Introduce configurable buffer size

client/config.go

@@ -11,6 +11,7 @@ import (
 type ClientConfig struct {
 	SerialAddress string `yaml:"serial_address"`
 	BaudRate      int    `yaml:"serial_baudrate"`
+	BufferSize    uint16 `yaml:"serial_buffer_size"`
 	Paranoid      bool   `yaml:"paranoid"`
 	Debug         bool   `yaml:"debug"`
 	GNUPGBinary   string `yaml:"gnupg_bin"`
@@ -21,6 +22,7 @@ type ClientConfig struct {
 var defaultConfig = ClientConfig{
 	SerialAddress: "/dev/ttyUSB0",
 	BaudRate:      115200,
+	BufferSize:    2048,
 	Paranoid:      false,
 	Debug:         false,
 	OpenSSLBinary: "/usr/bin/openssl",