// 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() {
spub, spriv, err := GenerateKeyFromSeed("s3Fy8h5LEcYVE8aofthKWHeJpygbntw5HgcekFw93K6XqTW4gEx")
if err != nil {
log.Fatal(err)
}
dpub, _, err := GenerateKeyFromSeed("sfkPCKA6XgaeHZH3NE57i3QrjVcw61c1noWQCgnHa6KJP2BrbXD")
if err != nil {
log.Fatal(err)
}
op := xdr.PaymentOp{
Destination: dpub.KeyData(),
Currency: xdr.NewCurrencyCurrencyTypeNative(),
Amount: 50 * 10000000,
}
tx := xdr.Transaction{
SourceAccount: spub.KeyData(),
Fee: 10,
SeqNum: xdr.SequenceNumber(1),
Memo: xdr.NewMemoMemoNone(),
Operations: []xdr.Operation{
{Body: xdr.NewOperationBodyPayment(op)},
},
}
var txBytes bytes.Buffer
_, err = xdr.Marshal(&txBytes, tx)
if err != nil {
log.Fatal(err)
}
txHash := Hash(txBytes.Bytes())
signature := spriv.Sign(txHash[:])
ds := xdr.DecoratedSignature{
Hint: spriv.Hint(),
Signature: xdr.Uint512(signature),
}
txe := xdr.TransactionEnvelope{
Tx: tx,
Signatures: []xdr.DecoratedSignature{ds},
}
var txeBytes bytes.Buffer
_, err = xdr.Marshal(&txeBytes, txe)
if err != nil {
log.Fatal(err)
}
txeHex := hex.EncodeToString(txeBytes.Bytes())
fmt.Printf("tx hex: %s", txeHex)
// Output: tx hex: 3658fe7598d20c7a6de3297f84bc52bd2a1ec8c0f1f6c5b41cc1c7571b4331f00000000a000000000000000100000000000000000000000100000000000000012d24692ed08bbf679ba199448870d2191e876fecd92fdd9f6d274da4e6de134100000000000000001dcd650000000001dd302d0c0cee527cf02f6a0aec6916966298712914c63e3c57de74a6e27c29ea234a555fcc36533417afe4e1147815a42529fbca3429bc7caf0a06dc6b383ca6e9d4d80f
}
// MutateTransactionEnvelope adds a signature to the provided envelope
func (m Sign) MutateTransactionEnvelope(txe *xdr.TransactionEnvelope) error {
tb := TransactionBuilder{TX: txe.Tx}
hash, err := tb.Hash()
if err != nil {
return err
}
if m.Key == nil {
return errors.New("Invalid key")
}
sig := m.Key.Sign(hash[:])
ds := xdr.DecoratedSignature{
Hint: m.Key.Hint(),
Signature: xdr.Uint512(sig),
}
txe.Signatures = append(txe.Signatures, ds)
return nil
}