如何使用RSA中的應用程序，我發現的代碼，但不知道如何實現

Question

如何我用這個RSA http://xtrace.blogspot.com/2012/03/rsa-demo-example.html?showComment=1349091173502#c199333123405145467 TUTOTIAL CODE IN我的登錄下面的代碼 我發現的代碼，但DNT知道如何實現

public class LoginScreen extends Activity implements OnClickListener{  

EditText mobile; 
EditText pin; 
Button btnLogin; 
Button btnClear; 

public void onCreate(Bundle icicle) 
{ 
    super.onCreate(icicle); 
    setContentView(R.layout.login.xml); 

    TextView lblMobileNo = (TextView)findViewById(R.id.lblMobileNo); 
    lblMobileNo.setTextColor(getResources().getColor(R.color.text_color_red)); 

    mobile = (EditText)findViewById(R.id.txtMobileNo); 

    TextView lblPinNo = (TextView)findViewById(R.id.lblPinNo); 
    lblPinNo.setTextColor(getResources().getColor(R.color.text_color_red)); 

    pin = (EditText)findViewById(R.id.txtPinNo); 

    btnLogin = (Button)findViewById(R.id.btnLogin); 
    btnClear = (Button)findViewById(R.id.btnClear); 

    btnLogin.setOnClickListener(new OnClickListener() { 
     public void onClick(View view) {     
      postLoginData(); 
     } 
     });   


    btnClear.setOnClickListener(new OnClickListener() 
    { 
    public void onClick(View v) 

    { 
     cleartext(); 
    } 

}); 

    /* 

    btnClear.setOnClickListener(new OnClickListener() { 
      public void onClick(View arg0) { 

      } 
      }); 
      */ 

} 

public void postLoginData() 


{ 

      Intent i = new Intent(this.getApplicationContext(),NEWCLASS.class); 
      Bundle bundle = new Bundle(); 
      bundle.putString("mno", mobile.getText().toString()); 
      bundle.putString("pinno", pin.getText().toString()); 
      i.putExtras(bundle); 
      startActivity(i);   } 
} 

@Override 
public void onClick(View v) { 

} 


public void cleartext() { 


    { 
     pin.setText("") ; 
     mobile.setText(""); 
    } 


} 


    } 

Answer 1

看這裏加密器/解密類的一些例子：How to encrypt String in Java

或者這裏，做一切你類的一個很好的例子：

public class Cryptos { 

private static final String ME = Cryptos.class.getSimpleName(); 
private static String strEncoding = "UTF-8"; 
private static String STATIC_STRING_IV_16 = "123456789"; 
private String iv; 
private String key; 
private IvParameterSpec mIvParameterSpec; 
private SecretKeySpec mSecretKeySpec; 
private Cipher mCipher; 

public Cryptos(String key) { 
    this(STATIC_STRING_IV_16,key); 
} 

public Cryptos(String iv, String key) { 
    this.iv = cut(iv, 16); 
    this.key = key; 

    mIvParameterSpec = new IvParameterSpec(this.iv.getBytes()); 
    mSecretKeySpec = new SecretKeySpec(this.key.getBytes(), "AES"); 

    try { 
     mCipher = Cipher.getInstance("AES/CBC/NoPadding"); 
    } catch (NoSuchAlgorithmException e) { 
     App.log.e(ME, "Got Exception while initializing mCipher: " + e.toString(), e); 
    } catch (NoSuchPaddingException e) { 
     App.log.e(ME, "Got Exception while initializing mCipher: " + e.toString(), e); 
    } 
} 


public byte[] decryptHex(String hexString) throws Exception { 
    if(hexString == null || hexString.length() == 0) { 
     throw new Exception("Emtpy string given"); 
    } 
    return byteTrim(decrypt(hexToBytes(hexString))); 
} 

