UNPKG

bitcoinfiles-node

Version:

Upload and Download files to Bitcoin Cash blockchain with Node and web

843 lines (707 loc) 33.1 kB
let utils = require('./utils'); let Network = require('./network'); let Bitdb = require('./bitdb'); // const BITBOXSDK = require('bitbox-sdk/lib/bitbox-sdk').default // , BITBOX = new BITBOXSDK() let bchrpc = require('grpc-bchrpc-node'); const sleep = ms => new Promise(resolve => setTimeout(resolve, ms)) class Bfp { constructor(BITBOX, network = 'mainnet', grpcUrl=null) { this.BITBOX = BITBOX; this.networkstring = network; this.network = new Network(this.BITBOX, grpcUrl); this.bitdb = new Bitdb(network); if(grpcUrl) this.client = new bchrpc.GrpcClient(grpcUrl); else this.client = new bchrpc.GrpcClient(); } static get lokadIdHex() { return "42465000" } async uploadHashOnlyObject(type, // file = 1, folder = 3 fundingUtxo, // object in form: { txid:'', satoshis:#, vout:# } fundingAddress, // string fundingWif, // hex string? objectDataArrayBuffer, // ArrayBuffer objectName=null, // string objectExt=null, // string prevObjectSha256Hex=null, // hex string objectExternalUri=null, // utf8 string objectReceiverAddress=null, // string signProgressCallback=null, signFinishedCallback=null, uploadProgressCallback=null, uploadFinishedCallback=null){ console.log('objectDataArrayBuffer', objectDataArrayBuffer) let fileSize = objectDataArrayBuffer.byteLength; let hash = this.BITBOX.Crypto.sha256(new Buffer(objectDataArrayBuffer)).toString('hex'); // chunks let chunkCount = 0; //Math.floor(fileSize / 220); // estimate cost // build empty meta data OpReturn let configEmptyMetaOpReturn = { msgType: type, chunkCount: chunkCount, fileName: objectName, fileExt: objectExt, fileSize: fileSize, fileSha256Hex: hash, prevFileSha256Hex: prevObjectSha256Hex, fileUri: objectExternalUri, chunkData: null }; //* ** building transaction let transactions = []; let txid = fundingUtxo.txid; let satoshis = fundingUtxo.satoshis; let vout = fundingUtxo.vout; let metaOpReturn = Bfp.buildMetadataOpReturn(configEmptyMetaOpReturn); // build meta data transaction let configMetaTx = { bfpMetadataOpReturn: metaOpReturn, input_utxo: { txid: txid,//chunksTx.getId(), vout: vout, satoshis: satoshis,//chunksTx.outs[1].value, wif: fundingWif }, fileReceiverAddress: objectReceiverAddress != null ? objectReceiverAddress : fundingAddress }; let metaTx = this.buildMetadataTx(configMetaTx); transactions.push(metaTx); // sign progress if(signProgressCallback != null){ signProgressCallback(100); } // progress : signing finished if(signFinishedCallback != null){ signFinishedCallback(); } //* ** sending transaction if(uploadProgressCallback != null){ uploadProgressCallback(0); } console.log('transaction: ', transactions[0].toHex()); var bfTxId = await this.network.sendTxWithRetry(transactions[0].toHex()); // progress if(uploadProgressCallback != null){ uploadProgressCallback(100); } bfTxId = 'bitcoinfile:' + bfTxId; if(uploadFinishedCallback != null){ uploadFinishedCallback(bfTxId); } return bfTxId; } async uploadFolderHashOnly(fundingUtxo, // object in form: { txid:'', satoshis:#, vout:# } fundingAddress, // string fundingWif, // hex string? folderDataArrayBuffer, // ArrayBuffer folderName=null, // string folderExt=null, // string prevFolderSha256Hex=null, // hex string folderExternalUri=null, // utf8 string folderReceiverAddress=null, // string signProgressCallback=null, signFinishedCallback=null, uploadProgressCallback=null, uploadFinishedCallback=null){ return await this.uploadHashOnlyObject(3, fundingUtxo, // object in form: { txid:'', satoshis:#, vout:# } fundingAddress, // string fundingWif, // hex string? folderDataArrayBuffer, // ArrayBuffer folderName, // string folderExt, // string prevFolderSha256Hex, // hex string folderExternalUri, // utf8 string folderReceiverAddress, // string