X-Git-Url: http://git.meshlink.io/?a=blobdiff_plain;f=src%2Fprotocol_key.c;h=b614494b74b55cc2b41fdc0daaffa7f1ef00ff9a;hb=963c5055505f2fc117cd5efa06eaa02c9b2bf85d;hp=24115563f8c937dd4894c80b68a516b56432d057;hpb=66741978e16cc407e5c760621c34d1aabb753cd2;p=meshlink diff --git a/src/protocol_key.c b/src/protocol_key.c index 24115563..b614494b 100644 --- a/src/protocol_key.c +++ b/src/protocol_key.c @@ -1,7 +1,6 @@ /* protocol_key.c -- handle the meta-protocol, key exchange - Copyright (C) 1999-2002 Ivo Timmermans , - 2000-2002 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 @@ -13,257 +12,400 @@ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. - You should have received a copy of the GNU General Public License - along with this program; if not, write to the Free Software - Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. - - $Id: protocol_key.c,v 1.1.4.11 2002/09/06 14:31:12 guus Exp $ + You should have received a copy of the GNU General Public License along + with this program; if not, write to the Free Software Foundation, Inc., + 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */ -#include "config.h" - -#include -#include -#include -#include -#include -#include - -#include -#include -#include +#include "system.h" -#include "conf.h" +#include "connection.h" +#include "logger.h" +#include "meshlink_internal.h" #include "net.h" #include "netutl.h" -#include "protocol.h" -#include "meta.h" -#include "connection.h" #include "node.h" +#include "prf.h" +#include "protocol.h" +#include "sptps.h" +#include "utils.h" +#include "xalloc.h" -#include "system.h" +static const int req_key_timeout = 2; -int mykeyused = 0; +bool key_changed_h(meshlink_handle_t *mesh, connection_t *c, const char *request) { + assert(request); + assert(*request); -int send_key_changed(connection_t *c, node_t *n) -{ -cp - /* Only send this message if some other daemon requested our key previously. - This reduces unnecessary key_changed broadcasts. - */ + char name[MAX_STRING_SIZE]; + node_t *n; - if(n == myself && !mykeyused) - return 0; -cp - return send_request(c, "%d %lx %s", KEY_CHANGED, random(), n->name); + if(sscanf(request, "%*d %*x " MAX_STRING, name) != 1) { + logger(mesh, MESHLINK_ERROR, "Got bad %s from %s", "KEY_CHANGED", c->name); + return false; + } + + if(seen_request(mesh, request)) { + return true; + } + + n = lookup_node(mesh, name); + + if(!n) { + 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, NULL, request); + + return true; } -int key_changed_h(connection_t *c) -{ - char name[MAX_STRING_SIZE]; - node_t *n; -cp - if(sscanf(c->buffer, "%*d %*x "MAX_STRING, name) != 1) - { - syslog(LOG_ERR, _("Got bad %s from %s (%s)"), "KEY_CHANGED", - c->name, c->hostname); - return -1; - } - - if(seen_request(c->buffer)) - return 0; - - n = lookup_node(name); - - if(!n) - { - syslog(LOG_ERR, _("Got %s from %s (%s) origin %s which does not exist"), "KEY_CHANGED", - c->name, c->hostname, name); - return -1; - } - - n->status.validkey = 0; - n->status.waitingforkey = 0; - - /* Tell the others */ - - forward_request(c); -cp - return 0; +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, NULL, "%d %s %s %d %s", REQ_KEY, mesh->self->name, to->name, REQ_KEY, buf); } -int send_req_key(connection_t *c, node_t *from, node_t *to) -{ -cp - return send_request(c, "%d %s %s", REQ_KEY, - from->name, to->name); +bool send_req_key(meshlink_handle_t *mesh, node_t *to) { + 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) { + 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); + sptps_stop(&to->sptps); + to->status.validkey = false; + to->status.waitingforkey = true; + to->last_req_key = mesh->loop.now.tv_sec; + return sptps_start(&to->sptps, to, true, true, mesh->private_key, to->ecdsa, label, sizeof(label) - 1, send_initial_sptps_data, receive_sptps_record); } -int req_key_h(connection_t *c) -{ - char from_name[MAX_STRING_SIZE]; - char to_name[MAX_STRING_SIZE]; - node_t *from, *to; -cp - if(sscanf(c->buffer, "%*d "MAX_STRING" "MAX_STRING, from_name, to_name) != 2) - { - syslog(LOG_ERR, _("Got bad %s from %s (%s)"), "REQ_KEY", - c->name, c->hostname); - return -1; - } - - from = lookup_node(from_name); - - if(!from) - { - syslog(LOG_ERR, _("Got %s from %s (%s) origin %s which does not exist in our connection list"), "REQ_KEY", - c->name, c->hostname, from_name); - return -1; - } - - to = lookup_node(to_name); - - if(!to) - { - syslog(LOG_ERR, _("Got %s from %s (%s) destination %s which does not exist in our connection list"), "REQ_KEY", - c->name, c->hostname, to_name); - return -1; - } - - /* Check if this key request is for us */ - - if(to == myself) /* Yes, send our own key back */ - { - mykeyused = 1; - from->received_seqno = 0; - send_ans_key(c, myself, from); - } - else - { -/* Proxy keys - if(to->status.validkey) - { - send_ans_key(c, to, from); - } - else -*/ - send_req_key(to->nexthop->connection, from, to); - } +/* 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->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; + } + + 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", "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; + } + + 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; + } + + 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; + } + } + + 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; + } + + 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; + + 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; + } + + 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; + } + + 