jan/cacert-gosigner
1
0
Fork 0
Code Issues Pull requests Releases Wiki Activity

Refactor signer code into command and package

Browse source
This commit is contained in:
Jan Dittberner 2021-01-04 14:15:12 +01:00
parent 3a2578ae55
commit 38566f35ef
13 changed files with 476 additions and 276 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

13
.editorconfig Normal file
View file

@ -0,0 +1,13 @@
root = true
[*]
charset = utf-8
end_of_line = lf
indent_size = 4
indent_style = space
insert_final_newline = false
max_line_length = 120
tab_width = 4
[{*.go,*.go2}]
indent_style = tab

4
client/main.go
View file

@ -2,7 +2,6 @@ package main
import (
"flag"
"io"
"os"
"os/signal"
"sync"
@ -45,13 +44,12 @@ func main() {
requestChannel := protocol.NewSignerProtocolRequestChannel()
responseChannel := make(chan *datastructures.SignerResponse, 1)
readWriteCloser := (io.ReadWriteCloser)(port)
clientProtocolConfig := protocol.NewSignerProtocolConfig()
if clientConfig.BufferSize != 0 {
clientProtocolConfig.BufferSize = int(clientConfig.BufferSize)
}
protocolHandler := protocol.NewProtocolHandler(
requestChannel, &responseChannel, &readWriteCloser, clientProtocolConfig,
requestChannel, &responseChannel, port, clientProtocolConfig,
)
cancelChannel := make(chan os.Signal, 1)

5
client/processing/process.go
View file

@ -2,7 +2,10 @@ package processing
import (
"fmt"
"git.cacert.org/cacert-gosigner/datastructures"
"git.cacert.org/cacert-gosigner/shared"
"github.com/sirupsen/logrus"
)
@ -11,7 +14,7 @@ func Process(response *datastructures.SignerResponse) (err error) {
logrus.Tracef("process response %+v", response)
switch response.Action {
case datastructures.ActionNul:
case shared.ActionNul:
logrus.Trace("received response for NUL request")
return
default:

