X-Git-Url: https://www.tinc-vpn.org/git/browse?a=blobdiff_plain;f=src%2Fprotocol_auth.c;h=04674e8dc9e8ff5758844e665c3ceb5fe7033741;hb=995444c4f96bafecf7fb5d59510b3034459cf85c;hp=f030b86bd1a43fbc45da8c723411eb148e25d5de;hpb=3c163a3796c984deb874fb1cca1ed9a85fc1d087;p=tinc

diff --git a/src/protocol_auth.c b/src/protocol_auth.c
index f030b86b..04674e8d 100644
--- a/src/protocol_auth.c
+++ b/src/protocol_auth.c
@@ -26,21 +26,27 @@
 #include "control_common.h"
 #include "cipher.h"
 #include "crypto.h"
+#include "device.h"
 #include "digest.h"
+#include "ecdsa.h"
 #include "edge.h"
 #include "graph.h"
 #include "logger.h"
 #include "meta.h"
+#include "names.h"
 #include "net.h"
 #include "netutl.h"
 #include "node.h"
 #include "prf.h"
 #include "protocol.h"
 #include "rsa.h"
+#include "script.h"
 #include "sptps.h"
 #include "utils.h"
 #include "xalloc.h"
 
+ecdsa_t *invitation_key = NULL;
+
 static bool send_proxyrequest(connection_t *c) {
 	switch(proxytype) {
 		case PROXY_HTTP: {
@@ -146,6 +152,137 @@ bool send_id(connection_t *c) {
 	return send_request(c, "%d %s %d.%d", ID, myself->connection->name, myself->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);
+
+	// Call invitation-accepted script
+	char *envp[7] = {NULL};
+	char *address, *port;
+
+	xasprintf(&envp[0], "NETNAME=%s", netname ? : "");
+        xasprintf(&envp[1], "DEVICE=%s", device ? : "");
+        xasprintf(&envp[2], "INTERFACE=%s", iface ? : "");
+        xasprintf(&envp[3], "NODE=%s", c->name);
+	sockaddr2str(&c->address, &address, &port);
+	xasprintf(&envp[4], "REMOTEADDRESS=%s", address);
+	xasprintf(&envp[5], "NAME=%s", myself->name);
+
+	execute_script("invitation-accepted", envp);
+
+	for(int i = 0; envp[i] && i < 7; i++)
+		free(envp[i]);
+
+	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
+	digest_t *digest = digest_open_by_name("sha256", 18);
+	if(!digest)
+		abort();
+	char *fingerprint = ecdsa_get_base64_public_key(invitation_key);
+	char hashbuf[18 + strlen(fingerprint)];
+	char cookie[25];
+	memcpy(hashbuf, data, 18);
+	memcpy(hashbuf + 18, fingerprint, sizeof hashbuf - 18);
+	digest_create(digest, hashbuf, sizeof hashbuf, cookie);
+	b64encode_urlsafe(cookie, cookie, 18);
+	digest_close(digest);
+	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];
 
@@ -168,6 +305,31 @@ bool id_h(connection_t *c, const char *request) {
 		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)) {
@@ -194,7 +356,7 @@ bool id_h(connection_t *c, const char *request) {
 
 	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);
+			c->name, c->hostname, c->protocol_major, c->protocol_minor);
 		return false;
 	}
 
@@ -216,15 +378,21 @@ bool id_h(connection_t *c, const char *request) {
 			return false;
 		}
 
-		if(experimental && c->protocol_minor >= 2) {
-			if(!read_ecdsa_public_key(c))
-				return false;
-		}
+		if(experimental)
+			read_ecdsa_public_key(c);
 	} else {
 		if(c->protocol_minor && !ecdsa_active(c->ecdsa))
 			c->protocol_minor = 1;
 	}
 
+	/* Forbid version rollback for nodes whose ECDSA key we know */
+
+	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;
+	}
+
 	c->allow_request = METAKEY;
 
 	if(c->protocol_minor >= 2) {
@@ -504,7 +672,8 @@ bool send_ack(connection_t *c) {
 	if(choice)
 		c->options |= OPTION_CLAMP_MSS;
 
-	get_config_int(lookup_config(c->config_tree, "Weight"), &c->estimated_weight);
+	if(!get_config_int(lookup_config(c->config_tree, "Weight"), &c->estimated_weight))
+		get_config_int(lookup_config(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));
 }