42d1e6e991
Add a main loop, move I/O code into io.go, move configuration into config.go. Use shared.Decode24BitLength instead of manually decoding block lengths. Fix response block decoding and checksum validation. Add constants for commonly used byte values and use these in the signer and the client.
87 lines
2.7 KiB
Go
87 lines
2.7 KiB
Go
package datastructures
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import (
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"bytes"
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"encoding/binary"
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"errors"
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"fmt"
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"time"
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)
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type SignerRequest struct {
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Version uint8
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Action Action
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System uint8
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Root uint8
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Configuration uint8
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Parameter1 uint8
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Parameter2 uint16
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Parameter3 uint8
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Content1 string
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Content2 string
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Content3 string
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}
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const protocolVersion = 1
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func SignerRequestFromData(lengthBytes []byte, blockData []byte, checkSum byte) (*SignerRequest, error) {
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headerLength := Decode24BitLength(blockData[0:3])
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headerBytes := blockData[3 : 3+headerLength]
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contentBytes := blockData[3+headerLength:]
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content1Length := Decode24BitLength(contentBytes[0:3])
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content1 := string(contentBytes[3 : 3+content1Length])
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content2Offset := 3 + content1Length
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content2Length := Decode24BitLength(contentBytes[content2Offset : content2Offset+3])
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content2 := string(contentBytes[3+content2Offset : 3+content2Offset+content2Length])
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content3Offset := 3 + content2Offset + content2Length
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content3Length := Decode24BitLength(contentBytes[content3Offset : content3Offset+3])
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content3 := string(contentBytes[3+content3Offset : 3+content3Offset+content3Length])
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calculated := CalculateXorCheckSum([][]byte{lengthBytes, blockData})
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if checkSum != calculated {
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return nil, errors.New(fmt.Sprintf("invalid checksum expected 0x%x got 0x%x", calculated, checkSum))
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}
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return &SignerRequest{
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Version: headerBytes[0],
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Action: Action(headerBytes[1]),
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System: headerBytes[2],
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Root: headerBytes[3],
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Configuration: headerBytes[4],
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Parameter1: headerBytes[5],
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Parameter2: binary.BigEndian.Uint16([]byte{headerBytes[6], headerBytes[7]}),
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Parameter3: headerBytes[8],
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Content1: content1,
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Content2: content2,
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Content3: content3,
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}, nil
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}
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func (r SignerRequest) Serialize() []byte {
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parameter2Bytes := make([]byte, 2)
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binary.BigEndian.PutUint16(parameter2Bytes, r.Parameter2)
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headerBytes := bytes.Join([][]byte{
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{r.Version, byte(r.Action), r.System, r.Root, r.Configuration, r.Parameter1},
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parameter2Bytes, {r.Parameter3}}, []byte{})
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content1Bytes := []byte(r.Content1)
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content2Bytes := []byte(r.Content2)
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content3Bytes := []byte(r.Content3)
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blockBytes := bytes.Join([][]byte{
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encode24BitLength(headerBytes), headerBytes,
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encode24BitLength(content1Bytes), content1Bytes,
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encode24BitLength(content2Bytes), content2Bytes,
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encode24BitLength(content3Bytes), content3Bytes,
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}, []byte{})
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return bytes.Join([][]byte{encode24BitLength(blockBytes), blockBytes}, []byte{})
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}
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func NewNulRequest() *SignerRequest {
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return &SignerRequest{
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Version: protocolVersion,
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Action: ActionNul,
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Content1: time.Now().UTC().Format("010203042006.05"),
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}
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}
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