signProgressCallback, signFinishedCallback, uploadProgressCallback, uploadFinishedCallback ) } async uploadFileHashOnly(fundingUtxo, // object in form: { txid:'', satoshis:#, vout:# } fundingAddress, // string fundingWif, // hex string? fileDataArrayBuffer, // ArrayBuffer fileName=null, // string fileExt=null, // string prevFileSha256Hex=null, // hex string fileExternalUri=null, // utf8 string fileReceiverAddress=null, // string signProgressCallback=null, signFinishedCallback=null, uploadProgressCallback=null, uploadFinishedCallback=null){ return await this.uploadHashOnlyObject(1, fundingUtxo, // object in form: { txid:'', satoshis:#, vout:# } fundingAddress, // string fundingWif, // hex string? fileDataArrayBuffer, // ArrayBuffer fileName, // string fileExt, // string prevFileSha256Hex, // hex string fileExternalUri, // utf8 string fileReceiverAddress, // string signProgressCallback, signFinishedCallback, uploadProgressCallback, uploadFinishedCallback ) } async uploadFile(fundingUtxo, // object in form: { txid:'', satoshis:#, vout:# } fundingAddress, // string fundingWif, // hex string? fileDataArrayBuffer, // ArrayBuffer fileName=null, // string fileExt=null, // string prevFileSha256Hex=null, // hex string fileExternalUri=null, // utf8 string fileReceiverAddress=null, // string signProgressCallback=null, signFinishedCallback=null, uploadProgressCallback=null, uploadFinishedCallback=null, delay_ms=500) { let fileSize = fileDataArrayBuffer.byteLength; let hash = this.BITBOX.Crypto.sha256(new Buffer(fileDataArrayBuffer)).toString('hex'); // chunks let chunks = []; let chunkCount = Math.floor(fileSize / 220); for (let nId = 0; nId < chunkCount; nId++) { chunks.push(fileDataArrayBuffer.slice(nId * 220, (nId + 1) * 220)); } // meta if (fileSize % 220) { chunks[chunkCount] = fileDataArrayBuffer.slice(chunkCount * 220, fileSize); chunkCount++; } // estimate cost // build empty meta data OpReturn let configEmptyMetaOpReturn = { msgType: 1, chunkCount: chunkCount, fileName: fileName, fileExt: fileExt, fileSize: fileSize, fileSha256Hex: hash, prevFileSha256Hex: prevFileSha256Hex, fileUri: fileExternalUri, chunkData: null }; //* ** building transaction let transactions = []; // show progress let nDiff = 100 / chunkCount; let nCurPos = 0; for (let nId = 0; nId < chunkCount; nId++) { // build chunk data OpReturn let chunkOpReturn = Bfp.buildDataChunkOpReturn(chunks[nId]); let txid = ''; let satoshis = 0; let vout = 1; if (nId === 0) { txid = fundingUtxo.txid; satoshis = fundingUtxo.satoshis; vout = fundingUtxo.vout; } else { txid = transactions[nId - 1].getId(); satoshis = transactions[nId - 1].outs[1].value; } // build chunk data transaction let configChunkTx = { bfpChunkOpReturn: chunkOpReturn, input_utxo: { address: fundingAddress, txid: txid, vout: vout, satoshis: satoshis, wif: fundingWif } }; let chunksTx = this.buildChunkTx(configChunkTx); if (nId === chunkCount - 1) { let emptyOpReturn = Bfp.buildMetadataOpReturn(configEmptyMetaOpReturn); let capacity = 223 - emptyOpReturn.length; if (capacity >= chunks[nId].byteLength) { // finish with just a single metadata txn // build meta data OpReturn let configMetaOpReturn = { msgType: 1, chunkCount: chunkCount, fileName: fileName, fileExt: fileExt, fileSize: fileSize, fileSha256Hex: hash, prevFileSha256Hex: prevFileSha256Hex, fileUri: fileExternalUri, chunkData: chunks[nId] }; let metaOpReturn = Bfp.buildMetadataOpReturn(configMetaOpReturn); // build meta data transaction let configMetaTx = { bfpMetadataOpReturn: metaOpReturn, input_utxo: { txid: txid, vout: vout, satoshis: satoshis, wif: fundingWif }, fileReceiverAddress: fileReceiverAddress != null ? fileReceiverAddress : fundingAddress }; let metaTx = this.buildMetadataTx(configMetaTx); transactions.push(metaTx); } else { // finish with both chunk txn and then final empty metadata txn transactions.push(chunksTx); let metaOpReturn = Bfp.buildMetadataOpReturn(configEmptyMetaOpReturn); // build meta data transaction let configMetaTx = { bfpMetadataOpReturn: metaOpReturn, input_utxo: { txid: chunksTx.getId(), vout: vout, satoshis: chunksTx.outs[1].value, wif: fundingWif }, fileReceiverAddress: fileReceiverAddress != null ? fileReceiverAddress : fundingAddress }; let metaTx = this.buildMetadataTx(configMetaTx); transactions.push(metaTx); } } else { // not last transaction transactions.push(chunksTx); } // sign progress if(signProgressCallback != null){ signProgressCallback(nCurPos) } nCurPos += nDiff; } // progress : signing finished if(signFinishedCallback != null){ signFinishedCallback(); } //* ** sending transaction nDiff = 100 / transactions.length; nCurPos = 0; if(uploadProgressCallback != null){ uploadProgressCallback(0); } for (let nId = 0; nId < transactions.length; nId++) { console.log('transaction: ', transactions[nId].toHex()); var bfTxId = await this.network.sendTxWithRetry(transactions[nId].toHex()); // progress if(uploadProgressCallback != null){ uploadProgressCallback(nCurPos); } nCurPos += nDiff; // delay between transactions await sleep(delay_ms); } bfTxId = 'bitcoinfile:' + bfTxId; if(uploadFinishedCallback != null){ uploadFinishedCallback(bfTxId); } return bfTxId; } async downloadFile(bfpUri, progressCallback=null) { let chunks = []; let size = 0; let txid = bfpUri.replace('bitcoinfile:', ''); txid = txid.replace('bitcoinfiles:', ''); let tx = await this.client.getTransaction({hash:txid, reversedHashOrder:true}); let prevHash = Buffer.from(tx.getTransaction().getInputsList()[0].getOutpoint().getHash_asU8()).toString('hex'); let metadata_opreturn_hex = Buffer.from(tx.getTransaction().getOutputsList()[0].getPubkeyScript_asU8()).toString('hex') let bfpMsg = this.parsebfpDataOpReturn(metadata_opreturn_hex); let downloadCount = bfpMsg.chunk_count; if(bfpMsg.chunk_count > 0 && bfpMsg.chunk != null) { downloadCount = bfpMsg.chunk_count - 1; chunks.push(bfpMsg.chunk) size += bfpMsg.chunk.length; } // Loop through raw transactions, parse out data for (let index = 0; index < downloadCount; index++) { // download prev txn let tx = await this.client.getTransaction({hash:prevHash}); prevHash = Buffer.from(tx.getTransaction().getInputsList()[0].getOutpoint().getHash_asU8()).toString('hex'); let op_return_hex = Buffer.from(tx.getTransaction().getOutputsList()[0].getPubkeyScript_asU8()).toString('hex'); // parse vout 0 for data, push onto chunks array let bfpMsg = this.parsebfpDataOpReturn(op_return_hex); chunks.push(bfpMsg.chunk); size += bfpMsg.chunk.length; if(progressCallback != null) { progressCallback(index/(downloadCount-1)); } } // reverse order of chunks chunks = chunks.reverse() let fileBuf = new Buffer.alloc(size); let index = 0; chunks.forEach(chunk => { chunk.copy(fileBuf, index) index += chunk.length; }); // TODO: check that metadata hash matches if one was provided. let passesHashCheck = false if(bfpMsg.sha256 != null){ let fileSha256 = this.BITBOX.Crypto.sha256(fileBuf); let res = Buffer.compare(fileSha256, bfpMsg.sha256); if(res === 0){ passesHashCheck = true; } } return { passesHashCheck, fileBuf }; } static buildMetadataOpReturn(config) { let script = []; // OP Return Prefix script.push(0x6a); // Lokad Id let lokadId = Buffer.from(Bfp.lokadIdHex, 'hex'); script.push(utils.getPushDataOpcode(lokadId)); lokadId.forEach((item) => script.push(item)); // Message Type script.push(utils.getPushDataOpcode([config.msgType])); script.push(config.msgType); // Chunk Count let chunkCount = utils.int2FixedBuffer(config.chunkCount, 1) script.push(utils.getPushDataOpcode(chunkCount)) chunkCount.forEach((item) => script.push(item)) // File Name if (config.fileName == null || config.fileName.length === 0 || config.fileName == '') { [0x4c, 0x00].forEach((item) => script.push(item)); } else { let fileName = Buffer.from(config.fileName, 