Java aes256 암호화 복호화

1. mvn의 경우 pom.xml에 commons-codec dependency를 추가해준다.

2. https://mvnrepository.com/artifact/commons-codec/commons-codec 원하는 버전을 선택한다.

3. util package를 만들어주고, AES256Util.java를 만든다.

package com.test.api.util;
 
import java.io.UnsupportedEncodingException;
import java.security.InvalidAlgorithmParameterException;
import java.security.InvalidKeyException;
import java.security.Key;
import java.security.NoSuchAlgorithmException;
 
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 org.apache.commons.codec.binary.Base64;
 
public class AES256Util {
    private String iv;
    private Key keySpec;
    
    public AES256Util(String key) throws UnsupportedEncodingException {
        this.iv = key.substring(0, 16);
        
        byte[] keyBytes = new byte[16];
        byte[] b = key.getBytes("UTF-8");
        int len = b.length;
        if (len > keyBytes.length) {
            len = keyBytes.length;
        }
        System.arraycopy(b, 0, keyBytes, 0, len);
        SecretKeySpec keySpec = new SecretKeySpec(keyBytes, "AES");
        
        this.keySpec = keySpec;
    }
 
    // 암호화
    public String aesEncode(String str) throws java.io.UnsupportedEncodingException, 
                                                    NoSuchAlgorithmException, 
                                                    NoSuchPaddingException, 
                                                    InvalidKeyException, 
                                                    InvalidAlgorithmParameterException, 
                                                    IllegalBlockSizeException, 
                                                    BadPaddingException {
        Cipher c = Cipher.getInstance("AES/CBC/PKCS5Padding");
        c.init(Cipher.ENCRYPT_MODE, keySpec, new IvParameterSpec(iv.getBytes()));
 
        byte[] encrypted = c.doFinal(str.getBytes("UTF-8"));
        String enStr = new String(Base64.encodeBase64(encrypted));
 
        return enStr;
    }
 
    //복호화
    public String aesDecode(String str) throws java.io.UnsupportedEncodingException,
                                                        NoSuchAlgorithmException,
                                                        NoSuchPaddingException, 
                                                        InvalidKeyException, 
                                                        InvalidAlgorithmParameterException,
                                                        IllegalBlockSizeException, 
                                                        BadPaddingException {
        Cipher c = Cipher.getInstance("AES/CBC/PKCS5Padding");
        c.init(Cipher.DECRYPT_MODE, keySpec, new IvParameterSpec(iv.getBytes("UTF-8")));
 
        byte[] byteStr = Base64.decodeBase64(str.getBytes());
 
        return new String(c.doFinal(byteStr),"UTF-8");
    }
 
}

#controller

String key = "aes256-test-key!!";    //key는 16자 이상
AES256Util aes256 = new AES256Util(key);
URLCodec codec = new URLCodec();

String enc_key = codec.encode(aes256.aesEncode(암호화할 키)); 
String dec_key = aes256.aesDecode(codec.decode(복호화할 키));

출처: http://aramk.tistory.com/32 [깨순이네]