X-Git-Url: https://www.tinc-vpn.org/git/browse?p=tinc;a=blobdiff_plain;f=src%2Fprotocol_key.c;h=a18cefc917b50a706f23e48d54c5bc61cb6cbf20;hp=af103c62d842d42d0c2e2352ba6da3398b904266;hb=af81c436d6e11a53803747af7cc8ecfd449ccd4c;hpb=214060ef20499332b0369030b664a8e239518661 diff --git a/src/protocol_key.c b/src/protocol_key.c index af103c62..a18cefc9 100644 --- a/src/protocol_key.c +++ b/src/protocol_key.c @@ -1,7 +1,7 @@ /* protocol_key.c -- handle the meta-protocol, key exchange Copyright (C) 1999-2005 Ivo Timmermans, - 2000-2013 Guus Sliepen + 2000-2017 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 @@ -36,13 +36,15 @@ static bool mykeyused = false; void send_key_changed(void) { +#ifndef DISABLE_LEGACY send_request(everyone, "%d %x %s", KEY_CHANGED, rand(), myself->name); /* Immediately send new keys to directly connected nodes to keep UDP mappings alive */ for list_each(connection_t, c, connection_list) - if(c->status.active && c->node && c->node->status.reachable && !c->node->status.sptps) + if(c->edge && c->node && c->node->status.reachable && !c->node->status.sptps) send_ans_key(c->node); +#endif /* Force key exchange for connections using SPTPS */ @@ -87,9 +89,13 @@ bool key_changed_h(connection_t *c, const char *request) { return true; } -static bool send_initial_sptps_data(void *handle, uint8_t type, const char *data, size_t len) { +static bool send_sptps_data_myself(void *handle, uint8_t type, const void *data, size_t len) { + return send_sptps_data(handle, myself, type, data, len); +} + +static bool send_initial_sptps_data(void *handle, uint8_t type, const void *data, size_t len) { node_t *to = handle; - to->sptps.send_data = send_sptps_data; + to->sptps.send_data = send_sptps_data_myself; char buf[len * 4 / 3 + 5]; b64encode(data, buf, len); return send_request(to->nexthop->connection, "%d %s %s %d %s", REQ_KEY, myself->name, to->name, REQ_KEY, buf); @@ -98,14 +104,11 @@ static bool send_initial_sptps_data(void *handle, uint8_t type, const char *data bool send_req_key(node_t *to) { if(to->status.sptps) { if(!node_read_ecdsa_public_key(to)) { - logger(DEBUG_PROTOCOL, LOG_DEBUG, "No ECDSA key known for %s (%s)", to->name, to->hostname); + logger(DEBUG_PROTOCOL, LOG_DEBUG, "No Ed25519 key known for %s (%s)", to->name, to->hostname); send_request(to->nexthop->connection, "%d %s %s %d", REQ_KEY, myself->name, to->name, REQ_PUBKEY); return true; } - if(to->sptps.label) - logger(DEBUG_ALWAYS, LOG_DEBUG, "send_req_key(%s) called while sptps->label != NULL!", to->name); - char label[25 + strlen(myself->name) + strlen(to->name)]; snprintf(label, sizeof label, "tinc UDP key expansion %s %s", myself->name, to->name); sptps_stop(&to->sptps); @@ -121,9 +124,59 @@ bool send_req_key(node_t *to) { /* REQ_KEY is overloaded to allow arbitrary requests to be routed between two nodes. */ -static bool req_key_ext_h(connection_t *c, const char *request, node_t *from, int reqno) { +static bool req_key_ext_h(connection_t *c, const char *request, node_t *from, node_t *to, int reqno) { + /* If this is a SPTPS packet, see if sending UDP info helps. + Note that we only do this if we're the destination or the static relay; + otherwise every hop would initiate its own UDP info message, resulting in elevated chatter. */ + if((reqno == REQ_KEY || reqno == SPTPS_PACKET) && to->via == myself) + send_udp_info(myself, from); + + if(reqno == SPTPS_PACKET) { + /* This is a SPTPS data packet. */ + + char buf[MAX_STRING_SIZE]; + int len; + if(sscanf(request, "%*d %*s %*s %*d " MAX_STRING, buf) != 1 || !