Java AES decrypt(String encryptedText, String key)

Description

decrypt

License

Apache License

Declaration

public static String decrypt(String encryptedText, String key) 

Method Source Code

//package com.java2s;
// Licensed under the Apache License, Version 2.0 (the "License");

import java.io.UnsupportedEncodingException;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;

import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.spec.SecretKeySpec;
import javax.xml.bind.DatatypeConverter;
import com.google.common.io.BaseEncoding;

public class Main {
    public static String decrypt(String encryptedText, String key) {
        try {//  w w w .  jav a2  s  . c  o m
            byte[] encrypted = BaseEncoding.base64Url().decode(encryptedText);
            Cipher cipher = Cipher.getInstance("AES");
            cipher.init(Cipher.DECRYPT_MODE, getAesKey(key));
            byte[] plain = cipher.doFinal(encrypted);
            if (plain == null || plain.length <= 8) {
                throw new RuntimeException("wrong encrypted text.");
            }
            byte[] data = new byte[plain.length - 8];
            System.arraycopy(plain, 8, data, 0, data.length);
            return new String(data, "ISO-8859-1");
        } catch (InvalidKeyException e) {
            throw new RuntimeException(e);
        } catch (NoSuchAlgorithmException e) {
            throw new RuntimeException(e);
        } catch (NoSuchPaddingException e) {
            throw new RuntimeException(e);
        } catch (IllegalBlockSizeException e) {
            throw new RuntimeException(e);
        } catch (BadPaddingException e) {
            throw new RuntimeException(e);
        } catch (UnsupportedEncodingException e) {
            throw new RuntimeException(e);
        }
    }

    private static SecretKeySpec getAesKey(String key) {
        final byte[] symKeyData = DatatypeConverter.parseHexBinary(key);
        return new SecretKeySpec(symKeyData, "AES");
    }
}

Related

1. aesCrypt(byte[] content, Key key, int crypt)
2. aesHandler(byte[] toBeHandleData, String password, boolean isEncrypt)
3. aesKey(int keySize)
4. aesStoreKeyToFile(Key secretKey, String path)
5. createSessionKey()
6. decrypt_aes(String key, String initVector, String encrypted)
7. encryptAes(String value)
8. encryptDecrypt(int mode, String data, String key, String salt, String iv)
9. getAesKey(String key)