public byte[] decrypt(byte[] input){ 
    try { 
     mCipher.init(Cipher.DECRYPT_MODE, mSecretKeySpec, mIvParameterSpec); 
     byte[] decrypted = new byte[mCipher.getOutputSize(input.length)]; 
     int dec_len = mCipher.update(input, 0, input.length, decrypted, 0); 
     dec_len += mCipher.doFinal(decrypted, dec_len); 
     return ARRAY.copyOf(decrypted, dec_len); 
    } catch (ShortBufferException e) { 
     e.printStackTrace(); 
    } catch (IllegalBlockSizeException e) { 
     e.printStackTrace(); 
    } catch (BadPaddingException e) { 
     e.printStackTrace(); 
    } catch (InvalidKeyException e) { 
     e.printStackTrace(); 
    } catch (InvalidAlgorithmParameterException e) { 
     e.printStackTrace(); 
    } 
    return null; 
} 



public byte[] encrypt(String text) throws Exception{ 
    if(text == null || text.length() == 0) throw new Exception("Empty string"); 
    return encrypt(text.getBytes(strEncoding)); 
} 

public byte[] encrypt(byte[] data){ 
    if(data==null) return null; 

    try { 
     int bts = data.length; 
     byte[] alignData = ARRAY.copyOf(data, bts+(16-bts%16)); 
     data = alignData; 
     mCipher.init(Cipher.ENCRYPT_MODE, mSecretKeySpec, mIvParameterSpec); 
     byte[] encrypted = new byte[mCipher.getOutputSize(data.length)]; 
     int enc_len = mCipher.update(data, 0, data.length, encrypted, 0); 
     enc_len += mCipher.doFinal(encrypted, enc_len); 
     return ARRAY.copyOf(encrypted, enc_len); 
    } catch (ShortBufferException e) { 
     e.printStackTrace(); 
    } catch (IllegalBlockSizeException e) { 
     e.printStackTrace(); 
    } catch (BadPaddingException e) { 
     e.printStackTrace(); 
    } catch (InvalidKeyException e) { 
     e.printStackTrace(); 
    } catch (InvalidAlgorithmParameterException e) { 
     e.printStackTrace(); 
    } 
    return null; 
} 

public static String bytesToHex(byte[] b){ 
    StringBuffer buf = new StringBuffer(); 
    int len = b.length; 
    for (int j=0; j<len; j++) 
     buf.append(byteToHex(b[j])); 
    return buf.toString(); 
} 

public static String byteToHex(byte b){ 
    char hexDigit[] = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'}; 
    char[] a = { hexDigit[(b >> 4) & 0x0f], hexDigit[b & 0x0f] }; 
    return new String(a); 
} 

public static byte[] hexToBytes(String str) { 
    if (str==null) { 
     return null; 
    } else if (str.length() < 2) { 
     return null; 
    } else { 
     int len = str.length()/2; 
     byte[] buffer = new byte[len]; 
     for (int i=0; i<len; i++) { 
      buffer[i] = (byte) Integer.parseInt(str.substring(i*2,i*2+2),16); 
     } 
     return buffer; 
    } 
} 


private byte[] byteTrim(byte[] bytes){ 
    if(bytes.length > 0){ 
     int trim = 0; 
     for(int i = bytes.length - 1; i >= 0; i--){ 
      if(bytes[i] == 0){ 
       trim++; 
      }else{ 
       break; 
      } 
     } 
     if(trim > 0){ 
      byte[] newArray = new byte[bytes.length - trim]; 
      System.arraycopy(bytes, 0, newArray, 0, bytes.length - trim); 
      return newArray; 
     } 
    } 
    return bytes; 
} 

private String cut(String s, int n) { 
    byte[] sBytes = s.getBytes(); 
    if(sBytes.length < n) { 
     n = sBytes.length; 
    } 
    boolean extraLong = false; 
    int i = 0, n16 = 0; 
    while(i < n) { 
     n16 += (extraLong) ? 2 : 1; 
     extraLong = false; 
     if((sBytes[i] & 0x80) == 0) { 
      i += 1; 
     } else if((sBytes[i] & 0xC0) == 0x80) { 
      i += 2; 
     } else if((sBytes[i] & 0xE0) == 0xC0) { 
      i += 3; 
     } else { 
      i += 4; 
      extraLong = true; 
     } 
    } 
    return s.substring(0, n16); 
} 

public static String encBase64(byte[] bytes){ 
    return Base64.encodeToString(bytes, Base64.DEFAULT); 
} 

public static byte[] decBase64(String data){ 
    return Base64.decode(data, Base64.DEFAULT); 
} 
}