package protocol import ( "bytes" "crypto/sha256" "encoding/base32" "errors" "fmt" "regexp" "strings" "github.com/calmh/syncthing/luhn" ) type NodeID [32]byte var LocalNodeID = NodeID{0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff} // NewNodeID generates a new node ID from the raw bytes of a certificate func NewNodeID(rawCert []byte) NodeID { var n NodeID hf := sha256.New() hf.Write(rawCert) hf.Sum(n[:0]) return n } func NodeIDFromString(s string) (NodeID, error) { var n NodeID err := n.UnmarshalText([]byte(s)) return n, err } func NodeIDFromBytes(bs []byte) NodeID { var n NodeID if len(bs) != len(n) { panic("incorrect length of byte slice representing node ID") } copy(n[:], bs) return n } // String returns the canonical string representation of the node ID func (n NodeID) String() string { id := base32.StdEncoding.EncodeToString(n[:]) id = strings.Trim(id, "=") id, err := luhnify(id) if err != nil { // Should never happen panic(err) } id = chunkify(id) return id } func (n NodeID) GoString() string { return n.String() } func (n NodeID) Compare(other NodeID) int { return bytes.Compare(n[:], other[:]) } func (n NodeID) Equals(other NodeID) bool { return bytes.Compare(n[:], other[:]) == 0 } func (n *NodeID) MarshalText() ([]byte, error) { return []byte(n.String()), nil } func (n *NodeID) UnmarshalText(bs []byte) error { id := string(bs) id = strings.Trim(id, "=") id = strings.ToUpper(id) id = untypeoify(id) id = unchunkify(id) var err error switch len(id) { case 56: // New style, with check digits id, err = unluhnify(id) if err != nil { return err } fallthrough case 52: // Old style, no check digits dec, err := base32.StdEncoding.DecodeString(id + "====") if err != nil { return err } copy(n[:], dec) return nil default: return errors.New("node ID invalid: incorrect length") } } func luhnify(s string) (string, error) { if len(s) != 52 { panic("unsupported string length") } res := make([]string, 0, 4) for i := 0; i < 4; i++ { p := s[i*13 : (i+1)*13] l, err := luhn.Base32.Generate(p) if err != nil { return "", err } res = append(res, fmt.Sprintf("%s%c", p, l)) } return res[0] + res[1] + res[2] + res[3], nil } func unluhnify(s string) (string, error) { if len(s) != 56 { return "", fmt.Errorf("unsupported string length %d", len(s)) } res := make([]string, 0, 4) for i := 0; i < 4; i++ { p := s[i*14 : (i+1)*14-1] l, err := luhn.Base32.Generate(p) if err != nil { return "", err } if g := fmt.Sprintf("%s%c", p, l); g != s[i*14:(i+1)*14] { return "", errors.New("check digit incorrect") } res = append(res, p) } return res[0] + res[1] + res[2] + res[3], nil } func chunkify(s string) string { s = regexp.MustCompile("(.{7})").ReplaceAllString(s, "$1-") s = strings.Trim(s, "-") return s } func unchunkify(s string) string { s = strings.Replace(s, "-", "", -1) s = strings.Replace(s, " ", "", -1) return s } func untypeoify(s string) string { s = strings.Replace(s, "0", "O", -1) s = strings.Replace(s, "1", "I", -1) s = strings.Replace(s, "8", "B", -1) return s }