func TestBase58(t *testing.T) {
// Base58Encode tests
for x, test := range stringTests {
tmp := []byte(test.in)
if res := btcutil.Base58Encode(tmp); res != test.out {
t.Errorf("Base58Encode test #%d failed: got: %s want: %s",
x, res, test.out)
continue
}
}
// Base58Decode 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 := btcutil.Base58Decode(test.out); bytes.Equal(res, b) != true {
t.Errorf("Base58Decode test #%d failed: got: %q want: %q",
x, res, test.in)
continue
}
}
// Base58Decode with invalid input
for x, test := range invalidStringTests {
if res := btcutil.Base58Decode(test.in); string(res) != test.out {
t.Errorf("Base58Decode invalidString test #%d failed: got: %q want: %q",
x, res, test.out)
continue
}
}
}
// 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 := btcutil.Base58Decode(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 := btcwire.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
}