server side checks

license/src/main/java/com/example/license/rest/LicenseRest.java

@@ -5,6 +5,12 @@ import java.io.FileInputStream;
 import java.io.FileOutputStream;
 import java.io.IOException;
 import java.nio.charset.StandardCharsets;
+import java.time.Instant;
+import java.time.LocalDate;
+import java.time.LocalTime;
+import java.time.ZoneId;
+import java.time.ZoneOffset;
+import java.time.ZonedDateTime;
 import java.util.Base64;
 import java.util.Properties;
 
@@ -34,7 +40,7 @@ public class LicenseRest {
 		String[] split = payload.split("\\.");
 		File directory = new File(licenseDirectory);
 
-		// TODO: extract ID, encrypted message and signature
+		// extract ID, encrypted message and signature
 		final var id = new String(Base64.getUrlDecoder().decode(split[0]), StandardCharsets.UTF_8);
 		final var encrypted = split[1];
 		final var signature = split[2];
@@ -58,33 +64,55 @@ public class LicenseRest {
 												KeyUtils.stringToPublicKey(props.getProperty("sender-public-key"))));
 						System.out.println("Decrypted: " + decrypted);
 
-						// TODO: verify signature
+						// verify signature
 						boolean isVerified = KeyUtils.verifySignature(decrypted, signature,
 								KeyUtils.stringToPublicKey(props.getProperty("sender-public-key")));
 						System.out.println("Is verified? " + isVerified);
 
-						// TODO: parse data
+						if (!isVerified) {
+							throw new RuntimeException("Invalid signature!");
+						}
+						// parse data
 						final var decryptedSplit = decrypted.split("\\:");
 						final var currentSenderIndex = decryptedSplit[0];
 						final var timestamp = Long.valueOf(decryptedSplit[1]);
 						final var currentLocalIndex = props.getProperty("index");
-						// TODO: check current local index if it matches with current sender index
+
+						// check current local index if it matches with current sender index
 						final var nextLocalIndex = DeterministicHexSequenceWithTimestamp
 								.nextValueString(props.getProperty("index"), timestamp);
 						System.out.println("Current sender index: " + currentSenderIndex + " timestamp = " + timestamp
 								+ " current local index = " + currentLocalIndex + " next index = " + nextLocalIndex);
 
-						// TODO: veryfy current index match, increment index using timestamp then send
-						// new index in response.
+						setExpiration(Instant.ofEpochMilli(timestamp));
+
+						// veryfy current index match, increment index using timestamp then send new
+						// index in response.
+						if (!currentSenderIndex.equals(currentLocalIndex)) {
+							throw new RuntimeException("Invalid current index!");
+						}
 						System.out.println("Props: " + props);
-						System.out.println(props.getProperty("index"));
 						if (!StringUtils.hasText(props.getProperty("index"))) {
 							props.setProperty("index", "1A3F");
 							saveProperties(filePath, props);
 						} else {
-							props.setProperty("index", DeterministicHexSequenceWithTimestamp
-									.nextValueString(props.getProperty("index"), 0));
+							props.setProperty("index", nextLocalIndex);
+							saveProperties(filePath, props);
+
+							final var messageResponse = nextLocalIndex + ":"
+									+ setExpiration(Instant.ofEpochMilli(timestamp)).toEpochMilli();
+							final var encryptedDataResponse = KeyUtils.encryptDataWithAESGCM(messageResponse,
+									KeyUtils.generateSharedSecret(
+											KeyUtils.stringToPrivateKey(props.getProperty("receiver-private-key")),
+											KeyUtils.stringToPublicKey(props.getProperty("sender-public-key"))));
+
+							final var encryptedResponse = Base64.getUrlEncoder()
+									.encodeToString(encryptedDataResponse);
+							final var signatureResponse = KeyUtils.signMessage(messageResponse,
+									KeyUtils.stringToPrivateKey(props.getProperty("receiver-private-key")));
+							return encryptedResponse + "." + signatureResponse;
 						}
+
 					}
 				}
 			}
@@ -108,4 +136,21 @@ public class LicenseRest {
 		}
 	}
 
+	public Instant setExpiration(Instant now) {
+
+		// Convert Instant to LocalDate in a specific time zone
+		ZoneId zoneId = ZoneId.systemDefault(); // Change if needed
+		LocalDate localDate = now.atZone(zoneId).toLocalDate();
+
+		// Set the time to 23:59:59.999999999
+		LocalTime endOfDay = LocalTime.MAX; // Equivalent to 23:59:59.999999999
+		ZonedDateTime endOfDayZoned = ZonedDateTime.of(localDate, endOfDay, ZoneOffset.UTC);
+
+		System.out.println("Now: " + now);
+		System.out.println("End of Day: " + endOfDayZoned);
+
+		// Convert back to Instant
+		return endOfDayZoned.toInstant();
+	}
+
 }

license/src/main/resources/application.properties

@@ -4,5 +4,6 @@ server.ssl.key-store=classpath:server.jks
 server.ssl.key-store-password=test
 server.ssl.key-store-type=JKS
 server.ssl.key-alias=torsim-license-server
+#server.ssl.key-alias=torsim-license-server-dummy
 
 license-folder=${user.home}/test/license/server