/*
protocol_auth.c -- handle the meta-protocol, authentication
- Copyright (C) 1999-2005 Ivo Timmermans,
- 2000-2013 Guus Sliepen <guus@tinc-vpn.org>
+ Copyright (C) 2014 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 "conf.h"
#include "connection.h"
-#include "control.h"
-#include "control_common.h"
#include "cipher.h"
#include "crypto.h"
#include "digest.h"
+#include "ecdsa.h"
#include "edge.h"
#include "graph.h"
#include "logger.h"
+#include "meshlink_internal.h"
#include "meta.h"
#include "net.h"
#include "netutl.h"
#include "node.h"
#include "prf.h"
#include "protocol.h"
-#include "rsa.h"
#include "sptps.h"
#include "utils.h"
#include "xalloc.h"
+#include "ed25519/sha512.h"
+
+ecdsa_t *invitation_key = NULL;
static bool send_proxyrequest(connection_t *c) {
switch(proxytype) {
bool send_id(connection_t *c) {
gettimeofday(&c->start, NULL);
- int minor = 0;
-
- if(experimental) {
- if(c->config_tree && !read_ecdsa_public_key(c))
- minor = 1;
- else
- minor = myself->connection->protocol_minor;
- }
+ int minor = mesh->self->connection->protocol_minor;
if(proxytype && c->outgoing)
if(!send_proxyrequest(c))
return false;
- return send_request(c, "%d %s %d.%d", ID, myself->connection->name, myself->connection->protocol_major, minor);
+ return send_request(c, "%d %s %d.%d", ID, mesh->self->connection->name, mesh->self->connection->protocol_major, minor);
+}
+
+static bool finalize_invitation(connection_t *c, const char *data, uint16_t len) {
+ if(strchr(data, '\n')) {
+ logger(DEBUG_ALWAYS, LOG_ERR, "Received invalid key from invited node %s (%s)!\n", c->name, c->hostname);
+ return false;
+ }
+
+ // Create a new host config file
+ char filename[PATH_MAX];
+ snprintf(filename, sizeof filename, "%s" SLASH "hosts" SLASH "%s", confbase, c->name);
+ if(!access(filename, F_OK)) {
+ logger(DEBUG_ALWAYS, LOG_ERR, "Host config file for %s (%s) already exists!\n", c->name, c->hostname);
+ return false;
+ }
+
+ FILE *f = fopen(filename, "w");
+ if(!f) {
+ logger(DEBUG_ALWAYS, LOG_ERR, "Error trying to create %s: %s\n", filename, strerror(errno));
+ return false;
+ }
+
+ fprintf(f, "ECDSAPublicKey = %s\n", data);
+ fclose(f);
+
+ logger(DEBUG_CONNECTIONS, LOG_INFO, "Key succesfully received from %s (%s)", c->name, c->hostname);
+
+ //TODO: callback to application to inform of an accepted invitation
+
+ sptps_send_record(&c->sptps, 2, data, 0);
+ return true;
+}
+
+static bool receive_invitation_sptps(void *handle, uint8_t type, const char *data, uint16_t len) {
+ connection_t *c = handle;
+
+ if(type == 128)
+ return true;
+
+ if(type == 1 && c->status.invitation_used)
+ return finalize_invitation(c, data, len);
+
+ if(type != 0 || len != 18 || c->status.invitation_used)
+ return false;
+
+ // Recover the filename from the cookie and the key
+ char *fingerprint = ecdsa_get_base64_public_key(invitation_key);
+ char hash[64];
+ char hashbuf[18 + strlen(fingerprint)];
+ char cookie[25];
+ memcpy(hashbuf, data, 18);
+ memcpy(hashbuf + 18, fingerprint, sizeof hashbuf - 18);
+ sha512(hashbuf, sizeof hashbuf, hash);
+ b64encode_urlsafe(hash, cookie, 18);
+ free(fingerprint);
+
+ char filename[PATH_MAX], usedname[PATH_MAX];
+ snprintf(filename, sizeof filename, "%s" SLASH "invitations" SLASH "%s", confbase, cookie);
+ snprintf(usedname, sizeof usedname, "%s" SLASH "invitations" SLASH "%s.used", confbase, cookie);
+
+ // Atomically rename the invitation file
+ if(rename(filename, usedname)) {
+ if(errno == ENOENT)
+ logger(DEBUG_ALWAYS, LOG_ERR, "Peer %s tried to use non-existing invitation %s\n", c->hostname, cookie);
+ else
+ logger(DEBUG_ALWAYS, LOG_ERR, "Error trying to rename invitation %s\n", cookie);
+ return false;
+ }
+
+ // Open the renamed file
+ FILE *f = fopen(usedname, "r");
+ if(!f) {
+ logger(DEBUG_ALWAYS, LOG_ERR, "Error trying to open invitation %s\n", cookie);
+ return false;
+ }