'utf8') script.push(utils.getPushDataOpcode(fileName)); fileName.forEach((item) => script.push(item)); } // File Ext if (config.fileExt == null || config.fileExt.length === 0 || config.fileExt == '') { [0x4c, 0x00].forEach((item) => script.push(item)); } else { let fileExt = Buffer.from(config.fileExt, 'utf8'); script.push(utils.getPushDataOpcode(fileExt)); fileExt.forEach((item) => script.push(item)); } let fileSize = utils.int2FixedBuffer(config.fileSize, 2) script.push(utils.getPushDataOpcode(fileSize)) fileSize.forEach((item) => script.push(item)) // File SHA256 var re = /^[0-9a-fA-F]+$/; if (config.fileSha256Hex == null || config.fileSha256Hex.length === 0 || config.fileSha256Hex == '') { [0x4c, 0x00].forEach((item) => script.push(item)); } else if (config.fileSha256Hex.length === 64 && re.test(config.fileSha256Hex)) { let fileSha256Buf = Buffer.from(config.fileSha256Hex, 'hex'); script.push(utils.getPushDataOpcode(fileSha256Buf)); fileSha256Buf.forEach((item) => script.push(item)); } else { throw Error("File hash must be provided as a 64 character hex string"); } // Previous File Version SHA256 if (config.prevFileSha256Hex == null || config.prevFileSha256Hex.length === 0 || config.prevFileSha256Hex == '') { [0x4c, 0x00].forEach((item) => script.push(item)); } else if (config.prevFileSha256Hex.length === 64 && re.test(config.prevFileSha256Hex)) { let prevFileSha256Buf = Buffer.from(config.prevFileSha256Hex, 'hex'); script.push(utils.getPushDataOpcode(prevFileSha256Buf)); prevFileSha256Buf.forEach((item) => script.push(item)); } else { throw Error("Previous File hash must be provided as a 64 character hex string") } // File URI if (config.fileUri == null || config.fileUri.length === 0 || config.fileUri == '') { [0x4c, 0x00].forEach((item) => script.push(item)); } else { let fileUri = Buffer.from(config.fileUri, 'utf8'); script.push(utils.getPushDataOpcode(fileUri)); fileUri.forEach((item) => script.push(item)); } // Chunk Data if (config.chunkData == null || config.chunkData.length === 0) { [0x4c, 0x00].forEach((item) => script.push(item)); } else { let chunkData = Buffer.from(config.chunkData); script.push(utils.getPushDataOpcode(chunkData)); chunkData.forEach((item) => script.push(item)); } //console.log('script: ', script); let encodedScript = utils.encodeScript(script); if (encodedScript.length > 223) { throw Error("Script too long, must be less than 223 bytes.") } return encodedScript; } static buildDataChunkOpReturn(chunkData) { let script = [] // OP Return Prefix script.push(0x6a) // Chunk Data if (chunkData === undefined || chunkData === null || chunkData.length === 0) { [0x4c, 0x00].forEach((item) => script.push(item)); } else { let chunkDataBuf = Buffer.from(chunkData); script.push(utils.getPushDataOpcode(chunkDataBuf)); chunkDataBuf.forEach((item) => script.push(item)); } let encodedScript = utils.encodeScript(script); if (encodedScript.length > 223) { throw Error("Script too long, must be less than 223 bytes."); } return encodedScript; } // We may not need this function since the web browser wallet will be receiving funds in a single txn. buildFundingTx(config) { // Example config: // let config = { // outputAddress: this.bfpAddress, // fundingAmountSatoshis: ____, // input_utxos: [{ // txid: utxo.txid, // vout: utxo.vout, // satoshis: utxo.satoshis, // wif: wif // }] // } let transactionBuilder; if(this.networkstring === 'mainnet') transactionBuilder = new this.BITBOX.TransactionBuilder('bitcoincash'); else transactionBuilder = new this.BITBOX.TransactionBuilder('bchtest'); let satoshis = 0; config.input_utxos.forEach(token_utxo => { transactionBuilder.addInput(token_utxo.txid, token_utxo.vout); satoshis += token_utxo.satoshis; }); let fundingMinerFee = this.BITBOX.BitcoinCash.getByteCount({ P2PKH: config.input_utxos.length }, { P2PKH: 1 }) let outputAmount = satoshis - fundingMinerFee; //assert