Java tutorial
/* * Copyright 2014 the original author or authors. * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. */ package de.schildbach.wallet.util; import java.math.BigInteger; import java.util.ArrayList; import java.util.List; import javax.annotation.Nonnull; import javax.annotation.Nullable; import org.bitcoin.protocols.payments.Protos; import com.google.bitcoin.core.Address; import com.google.bitcoin.core.ScriptException; import com.google.bitcoin.core.Transaction; import com.google.bitcoin.protocols.payments.PaymentRequestException; import com.google.bitcoin.protocols.payments.PaymentSession; import com.google.bitcoin.protocols.payments.PaymentSession.PkiVerificationData; import com.google.bitcoin.script.Script; import com.google.bitcoin.script.ScriptBuilder; import com.google.common.hash.Hashing; import com.google.protobuf.ByteString; import com.google.protobuf.InvalidProtocolBufferException; import com.google.protobuf.UninitializedMessageException; import de.schildbach.wallet.Constants; import de.schildbach.wallet.data.PaymentIntent; /** * @author Andreas Schildbach */ public final class PaymentProtocol { public static final String MIMETYPE_PAYMENTREQUEST = "application/bitcoin-paymentrequest"; // BIP 71 public static final String MIMETYPE_PAYMENT = "application/bitcoin-payment"; // BIP 71 public static final String MIMETYPE_PAYMENTACK = "application/bitcoin-paymentack"; // BIP 71 public static Protos.PaymentRequest createPaymentRequest(final BigInteger amount, @Nonnull final Address toAddress, final String memo, final String paymentUrl) { if (amount != null && amount.compareTo(BigInteger.valueOf(Long.MAX_VALUE)) > 0) throw new IllegalArgumentException("amount too big for protobuf: " + amount); final Protos.Output.Builder output = Protos.Output.newBuilder(); output.setAmount(amount != null ? amount.longValue() : 0); output.setScript(ByteString.copyFrom(ScriptBuilder.createOutputScript(toAddress).getProgram())); final Protos.PaymentDetails.Builder paymentDetails = Protos.PaymentDetails.newBuilder(); paymentDetails.setNetwork(Constants.NETWORK_PARAMETERS.getPaymentProtocolId()); paymentDetails.addOutputs(output); if (memo != null) paymentDetails.setMemo(memo); if (paymentUrl != null) paymentDetails.setPaymentUrl(paymentUrl); paymentDetails.setTime(System.currentTimeMillis()); final Protos.PaymentRequest.Builder paymentRequest = Protos.PaymentRequest.newBuilder(); paymentRequest.setSerializedPaymentDetails(paymentDetails.build().toByteString()); return paymentRequest.build(); } public static PaymentIntent parsePaymentRequest(@Nonnull final byte[] serializedPaymentRequest) throws PaymentRequestException { try { if (serializedPaymentRequest.length > 50000) throw new PaymentRequestException("payment request too big: " + serializedPaymentRequest.length); final Protos.PaymentRequest paymentRequest = Protos.PaymentRequest.parseFrom(serializedPaymentRequest); final String pkiName; final String pkiOrgName; final String pkiCaName; if (!"none".equals(paymentRequest.getPkiType())) { // implicitly verify PKI signature final PkiVerificationData verificationData = new PaymentSession(paymentRequest, true).pkiVerificationData; pkiName = verificationData.name; pkiOrgName = verificationData.orgName; pkiCaName = verificationData.rootAuthorityName; } else { pkiName = null; pkiOrgName = null; pkiCaName = null; } if (paymentRequest.getPaymentDetailsVersion() != 1) throw new PaymentRequestException.InvalidVersion( "cannot handle payment details version: " + paymentRequest.getPaymentDetailsVersion()); final Protos.PaymentDetails paymentDetails = Protos.PaymentDetails.newBuilder() .mergeFrom(paymentRequest.getSerializedPaymentDetails()).build(); final long currentTimeSecs = System.currentTimeMillis() / 1000; if (paymentDetails.hasExpires() && currentTimeSecs >= paymentDetails.getExpires()) throw new