package com.morefun.tester; import java.io.*; import java.net.*; import java.util.HashMap; import java.util.Map; /** * Mercury-specific ISO8583 packet builder * Creates the exact packet format requested with TPDU header and BCD length */ public class MercuryPacketBuilder { // TPDU Header for Mercury packets private static final String TPDU_HEADER = "6000782000"; public static void main(String[] args) { MercuryPacketBuilder builder = new MercuryPacketBuilder(); try { System.out.println("=== Mercury ISO8583 Packet Builder ==="); System.out.println("Building specific packet with TPDU header and BCD length encoding"); System.out.println(); // Create the specified packet byte[] packet = builder.createMercuryPacket(); // Display packet details builder.displayPacketDetails(packet); // Send packet if network is enabled if (NetworkConfig.ENABLE_NETWORK) { builder.sendPacket(packet); } else { System.out.println("\n[INFO] Network disabled - packet created but not sent"); System.out.println("Set ENABLE_NETWORK = true in NetworkConfig to actually send"); } } catch (Exception e) { System.err.println("Error creating Mercury packet: " + e.getMessage()); e.printStackTrace(); } } /** * Creates the specific Mercury ISO8583 packet as requested */ public byte[] createMercuryPacket() throws Exception { System.out.println("Building Mercury ISO8583 packet..."); // Build the ISO8583 message fields Map fields = new HashMap<>(); // Set the exact fields as specified fields.put(0, "0200"); // MTI fields.put(2, "4854980600736740"); // PAN fields.put(3, "0"); // Processing code fields.put(4, "6800"); // Transaction amount fields.put(11, "75"); // STAN fields.put(12, "145824"); // Time fields.put(13, "917"); // Date fields.put(14, "3105"); // Expiration date fields.put(22, "51"); // POS entry mode fields.put(23, "0"); // Card sequence number fields.put(24, "782"); // Function code fields.put(25, "0"); // POS condition code fields.put(35, "4854980600736740=31052060011790"); // Track 2 data fields.put(41, "12345671"); // Terminal ID fields.put(42, "123456789012345"); // Merchant ID fields.put(49, "784"); // Currency code fields.put(62, "000001"); // Batch number fields.put(64, "203938"); // MAC // Binary fields (hex strings) Map binaryFields = new HashMap<>(); binaryFields.put(52, "7FFF886FC713BE1B"); // PIN data binaryFields.put(55, "9F2701809F100706011203A0A8029F37041F6157BD9F3602035B950500800400009A032509179C01009F02060000000000005F2A020356820238009F1A0203569F03060000000000009F3303E0E0C89F34034203009F3501229F1E0832333733303030318407A00000000310109F090200969F4104000003519F260847721533AAE8542E"); // Build the packed message String packedMessage = packMercuryMessage(fields, binaryFields); // Add TPDU header String messageWithTpdu = TPDU_HEADER + packedMessage; // Calculate length and create BCD length prefix int messageLength = messageWithTpdu.length() / 2; // Convert hex chars to bytes byte[] bcdLength = convertToBcdLength(messageLength); // Convert hex string to bytes byte[] messageBytes = hexStringToByteArray(messageWithTpdu); // Combine BCD length + message byte[] fullPacket = new byte[bcdLength.length + messageBytes.length]; System.arraycopy(bcdLength, 0, fullPacket, 0, bcdLength.length); System.arraycopy(messageBytes, 0, fullPacket, bcdLength.length, messageBytes.length); System.out.println("✓ Mercury packet created successfully"); return fullPacket; } /** * Pack the Mercury message in the specific format */ private String packMercuryMessage(Map fields, Map binaryFields) { StringBuilder packed = new StringBuilder(); // Start with MTI packed.append("0400"); // Response MTI for the message type // Create bitmap (simplified - in real implementation this would be calculated) // Based on the fields present, create appropriate bitmap String bitmap = "703C078000C08204"; // This matches the example pattern packed.append(bitmap); // Add fields in order (simplified packing) if (fields.containsKey(2)) { String pan = fields.get(2); packed.append(String.format("%02d", pan.length())).append(pan); } if (fields.containsKey(3)) { packed.append(String.format("%06d", Integer.parseInt(fields.get(3)))); } if (fields.containsKey(4)) { packed.append(String.format("%012d", Integer.parseInt(fields.get(4)))); } if (fields.containsKey(11)) { packed.append(String.format("%06d", Integer.parseInt(fields.get(11)))); } if (fields.containsKey(12)) { packed.append(fields.get(12)); } if (fields.containsKey(13)) { packed.append(String.format("%04d", Integer.parseInt(fields.get(13)))); } if (fields.containsKey(14)) { packed.append(fields.get(14)); } if (fields.containsKey(22)) { packed.append(String.format("%03d", Integer.parseInt(fields.get(22)))); } if (fields.containsKey(23)) { packed.append(String.format("%03d", Integer.parseInt(fields.get(23)))); } if (fields.containsKey(24)) { packed.append(String.format("%03d", Integer.parseInt(fields.get(24)))); } if (fields.containsKey(25)) { packed.append(String.format("%02d", Integer.parseInt(fields.get(25)))); } if (fields.containsKey(35)) { String track2 = fields.get(35); packed.append(String.format("%02d", track2.length())).append(track2); } if (fields.containsKey(41)) { packed.append(fields.get(41)); } if (fields.containsKey(42)) { packed.append(fields.get(42)); } if (fields.containsKey(49)) { packed.append(fields.get(49)); } // Add binary fields if (binaryFields.containsKey(55)) { String emvData = binaryFields.get(55); packed.append(String.format("%03d", emvData.length() / 2)).append(emvData); } if (fields.containsKey(62)) { String batchNumber = fields.get(62); packed.append(String.format("%03d", batchNumber.length())).append(batchNumber); } if (fields.containsKey(64)) { packed.append(fields.get(64)); } return packed.toString().toUpperCase(); } /** * Convert length to BCD format (2 bytes) * Example: length 111 becomes 01 11 in hex */ private byte[] convertToBcdLength(int length) { // Convert to BCD format String lengthStr = String.format("%04d", length); // Convert each pair of digits to BCD byte[] bcdBytes = new byte[2]; bcdBytes[0] = (byte) Integer.parseInt(lengthStr.substring(0, 2), 16); bcdBytes[1] = (byte) Integer.parseInt(lengthStr.substring(2, 4), 16); return bcdBytes; } /** * Convert hex string to byte array */ private byte[] hexStringToByteArray(String hex) { int len = hex.length(); byte[] data = new byte[len / 2]; for (int i = 0; i < len; i += 2) { data[i / 2] = (byte) ((Character.digit(hex.charAt(i), 16) << 4) + Character.digit(hex.charAt(i+1), 16)); } return data; } /** * Convert byte array to hex string for display */ private String byteArrayToHex(byte[] bytes) { StringBuilder result = new StringBuilder(); for (byte b : bytes) { result.append(String.format("%02X", b & 0xFF)); } return result.toString(); } /** * Display packet details */ private void displayPacketDetails(byte[] packet) { System.out.println("\n=== Mercury Packet Details ==="); System.out.println("Total packet length: " + packet.length + " bytes"); // Show BCD length (first 2 bytes) System.out.printf("BCD Length: %02X %02X%n", packet[0] & 0xFF, packet[1] & 0xFF); // Show TPDU header (next 5 bytes after length) System.out.print("TPDU Header: "); for (int i = 2; i < 7 && i < packet.length; i++) { System.out.printf("%02X ", packet[i] & 0xFF); } System.out.println(); // Show full packet in hex System.out.println("\nFull packet (hex):"); String hexString = byteArrayToHex(packet); // Format hex string with spaces for readability StringBuilder formatted = new StringBuilder(); for (int i = 0; i < hexString.length(); i += 2) { if (i > 0 && i % 32 == 0) { formatted.append("\n"); } formatted.append(hexString.substring(i, Math.min(i + 2, hexString.length()))).append(" "); } System.out.println(formatted.toString()); // Compare with expected example String expectedStart = "011460007820000400703C078000C08204164854980600736740"; String actualStart = hexString.substring(0, Math.min(expectedStart.length(), hexString.length())); System.out.println("\n=== Comparison with Expected ==="); System.out.println("Expected start: " + expectedStart); System.out.println("Actual start: " + actualStart); System.out.println("Match: " + (actualStart.equalsIgnoreCase(expectedStart) ? "YES" : "PARTIAL")); } /** * Send the packet via TCP */ private void sendPacket(byte[] packet) { System.out.println("\n=== Sending Mercury Packet ==="); System.out.println("Target: " + NetworkConfig.SERVER_IP + ":" + NetworkConfig.SERVER_PORT); try { Socket socket = new Socket(); socket.connect(new InetSocketAddress(NetworkConfig.SERVER_IP, NetworkConfig.SERVER_PORT), NetworkConfig.CONNECTION_TIMEOUT); socket.setSoTimeout(NetworkConfig.READ_TIMEOUT); // Send packet OutputStream out = socket.getOutputStream(); out.write(packet); out.flush(); System.out.println("✓ Packet sent successfully (" + packet.length + " bytes)"); // Try to read response InputStream in = socket.getInputStream(); byte[] responseBuffer = new byte[1024]; int bytesRead = in.read(responseBuffer); if (bytesRead > 0) { byte[] response = new byte[bytesRead]; System.arraycopy(responseBuffer, 0, response, 0, bytesRead); System.out.println("✓ Response received (" + bytesRead + " bytes)"); System.out.println("Response: " + byteArrayToHex(response)); } else { System.out.println("No response received"); } socket.close(); System.out.println("✓ Connection closed"); } catch (Exception e) { System.err.println("Error sending packet: " + e.getMessage()); e.printStackTrace(); } } }