func HashXdr(x interface{}) (Hash, error) {
var msg bytes.Buffer
_, err := xdr.Marshal(&msg, x)
if err != nil {
var zero Hash
return zero, err
}
return Hash(sha256.Sum256(msg.Bytes())), nil
}
// HashTransaction derives the network specific hash for the provided
// transaction using the network identified by the supplied passphrase. The
// resulting hash is the value that can be signed by stellar secret key to
// authorize the transaction identified by the hash to stellar validators.
func HashTransaction(tx *xdr.Transaction, passphrase string) ([32]byte, error) {
var txBytes bytes.Buffer
_, err := fmt.Fprintf(&txBytes, "%s", ID(passphrase))
if err != nil {
return [32]byte{}, errors.Wrap(err, "fprint network id failed")
}
_, err = xdr.Marshal(&txBytes, xdr.EnvelopeTypeEnvelopeTypeTx)
if err != nil {
return [32]byte{}, errors.Wrap(err, "marshal type failed")
}
_, err = xdr.Marshal(&txBytes, tx)
if err != nil {
return [32]byte{}, errors.Wrap(err, "marshal tx failed")
}
return hash.Hash(txBytes.Bytes()), nil
}
// Bytes encodes the builder's underlying envelope to XDR
func (b *TransactionEnvelopeBuilder) Bytes() ([]byte, error) {
if b.Err != nil {
return nil, b.Err
}
var txBytes bytes.Buffer
_, err := xdr.Marshal(&txBytes, b.E)
if err != nil {
return nil, err
}
return txBytes.Bytes(), nil
}
func WriteFramedXdr(out io.Writer, in interface{}) error {
var tmp bytes.Buffer
n, err := xdr.Marshal(&tmp, in)
un := uint32(n)
if un > 0x7fffffff {
return fmt.Errorf("Overlong write: %d bytes", n)
}
un = un | 0x80000000
binary.Write(out, binary.BigEndian, &un)
k, err := tmp.WriteTo(out)
if int64(n) != k {
return fmt.Errorf("Mismatched write length: %d vs. %d", n, k)
}
return err
}
func HashTxSet(txset *xdr.TransactionSet) (Hash, error) {
err := SortTxsForHash(txset)
var h Hash
if err != nil {
return h, err
}
hsh := sha256.New()
hsh.Write(txset.PreviousLedgerHash[:])
for _, env := range txset.Txs {
_, err := xdr.Marshal(hsh, &env)
if err != nil {
return h, err
}
}
sum := hsh.Sum([]byte{})
copy(h[:], sum[:])
return h, nil
}
// ExampleLowLevelTransaction creates and signs a simple transaction, and then
// encodes it into a hex string capable of being submitted to stellar-core.
//
// It uses the low-level xdr facilities to create the transaction.