(len = b64decode(buf, buf, strlen(buf)))) { + logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s) to %s (%s): %s", "SPTPS_PACKET", from->name, from->hostname, to->name, to->hostname, "invalid SPTPS data"); + return true; + } + + if(to != myself) { + /* We don't just forward the request, because we want to use UDP if it's available. */ + send_sptps_data(to, from, 0, buf, len); + try_tx(to, true); + } else { + /* The packet is for us */ + if(!sptps_receive_data(&from->sptps, buf, len)) { + /* Uh-oh. It might be that the tunnel is stuck in some corrupted state, + so let's restart SPTPS in case that helps. But don't do that too often + to prevent storms. */ + if(from->last_req_key < now.tv_sec - 10) { + logger(DEBUG_PROTOCOL, LOG_ERR, "Failed to decode TCP packet from %s (%s), restarting SPTPS", from->name, from->hostname); + send_req_key(from); + } + return true; + } + send_mtu_info(myself, from, MTU); + } + + return true; + } + + /* Requests that are not SPTPS data packets are forwarded as-is. */ + + if (to != myself) + return send_request(to->nexthop->connection, "%s", request); + + /* The request is for us */ + switch(reqno) { case REQ_PUBKEY: { + if(!node_read_ecdsa_public_key(from)) { + /* Request their key *before* we send our key back. Otherwise the first SPTPS packet from them will get dropped. */ + logger(DEBUG_PROTOCOL, LOG_DEBUG, "Preemptively requesting Ed25519 key for %s (%s)", from->name, from->hostname); + send_request(from->nexthop->connection, "%d %s %s %d", REQ_KEY, myself->name, from->name, REQ_PUBKEY); + } char *pubkey = ecdsa_get_base64_public_key(myself->connection->ecdsa); send_request(from->nexthop->connection, "%d %s %s %d %s", REQ_KEY, myself->name, from->name, ANS_PUBKEY, pubkey); free(pubkey); @@ -142,14 +195,14 @@ static bool req_key_ext_h(connection_t *c, const char *request, node_t *from, in return true; } - logger(DEBUG_PROTOCOL, LOG_INFO, "Learned ECDSA public key from %s (%s)", from->name, from->hostname); - append_config_file(from->name, "ECDSAPublicKey", pubkey); + logger(DEBUG_PROTOCOL, LOG_INFO, "Learned Ed25519 public key from %s (%s)", from->name, from->hostname); + append_config_file(from->name, "Ed25519PublicKey", pubkey); return true; } case REQ_KEY: { if(!node_read_ecdsa_public_key(from)) { - logger(DEBUG_PROTOCOL, LOG_DEBUG, "No ECDSA key known for %s (%s)", from->name, from->hostname); + logger(DEBUG_PROTOCOL, LOG_DEBUG, "No Ed25519 key known for %s (%s)", from->name, from->hostname); send_request(from->nexthop->connection, "%d %s %s %d", REQ_KEY, myself->name, from->name, REQ_PUBKEY); return true; } @@ -158,11 +211,12 @@ static bool req_key_ext_h(connection_t *c, const char *request, node_t *from, in logger(DEBUG_ALWAYS, LOG_DEBUG, "Got REQ_KEY from %s while we already started a SPTPS session!", from->name); char buf[MAX_STRING_SIZE]; - if(sscanf(request, "%*d %*s %*s %*d " MAX_STRING, buf) != 1) { + int len; + + if(sscanf(request, "%*d %*s %*s %*d " MAX_STRING, buf) != 1 || !(len = b64decode(buf, buf, strlen(buf)))) { logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s): %s", "REQ_SPTPS_START", from->name, from->hostname, "invalid SPTPS data"); return true; } - int len = b64decode(buf, buf, strlen(buf)); char label[25 + strlen(from->name) + strlen(myself->name)]; snprintf(label, sizeof label, "tinc UDP key expansion %s %s", from->name, myself->name); @@ -170,24 +224,9 @@ static bool req_key_ext_h(connection_t *c, const char *request, node_t *from, in from->status.validkey = false; from->status.waitingforkey = true; from->last_req_key = now.tv_sec; - sptps_start(&from->sptps, from, false, true, myself->connection->ecdsa, from->ecdsa, label, sizeof label, send_sptps_data, receive_sptps_record); - sptps_receive_data(&from->sptps, buf, len); - return true; - } - - case REQ_SPTPS: { - if(!from->status.validkey) { - logger(DEBUG_PROTOCOL, LOG_ERR, "Got REQ_SPTPS from %s (%s) but we don't have a valid key