72 lines
1.9 KiB
Go
72 lines
1.9 KiB
Go
package datastructures
|
|
|
|
import (
|
|
"bytes"
|
|
"errors"
|
|
"fmt"
|
|
|
|
"git.cacert.org/cacert-gosigner/shared"
|
|
)
|
|
|
|
type SignerResponse struct {
|
|
Version uint8
|
|
Action shared.Action
|
|
Reserved1 uint8
|
|
Reserved2 uint8
|
|
Content1 string
|
|
Content2 string
|
|
Content3 string
|
|
}
|
|
|
|
func SignerResponseFromData(lengthBytes []byte, blockData []byte, checkSum byte) (*SignerResponse, error) {
|
|
if len(blockData) < 3 {
|
|
return nil, errors.New("begin of structure corrupt")
|
|
}
|
|
|
|
offset := 0
|
|
headerLength := Decode24BitLength(blockData[offset : offset+3])
|
|
offset += 3
|
|
headerBytes := blockData[offset : offset+headerLength]
|
|
offset += headerLength
|
|
|
|
content := make([]string, 3)
|
|
for offset < len(blockData) {
|
|
dataLength := Decode24BitLength(blockData[offset : offset+3])
|
|
if len(blockData)-3 < dataLength {
|
|
return nil, errors.New("structure cut off")
|
|
}
|
|
offset += 3
|
|
content = append(content, string(blockData[offset:offset+dataLength]))
|
|
offset += dataLength
|
|
}
|
|
|
|
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 &SignerResponse{
|
|
Version: headerBytes[0],
|
|
Action: shared.Action(headerBytes[1]),
|
|
Reserved1: headerBytes[2],
|
|
Reserved2: headerBytes[3],
|
|
Content1: content[0],
|
|
Content2: content[1],
|
|
Content3: content[2],
|
|
}, nil
|
|
}
|
|
|
|
func (r SignerResponse) Serialize() []byte {
|
|
headerBytes := []byte{r.Version, byte(r.Action), r.Reserved1, r.Reserved2}
|
|
content1Bytes := []byte(r.Content1)
|
|
content2Bytes := []byte(r.Content2)
|
|
content3Bytes := []byte(r.Content3)
|
|
blockBytes := bytes.Join([][]byte{
|
|
encode24BitLength(headerBytes), headerBytes,
|
|
encode24BitLength(content1Bytes), content1Bytes,
|
|
encode24BitLength(content2Bytes), content2Bytes,
|
|
encode24BitLength(content3Bytes), content3Bytes,
|
|
}, []byte{})
|
|
return bytes.Join([][]byte{encode24BitLength(blockBytes), blockBytes}, []byte{})
|
|
}
|