func ExampleLowLevelTransaction() {
skp := keypair.MustParse("SA26PHIKZM6CXDGR472SSGUQQRYXM6S437ZNHZGRM6QA4FOPLLLFRGDX")
dkp := keypair.MustParse("SBQHO2IMYKXAYJFCWGXC7YKLJD2EGDPSK3IUDHVJ6OOTTKLSCK6Z6POM")
asset, err := xdr.NewAsset(xdr.AssetTypeAssetTypeNative, nil)
if err != nil {
panic(err)
}
var destination xdr.AccountId
err = destination.SetAddress(dkp.Address())
if err != nil {
panic(err)
}
op := xdr.PaymentOp{
Destination: destination,
Asset: asset,
Amount: 50 * 10000000,
}
memo, err := xdr.NewMemo(xdr.MemoTypeMemoNone, nil)
var source xdr.AccountId
err = source.SetAddress(skp.Address())
if err != nil {
panic(err)
}
body, err := xdr.NewOperationBody(xdr.OperationTypePayment, op)
if err != nil {
panic(err)
}
tx := xdr.Transaction{
SourceAccount: source,
Fee: 10,
SeqNum: xdr.SequenceNumber(1),
Memo: memo,
Operations: []xdr.Operation{
{Body: body},
},
}
var txBytes bytes.Buffer
_, err = xdr.Marshal(&txBytes, tx)
if err != nil {
panic(err)
}
txHash := hash.Hash(txBytes.Bytes())
signature, err := skp.Sign(txHash[:])
if err != nil {
panic(err)
}
ds := xdr.DecoratedSignature{
Hint: skp.Hint(),
Signature: xdr.Signature(signature[:]),
}
txe := xdr.TransactionEnvelope{
Tx: tx,
Signatures: []xdr.DecoratedSignature{ds},
}
var txeBytes bytes.Buffer
_, err = xdr.Marshal(&txeBytes, txe)
if err != nil {
panic(err)
}
txeB64 := base64.StdEncoding.EncodeToString(txeBytes.Bytes())
fmt.Printf("tx base64: %s", txeB64)
// Output: tx base64: AAAAAAU08yUQ8sHqhY8j9mXWwERfHC/3cKFSe/spAr0rGtO2AAAACgAAAAAAAAABAAAAAAAAAAAAAAABAAAAAAAAAAEAAAAA+fnTe7/v4whpBUx96oj92jfZPz7S00l3O2xeyeqWIA0AAAAAAAAAAB3NZQAAAAAAAAAAASsa07YAAABAieruUIGcQH6RlQ+prYflPFU3nED2NvWhtaC+tgnKsqgiKURK4xo/W7EgH0+I6aQok52awbE+ksOxEQ5MLJ9eAw==
}
func TestXdrDecode(t *testing.T) {
xdrbytes := []byte{
0, 0, 0, 0, // entry type 0, liveentry
0, 32, 223, 100, // lastmodified 2154340
0, 0, 0, 0, // entry type 0, account
0, 0, 0, 0, // key type 0
23, 140, 68, 253, // ed25519 key (32 bytes)
184, 162, 186, 195,
118, 239, 158, 210,
100, 241, 174, 254,
108, 110, 165, 140,
75, 76, 83, 141,
104, 212, 227, 80,
1, 214, 157, 7,
0, 0, 0, 29, // 64bit balance: 125339976000
46, 216, 65, 64,
0, 0, 129, 170, // 64bit seqnum: 142567144423475
0, 0, 0, 51,
0, 0, 0, 1, // numsubentries: 1
0, 0, 0, 1, // inflationdest type, populated
0, 0, 0, 0, // key type 0
87, 240, 19, 71, // ed25519 key (32 bytes)
52, 91, 9, 62,
213, 239, 178, 85,
161, 119, 108, 251,
168, 90, 76, 116,
12, 48, 134, 248,
115, 255, 117, 50,
19, 18, 170, 203,
0, 0, 0, 0, // flags
0, 0, 0, 19, // homedomain: 19 bytes + 1 null padding
99, 101, 110, 116, // "centaurus.xcoins.de"
97, 117, 114, 117,
115, 46, 120, 99,
111, 105, 110, 115,
46, 100, 101, 0,
1, 0, 0, 0, // thresholds
0, 0, 0, 0, // signers (null)
0, 0, 0, 0, // entry.account.ext.v: 0
0, 0, 0, 0, // entry.ext.v: 0
}
assert.Equal(t, len(xdrbytes), 152)
var tmp xdr.BucketEntry
n, err := xdr.Unmarshal(bytes.NewReader(xdrbytes[:]), &tmp)
fmt.Printf("Decoded %d bytes\n", n)
if err != nil {
panic(err)
}
assert.Equal(t, len(xdrbytes), n)
var out bytes.Buffer
n, err = xdr.Marshal(&out, &tmp)
fmt.Printf("Encoded %d bytes\n", n)
if err != nil {
panic(err)
}
assert.Equal(t, out.Len(), n)
assert.Equal(t, out.Bytes(), xdrbytes)
}