+
+ // Read the new node's Name from the file
+ char buf[1024];
+ fgets(buf, sizeof buf, f);
+ if(*buf)
+ buf[strlen(buf) - 1] = 0;
+
+ len = strcspn(buf, " \t=");
+ char *name = buf + len;
+ name += strspn(name, " \t");
+ if(*name == '=') {
+ name++;
+ name += strspn(name, " \t");
+ }
+ buf[len] = 0;
+
+ if(!*buf || !*name || strcasecmp(buf, "Name") || !check_id(name)) {
+ logger(DEBUG_ALWAYS, LOG_ERR, "Invalid invitation file %s\n", cookie);
+ fclose(f);
+ return false;
+ }
+
+ free(c->name);
+ c->name = xstrdup(name);
+
+ // Send the node the contents of the invitation file
+ rewind(f);
+ size_t result;
+ while((result = fread(buf, 1, sizeof buf, f)))
+ sptps_send_record(&c->sptps, 0, buf, result);
+ sptps_send_record(&c->sptps, 1, buf, 0);
+ fclose(f);
+ unlink(usedname);
+
+ c->status.invitation_used = true;
+
+ logger(DEBUG_CONNECTIONS, LOG_INFO, "Invitation %s succesfully sent to %s (%s)", cookie, c->name, c->hostname);
+ return true;
}
bool id_h(connection_t *c, const char *request) {
return false;
}
- /* Check if this is a control connection */
+ /* Check if this is an invitation */
- if(name[0] == '^' && !strcmp(name + 1, controlcookie)) {
- c->status.control = true;
- c->allow_request = CONTROL;
- c->last_ping_time = now.tv_sec + 3600;
+ if(name[0] == '?') {
+ if(!invitation_key) {
+ logger(DEBUG_ALWAYS, LOG_ERR, "Got invitation from %s but we don't have an invitation key", c->hostname);
+ return false;
+ }
- free(c->name);
- c->name = xstrdup("<control>");
+ c->ecdsa = ecdsa_set_base64_public_key(name + 1);
+ if(!c->ecdsa) {
+ logger(DEBUG_ALWAYS, LOG_ERR, "Got bad invitation from %s", c->hostname);
+ return false;
+ }
- return send_request(c, "%d %d %d", ACK, TINC_CTL_VERSION_CURRENT, getpid());
+ c->status.invitation = true;
+ char *mykey = ecdsa_get_base64_public_key(invitation_key);
+ if(!mykey)
+ return false;
+ if(!send_request(c, "%d %s", ACK, mykey))
+ return false;
+ free(mykey);
+
+ c->protocol_minor = 2;
+
+ return sptps_start(&c->sptps, c, false, false, invitation_key, c->ecdsa, "tinc invitation", 15, send_meta_sptps, receive_invitation_sptps);
}
/* Check if identity is a valid name */
/* Check if version matches */
- if(c->protocol_major != myself->connection->protocol_major) {
+ if(c->protocol_major != mesh->self->connection->protocol_major) {
logger(DEBUG_ALWAYS, LOG_ERR, "Peer %s (%s) uses incompatible version %d.%d",
- c->name, c->hostname, c->protocol_major, c->protocol_minor);
+ c->name, c->hostname, c->protocol_major, c->protocol_minor);
return false;
}
return send_ack(c);
}
- if(!experimental)
- c->protocol_minor = 0;
-
if(!c->config_tree) {
init_configuration(&c->config_tree);
return false;
}
- if(experimental && c->protocol_minor >= 2) {
- if(!read_ecdsa_public_key(c))
- return false;
- }
+ read_ecdsa_public_key(c);
} else {
if(c->protocol_minor && !ecdsa_active(c->ecdsa))
c->protocol_minor = 1;
}
- c->allow_request = METAKEY;
-
- if(c->protocol_minor >= 2) {
- c->allow_request = ACK;
- char label[25 + strlen(myself->name) + strlen(c->name)];
-
- if(c->outgoing)
- snprintf(label, sizeof label, "tinc TCP key expansion %s %s", myself->name, c->name);
- else
- snprintf(label, sizeof label, "tinc TCP key expansion %s %s", c->name, myself->name);
-
- return sptps_start(&c->sptps, c, c->outgoing, false, myself->connection->ecdsa, c->ecdsa, label, sizeof label, send_meta_sptps, receive_meta_sptps);
- } else {
- return send_metakey(c);
- }
-}
-
-bool send_metakey(connection_t *c) {
- if(!read_rsa_public_key(c))
- return false;
-
- if(!(c->outcipher = cipher_open_blowfish_ofb()))
- return false;
-
- if(!(c->outdigest = digest_open_sha1(-1)))
- return false;
-
- size_t len = rsa_size(c->rsa);
- char key[len];
- char enckey[len];
- char hexkey[2 * len + 1];
-
- /* Create a random key */
-
- randomize(key, 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.