config.fundingAmountSatoshis == outputAmount //TODO: Use JS syntax and throw on error // Output exact funding amount transactionBuilder.addOutput(config.outputAddress, outputAmount); // sign inputs let i = 0; for (const txo of config.input_utxos) { let paymentKeyPair = this.BITBOX.ECPair.fromWIF(txo.wif); transactionBuilder.sign(i, paymentKeyPair, null, transactionBuilder.hashTypes.SIGHASH_ALL, txo.satoshis); i++; } return transactionBuilder.build(); } buildChunkTx(config) { // Example config: // let config = { // bfpChunkOpReturn: chunkOpReturn, // input_utxo: { // address: utxo.address?? // txid: utxo.txid, // vout: utxo.vout, // satoshis: utxo.satoshis, // wif: wif // } // } let transactionBuilder if(this.networkstring === 'mainnet') transactionBuilder = new this.BITBOX.TransactionBuilder('bitcoincash'); else transactionBuilder = new this.BITBOX.TransactionBuilder('bchtest'); transactionBuilder.addInput(config.input_utxo.txid, config.input_utxo.vout); let chunkTxFee = this.calculateDataChunkMinerFee(config.bfpChunkOpReturn.length); let outputAmount = config.input_utxo.satoshis - chunkTxFee; // Chunk OpReturn transactionBuilder.addOutput(config.bfpChunkOpReturn, 0); // Genesis token mint transactionBuilder.addOutput(config.input_utxo.address, outputAmount); // sign inputs let paymentKeyPair = this.BITBOX.ECPair.fromWIF(config.input_utxo.wif); transactionBuilder.sign(0, paymentKeyPair, null, transactionBuilder.hashTypes.SIGHASH_ALL, config.input_utxo.satoshis); return transactionBuilder.build(); } buildMetadataTx(config) { // Example config: // let config = { // bfpMetadataOpReturn: metadataOpReturn, // input_utxo: // { // txid: previousChunkTxid, // vout: 1, // satoshis: previousChunkTxData.satoshis, // wif: fundingWif // }, // fileReceiverAddress: outputAddress // } let transactionBuilder if(this.networkstring === 'mainnet') transactionBuilder = new this.BITBOX.TransactionBuilder('bitcoincash'); else transactionBuilder = new this.BITBOX.TransactionBuilder('bchtest'); let inputSatoshis = 0; transactionBuilder.addInput(config.input_utxo.txid, config.input_utxo.vout); inputSatoshis += config.input_utxo.satoshis; let metadataFee = this.calculateMetadataMinerFee(config.bfpMetadataOpReturn.length); //TODO: create method for calculating miner fee let output = inputSatoshis - metadataFee; // Metadata OpReturn transactionBuilder.addOutput(config.bfpMetadataOpReturn, 0); // outputs let outputAddress = this.BITBOX.Address.toCashAddress(config.fileReceiverAddress); transactionBuilder.addOutput(outputAddress, output); // sign inputs let paymentKeyPair = this.BITBOX.ECPair.fromWIF(config.input_utxo.wif); transactionBuilder.sign(0, paymentKeyPair, null, transactionBuilder.hashTypes.SIGHASH_ALL, config.input_utxo.satoshis); return transactionBuilder.build(); } calculateMetadataMinerFee(genesisOpReturnLength, feeRate = 1) { let fee = this.BITBOX.BitcoinCash.getByteCount({ P2PKH: 1 }, { P2PKH: 1 }) fee += genesisOpReturnLength fee += 10 // added to account for OP_RETURN ammount of 0000000000000000 fee *= feeRate return fee } calculateDataChunkMinerFee(sendOpReturnLength, feeRate = 1) { let fee = this.BITBOX.BitcoinCash.getByteCount({ P2PKH: 1 }, { P2PKH: 1 }) fee += sendOpReturnLength fee += 10 // added to account for OP_RETURN ammount of 0000000000000000 fee *= feeRate return fee } static calculateFileUploadCost(fileSizeBytes, configMetadataOpReturn, fee_rate = 1){ let byte_count = fileSizeBytes; let whole_chunks_count = Math.floor(fileSizeBytes / 220); let last_chunk_size = fileSizeBytes % 220; // cost of final transaction's op_return w/o any chunkdata let final_op_return_no_chunk = Bfp.buildMetadataOpReturn(configMetadataOpReturn); byte_count += final_op_return_no_chunk.length; // cost of final transaction's input/outputs byte_count += 35; byte_count += 148 + 1; // cost of chunk trasnsaction op_returns