-int send_metakey(connection_t *c)
-{
- char buffer[MAX_STRING_SIZE];
- int len, x;
-cp
- len = RSA_size(c->rsa_key);
-
- /* Allocate buffers for the meta key */
-
- if(!c->outkey)
- c->outkey = xmalloc(len);
-
- if(!c->outctx)
- c->outctx = xmalloc(sizeof(*c->outctx));
-cp
- /* Copy random data to the buffer */
-
- RAND_bytes(c->outkey, 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.
- */
-
- c->outkey[0] &= 0x7F;
-
- if(debug_lvl >= DEBUG_SCARY_THINGS)
- {
- bin2hex(c->outkey, buffer, len);
- buffer[len*2] = '\0';
- syslog(LOG_DEBUG, _("Generated random meta key (unencrypted): %s"), buffer);
- }
-
- /* 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(len, c->outkey, buffer, c->rsa_key, RSA_NO_PADDING) != len)
- {
- syslog(LOG_ERR, _("Error during encryption of meta key for %s (%s)"), c->name, c->hostname);
- return -1;
- }
-cp
- /* Convert the encrypted random data to a hexadecimal formatted string */
-
- bin2hex(buffer, buffer, len);
- buffer[len*2] = '\0';
-
- /* Send the meta key */
-
- x = send_request(c, "%d %d %d %d %d %s", METAKEY,
- c->outcipher?c->outcipher->nid:0, c->outdigest?c->outdigest->type:0,
- c->outmaclength, c->outcompression, buffer);
-
- /* Further outgoing requests are encrypted with the key we just generated */
-
- if(c->outcipher)
- {
- EVP_EncryptInit(c->outctx, c->outcipher,
- c->outkey + len - c->outcipher->key_len,
- c->outkey + len - c->outcipher->key_len - c->outcipher->iv_len);
-
- c->status.encryptout = 1;
- }
-cp
- return x;
+static bool receive_invitation_sptps(void *handle, uint8_t type, const void *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 hashbuf[18 + strlen(fingerprint)];
+ char cookie[64];
+ memcpy(hashbuf, data, 18);
+ memcpy(hashbuf + 18, fingerprint, sizeof hashbuf - 18);
+ sha512(hashbuf, sizeof hashbuf, cookie);
+ b64encode_urlsafe(cookie, 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) {
+ char name[MAX_STRING_SIZE];
+
+ if(sscanf(request, "%*d " MAX_STRING " %d.%d", name, &c->protocol_major, &c->protocol_minor) < 2) {
+ logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s)", "ID", c->name,
+ c->hostname);
+ return false;
+ }
+
+ /* Check if this is a control connection */
+
+ if(name[0] == '^' && !strcmp(name + 1, controlcookie)) {
+ c->status.control = true;
+ c->allow_request = CONTROL;
+ c->last_ping_time = now.tv_sec + 3600;
+
+ free(c->name);
+ c->name = xstrdup("<control>");
+
+ return send_request(c, "%d %d %d", ACK, TINC_CTL_VERSION_CURRENT, getpid());
+ }
+
+ 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;
+ }
+
+ 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;
+ }
+
+ 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 */
+
+ if(!check_id(name)) {
+ logger(DEBUG_ALWAYS, LOG_ERR, "Got bad %s from %s (%s): %s", "ID", c->name,
+ c->hostname, "invalid name");
+ return false;
+ }
+
+ /* If this is an outgoing connection, make sure we are connected to the right host */
+
+ if(c->outgoing) {
+ if(strcmp(c->name, name)) {
+ logger(DEBUG_ALWAYS, LOG_ERR, "Peer %s is %s instead of %s", c->hostname, name,
+ c->name);
+ return false;
+ }
+ } else {
+ if(c->name)
+ free(c->name);
+ c->name = xstrdup(name);
+ }
+
+ /* Check if version matches */
+
+ if(c->protocol_major != myself->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);
+ return false;
+ }
+
+ if(bypass_security) {
+ if(!c->config_tree)
+ init_configuration(&c->config_tree);
+ c->allow_request = ACK;
+ return send_ack(c);
+ }
+
+ if(!experimental)
+ c->protocol_minor = 0;
+
+ if(!c->config_tree) {
+ init_configuration(&c->config_tree);
+
+ if(!read_host_config(c->config_tree, c->name)) {
+ logger(DEBUG_ALWAYS, LOG_ERR, "Peer %s had unknown identity (%s)", c->hostname, c->name);
+ return false;
+ }
+
+ if(experimental)
+ read_ecdsa_public_key(c);
+ /* Ignore failures if no key known yet */
+ }
+
+ if(c->protocol_minor && !ecdsa_active(c->ecdsa))
+ c->protocol_minor = 1;
+
+ /* Forbid version rollback for nodes whose Ed25519 key we know */
+
+ if(ecdsa_active(c->ecdsa) && c->protocol_minor < 1) {
+ 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;
+ }
+
+ 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);
+ }