X-Git-Url: https://tinc-vpn.org/git/browse?a=blobdiff_plain;f=src%2Fprotocol_auth.c;h=d69c8ab722913732c2521ec94356df5ec9e35106;hb=9699f08afc6420d2bdac1063ea6789b585aaf42e;hp=05724d6faa88059d1ece5bcfca0e6c0cb714f675;hpb=ced4c1a327b321a6d73028a3a15b41b0be64d910;p=tinc

diff --git a/src/protocol_auth.c b/src/protocol_auth.c
index 05724d6f..d69c8ab7 100644
--- a/src/protocol_auth.c
+++ b/src/protocol_auth.c
@@ -174,6 +174,7 @@ static bool finalize_invitation(connection_t *c, const char *data, uint16_t len)
 	fclose(f);
 
 	logger(DEBUG_CONNECTIONS, LOG_INFO, "Key succesfully received from %s (%s)", c->name, c->hostname);
+	sptps_send_record(&c->sptps, 2, data, 0);
 	return true;
 }
 
@@ -189,8 +190,19 @@ static bool receive_invitation_sptps(void *handle, uint8_t type, const char *dat
 	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];
-	b64encode_urlsafe(data, cookie, 18);
+	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);
@@ -324,7 +336,7 @@ 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;
 	}
 
@@ -346,15 +358,21 @@ 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) {