- */
-
- key[0] &= 0x7F;
-
- if(!cipher_set_key_from_rsa(c->outcipher, key, len, true))
- return false;
-
- if(debug_level >= DEBUG_SCARY_THINGS) {
- bin2hex(key, hexkey, len);
- logger(DEBUG_SCARY_THINGS, LOG_DEBUG, "Generated random meta key (unencrypted): %s", hexkey);
- }
-
- /* 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(c->rsa, key, len, enckey)) {
- logger(DEBUG_ALWAYS, LOG_ERR, "Error during encryption of meta key for %s (%s)", c->name, c->hostname);
- return false;
- }
-
- /* Convert the encrypted random data to a hexadecimal formatted string */
-
- bin2hex(enckey, hexkey, len);
-
- /* Send the meta key */
-
- bool result = send_request(c, "%d %d %d %d %d %s", METAKEY,
- cipher_get_nid(c->outcipher),
- digest_get_nid(c->outdigest), c->outmaclength,
- c->outcompression, hexkey);
-
- c->status.encryptout = true;
- return result;
-}
-
-bool metakey_h(connection_t *c, const char *request) {
- char hexkey[MAX_STRING_SIZE];
- int cipher, digest, maclength, compression;
- size_t len = rsa_size(myself->connection->rsa);
- char enckey[len];
- char key[len];
-
- if(sscanf(request, "%*d %d %d %d %d " MAX_STRING, &cipher, &digest, &maclength, &compression, hexkey) != 5) {
- logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s)", "METAKEY", c->name, c->hostname);
- return false;
- }
-
- /* Convert the challenge from hexadecimal back to binary */
+ /* Forbid version rollback for nodes whose ECDSA key we know */
- int inlen = hex2bin(hexkey, enckey, sizeof enckey);
-
- /* Check if the length of the meta key is all right */
-
- if(inlen != len) {
- logger(DEBUG_ALWAYS, LOG_ERR, "Possible intruder %s (%s): %s", c->name, c->hostname, "wrong keylength");
- return false;
- }
-
- /* Decrypt the meta key */
-
- if(!rsa_private_decrypt(myself->connection->rsa, enckey, len, key)) {
- logger(DEBUG_ALWAYS, LOG_ERR, "Error during decryption of meta key for %s (%s)", c->name, c->hostname);
- return false;
- }
-
- if(debug_level >= DEBUG_SCARY_THINGS) {
- bin2hex(key, hexkey, len);
- logger(DEBUG_SCARY_THINGS, LOG_DEBUG, "Received random meta key (unencrypted): %s", hexkey);
- }
-
- /* Check and lookup cipher and digest algorithms */
-
- if(!(c->incipher = cipher_open_by_nid(cipher)) || !cipher_set_key_from_rsa(c->incipher, key, len, false)) {
- logger(DEBUG_ALWAYS, LOG_ERR, "Error during initialisation of cipher from %s (%s)", c->name, c->hostname);
- return false;
- }
-
- if(!(c->indigest = digest_open_by_nid(digest, -1))) {
- logger(DEBUG_ALWAYS, LOG_ERR, "Error during initialisation of digest from %s (%s)", c->name, c->hostname);
- return false;
- }
-
- c->status.decryptin = true;
-
- c->allow_request = CHALLENGE;
-
- return send_challenge(c);
