func TestEncodeDecodeWIF(t *testing.T) {
priv1, _ := btcec.PrivKeyFromBytes(btcec.S256(), []byte{
0x0c, 0x28, 0xfc, 0xa3, 0x86, 0xc7, 0xa2, 0x27,
0x60, 0x0b, 0x2f, 0xe5, 0x0b, 0x7c, 0xae, 0x11,
0xec, 0x86, 0xd3, 0xbf, 0x1f, 0xbe, 0x47, 0x1b,
0xe8, 0x98, 0x27, 0xe1, 0x9d, 0x72, 0xaa, 0x1d})
priv2, _ := btcec.PrivKeyFromBytes(btcec.S256(), []byte{
0xdd, 0xa3, 0x5a, 0x14, 0x88, 0xfb, 0x97, 0xb6,
0xeb, 0x3f, 0xe6, 0xe9, 0xef, 0x2a, 0x25, 0x81,
0x4e, 0x39, 0x6f, 0xb5, 0xdc, 0x29, 0x5f, 0xe9,
0x94, 0xb9, 0x67, 0x89, 0xb2, 0x1a, 0x03, 0x98})
wif1, err := NewWIF(priv1, &btcnet.MainNetParams, false)
if err != nil {
t.Fatal(err)
}
wif2, err := NewWIF(priv2, &btcnet.TestNet3Params, true)
if err != nil {
t.Fatal(err)
}
tests := []struct {
wif *WIF
encoded string
}{
{
wif1,
"5HueCGU8rMjxEXxiPuD5BDku4MkFqeZyd4dZ1jvhTVqvbTLvyTJ",
},
{
wif2,
"cV1Y7ARUr9Yx7BR55nTdnR7ZXNJphZtCCMBTEZBJe1hXt2kB684q",
},
}
for _, test := range tests {
// Test that encoding the WIF structure matches the expected string.
s := test.wif.String()
if s != test.encoded {
t.Errorf("TestEncodeDecodePrivateKey failed: want '%s', got '%s'",
test.encoded, s)
continue
}
// Test that decoding the expected string results in the original WIF
// structure.
w, err := DecodeWIF(test.encoded)
if err != nil {
t.Error(err)
continue
}
if got := w.String(); got != test.encoded {
t.Errorf("NewWIF failed: want '%v', got '%v'", test.wif, got)
}
}
}
// ECPrivKey converts the extended key to a btcec private key and returns it.
// As you might imagine this is only possible if the extended key is a private
// extended key (as determined by the IsPrivate function). The ErrNotPrivExtKey
// error will be returned if this function is called on a public extended key.
func (k *ExtendedKey) ECPrivKey() (*btcec.PrivateKey, error) {
if !k.isPrivate {
return nil, ErrNotPrivExtKey
}
privKey, _ := btcec.PrivKeyFromBytes(btcec.S256(), k.key)
return privKey, 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 := Base58Decode(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 := btcwire.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
}