yet", from->name, from->hostname); - return true; - } - - char buf[MAX_STRING_SIZE]; - if(sscanf(request, "%*d %*s %*s %*d " MAX_STRING, buf) != 1) { - logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s): %s", "REQ_SPTPS", from->name, from->hostname, "invalid SPTPS data"); - return true; - } - int len = b64decode(buf, buf, strlen(buf)); + sptps_start(&from->sptps, from, false, true, myself->connection->ecdsa, from->ecdsa, label, sizeof label, send_sptps_data_myself, receive_sptps_record); sptps_receive_data(&from->sptps, buf, len); + send_mtu_info(myself, from, MTU); return true; } @@ -235,7 +274,7 @@ bool req_key_h(connection_t *c, const char *request) { if(to == myself) { /* Yes */ /* Is this an extended REQ_KEY message? */ if(experimental && reqno) - return req_key_ext_h(c, request, from, reqno); + return req_key_ext_h(c, request, from, to, reqno); /* No, just send our key back */ send_ans_key(from); @@ -249,6 +288,10 @@ bool req_key_h(connection_t *c, const char *request) { return true; } + /* Is this an extended REQ_KEY message? */ + if(experimental && reqno) + return req_key_ext_h(c, request, from, to, reqno); + send_request(to->nexthop->connection, "%s", request); } @@ -259,24 +302,34 @@ bool send_ans_key(node_t *to) { if(to->status.sptps) abort(); - size_t keylen = cipher_keylength(myself->incipher); +#ifdef DISABLE_LEGACY + return false; +#else + size_t keylen = myself->incipher ? cipher_keylength(myself->incipher) : 1; char key[keylen * 2 + 1]; + randomize(key, keylen); + cipher_close(to->incipher); digest_close(to->indigest); - to->incipher = cipher_open_by_nid(cipher_get_nid(myself->incipher)); - to->indigest = digest_open_by_nid(digest_get_nid(myself->indigest), digest_length(myself->indigest)); - to->incompression = myself->incompression; + if(myself->incipher) { + to->incipher = cipher_open_by_nid(cipher_get_nid(myself->incipher)); + if(!to->incipher) + abort(); + if(!cipher_set_key(to->incipher, key, false)) + abort(); + } - if(!to->incipher || !to->indigest) - abort(); + if(myself->indigest) { + to->indigest = digest_open_by_nid(digest_get_nid(myself->indigest), digest_length(myself->indigest)); + if(!to->indigest) + abort(); + if(!digest_set_key(to->indigest, key, keylen)) + abort(); + } - randomize(key, keylen); - if(!cipher_set_key(to->incipher, key, false)) - abort(); - if(!digest_set_key(to->indigest, key, keylen)) - abort(); + to->incompression = myself->incompression; bin2hex(key, key, keylen); @@ -286,12 +339,15 @@ bool send_ans_key(node_t *to) { to->received = 0; if(replaywin) memset(to->late, 0, replaywin); + to->status.validkey_in = true; + return send_request(to->nexthop->connection, "%d %s %s %s %d %d %d %d", ANS_KEY, myself->name, to->name, key, cipher_get_nid(to->incipher), digest_get_nid(to->indigest), (int)digest_length(to->indigest), to->incompression); +#endif } bool ans_key_h(connection_t *c, const char *request) { @@ -300,7 +356,7 @@ bool ans_key_h(connection_t *c, const char *request) { char key[MAX_STRING_SIZE]; char address[MAX_STRING_SIZE] = ""; char port[MAX_STRING_SIZE] = ""; - int cipher, digest, maclength, compression, keylen; + int cipher, digest, maclength, compression; node_t *from, *to; if(sscanf(request, "%*d "MAX_STRING" "MAX_STRING" "MAX_STRING" %d %d %d %d "MAX_STRING" "MAX_STRING, @@ -344,7 +400,7 @@ bool ans_key_h(connection_t *c, const char *request) { return true; } - if(!*address && from->address.sa.sa_family != AF_UNSPEC) { + if(!