forked from kaspanet/kaspad
/
serialization.go
148 lines (132 loc) · 4.58 KB
/
serialization.go
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package bip32
import (
"encoding/binary"
"github.com/Kash-Protocol/kashd/cmd/kashwallet/libkashwallet/bip32/base58"
"github.com/kaspanet/go-secp256k1"
"github.com/pkg/errors"
)
const (
versionSerializationLen = 4
depthSerializationLen = 1
fingerprintSerializationLen = 4
childNumberSerializationLen = 4
chainCodeSerializationLen = 32
keySerializationLen = 33
checkSumLen = 4
)
const extendedKeySerializationLen = versionSerializationLen +
depthSerializationLen +
fingerprintSerializationLen +
childNumberSerializationLen +
chainCodeSerializationLen +
keySerializationLen +
checkSumLen
// DeserializeExtendedKey deserialized the given base58 string and returns an extended key
func DeserializeExtendedKey(extKeyString string) (*ExtendedKey, error) {
serializedBytes := base58.Decode(extKeyString)
return deserializeExtendedPrivateKey(serializedBytes)
}
func deserializeExtendedPrivateKey(serialized []byte) (*ExtendedKey, error) {
if len(serialized) != extendedKeySerializationLen {
return nil, errors.Errorf("key length must be %d bytes but got %d", extendedKeySerializationLen, len(serialized))
}
err := validateChecksum(serialized)
if err != nil {
return nil, err
}
extKey := &ExtendedKey{}
copy(extKey.Version[:], serialized[:versionSerializationLen])
extKey.Depth = serialized[versionSerializationLen]
copy(extKey.ParentFingerprint[:], serialized[versionSerializationLen+depthSerializationLen:])
extKey.ChildNumber = binary.BigEndian.Uint32(
serialized[versionSerializationLen+depthSerializationLen+fingerprintSerializationLen:],
)
copy(
extKey.ChainCode[:],
serialized[versionSerializationLen+depthSerializationLen+fingerprintSerializationLen+childNumberSerializationLen:],
)
isPrivate := isPrivateVersion(extKey.Version)
if isPrivate {
privateKeyPadding := serialized[versionSerializationLen+
depthSerializationLen+
fingerprintSerializationLen+
childNumberSerializationLen+
chainCodeSerializationLen]
if privateKeyPadding != 0 {
return nil, errors.Errorf("expected 0 padding for private key but got %d", privateKeyPadding)
}
extKey.privateKey, err = secp256k1.DeserializeECDSAPrivateKeyFromSlice(serialized[versionSerializationLen+
depthSerializationLen+
fingerprintSerializationLen+
childNumberSerializationLen+
chainCodeSerializationLen+1 : versionSerializationLen+
depthSerializationLen+
fingerprintSerializationLen+
childNumberSerializationLen+
chainCodeSerializationLen+
keySerializationLen])
if err != nil {
return nil, err
}
} else {
extKey.publicKey, err = secp256k1.DeserializeECDSAPubKey(serialized[versionSerializationLen+
depthSerializationLen+
fingerprintSerializationLen+
childNumberSerializationLen+
chainCodeSerializationLen : versionSerializationLen+
depthSerializationLen+
fingerprintSerializationLen+
childNumberSerializationLen+
chainCodeSerializationLen+
keySerializationLen])
if err != nil {
return nil, err
}
}
return extKey, nil
}
func (extKey *ExtendedKey) serialize() ([]byte, error) {
var serialized [extendedKeySerializationLen]byte
copy(serialized[:], extKey.Version[:])
serialized[versionSerializationLen] = extKey.Depth
copy(serialized[versionSerializationLen+depthSerializationLen:], extKey.ParentFingerprint[:])
binary.BigEndian.PutUint32(
serialized[versionSerializationLen+depthSerializationLen+fingerprintSerializationLen:],
extKey.ChildNumber,
)
copy(
serialized[versionSerializationLen+depthSerializationLen+fingerprintSerializationLen+childNumberSerializationLen:],
extKey.ChainCode[:],
)
if extKey.IsPrivate() {
serialized[versionSerializationLen+depthSerializationLen+fingerprintSerializationLen+childNumberSerializationLen+chainCodeSerializationLen] = 0
copy(
serialized[versionSerializationLen+
depthSerializationLen+
fingerprintSerializationLen+
childNumberSerializationLen+
chainCodeSerializationLen+
1:],
extKey.privateKey.Serialize()[:],
)
} else {
publicKey, err := extKey.PublicKey()
if err != nil {
return nil, err
}
serializedPublicKey, err := publicKey.Serialize()
if err != nil {
return nil, err
}
copy(
serialized[versionSerializationLen+depthSerializationLen+fingerprintSerializationLen+childNumberSerializationLen+chainCodeSerializationLen:],
serializedPublicKey[:],
)
}
checkSum := doubleSha256(serialized[:len(serialized)-checkSumLen])
copy(
serialized[versionSerializationLen+depthSerializationLen+fingerprintSerializationLen+childNumberSerializationLen+chainCodeSerializationLen+keySerializationLen:],
checkSum,
)
return serialized[:], nil
}