31
client/protocol/protocol.go
View file

@ -3,12 +3,14 @@ package protocol
import (
"bytes"
"fmt"
"git.cacert.org/cacert-gosigner/datastructures"
"git.cacert.org/cacert-gosigner/shared"
log "github.com/sirupsen/logrus"
"io"
"sync"
"time"
log "github.com/sirupsen/logrus"
"git.cacert.org/cacert-gosigner/datastructures"
"git.cacert.org/cacert-gosigner/shared"
)
type SignerProtocolHandler interface {
@ -52,7 +54,7 @@ func (rc *SignerProtocolRequestChannel) IsClosed() bool {
type protocolHandler struct {
requestChannel *SignerProtocolRequestChannel
responseChannel *chan *datastructures.SignerResponse
serialConnection *io.ReadWriteCloser
serialConnection io.ReadWriteCloser
config *signerProtocolConfig
}
@ -76,7 +78,12 @@ func (ph *protocolHandler) Close() error {
return nil
}
func NewProtocolHandler(requests *SignerProtocolRequestChannel, response *chan *datastructures.SignerResponse, serialConnection *io.ReadWriteCloser, config *signerProtocolConfig) SignerProtocolHandler {
func NewProtocolHandler(
requests *SignerProtocolRequestChannel,
response *chan *datastructures.SignerResponse,
serialConnection io.ReadWriteCloser,
config *signerProtocolConfig,
) SignerProtocolHandler {
return &protocolHandler{
requestChannel: requests,
responseChannel: response,
@ -123,13 +130,13 @@ func (ph *protocolHandler) HandleSignerProtocol() error {
func (ph *protocolHandler) sendHandshake() (err error) {
var bytesWritten, bytesRead int
if bytesWritten, err = (*ph.serialConnection).Write([]byte{shared.HandshakeByte}); err != nil {
if bytesWritten, err = ph.serialConnection.Write([]byte{shared.HandshakeByte}); err != nil {
return
} else {
log.Tracef("wrote %d bytes of handshake info", bytesWritten)
}
data := make([]byte, 1)
if bytesRead, err = (*ph.serialConnection).Read(data); err != nil {
if bytesRead, err = ph.serialConnection.Read(data); err != nil {
return
}
log.Tracef("%d bytes read", bytesRead)
@ -142,13 +149,13 @@ func (ph *protocolHandler) sendHandshake() (err error) {
func (ph *protocolHandler) sendRequest(requestBytes *[]byte) error {
for {
if length, err := (*ph.serialConnection).Write(*requestBytes); err != nil {
if length, err := ph.serialConnection.Write(*requestBytes); err != nil {
return err
} else {
log.Tracef("wrote %d request bytes", length)
}
if length, err := (*ph.serialConnection).Write([]byte{
if length, err := ph.serialConnection.Write([]byte{
datastructures.CalculateXorCheckSum([][]byte{*requestBytes}),
}); err != nil {
return err
@ -156,7 +163,7 @@ func (ph *protocolHandler) sendRequest(requestBytes *[]byte) error {