*address && from->address.sa.sa_family != AF_UNSPEC && to->minmtu) { char *address, *port; logger(DEBUG_PROTOCOL, LOG_DEBUG, "Appending reflexive UDP address to ANS_KEY from %s to %s", from->name, to->name); sockaddr2str(&from->address, &address, &port); @@ -357,10 +413,12 @@ bool ans_key_h(connection_t *c, const char *request) { return send_request(to->nexthop->connection, "%s", request); } +#ifndef DISABLE_LEGACY /* Don't use key material until every check has passed. */ cipher_close(from->outcipher); digest_close(from->outdigest); - from->status.validkey = false; +#endif + if (!from->status.sptps) from->status.validkey = false; if(compression < 0 || compression > 11) { logger(DEBUG_ALWAYS, LOG_ERR, "Node %s (%s) uses bogus compression level!", from->name, from->hostname); @@ -374,9 +432,18 @@ bool ans_key_h(connection_t *c, const char *request) { if(from->status.sptps) { char buf[strlen(key)]; int len = b64decode(key, buf, strlen(key)); - - if(!sptps_receive_data(&from->sptps, buf, len)) - logger(DEBUG_ALWAYS, LOG_ERR, "Error processing SPTPS data from %s (%s)", from->name, from->hostname); + if(!len || !sptps_receive_data(&from->sptps, buf, len)) { + /* Uh-oh. It might be that the tunnel is stuck in some corrupted state, + so let's restart SPTPS in case that helps. But don't do that too often + to prevent storms. + Note that simply relying on handshake timeout is not enough, because + that doesn't apply to key regeneration. */ + if(from->last_req_key < now.tv_sec - 10) { + logger(DEBUG_PROTOCOL, LOG_ERR, "Failed to decode handshake TCP packet from %s (%s), restarting SPTPS", from->name, from->hostname); + send_req_key(from); + } + return true; + } if(from->status.validkey) { if(*address && *port) { @@ -384,24 +451,35 @@ bool ans_key_h(connection_t *c, const char *request) { sockaddr_t sa = str2sockaddr(address, port); update_node_udp(from, &sa); } - - if(from->options & OPTION_PMTU_DISCOVERY) - send_mtu_probe(from); } + send_mtu_info(myself, from, MTU); + return true; } +#ifdef DISABLE_LEGACY + logger(DEBUG_ALWAYS, LOG_ERR, "Node %s (%s) uses legacy protocol!", from->name, from->hostname); + return false; +#else /* Check and lookup cipher and digest algorithms */ - if(!(from->outcipher = cipher_open_by_nid(cipher))) { - logger(DEBUG_ALWAYS, LOG_ERR, "Node %s (%s) uses unknown cipher!", from->name, from->hostname); - return false; + if(cipher) { + if(!(from->outcipher = cipher_open_by_nid(cipher))) { + logger(DEBUG_ALWAYS, LOG_ERR, "Node %s (%s) uses unknown cipher!", from->name, from->hostname); + return false; + } + } else { + from->outcipher = NULL; } - if(!(from->outdigest = digest_open_by_nid(digest, maclength))) { - logger(DEBUG_ALWAYS, LOG_ERR, "Node %s (%s) uses unknown digest!", from->name, from->hostname); - return false; + if(digest) { + if(!(from->outdigest = digest_open_by_nid(digest, maclength))) { + logger(DEBUG_ALWAYS, LOG_ERR, "Node %s (%s) uses unknown digest!", from->name, from->hostname); + return false; + } + } else { + from->outdigest = NULL; } if(maclength != digest_length(from->outdigest)) { @@ -411,18 +489,18 @@ bool ans_key_h(connection_t *c, const char *request) { /* Process key */ - keylen = hex2bin(key, key, sizeof key); + int keylen = hex2bin(key, key, sizeof key); - if(keylen != cipher_keylength(from->outcipher)) { + if(keylen != (from->outcipher ? cipher_keylength(from->outcipher) : 1)) { logger(DEBUG_ALWAYS, LOG_ERR, "Node %s (%s) uses wrong keylength!", from->name, from->hostname); return true; } /* Update our copy of the origin's packet key */ - if(!cipher_set_key(from->outcipher, key, true)) + if(from->outcipher && !cipher_set_key(from->outcipher, key, true)) return false; - if(!digest_set_key(from->outdigest, key, keylen)) + if(from->outdigest && !digest_set_key(from->outdigest, key, keylen)) return false; from->status.validkey = true; @@ -434,8 +512,6 @@ bool ans_key_h(connection_t *c, const char *request) { update_node_udp(from, &sa); } - if(from->options & OPTION_PMTU_DISCOVERY) - send_mtu_probe(from); - return true; +#endif }