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Fix AES CTR decryption issue
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This commit is contained in:
Dmitry Isaenko 2023-01-20 23:55:40 +03:00
parent d63d2416ff
commit 5bb6a3c3f4
2 changed files with 10 additions and 1 deletions
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10
src/main/java/libKonogonka/ctraesclassic/AesCtrDecryptClassic.java
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@ -24,6 +24,7 @@ import javax.crypto.Cipher;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
import java.math.BigInteger;
import java.nio.ByteBuffer;
import java.security.Security;
public class AesCtrDecryptClassic {
@ -64,7 +65,14 @@ public class AesCtrDecryptClassic {
private byte[] calculateCtr(long offset){
BigInteger ctr = new BigInteger(ivArray);
BigInteger updateTo = BigInteger.valueOf(offset / 0x10L);
return ctr.add(updateTo).toByteArray();
byte[] ctrCalculated = ctr.add(updateTo).toByteArray();
if (ctrCalculated.length != 0x10) {
ByteBuffer ctrByteBuffer = ByteBuffer.allocate(0x10);
ctrByteBuffer.position(0x10 - ctrCalculated.length);
ctrByteBuffer.put(ctrCalculated);
return ctrByteBuffer.array();
}
return ctrCalculated;
}
/**

1
src/main/java/libKonogonka/ctraesclassic/InFileStreamClassicProducer.java
View file

@ -96,6 +96,7 @@ public class InFileStreamClassicProducer implements IProducer {
* @param encryptedEndOffset Offset since parent stream start at stream where encrypted section ends
* @param key AES-CTR Key
* @param iv CTR / IV (counter)
* @param fileSize File Size
*/
public InFileStreamClassicProducer(InFileStreamProducer parentProducer,
long offset,