Refactor signer code into command and package

shared/io.go

@@ -2,30 +2,37 @@ package shared
 
 import (
 	"fmt"
-	log "github.com/sirupsen/logrus"
 	"io"
 	"time"
+
+	log "github.com/sirupsen/logrus"
 )
 
 // receive at maximum the requested number of bytes from serial port and stop after the given timeout
-func ReceiveBytes(port *io.ReadWriteCloser, count int, timeout time.Duration) ([]byte, error) {
+func ReceiveBytes(port io.Reader, count int, timeout time.Duration) ([]byte, error) {
 	readCh := make(chan []byte, 1)
 	errCh := make(chan error, 1)
 	go func() {
-		data := make([]byte, count)
-		if readBytes, err := (*port).Read(data); err != nil {
-			errCh <- err
-		} else if readBytes > 0 {
-			log.Tracef("%d bytes read", readBytes)
-			readCh <- data[0:readBytes]
-		} else {
-			readCh <- make([]byte, 0)
+		sumRead := 0
+		for {
+			data := make([]byte, count)
+			if readBytes, err := port.Read(data); err != nil {
+				errCh <- err
+			} else if readBytes > 0 {
+				log.Tracef("%d bytes read", readBytes)
+				sumRead += readBytes
+				readCh <- data[0:readBytes]
+			} else {
+				readCh <- make([]byte, 0)
+			}
+			if sumRead >= count {
+				break
+			}
 		}
-		return
 	}()
 	select {
 	case <-time.After(timeout):
-		return nil, fmt.Errorf("timeout passed %v: %v", timeout)
+		return nil, fmt.Errorf("timeout passed %v", timeout)
 	case err := <-errCh:
 		return nil, err
 	case data := <-readCh:
@@ -33,11 +40,11 @@ func ReceiveBytes(port *io.ReadWriteCloser, count int, timeout time.Duration) ([
 	}
 }
 
-func SendByte(port *io.ReadWriteCloser, data byte) error {
-	if bytesWritten, err := (*port).Write([]byte{data}); err != nil {
+func SendBytes(port io.Writer, data []byte) error {
+	if bytesWritten, err := port.Write(data); err != nil {
 		return err
 	} else {
-		log.Tracef("wrote %d bytes of handshake info", bytesWritten)
+		log.Tracef("wrote %d bytes", bytesWritten)
 	}
 	return nil
 }

shared/shared.go

@@ -1,7 +1,36 @@
 package shared
 
-const MagicTrailer = "rie4Ech7"
+const (
+	ProtocolVersion = 1
 
-const HandshakeByte = 0x02
-const AckByte = 0x10
-const ResendByte = 0x11
+	HandshakeByte = 0x02
+	AckByte       = 0x10
+	ResendByte    = 0x11
+
+	MagicTrailer = "rie4Ech7"
+
+	LengthFieldSize   = 3
+	CheckSumFieldSize = 1
+	TrailerFieldSize  = len(MagicTrailer)
+)
+
+type Action uint8
+
+const (
+	ActionNul    = Action(0)
+	ActionSign   = Action(1)
+	ActionRevoke = Action(2)
+)
+
+func (a Action) String() string {
+	switch a {
+	case ActionNul:
+		return "NUL"
+	case ActionSign:
+		return "SIGN"
+	case ActionRevoke:
+		return "REVOKE"
+	default:
+		return "unknown"
+	}
+}