X-Git-Url: http://git.meshlink.io/?p=meshlink;a=blobdiff_plain;f=src%2Fprotocol_key.c;h=b614494b74b55cc2b41fdc0daaffa7f1ef00ff9a;hp=f493cde731a3029c06b6d1e9512ac0be86a6b607;hb=963c5055505f2fc117cd5efa06eaa02c9b2bf85d;hpb=f09edd4a80eeb1f41060d596e48ef2303e05713f diff --git a/src/protocol_key.c b/src/protocol_key.c index f493cde7..b614494b 100644 --- a/src/protocol_key.c +++ b/src/protocol_key.c @@ -1,6 +1,6 @@ /* protocol_key.c -- handle the meta-protocol, key exchange - Copyright (C) 2014 Guus Sliepen + Copyright (C) 2014-2017 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 @@ -31,187 +31,226 @@ #include "utils.h" #include "xalloc.h" -void send_key_changed(meshlink_handle_t *mesh) { - send_request(mesh, mesh->everyone, "%d %x %s", KEY_CHANGED, rand(), mesh->self->name); - - /* Force key exchange for connections using SPTPS */ - - for splay_each(node_t, n, mesh->nodes) - if(n->status.reachable && n->status.validkey) - sptps_force_kex(&n->sptps); -} +static const int req_key_timeout = 2; bool key_changed_h(meshlink_handle_t *mesh, connection_t *c, const char *request) { + assert(request); + assert(*request); + char name[MAX_STRING_SIZE]; node_t *n; if(sscanf(request, "%*d %*x " MAX_STRING, name) != 1) { - logger(mesh, MESHLINK_ERROR, "Got bad %s from %s (%s)", "KEY_CHANGED", - c->name, c->hostname); + logger(mesh, MESHLINK_ERROR, "Got bad %s from %s", "KEY_CHANGED", c->name); return false; } - if(seen_request(mesh, request)) + if(seen_request(mesh, request)) { return true; + } n = lookup_node(mesh, name); if(!n) { - logger(mesh, MESHLINK_ERROR, "Got %s from %s (%s) origin %s which does not exist", - "KEY_CHANGED", c->name, c->hostname, name); + logger(mesh, MESHLINK_ERROR, "Got %s from %s origin %s which does not exist", "KEY_CHANGED", c->name, name); return true; } /* Tell the others */ - forward_request(mesh, c, request); + forward_request(mesh, c, NULL, request); return true; } static bool send_initial_sptps_data(void *handle, uint8_t type, const void *data, size_t len) { + (void)type; + + assert(data); + assert(len); + node_t *to = handle; meshlink_handle_t *mesh = to->mesh; to->sptps.send_data = send_sptps_data; char buf[len * 4 / 3 + 5]; b64encode(data, buf, len); - return send_request(mesh, to->nexthop->connection, "%d %s %s %d %s", REQ_KEY, mesh->self->name, to->name, REQ_KEY, buf); + return send_request(mesh, to->nexthop->connection, NULL, "%d %s %s %d %s", REQ_KEY, mesh->self->name, to->name, REQ_KEY, buf); } bool send_req_key(meshlink_handle_t *mesh, node_t *to) { - if(!node_read_ecdsa_public_key(mesh, to)) { - logger(mesh, MESHLINK_DEBUG, "No ECDSA key known for %s (%s)", to->name, to->hostname); - send_request(mesh, to->nexthop->connection, "%d %s %s %d", REQ_KEY, mesh->self->name, to->name, REQ_PUBKEY); + if(!node_read_public_key(mesh, to)) { + logger(mesh, MESHLINK_DEBUG, "No ECDSA key known for %s", to->name); + send_request(mesh, to->nexthop->connection, NULL, "%d %s %s %d", REQ_KEY, mesh->self->name, to->name, REQ_PUBKEY); return true; } - if(to->sptps.label) + if(to->sptps.label) { logger(mesh, MESHLINK_DEBUG, "send_req_key(%s) called while sptps->label != NULL!", to->name); + } - char label[sizeof meshlink_udp_label + strlen(mesh->self->name) + strlen(to->name) + 2]; - snprintf(label, sizeof label, "%s %s %s", meshlink_udp_label, mesh->self->name, to->name); + char label[sizeof(meshlink_udp_label) + strlen(mesh->self->name) + strlen(to->name) + 2]; + snprintf(label, sizeof(label), "%s %s %s", meshlink_udp_label, mesh->self->name, to->name); sptps_stop(&to->sptps); to->status.validkey = false; to->status.waitingforkey = true; to->last_req_key = mesh->loop.now.tv_sec; - to->incompression = mesh->self->incompression; - return