.h" +#include "node.h" +#include "protocol.h" +#include "utils.h" +#include "xalloc.h" -#include "system.h" - -int send_id(connection_t *c) +bool send_ack(connection_t *c) { -cp - return send_request(c, "%d %s %d", ID, myself->connection->name, myself->connection->protocol_version); + char buf[MAX_STRING_SIZE]; + size_t len; + gnutls_x509_crt cert; + const gnutls_datum *cert_list; + int cert_list_size = 0, result; + char *p, *name; + + cert_list = gnutls_certificate_get_peers(c->session, &cert_list_size); + + if (!cert_list || !cert_list_size) { + logger(LOG_ERR, _("No certificates from %s"), c->hostname); + return false; + } + + len = sizeof buf; + gnutls_x509_crt_init(&cert); + result = gnutls_x509_crt_import(cert, &cert_list[0], GNUTLS_X509_FMT_DER) + ?: gnutls_x509_crt_get_dn(cert, buf, &len); + + if(result) { + logger(LOG_ERR, _("Error importing certificate from %s: %s"), c->hostname, gnutls_strerror(errno)); + gnutls_x509_crt_deinit(cert); + return false; + } + + name = strstr(buf, "CN="); + if(!name) { + logger(LOG_ERR, _("No name in certificate from %s"), c->hostname); + gnutls_x509_crt_deinit(cert); + return false; + } + name += 3; + for(p = name; *p && *p != ','; p++); + *p = '\0'; + + if(!check_id(name)) { + logger(LOG_ERR, _("Invalid name from %s"), c->hostname); + return false; + } + + if(c->name) { + if(strcmp(c->name, name)) { + logger(LOG_ERR, _("Peer %s is %s instead of %s"), c->hostname, name, c->hostname); + return false; + } + } else { + c->name = xstrdup(name); + } + + result = gnutls_certificate_verify_peers(c->session); + + if(result) { + if(result & GNUTLS_CERT_INVALID) + logger(LOG_ERR, _("Certificate from %s (%s) invalid"), c->name, c->hostname); + if(result & GNUTLS_CERT_REVOKED) + logger(LOG_ERR, _("Certificate from %s (%s) revoked"), c->name, c->hostname); + if(result & GNUTLS_CERT_SIGNER_NOT_FOUND) + logger(LOG_ERR, _("Certificate from %s (%s) has no known signer"), c->name, c->hostname); + if(result & GNUTLS_CERT_SIGNER_NOT_CA) + logger(LOG_ERR, _("Certificate from %s (%s) has no CA as signer"), c->name, c->hostname); + } + + if(!c->config_tree) { + init_configuration(&c->config_tree); + + if(!read_connection_config(c)) { + logger(LOG_ERR, _("Peer %s had unknown identity (%s)"), c->hostname, + c->name); + return false; + } + } + + /* ACK message contains rest of the information the other end needs + to create node_t and edge_t structures. */ + + struct timeval now; + bool choice; + + cp(); + + /* Estimate weight */ + + gettimeofday(&now, NULL); + c->estimated_weight = (now.tv_sec - c->start.tv_sec) * 1000 + (now.tv_usec - c->start.tv_usec) / 1000; + + /* Check some options */ + + if((get_config_bool(lookup_config(c->config_tree, "IndirectData"), &choice) && choice) || myself->options & OPTION_INDIRECT) + c->options |= OPTION_INDIRECT; + + if((get_config_bool(lookup_config(c->config_tree, "TCPOnly"), &choice) && choice) || myself->options & OPTION_TCPONLY) + c->options |= OPTION_TCPONLY | OPTION_INDIRECT; + + if((get_config_bool(lookup_config(c->config_tree, "PMTUDiscovery"), &choice) && choice) || myself->options & OPTION_PMTU_DISCOVERY) + c->options |= OPTION_PMTU_DISCOVERY; + + get_config_int(lookup_config(c->config_tree, "Weight"), &c->estimated_weight); + + return send_request(c, "%d %s %d %lx", ACK, myport, c->estimated_weight, c->options); } -int id_h(connection_t *c) +static