PaymentRequestException.Expired("payment details expired: current time " + currentTimeSecs + " after expiry time " + paymentDetails.getExpires()); if (!paymentDetails.getNetwork().equals(Constants.NETWORK_PARAMETERS.getPaymentProtocolId())) throw new PaymentRequestException.InvalidNetwork( "cannot handle payment request network: " + paymentDetails.getNetwork()); final ArrayList<PaymentIntent.Output> outputs = new ArrayList<PaymentIntent.Output>( paymentDetails.getOutputsCount()); for (final Protos.Output output : paymentDetails.getOutputsList()) outputs.add(parseOutput(output)); final String memo = paymentDetails.hasMemo() ? paymentDetails.getMemo() : null; final String paymentUrl = paymentDetails.hasPaymentUrl() ? paymentDetails.getPaymentUrl() : null; final byte[] merchantData = paymentDetails.hasMerchantData() ? paymentDetails.getMerchantData().toByteArray() : null; final byte[] paymentRequestHash = Hashing.sha256().hashBytes(serializedPaymentRequest).asBytes(); final PaymentIntent paymentIntent = new PaymentIntent(PaymentIntent.Standard.BIP70, pkiName, pkiOrgName, pkiCaName, outputs.toArray(new PaymentIntent.Output[0]), memo, paymentUrl, merchantData, null, paymentRequestHash); if (paymentIntent.hasPaymentUrl() && !paymentIntent.isSupportedPaymentUrl()) throw new PaymentRequestException.InvalidPaymentURL( "cannot handle payment url: " + paymentIntent.paymentUrl); return paymentIntent; } catch (final InvalidProtocolBufferException x) { throw new PaymentRequestException(x); } catch (final UninitializedMessageException x) { throw new PaymentRequestException(x); } } private static PaymentIntent.Output parseOutput(@Nonnull final Protos.Output output) throws PaymentRequestException.InvalidOutputs { try { final BigInteger amount = BigInteger.valueOf(output.getAmount()); final Script script = new Script(output.getScript().toByteArray()); return new PaymentIntent.Output(amount, script); } catch (final ScriptException x) { throw new PaymentRequestException.InvalidOutputs("unparseable script in output: " + output.toString()); } } public static Protos.Payment createPaymentMessage(@Nonnull final Transaction transaction, @Nullable final Address refundAddress, @Nullable final BigInteger refundAmount, @Nullable final String memo, @Nullable final byte[] merchantData) { final Protos.Payment.Builder builder = Protos.Payment.newBuilder(); builder.addTransactions(ByteString.copyFrom(transaction.unsafeBitcoinSerialize())); if (refundAddress != null) { if (refundAmount.compareTo(BigInteger.valueOf(Long.MAX_VALUE)) > 0) throw new IllegalArgumentException("refund amount too big for protobuf: " + refundAmount); final Protos.Output.Builder refundOutput = Protos.Output.newBuilder(); refundOutput.setAmount(refundAmount.longValue()); refundOutput .setScript(ByteString.copyFrom(ScriptBuilder.createOutputScript(refundAddress).getProgram())); builder.addRefundTo(refundOutput); } if (memo != null) builder.setMemo(memo); if (merchantData != null) builder.setMerchantData(ByteString.copyFrom(merchantData)); return builder.build(); } public static List<Transaction> parsePaymentMessage(final Protos.Payment paymentMessage) { final List<Transaction> transactions = new ArrayList<Transaction>(paymentMessage.getTransactionsCount()); for (final ByteString transaction : paymentMessage.getTransactionsList()) transactions.add(new Transaction(Constants.NETWORK_PARAMETERS, transaction.toByteArray())); return transactions; } public static Protos.PaymentACK createPaymentAck(@Nonnull final Protos.Payment paymentMessage, @Nullable final String memo) { final Protos.PaymentACK.Builder builder = Protos.PaymentACK.newBuilder(); builder.setPayment(paymentMessage); builder.setMemo(memo); return builder.build(); } public static String parsePaymentAck(@Nonnull final Protos.PaymentACK paymentAck) { final String memo = paymentAck.hasMemo() ? paymentAck.getMemo() : null; return memo; } }