Allow +/- 10m clock skew

psiphon/common/obfuscator/passthrough.go

@@ -35,7 +35,7 @@ import (
 const (
 	TLS_PASSTHROUGH_NONCE_SIZE   = 16
 	TLS_PASSTHROUGH_KEY_SIZE     = 32
-	TLS_PASSTHROUGH_TIME_PERIOD  = 15 * time.Minute
+	TLS_PASSTHROUGH_TIME_PERIOD  = 20 * time.Minute
 	TLS_PASSTHROUGH_MESSAGE_SIZE = 32
 )