void send_everything(connection_t *c) { - char name[MAX_STRING_SIZE]; - int bla; -cp - if(sscanf(c->buffer, "%*d "MAX_STRING" %d", name, &c->protocol_version) != 2) - { - syslog(LOG_ERR, _("Got bad %s from %s (%s)"), "ID", c->name, c->hostname); - return -1; - } - - /* Check if identity is a valid name */ - - if(check_id(name)) - { - syslog(LOG_ERR, _("Got bad %s from %s (%s): %s"), "ID", c->name, c->hostname, "invalid name"); - return -1; - } - - /* If we set c->name in advance, make sure we are connected to the right host */ - - if(c->name) - { - if(strcmp(c->name, name)) - { - syslog(LOG_ERR, _("Peer %s is %s instead of %s"), c->hostname, name, c->name); - return -1; - } - } - else - c->name = xstrdup(name); - - /* Check if version matches */ - - if(c->protocol_version != myself->connection->protocol_version) - { - syslog(LOG_ERR, _("Peer %s (%s) uses incompatible version %d"), - c->name, c->hostname, c->protocol_version); - return -1; - } - - if(bypass_security) - { - if(!c->config_tree) - init_configuration(&c->config_tree); - c->allow_request = ACK; - return send_ack(c); - } - - if(!c->config_tree) - { - init_configuration(&c->config_tree); - - if((bla = read_connection_config(c))) - { - syslog(LOG_ERR, _("Peer %s had unknown identity (%s)"), c->hostname, c->name); - return -1; - } - } - - if(read_rsa_public_key(c)) - { - return -1; - } - - /* Check some options */ - - if((get_config_bool(lookup_config(c->config_tree, "IndirectData"), &bla) && bla) || myself->options & OPTION_INDIRECT) - c->options |= OPTION_INDIRECT; - - if((get_config_bool(lookup_config(c->config_tree, "TCPOnly"), &bla) && bla) || myself->options & OPTION_TCPONLY) - c->options |= OPTION_TCPONLY | OPTION_INDIRECT; - - c->allow_request = METAKEY; -cp - return send_metakey(c); + avl_node_t *node, *node2; + node_t *n; + subnet_t *s; + edge_t *e; + + /* Send all known subnets and edges */ + + if(tunnelserver) { + for(node = myself->subnet_tree->head; node; node = node->next) { + s = node->data; + send_add_subnet(c, s); + } + + return; + } + + for(node = node_tree->head; node; node = node->next) { + n = node->data; + + for(node2 = n->subnet_tree->head; node2; node2 = node2->next) { + s = node2->data; + send_add_subnet(c, s); + } + + for(node2 = n->edge_tree->head; node2; node2 = node2->next) { + e = node2->data; + send_add_edge(c, e); + } + } } -int send_metakey(connection_t *c) +bool ack_h(connection_t *c) { - char buffer[MAX_STRING_SIZE]; - int len, x; -cp - len = RSA_size(c->rsa_key); - - /* Allocate buffers for the meta key */ - - if(!c->outkey) - c->outkey = xmalloc(len); - - if(!c->outctx) - c->outctx = xmalloc(sizeof(*c->outctx)); -cp - /* Copy random data to the buffer */ - - RAND_bytes(c->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. - */ - - c->outkey[0] &= 0x7F; - - if(debug_lvl >= DEBUG_SCARY_THINGS) - { - bin2hex(c->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, c->outkey, buffer, c->rsa_key, RSA_NO_PADDING) != len) - { - syslog(LOG_ERR, _("Error during encryption of meta key for %s (%s)"), c->name, c->hostname); - return -1; - } -cp - /* 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(c, "%d %s", METAKEY, buffer); - - /* Further outgoing requests are encrypted with the key we just generated */ - - EVP_EncryptInit(c->outctx, EVP_bf_cfb(), - c->outkey + len - EVP_bf_cfb()->key_len, - c->outkey + len - EVP_bf_cfb()->key_len - EVP_bf_cfb()->iv_len); - - c->status.encryptout = 1; -cp - return x; -} + char hisport[MAX_STRING_SIZE]; + char *hisaddress, *dummy; + int weight, mtu; + long int options; + node_t *n; -int metakey_h(connection_t *c) -{ - char buffer[MAX_STRING_SIZE]; - int len; -cp - if(sscanf(c->buffer, "%*d "MAX_STRING, buffer) != 1) - { - syslog(LOG_ERR, _("Got bad %s from %s (%s)"), "METAKEY", c->name, c->hostname); - return -1; - } -cp - len = RSA_size(myself->connection->rsa_key); - - /* Check if the length of the meta key is all right */ - - if(strlen(buffer) != len*2) - { - syslog(LOG_ERR, _("Possible intruder %s (%s): %s"), c->name, c->hostname, "wrong keylength"); - return -1; - } - - /* Allocate buffers for the meta key */ -cp - if(!c->inkey) - c->inkey = xmalloc(len); - - if(!c->inctx) - c->inctx = xmalloc(sizeof(*c->inctx)); - - /* Convert the challenge from hexadecimal back to binary */ -cp - hex2bin(buffer,buffer,len); - - /* Decrypt the meta key */ -cp - if(RSA_private_decrypt(len, buffer, c->inkey, myself->connection->rsa_key, RSA_NO_PADDING) != len) /* See challenge() */ - { - syslog(LOG_ERR, _("Error during encryption of meta key for %s (%s)"), c->name, c->hostname); - return -1; - } - - if(debug_lvl >= DEBUG_SCARY_THINGS) - { - bin2hex(c->inkey, buffer, len); - buffer[len*2] = '\0'; - syslog(LOG_DEBUG, _("Received random meta key (unencrypted): %s"), buffer); - } - - /* All incoming requests will now be encrypted. */ -cp - EVP_DecryptInit(c->inctx, EVP_bf_cfb(), - c->inkey + len - EVP_bf_cfb()->key_len, - c->inkey + len - EVP_bf_cfb()->key_len - EVP_bf_cfb()->iv_len); - - c->status.decryptin = 1; - - c->allow_request = CHALLENGE; -cp - return send_challenge(c); -} + cp(); -int send_challenge(connection_t *c) -{ - char buffer[MAX_STRING_SIZE]; - int len, x; -cp - /* CHECKME: what is most reasonable value for len? */ + if(sscanf(c->buffer, "%*d " MAX_STRING " %d %lx", hisport, &weight, &options) != 3) { + logger(LOG_ERR, _("Got bad %s from %s (%s)"), "ACK", c->name, + c->hostname); + return false; + } - len = RSA_size(c->rsa_key); + /* Check if we already have a node_t for him */ - /* Allocate buffers for the challenge */ + n = lookup_node(c->name); - if(!c->hischallenge) - c->hischallenge = xmalloc(len); -cp - /* Copy random data to the buffer */ + if(!n) { + n = new_node(); + n->name = xstrdup(c->name); + node_add(n); + } else { + if(n->connection) { + /* Oh dear, we already have a connection to this node. */ + ifdebug(CONNECTIONS) logger(LOG_DEBUG, _("Established a second connection with %s (%s), closing old connection"), + n->name, n->hostname); + terminate_connection(n->connection, false); + /* Run graph algorithm to purge key and make sure up/down scripts are rerun with new IP addresses and stuff */ + graph(); + } + } - RAND_bytes(c->hischallenge, len); + n->connection = c; + c->node = n; + c->options |= options; -cp - /* Convert to hex */ + if(get_config_int(lookup_config(c->config_tree, "PMTU"), &mtu) && mtu < n->mtu) + n->mtu = mtu; - bin2hex(c->hischallenge, buffer, len); - buffer[len*2] = '\0'; + if(get_config_int(lookup_config(myself->connection->config_tree, "PMTU"), &mtu) && mtu < n->mtu) + n->mtu = mtu; -cp - /* Send the challenge */ + /* Activate this connection */ - x = send_request(c, "%d %s", CHALLENGE, buffer); -cp - return x; -} + c->allow_request = ALL; + c->status.active = true; -int challenge_h(connection_t *c) -{ - char buffer[MAX_STRING_SIZE]; - int len; -cp - if(sscanf(c->buffer, "%*d "MAX_STRING, buffer) != 1) - { - syslog(LOG_ERR, _("Got bad %s from %s (%s)"), "CHALLENGE", c->name, c->hostname); - return -1; - } + ifdebug(CONNECTIONS) logger(LOG_NOTICE, _("Connection with %s (%s) activated"), c->name, + c->hostname); - len = RSA_size(myself->connection->rsa_key); + /* Send him everything we know */ - /* Check if the length of the challenge is all right */ + send_everything(c); - if(strlen(buffer) != len*2) - { - syslog(LOG_ERR, _("Possible intruder %s (%s): %s"), c->name, c->hostname, "wrong challenge length"); - return -1; - } + /* Create an edge_t for this connection */ - /* Allocate buffers for the challenge */ + c->edge = new_edge(); + cp(); + c->edge->from = myself; + c->edge->to = n; + sockaddr2str(&c->address, &hisaddress, &dummy); + c->edge->address = str2sockaddr(hisaddress, hisport); + free(hisaddress); + free(dummy); + c->edge->weight = (weight + c->estimated_weight) / 2; + c->edge->connection = c; + c->edge->options = c->options; - if(!c->mychallenge) - c->mychallenge = xmalloc(len); + edge_add(c->edge); - /* Convert the challenge from hexadecimal back to binary */ + /* Notify everyone of the new edge */ - hex2bin(buffer,c->mychallenge,len); + if(tunnelserver) + send_add_edge(c, c->edge); + else + send_add_edge(broadcast, c->edge); - c->allow_request = CHAL_REPLY; + /* Run MST and SSSP algorithms */ - /* Rest is done by send_chal_reply() */ -cp - return send_chal_reply(c); -} - -int send_chal_reply(connection_t *c) -{ - char hash[SHA_DIGEST_LENGTH*2+1]; -cp - /* Calculate the hash from the challenge we received */ - - SHA1(c->mychallenge, RSA_size(myself->connection->rsa_key), hash); - - /* Convert the hash to a hexadecimal formatted string */ + graph(); - bin2hex(hash,hash,SHA_DIGEST_LENGTH); - hash[SHA_DIGEST_LENGTH*2] = '\0'; - - /* Send the reply */ - -cp - return send_request(c, "%d %s", CHAL_REPLY, hash); -} - -int chal_reply_h(connection_t *c) -{ - char hishash[MAX_STRING_SIZE]; - char myhash[SHA_DIGEST_LENGTH]; -cp - if(sscanf(c->buffer, "%*d "MAX_STRING, hishash) != 1) - { - syslog(LOG_ERR, _("Got bad %s from %s (%s)"), "CHAL_REPLY", c->name, c->hostname); - return -1; - } - - /* Check if the length of the hash is all right */ - - if(strlen(hishash) != SHA_DIGEST_LENGTH*2) - { - syslog(LOG_ERR, _("Possible intruder %s (%s): %s"), c->name, c->hostname, _("wrong challenge reply length")); - return -1; - } - - /* Convert the hash to binary format */ - - hex2bin(hishash, hishash, SHA_DIGEST_LENGTH); - - /* Calculate the hash from the challenge we sent */ - - SHA1(c->hischallenge, RSA_size(c->rsa_key), myhash); - - /* Verify the incoming hash with the calculated hash */ - - if(memcmp(hishash, myhash, SHA_DIGEST_LENGTH)) - { - syslog(LOG_ERR, _("Possible intruder %s (%s): %s"), c->name, c->hostname, _("wrong challenge reply")); - if(debug_lvl >= DEBUG_SCARY_THINGS) - { - bin2hex(myhash, hishash, SHA_DIGEST_LENGTH); - hishash[SHA_DIGEST_LENGTH*2] = '\0'; - syslog(LOG_DEBUG, _("Expected challenge reply: %s"), hishash); - } - return -1; - } - - /* Identity has now been positively verified. - Send an acknowledgement with the rest of the information needed. - */ - - c->allow_request = ACK; -cp - return send_ack(c); -} - -int send_ack(connection_t *c) -{ - /* ACK message contains rest of the information the other end needs - to create node_t and edge_t structures. */ - - int x; - char *addrstr; - struct timeval now; -cp - /* Estimate weight */ - - gettimeofday(&now, NULL); - c->estimated_weight = (now.tv_sec - c->start.tv_sec) * 1000 + (now.tv_usec - c->start.tv_usec) / 1000; - addrstr = address2str(c->address); - x = send_request(c, "%d %hd %s %d %d", ACK, myself->port, addrstr, c->estimated_weight, c->options); - free(addrstr); -cp - return x; -} - -void send_everything(connection_t *c) -{ - avl_node_t *node, *node2; - node_t *n; - subnet_t *s; - edge_t *e; - - /* Send all known subnets */ - - for(node = node_tree->head; node; node = node->next) - { - n = (node_t *)node->data; - - for(node2 = n->subnet_tree->head; node2; node2 = node2->next) - { - s = (subnet_t *)node2->data; - send_add_subnet(c, s); - } - } - - /* Send all known edges */ - - for(node = edge_tree->head; node; node = node->next) - { - e = (edge_t *)node->data; - - if(e == c->edge) - continue; - - send_add_edge(c, e); - } -} - -int ack_h(connection_t *c) -{ - port_t hisport; - char addrstr[MAX_STRING_SIZE]; - int weight; - int options; - node_t *n; - connection_t *other; - avl_node_t *node; -cp - if(sscanf(c->buffer, "%*d %hd "MAX_STRING" %d %d", &hisport, addrstr, &weight, &options) != 4) - { - syslog(LOG_ERR, _("Got bad %s from %s (%s)"), "ACK", c->name, c->hostname); - return -1; - } - - /* Check if we already have a node_t for him */ - - n = lookup_node(c->name); - - if(!n) - { - n = new_node(); - n->name = xstrdup(c->name); - n->address = c->address; - n->hostname = xstrdup(c->hostname); - n->port = hisport; - - /* FIXME: Also check if no other tinc daemon uses the same IP and port for UDP traffic */ - - node_add(n); - } - else - { - if(n->connection) - { - /* Oh dear, we already have a connection to this node. */ - if(debug_lvl >= DEBUG_CONNECTIONS) - syslog(LOG_DEBUG, _("Established a second connection with %s (%s), closing old connection"), n->name, n->hostname); - terminate_connection(n->connection, 0); - } - - /* FIXME: check if information in existing node matches that of the other end of this connection */ - } - - n->connection = c; - c->node = n; - c->options |= options; - - /* Create an edge_t for this connection */ - - c->edge = new_edge(); - - c->edge->from.node = myself; - c->edge->from.address = str2address(addrstr); - c->edge->from.port = myself->port; - c->edge->to.node = n; - c->edge->to.address = c->address; - c->edge->to.port = hisport; - c->edge->weight = (weight + c->estimated_weight) / 2; - c->edge->connection = c; - c->edge->options = c->options; - - edge_add(c->edge); - - /* Activate this connection */ - - c->allow_request = ALL; - c->status.active = 1; - - if(debug_lvl >= DEBUG_CONNECTIONS) - syslog(LOG_NOTICE, _("Connection with %s (%s) activated"), c->name, c->hostname); - -cp - /* Send him everything we know */ - - send_everything(c); - - /* Notify others of this connection */ - - for(node = connection_tree->head; node; node = node->next) - { - other = (connection_t *)node->data; - - if(other->status.active && other != c) - send_add_edge(other, c->edge); - } - - /* Run MST and SSSP algorithms */ - - graph(); - - /* Succesful connection, reset timeout if this is an outgoing connection. */ - - if(c->outgoing) - c->outgoing->timeout = 0; -cp - return 0; + return true; }