AES 알고리즘을 사용한 암호화 및 해독

Question

내 앱용 암호화/암호 해독 모듈을 만들고 있습니다. 내가 따라간 This Tutorial

이것은 오류나 출력을 표시하지 않습니다.

로그 파일

07-23 07:29:06.480: W/System.err(795): javax.crypto.BadPaddingException: pad block corrupted 
07-23 07:29:06.629: W/System.err(795): at com.android.org.bouncycastle.jcajce.provider.symmetric.util.BaseBlockCipher.engineDoFinal(BaseBlockCipher.java:710) 
07-23 07:29:06.629: W/System.err(795): at javax.crypto.Cipher.doFinal(Cipher.java:1111) 
07-23 07:29:06.660: W/System.err(795): at com.example.generatesha384.AESHelper.decrypt(AESHelper.java:52) 
07-23 07:29:06.690: W/System.err(795): at com.example.generatesha384.AESHelper.decrypt(AESHelper.java:25) 
07-23 07:29:06.690: W/System.err(795): at com.example.generatesha384.MainActivity.onCreate(MainActivity.java:24) 
07-23 07:29:06.700: W/System.err(795): at android.app.Activity.performCreate(Activity.java:5133) 
07-23 07:29:06.730: W/System.err(795): at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1087) 
07-23 07:29:06.730: W/System.err(795): at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2175) 
07-23 07:29:06.770: W/System.err(795): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2261) 
07-23 07:29:06.770: W/System.err(795): at android.app.ActivityThread.access$600(ActivityThread.java:141) 
07-23 07:29:06.770: W/System.err(795): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1256) 
07-23 07:29:06.800: W/System.err(795): at android.os.Handler.dispatchMessage(Handler.java:99) 
07-23 07:29:06.800: W/System.err(795): at android.os.Looper.loop(Looper.java:137) 
07-23 07:29:06.840: W/System.err(795): at android.app.ActivityThread.main(ActivityThread.java:5103) 
07-23 07:29:06.840: W/System.err(795): at java.lang.reflect.Method.invokeNative(Native Method) 
07-23 07:29:06.872: W/System.err(795): at java.lang.reflect.Method.invoke(Method.java:525) 
07-23 07:29:06.880: W/System.err(795): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737) 
07-23 07:29:06.910: W/System.err(795): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553) 
07-23 07:29:06.910: W/System.err(795): at dalvik.system.NativeStart.main(Native Method) 

MainActivity.Java

String seedValue = "This Is MySecure"; 

@Override 
protected void onCreate(Bundle savedInstanceState) { 

    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_main); 

    TextView text = (TextView)findViewById(R.id.result); 

    String normalText = "VIJAY"; 
    String normalTextEnc; 

    try { 
     normalTextEnc = AESHelper.encrypt(seedValue, normalText); 
     String normalTextDec = AESHelper.decrypt(seedValue, normalTextEnc); 

     String textResult = "Normal Text ::" + normalText 
       + " \n Encrypted Value :: " + normalTextEnc 
       + " \n Decrypted value :: " + normalTextDec; 
     text.setText(textResult); 

    } catch (Exception e) { 
     // TODO Auto-generated catch block 
     e.printStackTrace(); 
    } 
} 

public class AESHelper { 

public static String encrypt(String seed, String cleartext) 
     throws Exception { 
    byte[] rawKey = getRawKey(seed.getBytes("UTF-8")); 
    byte[] result = encrypt(rawKey, cleartext.getBytes("UTF-8")); 
    return toHex(result); 
} 

public static String decrypt(String seed, String encrypted) 
     throws Exception { 
    byte[] rawKey = getRawKey(seed.getBytes("UTF-8")); 
    byte[] enc = toByte(encrypted); 
    byte[] result = decrypt(rawKey, enc); 
    return new String(result); 
} 

private static byte[] getRawKey(byte[] seed) throws Exception { 
    KeyGenerator kgen = KeyGenerator.getInstance("AES"); 
    SecureRandom sr = SecureRandom.getInstance("SHA1PRNG"); 
    sr.setSeed(seed); 
    kgen.init(128, sr); // 192 and 256 bits may not be available 
    SecretKey skey = kgen.generateKey(); 
    byte[] raw = skey.getEncoded(); 
    return raw; 
} 

private static byte[] encrypt(byte[] raw, byte[] clear) throws Exception { 
    SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES"); 
    Cipher cipher = Cipher.getInstance("AES"); 
    cipher.init(Cipher.ENCRYPT_MODE, skeySpec); 
    byte[] encrypted = cipher.doFinal(clear); 
    return encrypted; 
} 

private static byte[] decrypt(byte[] raw, byte[] encrypted) 
     throws Exception { 
    SecretKeySpec skeySpec = new SecretKeySpec(raw, "AES"); 
    Cipher cipher = Cipher.getInstance("AES"); 
    cipher.init(Cipher.DECRYPT_MODE, skeySpec); 
    byte[] decrypted = cipher.doFinal(encrypted); 
    Log.d("DEC", "Decrypted: " + decrypted); 
    return decrypted; 
} 

public static String toHex(String txt) { 
    return toHex(txt.getBytes()); 
} 

public static String fromHex(String hex) { 
    return new String(toByte(hex)); 
} 

public static byte[] toByte(String hexString) { 
    int len = hexString.length()/2; 
    byte[] result = new byte[len]; 
    for (int i = 0; i < len; i++) 
     result[i] = Integer.valueOf(hexString.substring(2 * i, 2 * i + 2), 
       16).byteValue(); 
    return result; 
} 

public static String toHex(byte[] buf) { 
    if (buf == null) 
     return ""; 
    StringBuffer result = new StringBuffer(2 * buf.length); 
    for (int i = 0; i < buf.length; i++) { 
     appendHex(result, buf[i]); 
    } 
    return result.toString(); 
} 

private final static String HEX = "ABCDEF"; 

private static void appendHex(StringBuffer sb, byte b) { 
    sb.append(HEX.charAt((b >> 4) & 0x0f)).append(HEX.charAt(b & 0x0f)); 
} 

}

AESHelper.java:52

AESHelper.Java

 byte[] decrypted = cipher.doFinal(encrypted); 

및 AESHelper.java:25

 byte[] result = decrypt(rawKey, enc); 

Answer 1

자바에서 AES 암호화/복호화를 연구하는 데 많은 시간을 보내고 난 후에, 나는 함께 I에 유래에서 읽을 모든 정보의 다음 문서를 넣어 - http://netnix.org/2015/04/19/aes-encryption-with-hmac-integrity-in-java/

아마도 도움이 될지도 모릅니다.