sptps_start(&to->sptps, to, true, true, mesh->self->connection->ecdsa, to->ecdsa, label, sizeof label - 1, send_initial_sptps_data, receive_sptps_record); + return sptps_start(&to->sptps, to, true, true, mesh->private_key, to->ecdsa, label, sizeof(label) - 1, send_initial_sptps_data, receive_sptps_record); } /* REQ_KEY is overloaded to allow arbitrary requests to be routed between two nodes. */ static bool req_key_ext_h(meshlink_handle_t *mesh, connection_t *c, const char *request, node_t *from, int reqno) { + (void)c; + switch(reqno) { - case REQ_PUBKEY: { - char *pubkey = ecdsa_get_base64_public_key(mesh->self->connection->ecdsa); - send_request(mesh, from->nexthop->connection, "%d %s %s %d %s", REQ_KEY, mesh->self->name, from->name, ANS_PUBKEY, pubkey); - free(pubkey); + case REQ_PUBKEY: { + char *pubkey = ecdsa_get_base64_public_key(mesh->private_key); + + if(!from->nexthop || !from->nexthop->connection) { + return false; + } + + send_request(mesh, from->nexthop->connection, NULL, "%d %s %s %d %s", REQ_KEY, mesh->self->name, from->name, ANS_PUBKEY, pubkey); + free(pubkey); + return true; + } + + case ANS_PUBKEY: { + if(node_read_public_key(mesh, from)) { + logger(mesh, MESHLINK_WARNING, "Got ANS_PUBKEY from %s even though we already have his pubkey", from->name); return true; } - case ANS_PUBKEY: { - if(node_read_ecdsa_public_key(mesh, from)) { - logger(mesh, MESHLINK_WARNING, "Got ANS_PUBKEY from %s (%s) even though we already have his pubkey", from->name, from->hostname); - return true; - } + char pubkey[MAX_STRING_SIZE]; - char pubkey[MAX_STRING_SIZE]; - if(sscanf(request, "%*d %*s %*s %*d " MAX_STRING, pubkey) != 1 || !(from->ecdsa = ecdsa_set_base64_public_key(pubkey))) { - logger(mesh, MESHLINK_ERROR, "Got bad %s from %s (%s): %s", "ANS_PUBKEY", from->name, from->hostname, "invalid pubkey"); - return true; + if(sscanf(request, "%*d %*s %*s %*d " MAX_STRING, pubkey) != 1 || !(from->ecdsa = ecdsa_set_base64_public_key(pubkey))) { + logger(mesh, MESHLINK_ERROR, "Got bad %s from %s: %s", "ANS_PUBKEY", from->name, "invalid pubkey"); + return true; + } + + logger(mesh, MESHLINK_INFO, "Learned ECDSA public key from %s", from->name); + from->status.dirty = true; + + /* If we are trying to form an outgoing connection to this node, retry immediately */ + for list_each(outgoing_t, outgoing, mesh->outgoings) { + if(outgoing->node == from && outgoing->ev.cb) { + outgoing->timeout = 0; + timeout_set(&mesh->loop, &outgoing->ev, &(struct timespec) { + 0, 0 + }); } + } + + /* Also reset any UTCP timers */ + utcp_reset_timers(from->utcp); + + return true; + } - logger(mesh, MESHLINK_INFO, "Learned ECDSA public key from %s (%s)", from->name, from->hostname); - append_config_file(mesh, from->name, "ECDSAPublicKey", pubkey); + case REQ_KEY: { + if(!node_read_public_key(mesh, from)) { + logger(mesh, MESHLINK_DEBUG, "No ECDSA key known for %s", from->name); + send_request(mesh, from->nexthop->connection, NULL, "%d %s %s %d", REQ_KEY, mesh->self->name, from->name, REQ_PUBKEY); return true; } - case REQ_KEY: { - if(!node_read_ecdsa_public_key(mesh, from)) { - logger(mesh, MESHLINK_DEBUG, "No ECDSA key known for %s (%s)", from->name, from->hostname); - send_request(mesh, from->nexthop->connection, "%d %s %s %d", REQ_KEY, mesh->self->name, from->name, REQ_PUBKEY); + if(from->sptps.label) { + logger(mesh, MESHLINK_DEBUG, "Got REQ_KEY from %s while we already started a SPTPS session!", from->name); + + if(mesh->loop.now.tv_sec < from->last_req_key + req_key_timeout && strcmp(mesh->self->name, from->name) < 0) { + logger(mesh, MESHLINK_DEBUG, "Ignoring REQ_KEY from %s.", from->name); return true; } + } - if(from->sptps.label) { - logger(mesh, MESHLINK_DEBUG, "Got REQ_KEY from %s while we already started a SPTPS session!", from->name); - if(strcmp(mesh->self->name, from->name) < 0) { - logger(mesh, MESHLINK_DEBUG, "Ignoring REQ_KEY from %s.", from->name); - return true; - } - } + char buf[MAX_STRING_SIZE]; + int len; - 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(mesh, MESHLINK_ERROR, "Got bad %s from %s: %s", "REQ_SPTPS_START", from->name, "invalid SPTPS data"); + return true; + } - if(sscanf(request, "%*d %*s %*s %*d " MAX_STRING, buf) != 1 || !