log.Tracef("wrote %d checksum bytes", length)
}
if length, err := (*ph.serialConnection).Write([]byte(shared.MagicTrailer)); err != nil {
if length, err := ph.serialConnection.Write([]byte(shared.MagicTrailer)); err != nil {
return err
} else {
log.Tracef("wrote %d trailer bytes", length)
@ -184,7 +191,7 @@ func (ph *protocolHandler) waitForResponseHandshake() (err error) {
log.Warnf("received invalid handshake byte 0x%x", data[0])
return UnExpectedHandshakeByte{data[0]}
}
if err = shared.SendByte(ph.serialConnection, shared.AckByte); err != nil {
if err = shared.SendBytes(ph.serialConnection, []byte{shared.AckByte}); err != nil {
return
}
@ -229,7 +236,7 @@ func (ph *protocolHandler) readResponse() (*[]byte, *[]byte, byte, error) {
if calculatedChecksum != checkSum {
return nil, nil, 0, fmt.Errorf("calculated checksum mismatch 0x%x vs 0x%x", calculatedChecksum, checkSum)
}
if err := shared.SendByte(ph.serialConnection, shared.AckByte); err != nil {
if err := shared.SendBytes(ph.serialConnection, []byte{shared.AckByte}); err != nil {
return nil, nil, 0, err
}

71
cmd/signer/main.go Normal file
View file

@ -0,0 +1,71 @@
package main
import (
"flag"
"os"
"os/signal"
log "github.com/sirupsen/logrus"
"go.bug.st/serial"
"git.cacert.org/cacert-gosigner/signer"
)
func main() {
var (
address string
baudRate int
)
flag.StringVar(&address, "a", "/dev/ttyUSB0", "address")
flag.IntVar(&baudRate, "b", 115200, "baud rate")
flag.Parse()
log.SetFormatter(&log.TextFormatter{
DisableColors: true,
FullTimestamp: true,
})
log.SetLevel(log.TraceLevel)
serialMode := &serial.Mode{
BaudRate: baudRate,
DataBits: 8,
StopBits: serial.OneStopBit,
Parity: serial.NoParity,
}
log.Infof("connecting to %s using %+v", address, serialMode)
port, err := serial.Open(address, serialMode)
if err != nil {
log.Fatalf("could not open serial port: %v", err)
}
log.Info("connected")
defer func() {
err := port.Close()
if err != nil {
log.Fatalf("could not close port: %v", err)
}
log.Info("serial port closed")
}()
done := make(chan bool)
quit := make(chan os.Signal, 1)
signal.Notify(quit, os.Interrupt)
go func() {
<-quit
log.Info("server is shutting down...")
close(done)
}()
go func() {
signerProcess := signer.NewSignerProcess(port)
signerProcess.MainLoop()
close(quit)
}()
<-done
log.Infoln("server stopped")
}

21
datastructures/common.go
View file

@ -2,27 +2,6 @@ package datastructures
import "encoding/binary"
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"
}
}
func encode24BitLength(data []byte) []byte {
lengthBytes := make([]byte, 4)
binary.BigEndian.PutUint32(lengthBytes, uint32(len(data)))

