ceremonyclient/go-libp2p/core/pnet/codec.go

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2023-08-21 03:50:38 +00:00
package pnet
import (
"bufio"
"bytes"
"encoding/base64"
"encoding/hex"
"fmt"
"io"
)
var (
pathPSKv1 = []byte("/key/swarm/psk/1.0.0/")
pathBin = "/bin/"
pathBase16 = "/base16/"
pathBase64 = "/base64/"
)
func readHeader(r *bufio.Reader) ([]byte, error) {
header, err := r.ReadBytes('\n')
if err != nil {
return nil, err
}
return bytes.TrimRight(header, "\r\n"), nil
}
func expectHeader(r *bufio.Reader, expected []byte) error {
header, err := readHeader(r)
if err != nil {
return err
}
if !bytes.Equal(header, expected) {
return fmt.Errorf("expected file header %s, got: %s", expected, header)
}
return nil
}
// DecodeV1PSK reads a Multicodec encoded V1 PSK.
func DecodeV1PSK(in io.Reader) (PSK, error) {
reader := bufio.NewReader(in)
if err := expectHeader(reader, pathPSKv1); err != nil {
return nil, err
}
header, err := readHeader(reader)
if err != nil {
return nil, err
}
var decoder io.Reader
switch string(header) {
case pathBase16:
decoder = hex.NewDecoder(reader)
case pathBase64:
decoder = base64.NewDecoder(base64.StdEncoding, reader)
case pathBin:
decoder = reader
default:
return nil, fmt.Errorf("unknown encoding: %s", header)
}
out := make([]byte, 32)
if _, err = io.ReadFull(decoder, out[:]); err != nil {
return nil, err
}
return out, nil
}