]> git.meshlink.io Git - meshlink/blobdiff - src/protocol_key.c
Avoid allocating packet buffers unnecessarily.
[meshlink] / src / protocol_key.c
index 8bbb6ad4e875e7eb04edf66a66e35a076c8d5877..b614494b74b55cc2b41fdc0daaffa7f1ef00ff9a 100644 (file)
@@ -1,7 +1,6 @@
 /*
     protocol_key.c -- handle the meta-protocol, key exchange
-    Copyright (C) 1999-2005 Ivo Timmermans,
-                  2000-2011 Guus Sliepen <guus@tinc-vpn.org>
+    Copyright (C) 2014-2017 Guus Sliepen <guus@meshlink.io>
 
     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
 
 #include "system.h"
 
-#include "splay_tree.h"
-#include "cipher.h"
 #include "connection.h"
-#include "crypto.h"
-#include "ecdh.h"
 #include "logger.h"
+#include "meshlink_internal.h"
 #include "net.h"
 #include "netutl.h"
 #include "node.h"
 #include "prf.h"
 #include "protocol.h"
+#include "sptps.h"
 #include "utils.h"
 #include "xalloc.h"
 
-static bool mykeyused = false;
+static const int req_key_timeout = 2;
 
-void send_key_changed(void) {
-       splay_node_t *node;
-       connection_t *c;
+bool key_changed_h(meshlink_handle_t *mesh, connection_t *c, const char *request) {
+       assert(request);
+       assert(*request);
 
-       send_request(broadcast, "%d %x %s", KEY_CHANGED, rand(), myself->name);
-
-       /* Immediately send new keys to directly connected nodes to keep UDP mappings alive */
-
-       for(node = connection_tree->head; node; node = node->next) {
-               c = node->data;
-               if(c->status.active && c->node && c->node->status.reachable)
-                       send_ans_key(c->node);
-       }
-}
-
-bool key_changed_h(connection_t *c, char *request) {
        char name[MAX_STRING_SIZE];
        node_t *n;
 
        if(sscanf(request, "%*d %*x " MAX_STRING, name) != 1) {
-               logger(LOG_ERR, "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(request))
+       if(seen_request(mesh, request)) {
                return true;
+       }
 
-       n = lookup_node(name);
+       n = lookup_node(mesh, name);
 
        if(!n) {
-               logger(LOG_ERR, "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;
        }
 
-       n->status.validkey = false;
-       n->last_req_key = 0;
-
        /* Tell the others */
 
-       if(!tunnelserver)
-               forward_request(c, request);
+       forward_request(mesh, c, NULL, request);
 
        return true;
 }
 
-bool send_req_key(node_t *to) {
-       return send_request(to->nexthop->connection, "%d %s %s 1", REQ_KEY, myself->name, to->name);
-}
+static bool send_initial_sptps_data(void *handle, uint8_t type, const void *data, size_t len) {
+       (void)type;
 
-bool req_key_h(connection_t *c, char *request) {
-       char from_name[MAX_STRING_SIZE];
-       char to_name[MAX_STRING_SIZE];
-       node_t *from, *to;
-       int kx_version = 0;
+       assert(data);
+       assert(len);
 
-       if(sscanf(request, "%*d " MAX_STRING " " MAX_STRING " %d", from_name, to_name, &kx_version) < 2) {
-               logger(LOG_ERR, "Got bad %s from %s (%s)", "REQ_KEY", c->name,
-                          c->hostname);
-               return false;
+       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);
+}
+
+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(!check_id(from_name) || !check_id(to_name)) {
-               logger(LOG_ERR, "Got bad %s from %s (%s): %s", "REQ_KEY", c->name, c->hostname, "invalid name");
-               return false;
+       if(to->sptps.label) {
+               logger(mesh, MESHLINK_DEBUG, "send_req_key(%s) called while sptps->label != NULL!", to->name);
        }
 
-       from = lookup_node(from_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);
+}
 
-       if(!from) {
-               logger(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 true;
-       }
+/* REQ_KEY is overloaded to allow arbitrary requests to be routed between two nodes. */
 