20
datastructures/signerrequest.go
View file

@ -3,14 +3,14 @@ package datastructures
import (
"bytes"
"encoding/binary"
"errors"
"fmt"
"time"
"git.cacert.org/cacert-gosigner/shared"
)
type SignerRequest struct {
Version uint8
Action Action
Action shared.Action
System uint8
Root uint8
Configuration uint8
@ -22,9 +22,7 @@ type SignerRequest struct {
Content3 string
}
const protocolVersion = 1
func SignerRequestFromData(lengthBytes []byte, blockData []byte, checkSum byte) (*SignerRequest, error) {
func SignerRequestFromData(blockData []byte) (*SignerRequest, error) {
headerLength := Decode24BitLength(blockData[0:3])
headerBytes := blockData[3 : 3+headerLength]
@ -40,13 +38,9 @@ func SignerRequestFromData(lengthBytes []byte, blockData []byte, checkSum byte)
content3Length := Decode24BitLength(contentBytes[content3Offset : content3Offset+3])
content3 := string(contentBytes[3+content3Offset : 3+content3Offset+content3Length])
calculated := CalculateXorCheckSum([][]byte{lengthBytes, blockData})
if checkSum != calculated {
return nil, errors.New(fmt.Sprintf("invalid checksum expected 0x%x got 0x%x", calculated, checkSum))
}
return &SignerRequest{
Version: headerBytes[0],
Action: Action(headerBytes[1]),
Action: shared.Action(headerBytes[1]),
System: headerBytes[2],
Root: headerBytes[3],
Configuration: headerBytes[4],
@ -79,8 +73,8 @@ func (r SignerRequest) Serialize() []byte {
func NewNulRequest() *SignerRequest {
return &SignerRequest{
Version: protocolVersion,
Action: ActionNul,
Version: shared.ProtocolVersion,
Action: shared.ActionNul,
Content1: time.Now().UTC().Format("010203042006.05"),
}
}

6
datastructures/signerresponse.go
View file

@ -4,11 +4,13 @@ import (
"bytes"
"errors"
"fmt"
"git.cacert.org/cacert-gosigner/shared"
)
type SignerResponse struct {
Version uint8
Action Action
Action shared.Action
Reserved1 uint8
Reserved2 uint8
Content1 string
@ -45,7 +47,7 @@ func SignerResponseFromData(lengthBytes []byte, blockData []byte, checkSum byte)
return &SignerResponse{
Version: headerBytes[0],
Action: Action(headerBytes[1]),
Action: shared.Action(headerBytes[1]),
Reserved1: headerBytes[2],
Reserved2: headerBytes[3],
Content1: content[0],

23
shared/io.go
View file

@ -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() {
sumRead := 0
for {
data := make([]byte, count)
if readBytes, err := (*port).Read(data); err != nil {
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)
}
return
if sumRead >= count {
break
}
}
}()
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
}

37
shared/shared.go
View file

@ -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"
}
}

90
signer/command_processor.go Normal file
View file

@ -0,0 +1,90 @@
package signer
import (
"errors"
"fmt"
"unsafe"
log "github.com/sirupsen/logrus"
"golang.org/x/sys/unix"
"git.cacert.org/cacert-gosigner/datastructures"
"git.cacert.org/cacert-gosigner/shared"
)
// The CommandProcessor takes parsed protocol data and executes the actual
// functionality.
type CommandProcessor struct {
}
// Process the signer request
func (p *CommandProcessor) Process(command datastructures.SignerRequest) (
response *datastructures.SignerResponse,
err error,
) {
log.Infof("analyze %+v", command)
switch command.Action {
case shared.ActionNul:
response, err = p.handleNulAction(command)
return
case shared.ActionSign:
response, err = p.handleSignAction(command)
return
case shared.ActionRevoke:
response, err = p.handleRevokeAction(command)
return
default:
return nil, errors.New(fmt.Sprintf(
"unsupported Action 0x%02x %s",
int(command.Action),
command.Action,
))
}
}
func (*CommandProcessor) handleNulAction(command datastructures.SignerRequest) (
*datastructures.SignerResponse,
error,
) {
var timeSpec unix.Timespec
err := unix.ClockGettime(unix.CLOCK_REALTIME, &timeSpec)
if err != nil {
log.Errorf("could not get system time: %v", err)
}
log.Debugf("current system time is %v", timeSpec)
// TODO: calculate the actual system time from the payload
_, _, e1 := unix.Syscall(
unix.SYS_CLOCK_SETTIME,
uintptr(unix.CLOCK_REALTIME),
uintptr(unsafe.Pointer(&timeSpec)),
0,
)
if e1 != 0 {
log.Errorf("could not set system time: %v", e1)
}
return &datastructures.SignerResponse{
Version: command.Version, Action: command.Action,
Content1: "", Content2: "", Content3: ""}, nil
}
func (p *CommandProcessor) handleSignAction(
command datastructures.SignerRequest,
) (
*datastructures.SignerResponse,
error,
) {
log.Debugf("handle sign call: %v", command)
return nil, errors.New("not implemented yet")
}
func (p *CommandProcessor) handleRevokeAction(
command datastructures.SignerRequest,
) (
*datastructures.SignerResponse,
error,
) {
log.Debugf("handle revoke call: %v", command)
return nil, errors.New("not implemented yet")
}