(len = b64decode(buf, buf, strlen(buf)))) { - logger(mesh, MESHLINK_ERROR, "Got bad %s from %s (%s): %s", "REQ_SPTPS_START", from->name, from->hostname, "invalid SPTPS data"); - return true; - } + char label[sizeof(meshlink_udp_label) + strlen(from->name) + strlen(mesh->self->name) + 2]; + snprintf(label, sizeof(label), "%s %s %s", meshlink_udp_label, from->name, mesh->self->name); + sptps_stop(&from->sptps); + from->status.validkey = false; + from->status.waitingforkey = true; + from->last_req_key = mesh->loop.now.tv_sec; - char label[sizeof meshlink_udp_label + strlen(from->name) + strlen(mesh->self->name) + 2]; - snprintf(label, sizeof label, "%s %s %s", meshlink_udp_label, from->name, mesh->self->name); - sptps_stop(&from->sptps); - from->status.validkey = false; - from->status.waitingforkey = true; - from->last_req_key = mesh->loop.now.tv_sec; - sptps_start(&from->sptps, from, false, true, mesh->self->connection->ecdsa, from->ecdsa, label, sizeof label - 1, send_sptps_data, receive_sptps_record); - sptps_receive_data(&from->sptps, buf, len); + if(!sptps_start(&from->sptps, from, false, true, mesh->private_key, from->ecdsa, label, sizeof(label) - 1, send_sptps_data, receive_sptps_record)) { + logger(mesh, MESHLINK_ERROR, "Could not start SPTPS session with %s: %s", from->name, strerror(errno)); return true; } - case REQ_SPTPS: { - if(!from->status.validkey) { - logger(mesh, MESHLINK_ERROR, "Got REQ_SPTPS from %s (%s) but we don't have a valid key yet", from->name, from->hostname); - return true; - } + if(!sptps_receive_data(&from->sptps, buf, len)) { + logger(mesh, MESHLINK_ERROR, "Could not process SPTPS data from %s: %s", from->name, strerror(errno)); + return true; + } - 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(mesh, MESHLINK_ERROR, "Got bad %s from %s (%s): %s", "REQ_SPTPS", from->name, from->hostname, "invalid SPTPS data"); - return true; - } - sptps_receive_data(&from->sptps, buf, len); + return true; + } + + case REQ_SPTPS: { + if(!from->status.validkey) { + logger(mesh, MESHLINK_ERROR, "Got REQ_SPTPS from %s but we don't have a valid key yet", from->name); return true; } - default: - logger(mesh, MESHLINK_ERROR, "Unknown extended REQ_KEY request from %s (%s): %s", from->name, from->hostname, request); + 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(mesh, MESHLINK_ERROR, "Got bad %s from %s: %s", "REQ_SPTPS", from->name, "invalid SPTPS data"); return true; + } + + if(!sptps_receive_data(&from->sptps, buf, len)) { + logger(mesh, MESHLINK_ERROR, "Could not process SPTPS data from %s: %s", from->name, strerror(errno)); + return true; + } + + return true; + } + + default: + logger(mesh, MESHLINK_ERROR, "Unknown extended REQ_KEY request from %s: %s", from->name, request); + return true; } } bool req_key_h(meshlink_handle_t *mesh, connection_t *c, const char *request) { + assert(request); + assert(*request); + char from_name[MAX_STRING_SIZE]; char to_name[MAX_STRING_SIZE]; node_t *from, *to; int reqno = 0; if(sscanf(request, "%*d " MAX_STRING " " MAX_STRING " %d", from_name, to_name, &reqno) < 2) { - logger(mesh, MESHLINK_ERROR, "Got bad %s from %s (%s)", "REQ_KEY", c->name, - c->hostname); + logger(mesh, MESHLINK_ERROR, "Got bad %s from %s", "REQ_KEY", c->name); return