-}
-
-bool send_challenge(connection_t *c) {
- size_t len = rsa_size(c->rsa);
- char buffer[len * 2 + 1];
-
- if(!c->hischallenge)
- c->hischallenge = xrealloc(c->hischallenge, len);
-
- /* Copy random data to the buffer */
-
- randomize(c->hischallenge, len);
-
- /* Convert to hex */
-
- bin2hex(c->hischallenge, buffer, len);
-
- /* Send the challenge */
-
- return send_request(c, "%d %s", CHALLENGE, buffer);
-}
-
-bool challenge_h(connection_t *c, const char *request) {
- char buffer[MAX_STRING_SIZE];
- size_t len = rsa_size(myself->connection->rsa);
- size_t digestlen = digest_length(c->indigest);
- char digest[digestlen];
-
- if(sscanf(request, "%*d " MAX_STRING, buffer) != 1) {
- logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s)", "CHALLENGE", c->name, c->hostname);
- return false;
- }
-
- /* Convert the challenge from hexadecimal back to binary */
-
- int inlen = hex2bin(buffer, buffer, sizeof buffer);
-
- /* Check if the length of the challenge is all right */
-
- if(inlen != len) {
- logger(DEBUG_ALWAYS, LOG_ERR, "Possible intruder %s (%s): %s", c->name, c->hostname, "wrong challenge length");
+ if(ecdsa_active(c->ecdsa) && c->protocol_minor < 2) {
+ logger(DEBUG_ALWAYS, LOG_ERR, "Peer %s (%s) tries to roll back protocol version to %d.%d",
+ c->name, c->hostname, c->protocol_major, c->protocol_minor);
return false;
}
- /* Calculate the hash from the challenge we received */
-
- if(!digest_create(c->indigest, buffer, len, digest))
- return false;
-
- /* Convert the hash to a hexadecimal formatted string */
-
- bin2hex(digest, buffer, digestlen);
-
- /* Send the reply */
-
- c->allow_request = CHAL_REPLY;
-
- return send_request(c, "%d %s", CHAL_REPLY, buffer);
-}
-
-bool chal_reply_h(connection_t *c, const char *request) {
- char hishash[MAX_STRING_SIZE];
-
- if(sscanf(request, "%*d " MAX_STRING, hishash) != 1) {
- logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s)", "CHAL_REPLY", c->name,
- c->hostname);
- return false;
- }
-
- /* Convert the hash to binary format */
-
- int inlen = hex2bin(hishash, hishash, sizeof hishash);
-
- /* Check if the length of the hash is all right */
-
- if(inlen != digest_length(c->outdigest)) {
- logger(DEBUG_ALWAYS, LOG_ERR, "Possible intruder %s (%s): %s", c->name, c->hostname, "wrong challenge reply length");
- return false;
- }
-
-
- /* Verify the hash */
-
- if(!digest_verify(c->outdigest, c->hischallenge, rsa_size(c->rsa), hishash)) {
- logger(DEBUG_ALWAYS, LOG_ERR, "Possible intruder %s (%s): %s", c->name, c->hostname, "wrong challenge reply");
- return false;
- }
-
- /* Identity has now been positively verified.
- Send an acknowledgement with the rest of the information needed.
