From 75680b2e9320e4d260b6bc4f1f2d7ababed15ef9 Mon Sep 17 00:00:00 2001
From: TheArrayser <thearrayser@cringe-studios.com>
Date: Sun, 25 Jun 2023 22:14:12 +0200
Subject: [PATCH] Added Time correction setting to OTP.java

---
 .../cringe_authenticator_library/OTP.java             | 11 +++++++++++
 .../cringe_authenticator_library/impl/TOTP.java       |  2 +-
 2 files changed, 12 insertions(+), 1 deletion(-)

diff --git a/src/main/java/com/cringe_studios/cringe_authenticator_library/OTP.java b/src/main/java/com/cringe_studios/cringe_authenticator_library/OTP.java
index 5c8aadd..9182489 100644
--- a/src/main/java/com/cringe_studios/cringe_authenticator_library/OTP.java
+++ b/src/main/java/com/cringe_studios/cringe_authenticator_library/OTP.java
@@ -14,6 +14,7 @@ public abstract class OTP {
 	protected long counter;
 	protected long period;
 	protected boolean checksum;
+	static protected long timeOffset;
 	
 	protected OTP(OTPType nType, String nSecret, OTPAlgorithm nAlgorithm, int nDigits, long nCounter, long nPeriodInSeconds, boolean nChecksum) {
 		this.secret = Base32.decode(nSecret);
@@ -81,4 +82,14 @@ public abstract class OTP {
 	public boolean hasChecksum() {
 		return checksum;
 	}
+	
+	// Seconds towards positive infinity means a positive correction into the future (seconds = 2 -> 5 becomes 7)
+	// Seconds towards negative infinity means a negative correction into the past   (seconds = -2 -> 5 becomes 3)
+	public static void setTimeCorrection(long seconds) {
+		timeOffset = seconds;
+	}
+	
+	public static long getTimeCorrection() {
+		return timeOffset;
+	}
 }
\ No newline at end of file
diff --git a/src/main/java/com/cringe_studios/cringe_authenticator_library/impl/TOTP.java b/src/main/java/com/cringe_studios/cringe_authenticator_library/impl/TOTP.java
index 9669882..e9623a3 100644
--- a/src/main/java/com/cringe_studios/cringe_authenticator_library/impl/TOTP.java
+++ b/src/main/java/com/cringe_studios/cringe_authenticator_library/impl/TOTP.java
@@ -37,7 +37,7 @@ public class TOTP extends HOTP {
 
 	@Override
 	public long getCounter() {
-		return getCounterAt(Instant.now().getEpochSecond());
+		return getCounterAt(Instant.now().getEpochSecond() - super.getTimeCorrection());
 	}
 	
 	private long getCounterAt(long unixSecond) {