false; } if(!check_id(from_name) || !check_id(to_name)) { - logger(mesh, MESHLINK_ERROR, "Got bad %s from %s (%s): %s", "REQ_KEY", c->name, c->hostname, "invalid name"); + logger(mesh, MESHLINK_ERROR, "Got bad %s from %s: %s", "REQ_KEY", c->name, "invalid name"); return false; } from = lookup_node(mesh, from_name); if(!from) { - logger(mesh, MESHLINK_ERROR, "Got %s from %s (%s) origin %s which does not exist in our connection list", - "REQ_KEY", c->name, c->hostname, from_name); + logger(mesh, MESHLINK_ERROR, "Got %s from %s origin %s which does not exist in our connection list", + "REQ_KEY", c->name, from_name); return true; } to = lookup_node(mesh, to_name); if(!to) { - logger(mesh, MESHLINK_ERROR, "Got %s from %s (%s) destination %s which does not exist in our connection list", - "REQ_KEY", c->name, c->hostname, to_name); + logger(mesh, MESHLINK_ERROR, "Got %s from %s destination %s which does not exist in our connection list", + "REQ_KEY", c->name, to_name); return true; } @@ -219,29 +258,29 @@ bool req_key_h(meshlink_handle_t *mesh, connection_t *c, const char *request) { if(to == mesh->self) { /* Yes */ /* Is this an extended REQ_KEY message? */ - if(reqno) + if(reqno) { return req_key_ext_h(mesh, c, request, from, reqno); + } - /* No, just send our key back */ - send_ans_key(mesh, from); + /* This should never happen. Ignore it, unless it came directly from the connected peer, in which case we disconnect. */ + return from->connection != c; } else { if(!to->status.reachable) { - logger(mesh, MESHLINK_WARNING, "Got %s from %s (%s) destination %s which is not reachable", - "REQ_KEY", c->name, c->hostname, to_name); + logger(mesh, MESHLINK_WARNING, "Got %s from %s destination %s which is not reachable", + "REQ_KEY", c->name, to_name); return true; } - send_request(mesh, to->nexthop->connection, "%s", request); + send_request(mesh, to->nexthop->connection, NULL, "%s", request); } return true; } -bool send_ans_key(meshlink_handle_t *mesh, node_t *to) { - abort(); -} - bool ans_key_h(meshlink_handle_t *mesh, connection_t *c, const char *request) { + assert(request); + assert(*request); + char from_name[MAX_STRING_SIZE]; char to_name[MAX_STRING_SIZE]; char key[MAX_STRING_SIZE]; @@ -251,31 +290,30 @@ bool ans_key_h(meshlink_handle_t *mesh, connection_t *c, const char *request) { node_t *from, *to; if(sscanf(request, "%*d "MAX_STRING" "MAX_STRING" "MAX_STRING" %d %d %d %d "MAX_STRING" "MAX_STRING, - from_name, to_name, key, &cipher, &digest, &maclength, - &compression, address, port) < 7) { - logger(mesh, MESHLINK_ERROR, "Got bad %s from %s (%s)", "ANS_KEY", c->name, - c->hostname); + from_name, to_name, key, &cipher, &digest, &maclength, + &compression, address, port) < 7) { + logger(mesh, MESHLINK_ERROR, "Got bad %s from %s", "ANS_KEY", c->name); return false; } if(!check_id(from_name) || !check_id(to_name)) { - logger(mesh, MESHLINK_ERROR, "Got bad %s from %s (%s): %s", "ANS_KEY", c->name, c->hostname, "invalid name"); + logger(mesh, MESHLINK_ERROR, "Got bad %s from %s: %s", "ANS_KEY", c->name, "invalid name"); return false; } from = lookup_node(mesh, from_name); if(!from) { - logger(mesh, MESHLINK_ERROR, "Got %s from %s (%s) origin %s which does not exist in our connection list", - "ANS_KEY", c->name, c->hostname, from_name); + logger(mesh, MESHLINK_ERROR, "Got %s from %s origin %s which does not exist in our connection list", + "ANS_KEY", c->name, from_name); return true; } to = lookup_node(mesh, to_name); if(!to) { - logger(mesh, MESHLINK_ERROR, "Got %s from %s (%s) destination %s which does not exist in our connection list", - "ANS_KEY", c->name, c->hostname, to_name); + logger(mesh, MESHLINK_ERROR, "Got %s from %s destination %s which does not exist in our connection list", + "ANS_KEY", c->name, to_name); return true; } @@ -283,41 +321,81 @@ bool ans_key_h(meshlink_handle_t *mesh, connection_t *c, const char *request) { if(to != mesh->self) { if(!to->status.reachable) { - logger(mesh, MESHLINK_WARNING, "Got %s from %s (%s) destination %s which is not reachable", - "ANS_KEY", c->name, c->hostname, to_name); + logger(mesh, MESHLINK_WARNING, "Got %s from %s destination %s which is not reachable", + "ANS_KEY", c->name, to_name); return true; } - if(!