205
signer/main.go
View file

@ -1,205 +0,0 @@
package main
import (
"errors"
"flag"
"fmt"
"io"
"time"
log "github.com/sirupsen/logrus"
"go.bug.st/serial"
"git.cacert.org/cacert-gosigner/datastructures"
"git.cacert.org/cacert-gosigner/shared"
)
var (
address string
baudrate int
)
func main() {
flag.StringVar(&address, "a", "/dev/ttyUSB0", "address")
flag.IntVar(&baudrate, "b", 115200, "baud rate")
flag.Parse()
log.SetFormatter(&log.TextFormatter{
DisableColors: true,
FullTimestamp: true,
})
serialMode := &serial.Mode{
BaudRate: baudrate,
DataBits: 8,
StopBits: serial.OneStopBit,
Parity: serial.NoParity,
}
log.Infof("connecting to %s using %+v", address, serialMode)
port, err := serial.Open(address, serialMode)
if err != nil {
log.Fatalf("could not open serial port: %v", err)
}
log.Info("connected")
count := 0
defer func() {
err := port.Close()
if err != nil {
log.Fatalf("could not close port: %v", err)
}
log.Info("closed")
}()
readLoop:
for {
// timeout if no command has been received within 15 seconds
timeout := time.After(15 * time.Second)
commandChan := make(chan datastructures.SignerRequest, 1)
errChan := make(chan error, 1)
readWriteCloser := (io.ReadWriteCloser)(port)
go Receive(&readWriteCloser, &commandChan, &errChan)
select {
case command := <-commandChan:
response, err := Process(command)
if err != nil {
log.Errorf("error processing command: %v", err)
break readLoop
}
_ = SendResponse(&readWriteCloser, response)
case <-timeout:
log.Error("timeout in main loop")
break readLoop
case err := <-errChan:
log.Errorf("error from io goroutine %v", err)
}
count++
log.Infof("%d requests processed. Waiting for next request ...", count)
}
}
// Send a response to the client
func SendResponse(port *io.ReadWriteCloser, response *datastructures.SignerResponse) error {
if _, err := (*port).Write([]byte{0x02}); err != nil {
return err
}
if ack, err := shared.ReceiveBytes(port, 1, 5*time.Second); err != nil {
return err
} else if ack[0] != 0x10 {
return errors.New(fmt.Sprintf("invalid ack byte 0x%02x", ack[0]))
}
tryAgain := true
for tryAgain {
data := response.Serialize()
if _, err := (*port).Write(data); err != nil {
return err
}
checksum := datastructures.CalculateXorCheckSum([][]byte{data})
if _, err := (*port).Write([]byte{checksum}); err != nil {
return err
}
if _, err := (*port).Write([]byte(shared.MagicTrailer)); err != nil {
return err
}
if ack, err := shared.ReceiveBytes(port, 1, 5*time.Second); err != nil {
return err
} else if ack[0] == 0x10 {
tryAgain = false
} else if ack[0] != 0x11 {
return errors.New(fmt.Sprintf("invalid ack byte 0x%02x", ack[0]))
}
}
return nil
}
// Process the signer request
func Process(command datastructures.SignerRequest) (response *datastructures.SignerResponse, err error) {
log.Infof("analyze %+v", command)
switch command.Action {
case datastructures.ActionNul:
response, err = handleNulAction(command)
return
default:
return nil, errors.New(fmt.Sprintf(
"unsupported Action 0x%02x %s",
int(command.Action),
command.Action,
))
}
}
func handleNulAction(command datastructures.SignerRequest) (*datastructures.SignerResponse, error) {
// todo: generate script to set system time from command time data in command.content1
return &datastructures.SignerResponse{
Version: command.Version, Action: command.Action,
Content1: "", Content2: "", Content3: ""}, nil
}
// Receive a request and generate a request data structure
func Receive(port *io.ReadWriteCloser, commandChan *chan datastructures.SignerRequest, errorChan *chan error) {
header, err := shared.ReceiveBytes(port, 1, 20*time.Second)
if err != nil {
*errorChan <- err
return
}
if header[0] != shared.HandshakeByte {
*errorChan <- fmt.Errorf("unexpected byte 0x%x expected 0x%x", header[0], shared.HandshakeByte)
}
if _, err := (*port).Write([]byte{shared.AckByte}); err != nil {
*errorChan <- errors.New("could not write ACK")
return
}
lengthBytes, err := shared.ReceiveBytes(port, 3, 2*time.Second)
if err != nil {
*errorChan <- err
return
}
blockLength := datastructures.Decode24BitLength(lengthBytes)
blockData, err := shared.ReceiveBytes(port, blockLength, 5*time.Second)
if err != nil {
*errorChan <- err
return
}
checkSum, err := shared.ReceiveBytes(port, 1, 2*time.Second)
if err != nil {
*errorChan <- err
return
}
command, err := datastructures.SignerRequestFromData(lengthBytes, blockData, checkSum[0])
if err != nil {
*errorChan <- err
return
}
trailer, err := shared.ReceiveBytes(port, len(shared.MagicTrailer), 2*time.Second)
if err != nil {
*errorChan <- err
return
}
if string(trailer) != shared.MagicTrailer {
*errorChan <- errors.New("expected trailer bytes not found")
return
}
if _, err := (*port).Write([]byte{0x10}); err != nil {
*errorChan <- err
return
}
*commandChan <- *command
}

