The IV that your using for decryption is incorrect. Replace this code
//Decrypt cipher
Cipher decryptCipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
IvParameterSpec ivParameterSpec = new IvParameterSpec(aesKey.getEncoded());
decryptCipher.init(Cipher.DECRYPT_MODE, aesKey, ivParameterSpec);
With this code
//Decrypt cipher
Cipher decryptCipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
IvParameterSpec ivParameterSpec = new IvParameterSpec(encryptCipher.getIV());
decryptCipher.init(Cipher.DECRYPT_MODE, aesKey, ivParameterSpec);
And that should solve your problem.
Below includes an example of a simple AES class in Java. I do not recommend using this class in production environments, as it may not account for all of the specific needs of your application.
import java.nio.charset.StandardCharsets;
import java.security.InvalidAlgorithmParameterException;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.security.SecureRandom;
import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
import java.util.Base64;
public class AES
{
public static byte[] encrypt(final byte[] keyBytes, final byte[] ivBytes, final byte[] messageBytes) throws InvalidKeyException, InvalidAlgorithmParameterException
{
return AES.transform(Cipher.ENCRYPT_MODE, keyBytes, ivBytes, messageBytes);
}
public static byte[] decrypt(final byte[] keyBytes, final byte[] ivBytes, final byte[] messageBytes) throws InvalidKeyException, InvalidAlgorithmParameterException
{
return AES.transform(Cipher.DECRYPT_MODE, keyBytes, ivBytes, messageBytes);
}
private static byte[] transform(final int mode, final byte[] keyBytes, final byte[] ivBytes, final byte[] messageBytes) throws InvalidKeyException, InvalidAlgorithmParameterException
{
final SecretKeySpec keySpec = new SecretKeySpec(keyBytes, "AES");
final IvParameterSpec ivSpec = new IvParameterSpec(ivBytes);
byte[] transformedBytes = null;
try
{
final Cipher cipher = Cipher.getInstance("AES/CTR/NoPadding");
cipher.init(mode, keySpec, ivSpec);
transformedBytes = cipher.doFinal(messageBytes);
}
catch (NoSuchAlgorithmException | NoSuchPaddingException | IllegalBlockSizeException | BadPaddingException e)
{
e.printStackTrace();
}
return transformedBytes;
}
public static void main(final String[] args) throws InvalidKeyException, InvalidAlgorithmParameterException
{
//Retrieved from a protected local file.
//Do not hard-code and do not version control.
final String base64Key = "ABEiM0RVZneImaq7zN3u/w==";
//Retrieved from a protected database.
//Do not hard-code and do not version control.
final String shadowEntry = "AAECAwQFBgcICQoLDA0ODw==:ZtrkahwcMzTu7e/WuJ3AZmF09DE=";
//Extract the iv and the ciphertext from the shadow entry.
final String[] shadowData = shadowEntry.split(":");
final String base64Iv = shadowData[0];
final String base64Ciphertext = shadowData[1];
//Convert to raw bytes.
final byte[] keyBytes = Base64.getDecoder().decode(base64Key);
final byte[] ivBytes = Base64.getDecoder().decode(base64Iv);
final byte[] encryptedBytes = Base64.getDecoder().decode(base64Ciphertext);
//Decrypt data and do something with it.
final byte[] decryptedBytes = AES.decrypt(keyBytes, ivBytes, encryptedBytes);
//Use non-blocking SecureRandom implementation for the new IV.
final SecureRandom secureRandom = new SecureRandom();
//Generate a new IV.
secureRandom.nextBytes(ivBytes);
//At this point instead of printing to the screen,
//one should replace the old shadow entry with the new one.
System.out.println("Old Shadow Entry = " + shadowEntry);
System.out.println("Decrytped Shadow Data = " + new String(decryptedBytes, StandardCharsets.UTF_8));
System.out.println("New Shadow Entry = " + Base64.getEncoder().encodeToString(ivBytes) + ":" + Base64.getEncoder().encodeToString(AES.encrypt(keyBytes, ivBytes, decryptedBytes)));
}
}
Note that AES has nothing to do with encoding, which is why I chose to handle it separately and without the need of any third party libraries.