*address && from->address.sa.sa_family != AF_UNSPEC) { + if(from == to) { + logger(mesh, MESHLINK_WARNING, "Got %s from %s from %s to %s", + "ANS_KEY", c->name, from_name, to_name); + return true; + } + + /* Append the known UDP address of the from node, if we have a confirmed one */ + if(!*address && from->status.udp_confirmed && from->address.sa.sa_family != AF_UNSPEC) { char *address, *port; logger(mesh, MESHLINK_DEBUG, "Appending reflexive UDP address to ANS_KEY from %s to %s", from->name, to->name); sockaddr2str(&from->address, &address, &port); - send_request(mesh, to->nexthop->connection, "%s %s %s", request, address, port); + send_request(mesh, to->nexthop->connection, NULL, "%s %s %s", request, address, port); free(address); free(port); return true; } - return send_request(mesh, to->nexthop->connection, "%s", request); + return send_request(mesh, to->nexthop->connection, NULL, "%s", request); } - /* Don't use key material until every check has passed. */ - from->status.validkey = false; + /* Is this an ANS_KEY informing us of our own reflexive UDP address? */ + + if(from == mesh->self) { + if(*key == '.' && *address && *port) { + logger(mesh, MESHLINK_DEBUG, "Learned our own reflexive UDP address from %s: %s port %s", c->name, address, port); + + /* Inform all other nodes we want to communicate with and which are reachable via this connection */ + for splay_each(node_t, n, mesh->nodes) { + if(n->nexthop != c->node) { + continue; + } + + if(n->status.udp_confirmed) { + continue; + } + + if(!n->status.waitingforkey && !n->status.validkey) { + continue; + } + + logger(mesh, MESHLINK_DEBUG, "Forwarding our own reflexive UDP address to %s", n->name); + send_request(mesh, c, NULL, "%d %s %s . -1 -1 -1 0 %s %s", ANS_KEY, mesh->self->name, n->name, address, port); + } + } else { + logger(mesh, MESHLINK_WARNING, "Got %s from %s from %s to %s", + "ANS_KEY", c->name, from_name, to_name); + } - if(compression < 0 || compression > 11) { - logger(mesh, MESHLINK_ERROR, "Node %s (%s) uses bogus compression level!", from->name, from->hostname); return true; } - from->outcompression = compression; + /* Process SPTPS data if present */ - /* SPTPS or old-style key exchange? */ + if(*key != '.') { + /* Don't use key material until every check has passed. */ + from->status.validkey = false; - char buf[strlen(key)]; - int len = b64decode(key, buf, strlen(key)); + /* Compression is not supported. */ + if(compression != 0) { + logger(mesh, MESHLINK_ERROR, "Node %s uses bogus compression level!", from->name); + return true; + } + + char buf[strlen(key)]; + int len = b64decode(key, buf, strlen(key)); - if(!len || !sptps_receive_data(&from->sptps, buf, len)) - logger(mesh, MESHLINK_ERROR, "Error processing SPTPS data from %s (%s)", from->name, from->hostname); + if(!len || !sptps_receive_data(&from->sptps, buf, len)) { + logger(mesh, MESHLINK_ERROR, "Error processing SPTPS data from %s", from->name); + } + } if(from->status.validkey) { if(*address && *port) { @@ -326,8 +404,7 @@ bool ans_key_h(meshlink_handle_t *mesh, connection_t *c, const char *request) { update_node_udp(mesh, from, &sa); } - if(from->options & OPTION_PMTU_DISCOVERY && !(from->options & OPTION_TCPONLY)) - send_mtu_probe(mesh, from); + send_mtu_probe(mesh, from); } return true;