-       to = lookup_node(to_name);
+static bool req_key_ext_h(meshlink_handle_t *mesh, connection_t *c, const char *request, node_t *from, int reqno) {
+       (void)c;
 
-       if(!to) {
-               logger(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);
+       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;
        }
 
-       /* Check if this key request is for us */
-
-       if(to == myself) {                      /* Yes, send our own key back */
-               if(kx_version > 0) {
-                       logger(LOG_DEBUG, "Got ECDH key request from %s", from->name);
-                       from->status.ecdh = true;
-               }
-               send_ans_key(from);
-       } else {
-               if(tunnelserver)
+       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;
+               }
 
-               if(!to->status.reachable) {
-                       logger(LOG_WARNING, "Got %s from %s (%s) destination %s which is not reachable",
-                               "REQ_KEY", c->name, c->hostname, to_name);
+               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;
                }
 
-               send_request(to->nexthop->connection, "%s", request);
+               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;
        }
 
-       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;
+               }
 
-bool send_ans_key_ecdh(node_t *to) {
-       char key[ECDH_SIZE * 2 + 1];
+               if(from->sptps.label) {
+                       logger(mesh, MESHLINK_DEBUG, "Got REQ_KEY from %s while we already started a SPTPS session!", from->name);
 
-       ecdh_generate_public(&to->ecdh, key);
+                       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;
+                       }
+               }
 
-       bin2hex(key, key, ECDH_SIZE);
-       key[ECDH_SIZE * 2] = '\0';
+               char buf[MAX_STRING_SIZE];
+               int len;
 
-       return send_request(to->nexthop->connection, "%d %s %s ECDH:%s %d %d %zu %d", ANS_KEY,
-                                               myself->name, to->name, key,
-                                               cipher_get_nid(&myself->incipher),
-                                               digest_get_nid(&myself->indigest),
-                                               digest_length(&myself->indigest),
-                                               myself->incompression);
-}
+               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;
 
-bool send_ans_key(node_t *to) {
-       if(to->status.ecdh)
-               return send_ans_key_ecdh(to);
+               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;
+               }
 
-       size_t keylen = cipher_keylength(&myself->incipher);
-       char key[keylen * 2 + 1];
+               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;
+               }
 
-       cipher_open_by_nid(&to->incipher, cipher_get_nid(&myself->incipher));
-       digest_open_by_nid(&to->indigest, digest_get_nid(&myself->indigest), digest_length(&myself->indigest));
-       to->incompression = myself->incompression;
+               return true;
+       }
 
-       randomize(key, keylen);
-       cipher_set_key(&to->incipher, key, true);
-       digest_set_key(&to->indigest, key, keylen);
+       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;
+               }
 
-       bin2hex(key, key, keylen);
-       key[keylen * 2] = '\0';
+               char buf[MAX_STRING_SIZE];
+               int len;
 
-       // Reset sequence number and late packet window
-       mykeyused = true;
-       to->received_seqno = 0;
-       if(replaywin) memset(to->late, 0, replaywin);
+               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;
+       }
 
-       return send_request(to->nexthop->connection, "%d %s %s %s %d %d %zu %d", ANS_KEY,
-                                               myself->name, to->name, key,
-                                               cipher_get_nid(&to->incipher),
-                                               digest_get_nid(&to->indigest),
-                                               digest_length(&to->indigest),
-                                               to->incompression);
+       default:
+               logger(mesh, MESHLINK_ERROR, "Unknown extended REQ_KEY request from %s: %s", from->name, request);
+               return true;
+       }
 }
 
-bool ans_key_h(connection_t *c, char *request) {
+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];
-       char key[MAX_STRING_SIZE];
-        char address[MAX_STRING_SIZE] = "";
-        char port[MAX_STRING_SIZE] = "";
-       int cipher, digest, maclength, compression, keylen;
        node_t *from, *to;
+       int reqno = 0;
 