212
signer/port_handler.go Normal file
View file

@ -0,0 +1,212 @@
package signer
import (
"errors"
"fmt"
"io"
"time"
log "github.com/sirupsen/logrus"
"git.cacert.org/cacert-gosigner/datastructures"
"git.cacert.org/cacert-gosigner/shared"
)
const (
waitForHandShake = time.Second * 5
waitForInitialByte = time.Second * 20
waitForLengthBytes = time.Second * 2
waitForChecksumByte = time.Second * 2
waitForTrailerBytes = time.Second * 2
waitForBlock = time.Minute * 1
maxTriesPerBlock = 10_000
)
// The PortHandler takes care of reading and writing of raw bytes from/to a serial port
type PortHandler struct {
port io.ReadWriteCloser
processor *CommandProcessor
errors chan error
commandChan chan *datastructures.SignerRequest
}
func (p *PortHandler) MainLoop() {
count := 0
for {
go p.Receive()
select {
case command := <-p.commandChan:
if command == nil {
log.Infof("command channel has been closed. stopping execution.")
return
}
log.Debugf("received command %v", command)
response, err := p.processor.Process(*command)
if err != nil {
log.Errorf("error processing command: %v", err)
close(p.commandChan)
} else {
_ = p.SendResponse(response)
}
case err := <-p.errors:
log.Errorf("error from io goroutine %v", err)
}
count++
log.Infof("%d requests processed. Waiting for next request ...", count)
}
}
// Receive a request and generate a request data structure
func (p *PortHandler) Receive() {
header, err := shared.ReceiveBytes(p.port, 1, waitForInitialByte)
if err != nil {
p.errors <- err
return
}
if header[0] != shared.HandshakeByte {
p.errors <- fmt.Errorf(
"unexpected byte 0x%x expected 0x%x",
header[0],
shared.HandshakeByte,
)
return
}
tries := maxTriesPerBlock
var command *datastructures.SignerRequest
for {
if tries <= 0 {
p.errors <- errors.New("tried reading block too often")
break
}
tries--
if err := shared.SendBytes(p.port, []byte{shared.AckByte}); err != nil {
p.errors <- fmt.Errorf("could not write ACK byte: %v", err)
break
}
lengthBytes, err := shared.ReceiveBytes(p.port, shared.LengthFieldSize, waitForLengthBytes)
if err != nil {
p.errors <- fmt.Errorf("could not read lenght bytes: %v", err)
break
}
blockLength := datastructures.Decode24BitLength(lengthBytes)
blockData, err := shared.ReceiveBytes(p.port, blockLength, waitForBlock)
if err != nil {
p.errors <- fmt.Errorf("could not read data block: %v", err)
if !p.requestResend() {
break
}
continue
}
checkSum, err := shared.ReceiveBytes(p.port, shared.CheckSumFieldSize, waitForChecksumByte)
if err != nil {
p.errors <- fmt.Errorf("could not read checksum byte: %v", err)
break
}
calculated := datastructures.CalculateXorCheckSum([][]byte{lengthBytes, blockData})
if checkSum[0] != calculated {
p.errors <- fmt.Errorf("CRC error. expected 0x%02x, got 0x%02x", calculated, checkSum[0])
if !p.requestResend() {
break
}
continue
}
trailer, err := shared.ReceiveBytes(p.port, shared.TrailerFieldSize, waitForTrailerBytes)
if err != nil {
p.errors <- fmt.Errorf("could not read trailer bytes: %v", err)
break
}
if string(trailer) != shared.MagicTrailer {
p.errors <- fmt.Errorf(
"BROKEN block detected, expected trailer bytes '%s' not found, got '%s' instead",
shared.MagicTrailer,
trailer,
)
if !p.requestResend() {
break
}
continue
}
command, err = datastructures.SignerRequestFromData(blockData)
if err != nil {
p.errors <- fmt.Errorf("failed to parse block as signer request: %v", err)
break
}
if err := shared.SendBytes(p.port, []byte{shared.AckByte}); err != nil {
p.errors <- fmt.Errorf("failed to send ACK byte: %v", err)
break
}
p.commandChan <- command
break
}
}
func (p *PortHandler) requestResend() bool {
if err := shared.SendBytes(p.port, []byte{shared.ResendByte}); err != nil {
p.errors <- err
return false
}
return true
}
// Send a response to the client
func (p *PortHandler) SendResponse(response *datastructures.SignerResponse) error {
if err := shared.SendBytes(p.port, []byte{shared.HandshakeByte}); err != nil {
return err
}
if ack, err := shared.ReceiveBytes(p.port, 1, waitForHandShake); err != nil {
return err
} else if ack[0] != shared.AckByte {
return errors.New(fmt.Sprintf("invalid ack byte 0x%02x", ack[0]))
}
tryAgain := true
for tryAgain {
data := response.Serialize()
if err := shared.SendBytes(p.port, data); err != nil {
return err
}
checksum := datastructures.CalculateXorCheckSum([][]byte{data})
if err := shared.SendBytes(p.port, []byte{checksum}); err != nil {
return err
}
if err := shared.SendBytes(p.port, []byte(shared.MagicTrailer)); err != nil {
return err
}
if ack, err := shared.ReceiveBytes(p.port, 1, waitForHandShake); err != nil {
return err
} else if ack[0] == shared.AckByte {
tryAgain = false
} else if ack[0] != 0x11 {
return errors.New(fmt.Sprintf("invalid ack byte 0x%02x", ack[0]))
}
}
return nil
}
func NewSignerProcess(port io.ReadWriteCloser) *PortHandler {
errorChan := make(chan error)
return &PortHandler{
port: port,
errors: errorChan,
commandChan: make(chan *datastructures.SignerRequest, 1),
processor: &CommandProcessor{},
}
}