Java AES Descrypt aesDecrypt(String encryptStr, String decryptKey)

Description

aes Decrypt

License

Open Source License

Declaration

public static String aesDecrypt(String encryptStr, String decryptKey) 

Method Source Code

//package com.java2s;
/*/*  ww w  .  ja  va2  s  .  c  om*/
 * Project Name: zc-collect-common
 * File Name: EncryptUtil.java
 * Class Name: EncryptUtil
 *
 * Copyright 2014 Hengtian Software Inc
 *
 * Licensed under the Hengtiansoft
 *
 * http://www.hengtiansoft.com
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
 * implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import java.security.SecureRandom;
import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.spec.SecretKeySpec;

public class Main {

    public static String aesDecrypt(String encryptStr, String decryptKey) {
        return aesDecryptByBytes(parseHexStr2Byte(encryptStr), decryptKey);
    }

    public static String aesDecryptByBytes(byte[] encryptBytes, String decryptKey) {
        try {
            SecureRandom random = SecureRandom.getInstance("SHA1PRNG");
            random.setSeed(decryptKey.getBytes());

            KeyGenerator kgen = KeyGenerator.getInstance("AES");
            kgen.init(128, random);

            Cipher cipher = Cipher.getInstance("AES");
            cipher.init(Cipher.DECRYPT_MODE, new SecretKeySpec(kgen.generateKey().getEncoded(), "AES"));
            byte[] decryptBytes = cipher.doFinal(encryptBytes);
            return new String(decryptBytes);
        } catch (Exception e) {
        }
        return null;
    }

    public static byte[] parseHexStr2Byte(String hexStr) {
        if (hexStr.length() < 1)
            return null;
        byte[] result = new byte[hexStr.length() / 2];
        for (int i = 0; i < hexStr.length() / 2; i++) {
            int high = Integer.parseInt(hexStr.substring(i * 2, i * 2 + 1), 16);
            int low = Integer.parseInt(hexStr.substring(i * 2 + 1, i * 2 + 2), 16);
            result[i] = (byte) (high * 16 + low);
        }
        return result;
    }
}

Related

1. aesDecrypt(byte[] content, Key key)
2. AESDecrypt(byte[] encrypted, byte[] key, byte[] iv)
3. aesDecrypt(byte[] input, Key key)
4. aesDecryptByBytes(byte[] encryptBytes, String decryptKey)