-       if(sscanf(request, "%*d "MAX_STRING" "MAX_STRING" "MAX_STRING" %d %d %d %d "MAX_STRING" "MAX_STRING" %d",
-               from_name, to_name, key, &cipher, &digest, &maclength,
-               &compression, address, port) < 7) {
-               logger(LOG_ERR, "Got bad %s from %s (%s)", "ANS_KEY", c->name,
-                          c->hostname);
+       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(LOG_ERR, "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", "REQ_KEY", c->name, "invalid name");
                return false;
        }
 
-       from = lookup_node(from_name);
+       from = lookup_node(mesh, from_name);
 
        if(!from) {
-               logger(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);
+               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(to_name);
+       to = lookup_node(mesh, to_name);
 
        if(!to) {
-               logger(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);
+               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;
        }
 
-       /* Forward it if necessary */
-
-       if(to != myself) {
-               if(tunnelserver)
-                       return true;
+       /* Check if this key request is for us */
 
-               if(!to->status.reachable) {
-                       logger(LOG_WARNING, "Got %s from %s (%s) destination %s which is not reachable",
-                                  "ANS_KEY", c->name, c->hostname, to_name);
-                       return true;
+       if(to == mesh->self) {                      /* Yes */
+               /* Is this an extended REQ_KEY message? */
+               if(reqno) {
+                       return req_key_ext_h(mesh, c, request, from, reqno);
                }
 
-               if(!*address && from->address.sa.sa_family != AF_UNSPEC) {
-                       char *address, *port;
-                       ifdebug(PROTOCOL) logger(LOG_DEBUG, "Appending reflexive UDP address to ANS_KEY from %s to %s", from->name, to->name);
-                       sockaddr2str(&from->address, &address, &port);
-                       send_request(to->nexthop->connection, "%s %s %s", request, address, port);
-                       free(address);
-                       free(port);
+               /* 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;
                }
 
-               return send_request(to->nexthop->connection, "%s", request);
+               send_request(mesh, to->nexthop->connection, NULL, "%s", request);
        }
 
-       /* Check and lookup cipher and digest algorithms */
+       return true;
+}
 
-       if(!cipher_open_by_nid(&from->outcipher, cipher)) {
-               logger(LOG_ERR, "Node %s (%s) uses unknown cipher!", from->name, from->hostname);
-               return false;
-       }
+bool ans_key_h(meshlink_handle_t *mesh, connection_t *c, const char *request) {
+       assert(request);
+       assert(*request);
 
-       if(!digest_open_by_nid(&from->outdigest, digest, maclength)) {
-               logger(LOG_ERR, "Node %s (%s) uses unknown digest!", from->name, from->hostname);
+       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(maclength != digest_length(&from->outdigest)) {
-               logger(LOG_ERR, "Node %s (%s) uses bogus MAC length!", from->name, from->hostname);
+       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(compression < 0 || compression > 11) {
-               logger(LOG_ERR, "Node %s (%s) uses bogus compression level!", from->name, from->hostname);
+       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;
        }
 
-       from->outcompression = compression;
+       to = lookup_node(mesh, to_name);
 
-       /* ECDH or old-style key exchange? */
-       /* TODO: look at SSH and TLS to see how they derive cipher and HMAC keys from shared secret properly */
-       
-       if(!strncmp(key, "ECDH:", 5)) {
-               logger(LOG_DEBUG, "Got ECDH key from %s", from->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;
+       }
 
-               keylen = (strlen(key) - 5) / 2;
+       /* Forward it if necessary */
 
-               if(keylen != ECDH_SIZE) {
-                       logger(LOG_ERR, "Node %s (%s) uses wrong keylength!", from->name, from->hostname);
-                       return false;
+       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(ECDH_SHARED_SIZE < cipher_keylength(&from->outcipher)) {
-                       logger(LOG_ERR, "ECDH key too short for cipher of %s!", from->name);
-                       return false;
+               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;
                }
 
-               if(!from->ecdh) {
-                       logger(LOG_DEBUG, "Woops, we didn't generate our public key yet");
-                       from->status.ecdh = true;
-                       if(!send_ans_key(from))
-                               return false;
+               /* 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;
                }
 