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; + } + + 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; + } -cp - return 0; + default: + logger(mesh, MESHLINK_ERROR, "Unknown extended REQ_KEY request from %s: %s", from->name, request); + return true; + } } -int send_ans_key(connection_t *c, node_t *from, node_t *to) -{ - char key[MAX_STRING_SIZE]; -cp - bin2hex(from->key, key, from->keylength); - key[from->keylength * 2] = '\0'; -cp - return send_request(c, "%d %s %s %s %d %d %d %d", ANS_KEY, - from->name, to->name, key, from->cipher?from->cipher->nid:0, from->digest?from->digest->type:0, from->maclength, from->compression); +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", "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", "REQ_KEY", c->name, "invalid name"); + return false; + } + + from = lookup_node(mesh, from_name); + + if(!from) { + 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 destination %s which does not exist in our connection list", + "REQ_KEY", c->name, to_name); + return true; + } + + /* Check if this key request is for us */ + + if(to == mesh->self) { /* Yes */ + /* Is this an extended REQ_KEY message? */ + if(reqno) { + return req_key_ext_h(mesh, c, request, from, reqno); + } + + /* 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 destination %s which is not reachable", + "REQ_KEY", c->name, to_name); + return true; + } + + send_request(mesh, to->nexthop->connection, NULL, "%s", request); + } + + return true; } -int ans_key_h(connection_t *c) -{ - char from_name[MAX_STRING_SIZE]; - char to_name[MAX_STRING_SIZE]; - char key[MAX_STRING_SIZE]; - int cipher, digest, maclength, compression; - node_t *from, *to; -cp - if(sscanf(c->buffer, "%*d "MAX_STRING" "MAX_STRING" "MAX_STRING" %d %d %d %d", from_name, to_name, key, &cipher, &digest, &maclength, &compression) != 7) - { - syslog(LOG_ERR, _("Got bad %s from %s (%s)"), "ANS_KEY", - c->name, c->hostname); - return -1; - } - - from = lookup_node(from_name); - - if(!from) - { - syslog(LOG_ERR, _("Got %s from %s (%s) origin %s which does not exist in our connection list"), "ANS_KEY", - c->name, c->hostname, from_name); - return -1; - } - - to = lookup_node(to_name); - - if(!to) - { - syslog(LOG_ERR, _("Got %s from %s (%s) destination %s which does not exist in our connection list"), "ANS_KEY", - c->name, c->hostname, to_name); - return -1; - } - - /* Forward it if necessary */ - - if(to != myself) - { - return send_request(to->nexthop->connection, "%s", c->buffer); - } - - /* Update our copy of the origin's packet key */ - - if(from->key) - free(from->key); - - from->key = xstrdup(key); - from->keylength = strlen(key) / 2; - hex2bin(from->key, from->key, from->keylength); - from->key[from->keylength] = '\0'; - - from->status.validkey = 1; - from->status.waitingforkey = 0; - from->sent_seqno = 0; - - /* Check and lookup cipher and digest algorithms */ - - if(cipher) - { - from->cipher = EVP_get_cipherbynid(cipher); - if(!from->cipher) - { - syslog(LOG_ERR, _("Node %s (%s) uses unknown cipher!"), from->name, from->hostname); - return -1; +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]; + char address[MAX_STRING_SIZE] = ""; + char port[MAX_STRING_SIZE] = ""; + 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, + 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(from->keylength != from->cipher->key_len + from->cipher->iv_len) - { - syslog(LOG_ERR, _("Node %s (%s) uses wrong keylength!"), from->name, from->hostname); - return -1; - } - } - else - { - from->cipher = NULL; - } - - from->maclength = maclength; - - if(digest) - { - from->digest = EVP_get_digestbynid(digest); - if(!from->digest) - { - syslog(LOG_ERR, _("Node %s (%s) uses unknown digest!"), from->name, from->hostname); - return -1; + + if(!check_id(from_name) || !check_id(to_name)) { + logger(mesh, MESHLINK_ERROR, "Got bad %s from %s: %s", "ANS_KEY", c->name, "invalid name"); + return false; } - if(from->maclength > from->digest->md_size || from->maclength < 0) - { - syslog(LOG_ERR, _("Node %s (%s) uses bogus MAC length!"), from->name, from->hostname); - return -1; + + from = lookup_node(mesh, from_name); + + if(!from) { + 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; } - } - else - { - from->digest = NULL; - } - - from->compression = compression; - - flush_queue(from); -cp - return 0; + + to = lookup_node(mesh, to_name); + + if(!to) { + 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; + } + + /* Forward it if necessary */ + + if(to != mesh->self) { + if(!to->status.reachable) { + logger(mesh, MESHLINK_WARNING, "Got %s from %s destination %s which is not reachable", + "ANS_KEY", c->name, to_name); + return true; + } + + 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, NULL, "%s %s %s", request, address, port); + free(address); + free(port); + return true; + } + + return send_request(mesh, to->nexthop->connection, NULL, "%s", request); + } + + /* 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); + } + + return true; + } + + /* Process SPTPS data if present */ + + if(*key != '.') { + /* Don't use key material until every check has passed. */ + from->status.validkey = false; + + /* 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", from->name); + } + } + + if(from->status.validkey) { + if(*address && *port) { + logger(mesh, MESHLINK_DEBUG, "Using reflexive UDP address from %s: %s port %s", from->name, address, port); + sockaddr_t sa = str2sockaddr(address, port); + update_node_udp(mesh, from, &sa); + } + + send_mtu_probe(mesh, from); + } + + return true; }