func TestBase58(t *testing.T) {
// Encode tests
for x, test := range stringTests {
tmp := []byte(test.in)
if res := base58.Encode(tmp); res != test.out {
t.Errorf("Encode test #%d failed: got: %s want: %s",
x, res, test.out)
continue
}
}
// Decode tests
for x, test := range hexTests {
b, err := hex.DecodeString(test.in)
if err != nil {
t.Errorf("hex.DecodeString failed failed #%d: got: %s", x, test.in)
continue
}
if res := base58.Decode(test.out); bytes.Equal(res, b) != true {
t.Errorf("Decode test #%d failed: got: %q want: %q",
x, res, test.in)
continue
}
}
// Decode with invalid input
for x, test := range invalidStringTests {
if res := base58.Decode(test.in); string(res) != test.out {
t.Errorf("Decode invalidString test #%d failed: got: %q want: %q",
x, res, test.out)
continue
}
}
}
// This example demonstrates how to decode modified base58 encoded data.
func ExampleDecode() {
// Decode example modified base58 encoded data.
encoded := "25JnwSn7XKfNQ"
decoded := base58.Decode(encoded)
// Show the decoded data.
fmt.Println("Decoded Data:", string(decoded))
// Output:
// Decoded Data: Test data
}
func BenchmarkBase58Decode(b *testing.B) {
b.StopTimer()
data := bytes.Repeat([]byte{0xff}, 5000)
encoded := base58.Encode(data)
b.SetBytes(int64(len(encoded)))
b.StartTimer()
for i := 0; i < b.N; i++ {
base58.Decode(encoded)
}
}
// NewKeyFromString returns a new extended key instance from a base58-encoded
// extended key.
func NewKeyFromString(key string) (*ExtendedKey, error) {
// The base58-decoded extended key must consist of a serialized payload
// plus an additional 4 bytes for the checksum.
decoded := base58.Decode(key)
if len(decoded) != serializedKeyLen+4 {
return nil, ErrInvalidKeyLen
}
// The serialized format is:
// version (4) || depth (1) || parent fingerprint (4)) ||
// child num (4) || chain code (32) || key data (33) || checksum (4)
// Split the payload and checksum up and ensure the checksum matches.
payload := decoded[:len(decoded)-4]
checkSum := decoded[len(decoded)-4:]
expectedCheckSum := wire.DoubleSha256(payload)[:4]
if !bytes.Equal(checkSum, expectedCheckSum) {
return nil, ErrBadChecksum
}
// Deserialize each of the payload fields.
version := payload[:4]
depth := uint16(payload[4:5][0])
parentFP := payload[5:9]
childNum := binary.BigEndian.Uint32(payload[9:13])
chainCode := payload[13:45]
keyData := payload[45:78]
// The key data is a private key if it starts with 0x00. Serialized
// compressed pubkeys either start with 0x02 or 0x03.
isPrivate := keyData[0] == 0x00
if isPrivate {
// Ensure the private key is valid. It must be within the range
// of the order of the secp256k1 curve and not be 0.
keyData = keyData[1:]
keyNum := new(big.Int).SetBytes(keyData)
if keyNum.Cmp(btcec.S256().N) >= 0 || keyNum.Sign() == 0 {
return nil, ErrUnusableSeed
}
} else {
// Ensure the public key parses correctly and is actually on the
// secp256k1 curve.
_, err := btcec.ParsePubKey(keyData, btcec.S256())
if err != nil {
return nil, err
}
}
return newExtendedKey(version, keyData, chainCode, parentFP, depth,
childNum, isPrivate), nil
}
// DecodeWIF creates a new WIF structure by decoding the string encoding of
// the import format.
//
// The WIF string must be a base58-encoded string of the following byte
// sequence:
//
// * 1 byte to identify the network, must be 0x80 for mainnet or 0xef for
// either testnet3 or the regression test network
// * 32 bytes of a binary-encoded, big-endian, zero-padded private key
// * Optional 1 byte (equal to 0x01) if the address being imported or exported
// was created by taking the RIPEMD160 after SHA256 hash of a serialized
// compressed (33-byte) public key
// * 4 bytes of checksum, must equal the first four bytes of the double SHA256
// of every byte before the checksum in this sequence
//
// If the base58-decoded byte sequence does not match this, DecodeWIF will
// return a non-nil error. ErrMalformedPrivateKey is returned when the WIF
// is of an impossible length or the expected compressed pubkey magic number
// does not equal the expected value of 0x01. ErrChecksumMismatch is returned
// if the expected WIF checksum does not match the calculated checksum.
func DecodeWIF(wif string) (*WIF, error) {
decoded := base58.Decode(wif)
decodedLen := len(decoded)
var compress bool
// Length of base58 decoded WIF must be 32 bytes + an optional 1 byte
// (0x01) if compressed, plus 1 byte for netID + 4 bytes of checksum.
switch decodedLen {
case 1 + btcec.PrivKeyBytesLen + 1 + 4:
if decoded[33] != compressMagic {
return nil, ErrMalformedPrivateKey
}
compress = true
case 1 + btcec.PrivKeyBytesLen + 4:
compress = false
default:
return nil, ErrMalformedPrivateKey
}
// Checksum is first four bytes of double SHA256 of the identifier byte
// and privKey. Verify this matches the final 4 bytes of the decoded
// private key.
var tosum []byte
if compress {
tosum = decoded[:1+btcec.PrivKeyBytesLen+1]
} else {
tosum = decoded[:1+btcec.PrivKeyBytesLen]
}
cksum := wire.DoubleSha256(tosum)[:4]
if !bytes.Equal(cksum, decoded[decodedLen-4:]) {
return nil, ErrChecksumMismatch
}
netID := decoded[0]
privKeyBytes := decoded[1 : 1+btcec.PrivKeyBytesLen]
privKey, _ := btcec.PrivKeyFromBytes(btcec.S256(), privKeyBytes)
return &WIF{privKey, compress, netID}, nil
}