-               char shared[ECDH_SHARED_SIZE * 2 + 1];
-               char hex[ECDH_SHARED_SIZE * 2 + 1];
-               hex2bin(key + 5, key + 5, keylen);
+               return send_request(mesh, to->nexthop->connection, NULL, "%s", request);
+       }
 
-               if(!ecdh_compute_shared(&from->ecdh, key + 5, shared))
-                       return false;
+       /* Is this an ANS_KEY informing us of our own reflexive UDP address? */
 
-               /* Update our crypto end */
+       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);
 
-               size_t mykeylen = cipher_keylength(&myself->incipher);
-               keylen = cipher_keylength(&from->outcipher);
+                       /* 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;
+                               }
 
-               char *mykey;
-               char *seed = NULL;
-               
-               if(strcmp(myself->name, from->name) < 0) {
-                       logger(LOG_DEBUG, "Using left half of shared secret");
-                       mykey = key;
-                       xasprintf(&seed, "tinc key expansion %s %s", myself->name, from->name);
-               } else {
-                       logger(LOG_DEBUG, "Using right half of shared secret");
-                       mykey = key + keylen;
-                       xasprintf(&seed, "tinc key expansion %s %s", from->name, myself->name);
-               }
+                               if(n->status.udp_confirmed) {
+                                       continue;
+                               }
 
-               if(!prf(shared, ECDH_SHARED_SIZE, seed, strlen(seed), key, keylen + mykeylen))
-                       return false;
+                               if(!n->status.waitingforkey && !n->status.validkey) {
+                                       continue;
+                               }
 
-               free(seed);
+                               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);
+               }
 
-               cipher_open_by_nid(&from->incipher, cipher_get_nid(&myself->incipher));
-               digest_open_by_nid(&from->indigest, digest_get_nid(&myself->indigest), digest_length(&myself->indigest));
-               from->incompression = myself->incompression;
+               return true;
+       }
 
-               cipher_set_key(&from->incipher, mykey, true);
-               digest_set_key(&from->indigest, mykey, mykeylen);
+       /* Process SPTPS data if present */
 
-               // Reset sequence number and late packet window
-               mykeyused = true;
-               from->received_seqno = 0;
-               if(replaywin)
-                       memset(from->late, 0, replaywin);
+       if(*key != '.') {
+               /* Don't use key material until every check has passed. */
+               from->status.validkey = false;
 
-               if(strcmp(myself->name, from->name) < 0)
-                       memmove(key, key + mykeylen, keylen);
-       } else {
-               keylen = strlen(key) / 2;
-               hex2bin(key, key, keylen);
-       }
+               /* Compression is not supported. */
+               if(compression != 0) {
+                       logger(mesh, MESHLINK_ERROR, "Node %s uses bogus compression level!", from->name);
+                       return true;
+               }
 
-       /* Update our copy of the origin's packet key */
+               char buf[strlen(key)];
+               int len = b64decode(key, buf, strlen(key));
 
-       if(keylen != cipher_keylength(&from->outcipher)) {
-               logger(LOG_ERR, "Node %s (%s) uses wrong keylength!", from->name, from->hostname);
-               return false;
+               if(!len || !sptps_receive_data(&from->sptps, buf, len)) {
+                       logger(mesh, MESHLINK_ERROR, "Error processing SPTPS data from %s", from->name);
+               }
        }
 
-       cipher_set_key(&from->outcipher, key, false);
-       digest_set_key(&from->outdigest, key, keylen);
-
-       from->status.validkey = true;
-       from->sent_seqno = 0;
+       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);
+               }
 
-       if(*address && *port) {
-               ifdebug(PROTOCOL) logger(LOG_DEBUG, "Using reflexive UDP address from %s: %s port %s", from->name, address, port);
-               sockaddr_t sa = str2sockaddr(address, port);
-               update_node_udp(from, &sa);
+               send_mtu_probe(mesh, from);
        }
 
-       if(from->options & OPTION_PMTU_DISCOVERY)
-               send_mtu_probe(from);
-
        return true;
 }