- */
-
- free(c->hischallenge);
- c->hischallenge = NULL;
c->allow_request = ACK;
+ char label[25 + strlen(mesh->self->name) + strlen(c->name)];
- return send_ack(c);
-}
-
-static bool send_upgrade(connection_t *c) {
- /* Special case when protocol_minor is 1: the other end is ECDSA capable,
- * but doesn't know our key yet. So send it now. */
-
- char *pubkey = ecdsa_get_base64_public_key(myself->connection->ecdsa);
-
- if(!pubkey)
- return false;
+ if(c->outgoing)
+ snprintf(label, sizeof label, "tinc TCP key expansion %s %s", mesh->self->name, c->name);
+ else
+ snprintf(label, sizeof label, "tinc TCP key expansion %s %s", c->name, mesh->self->name);
- bool result = send_request(c, "%d %s", ACK, pubkey);
- free(pubkey);
- return result;
+ return sptps_start(&c->sptps, c, c->outgoing, false, mesh->self->connection->ecdsa, c->ecdsa, label, sizeof label, send_meta_sptps, receive_meta_sptps);
}
bool send_ack(connection_t *c) {
- if(c->protocol_minor == 1)
- return send_upgrade(c);
-
/* ACK message contains rest of the information the other end needs
to create node_t and edge_t structures. */
/* 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(myself->options & OPTION_PMTU_DISCOVERY)
+ if(mesh->self->options & OPTION_PMTU_DISCOVERY)
c->options |= OPTION_PMTU_DISCOVERY;
- choice = myself->options & OPTION_CLAMP_MSS;
- get_config_bool(lookup_config(c->config_tree, "ClampMSS"), &choice);
- if(choice)
- c->options |= OPTION_CLAMP_MSS;
-
- get_config_int(lookup_config(c->config_tree, "Weight"), &c->estimated_weight);
-
- return send_request(c, "%d %s %d %x", ACK, myport, c->estimated_weight, (c->options & 0xffffff) | (experimental ? (PROT_MINOR << 24) : 0));
+ return send_request(c, "%d %s %d %x", ACK, myport, c->estimated_weight, (c->options & 0xffffff) | (PROT_MINOR << 24));
}
static void send_everything(connection_t *c) {
/* Send all known subnets and edges */
+ // TODO: remove this
if(disablebuggypeers) {
static struct {
vpn_packet_t pkt;
send_tcppacket(c, &zeropkt.pkt);
}
- if(tunnelserver) {
- for splay_each(subnet_t, s, myself->subnet_tree)
- send_add_subnet(c, s);
-
- return;
- }
-
for splay_each(node_t, n, node_tree) {
- for splay_each(subnet_t, s, n->subnet_tree)
- send_add_subnet(c, s);
-
for splay_each(edge_t, e, n->edge_tree)
send_add_edge(c, e);
}
}
-static bool upgrade_h(connection_t *c, const char *request) {
- char pubkey[MAX_STRING_SIZE];
-
- if(sscanf(request, "%*d " MAX_STRING, pubkey) != 1) {
- logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s)", "ACK", c->name, c->hostname);
- return false;
- }
-
- if(ecdsa_active(c->ecdsa) || read_ecdsa_public_key(c)) {
- logger(DEBUG_ALWAYS, LOG_INFO, "Already have ECDSA public key from %s (%s), not upgrading.", c->name, c->hostname);
- return false;
- }
-
- logger(DEBUG_ALWAYS, LOG_INFO, "Got ECDSA public key from %s (%s), upgrading!", c->name, c->hostname);
- append_config_file(c->name, "ECDSAPublicKey", pubkey);
- c->allow_request = TERMREQ;
- return send_termreq(c);
-}
-
bool ack_h(connection_t *c, const char *request) {
- if(c->protocol_minor == 1)
- return upgrade_h(c, request);
-
char hisport[MAX_STRING_SIZE];
char *hisaddress;
int weight, mtu;
}
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 */
+ /* Run graph algorithm to keep things in sync */
graph();
}
}
}
c->options |= options;
- if(get_config_int(lookup_config(c->config_tree, "PMTU"), &mtu) && mtu < n->mtu)
- n->mtu = mtu;
-
- if(get_config_int(lookup_config(config_tree, "PMTU"), &mtu) && mtu < n->mtu)
- n->mtu = mtu;
-
- if(get_config_bool(lookup_config(c->config_tree, "ClampMSS"), &choice)) {
- if(choice)
- c->options |= OPTION_CLAMP_MSS;
- else
- c->options &= ~OPTION_CLAMP_MSS;
- }
-
/* Activate this connection */
c->allow_request = ALL;
/* Create an edge_t for this connection */
c->edge = new_edge();
- c->edge->from = myself;
+ c->edge->from = mesh->self;
c->edge->to = n;
sockaddr2str(&c->address, &hisaddress, NULL);
c->edge->address = str2sockaddr(hisaddress, hisport);
/* Notify everyone of the new edge */
- if(tunnelserver)
- send_add_edge(c, c->edge);
- else
- send_add_edge(everyone, c->edge);
+ send_add_edge(everyone, c->edge);
/* Run MST and SSSP algorithms */