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 }