在android中加密

Question

在android中如何使用Triple DES完成加密？是否有預定義的類可用？

Answer 1

這可能會或可能不會爲你工作。 玩得開心，JAL

public BoolString tryEncrypt(String inString, String key){ 
     boolean success= true; 
     String err=""; 
     String outString="Encrypted"; // BoolString.value 

     try { 
      byte[] byteKey= key.getBytes("UTF8"); 
      if (byteKey.length != 24) { 
       success= false; 
       err= "Key is "+byteKey.length+" bytes. Key must be exactly 24 bytes in length."; 
       throw new Exception(err); // could also return here 
      } 
      KeySpec ks= new DESedeKeySpec(byteKey); 
      SecretKeyFactory skf= SecretKeyFactory.getInstance("DESede"); 
      SecretKey sk= skf.generateSecret(ks); 
      Cipher cph=Cipher.getInstance("DESede"); 
      cph.init(Cipher.ENCRYPT_MODE, sk); 
      byte[] byteInString= inString.getBytes("UTF8"); 
      byte[] byteEncoded= cph.doFinal(byteInString); 
      outString= Base64.encodeToString(byteEncoded, Base64.DEFAULT); 
     } 
     catch (UnsupportedEncodingException e){err="Unable to convert key to byte array."; success= false;} 
     catch (InvalidKeyException e){err="Unable to generate KeySpec from key";success= false;} 
     catch (NoSuchAlgorithmException e){err="Unable to find algorithm.";success= false;} 
     catch (InvalidKeySpecException e){err="Invalid Key Specification";success= false;} 
     catch (NoSuchPaddingException e){err="No such padding";success= false;} 
     catch (IllegalArgumentException e){err="Illegal argument";success= false;} 
     catch (Exception e){err=e.getMessage();success= false;} 

     return new BoolString(success,err,outString); 
    } 

// a utility class to signal success or failure, return an error message, and return a useful String value 
// see Try Out in C# 
public final class BoolString { 
    public final boolean success; 
    public final String err; 
    public final String value; 

    public BoolString(boolean success, String err, String value){ 
     this.success= success; 
     this.err= err; 
     this.value= value; 
    } 
} 

Answer 2

您需要指定「DESede」作爲密碼;見DESedeKeySpec和this example。

Answer 3

有一些可以用來加密任何類型的數據更加密算法。 我更喜歡使用AES（高級加密標準），原因很多。首先，它提供了更大的密鑰大小，在創建加密應用程序之前，沒有必須識別的弱和半弱密鑰。此外，AES不容易受到其他理論攻擊，例如差分密碼分析等...