From 39575e85420bd57bc3a7a4aa7c9f09902ec08b97 Mon Sep 17 00:00:00 2001 From: CalDescent Date: Sat, 22 May 2021 10:09:28 +0100 Subject: [PATCH] Added /refund/LITECOIN/{ataddress} API This is designed to be called by the buyer, and will force refund their P2SH transaction associated with the supplied AT. The tradebot responsible for this trade must be present in the user's db for this API access the necessary data. It must be called after lockTime has passed, which for LTC is currently 60 minutes from the time that the P2SH was funded. Trying to refund before this time will result in a FOREIGN_BLOCKCHAIN_TOO_SOON error. --- .../api/resource/CrossChainHtlcResource.java | 97 ++++++++++++++++++- 1 file changed, 95 insertions(+), 2 deletions(-) diff --git a/src/main/java/org/qortal/api/resource/CrossChainHtlcResource.java b/src/main/java/org/qortal/api/resource/CrossChainHtlcResource.java index 415a7f3a..92091896 100644 --- a/src/main/java/org/qortal/api/resource/CrossChainHtlcResource.java +++ b/src/main/java/org/qortal/api/resource/CrossChainHtlcResource.java @@ -28,6 +28,7 @@ import org.qortal.api.model.CrossChainBitcoinyHTLCStatus; import org.qortal.crosschain.*; import org.qortal.data.at.ATData; import org.qortal.data.crosschain.CrossChainTradeData; +import org.qortal.data.crosschain.TradeBotData; import org.qortal.repository.DataException; import org.qortal.repository.Repository; import org.qortal.repository.RepositoryManager; @@ -174,8 +175,6 @@ public class CrossChainHtlcResource { } } - // TODO: refund - @GET @Path("/redeem/LITECOIN/{ataddress}/{tradePrivateKey}/{secret}/{receivingAddress}") @Operation( @@ -282,6 +281,100 @@ public class CrossChainHtlcResource { return false; } + @GET + @Path("/refund/LITECOIN/{ataddress}") + @Operation( + summary = "Refunds HTLC associated with supplied AT", + responses = { + @ApiResponse( + content = @Content(mediaType = MediaType.TEXT_PLAIN, schema = @Schema(type = "boolean")) + ) + } + ) + @ApiErrors({ApiError.INVALID_CRITERIA, ApiError.INVALID_ADDRESS, ApiError.ADDRESS_UNKNOWN}) + public boolean refundHtlc(@PathParam("ataddress") String atAddress) { + Security.checkApiCallAllowed(request); + + try (final Repository repository = RepositoryManager.getRepository()) { + ATData atData = repository.getATRepository().fromATAddress(atAddress); + if (atData == null) + throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.ADDRESS_UNKNOWN); + + ACCT acct = SupportedBlockchain.getAcctByCodeHash(atData.getCodeHash()); + if (acct == null) + throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_CRITERIA); + + CrossChainTradeData crossChainTradeData = acct.populateTradeData(repository, atData); + if (crossChainTradeData == null) + throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_CRITERIA); + + List allTradeBotData = repository.getCrossChainRepository().getAllTradeBotData(); + TradeBotData tradeBotData = allTradeBotData.stream().filter(tradeBotDataItem -> tradeBotDataItem.getAtAddress().equals(atAddress)).findFirst().orElse(null); + if (tradeBotData == null) + throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.INVALID_CRITERIA); + + + int lockTime = tradeBotData.getLockTimeA(); + + // We can't refund P2SH-A until lockTime-A has passed + if (NTP.getTime() <= lockTime * 1000L) + throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.FOREIGN_BLOCKCHAIN_TOO_SOON); + + Litecoin litecoin = Litecoin.getInstance(); + + // We can't refund P2SH-A until median block time has passed lockTime-A (see BIP113) + int medianBlockTime = litecoin.getMedianBlockTime(); + if (medianBlockTime <= lockTime) + throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.FOREIGN_BLOCKCHAIN_TOO_SOON); + + byte[] redeemScriptA = BitcoinyHTLC.buildScript(tradeBotData.getTradeForeignPublicKeyHash(), lockTime, crossChainTradeData.creatorForeignPKH, tradeBotData.getHashOfSecret()); + String p2shAddressA = litecoin.deriveP2shAddress(redeemScriptA); + + // Fee for redeem/refund is subtracted from P2SH-A balance. + long feeTimestamp = calcFeeTimestamp(lockTime, crossChainTradeData.tradeTimeout); + long p2shFee = Litecoin.getInstance().getP2shFee(feeTimestamp); + long minimumAmountA = crossChainTradeData.expectedForeignAmount + p2shFee; + BitcoinyHTLC.Status htlcStatusA = BitcoinyHTLC.determineHtlcStatus(litecoin.getBlockchainProvider(), p2shAddressA, minimumAmountA); + + switch (htlcStatusA) { + case UNFUNDED: + case FUNDING_IN_PROGRESS: + // Still waiting for P2SH-A to be funded... + throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.FOREIGN_BLOCKCHAIN_TOO_SOON); + + case REDEEM_IN_PROGRESS: + case REDEEMED: + case REFUND_IN_PROGRESS: + case REFUNDED: + // Too late! + return false; + + case FUNDED:{ + Coin refundAmount = Coin.valueOf(crossChainTradeData.expectedForeignAmount); + ECKey refundKey = ECKey.fromPrivate(tradeBotData.getTradePrivateKey()); + List fundingOutputs = litecoin.getUnspentOutputs(p2shAddressA); + + // Determine receive address for refund + String receiveAddress = litecoin.getUnusedReceiveAddress(tradeBotData.getForeignKey()); + Address receiving = Address.fromString(litecoin.getNetworkParameters(), receiveAddress); + + Transaction p2shRefundTransaction = BitcoinyHTLC.buildRefundTransaction(litecoin.getNetworkParameters(), refundAmount, refundKey, + fundingOutputs, redeemScriptA, lockTime, receiving.getHash()); + + litecoin.broadcastTransaction(p2shRefundTransaction); + return true; // TODO: validate? + } + } + + } catch (DataException e) { + throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.REPOSITORY_ISSUE, e); + } catch (ForeignBlockchainException e) { + throw ApiExceptionFactory.INSTANCE.createException(request, ApiError.FOREIGN_BLOCKCHAIN_BALANCE_ISSUE, e); + } + + return false; + } + private long calcFeeTimestamp(int lockTimeA, int tradeTimeout) { return (lockTimeA - tradeTimeout * 60) * 1000L; }