byte_count += (whole_chunks_count + 1) * 3; if (!Bfp.chunk_can_fit_in_final_opreturn(final_op_return_no_chunk.length, last_chunk_size)) { // add fees for an extra chunk transaction input/output byte_count += 149 + 35; // opcode cost for chunk op_return byte_count += 16; } // output p2pkh byte_count += 35 * (whole_chunks_count); // dust input bytes (this is the initial payment for the file upload) byte_count += (148 + 1) * whole_chunks_count; // other unaccounted per txn byte_count += 22 * (whole_chunks_count + 1); // dust output to be passed along each txn let dust_amount = 546; return byte_count * fee_rate + dust_amount; } static chunk_can_fit_in_final_opreturn (script_length, chunk_data_length) { if (chunk_data_length === 0) { return true; } let op_return_capacity = 223 - script_length; if (op_return_capacity >= chunk_data_length) { return true; } return false; } // static getFileUploadPaymentInfoFromHdNode(masterHdNode) { // let hdNode = this.BITBOX.HDNode.derivePath(masterHdNode, "m/44'/145'/1'"); // let node0 = this.BITBOX.HDNode.derivePath(hdNode, '0/0'); // let keyPair = this.BITBOX.HDNode.toKeyPair(node0); // let wif = this.BITBOX.ECPair.toWIF(keyPair); // let ecPair = this.BITBOX.ECPair.fromWIF(wif); // let address = this.BITBOX.ECPair.toLegacyAddress(ecPair); // let cashAddress = this.BITBOX.Address.toCashAddress(address); // return {address: cashAddress, wif: wif}; // } // getFileUploadPaymentInfoFromSeedPhrase(seedPhrase) { // let phrase = seedPhrase; // let seedBuffer = this.BITBOX.Mnemonic.toSeed(phrase); // // create HDNode from seed buffer // let hdNode = this.BITBOX.HDNode.fromSeed(seedBuffer); // let hdNode2 = this.BITBOX.HDNode.derivePath(hdNode, "m/44'/145'/1'"); // let node0 = this.BITBOX.HDNode.derivePath(hdNode2, '0/0'); // let keyPair = this.BITBOX.HDNode.toKeyPair(node0); // let wif = this.BITBOX.ECPair.toWIF(keyPair); // let ecPair = this.BITBOX.ECPair.fromWIF(wif); // let address = this.BITBOX.ECPair.toLegacyAddress(ecPair); // let cashAddress = this.BITBOX.Address.toCashAddress(address); // return {address: cashAddress, wif: wif}; // } parsebfpDataOpReturn(hex) { const script = this.BITBOX.Script.toASM(Buffer.from(hex, 'hex')).split(' '); let bfpData = {} bfpData.type = 'metadata' if(script.length == 2) { bfpData.type = 'chunk'; try { bfpData.chunk = Buffer.from(script[1], 'hex'); } catch(e) { bfpData.chunk = null; } return bfpData; } if (script[0] != 'OP_RETURN') { throw new Error('Not an OP_RETURN'); } if (script[1] !== Bfp.lokadIdHex) { throw new Error('Not a BFP OP_RETURN'); } // 01 = On-chain File if (script[2] != 'OP_1') { // NOTE: bitcoincashlib-js converts hex 01 to OP_1 due to BIP62.3 enforcement throw new Error('Not a BFP file (type 0x01)'); } // chunk count bfpData.chunk_count = parseInt(script[3], 16); if(script[3].includes('OP_')){ let val = script[3].replace('OP_', ''); bfpData.chunk_count = parseInt(val); } // filename if(script[4] == 'OP_0'){ bfpData.filename = null } else { bfpData.filename = Buffer.from(script[4], 'hex').toString('utf8'); } // fileext if(script[5] == 'OP_0'){ bfpData.fileext = null } else { bfpData.fileext = Buffer.from(script[5], 'hex').toString('utf8'); } // filesize if(script[6] == 'OP_0'){ bfpData.filesize = null } else { bfpData.filesize = parseInt(script[6], 16); } // file_sha256 if(script[7] == 'OP_0'){ bfpData.sha256 = null } else { bfpData.sha256 = Buffer.from(script[7], 'hex'); } // prev_file_sha256 if(script[8] == 'OP_0'){ bfpData.prevsha256 = null } else { bfpData.prevsha256 = Buffer.from(script[8], 'hex'); } // uri if(script[9] == 'OP_0'){ bfpData.uri = null } else { bfpData.uri = Buffer.from(script[9], 'hex').toString('utf8'); } // chunk_data if(script[10] == 'OP_0'){ bfpData.chunk = null } else { try { bfpData.chunk = Buffer.from(script[10], 'hex'); } catch(e) { bfpData.chunk = null } } return bfpData; } } module.exports = Bfp;