import javax.crypto.Cipher;

import javax.crypto.SecretKey;

import javax.crypto.SecretKeyFactory;

import javax.crypto.spec.DESKeySpec;

import org.apache.commons.codec.binary.Base64;

.Net 加密的程式如下: PaddingMode.None  

//建立一個Mode=ECB, Padding=None, Key為12345678的DESCryptoServiceProvider

DESCryptoServiceProvider objDESCryptoServiceProvider = new DESCryptoServiceProvider();

//Key的長度要64bits -> 8bytes;用ASCII編碼將Key轉為byte[]

objDESCryptoServiceProvider.Key = Encoding.ASCII.GetBytes("12345678");

objDESCryptoServiceProvider.Mode = CipherMode.ECB;

objDESCryptoServiceProvider.Padding = PaddingMode.None;  

//用UTF-8編碼, 將字串轉為byte[]

byte[] bysData = Encoding.UTF8.GetBytes("我是一個PaddingMode.None的測試字串！");

//因為PaddingMode.None的關係, byte[]的長度要是8的倍數

byte[] bysFixSizeData = new byte[(int)Math.Ceiling(bysData.Length / 8.0) * 8];

//將資料複製到長度為8的倍數的byte[]

Array.Copy(bysData, bysFixSizeData, bysData.Length);  

//進行加密

byte[] bysEncrypted = objDESCryptoServiceProvider.CreateEncryptor()

  .TransformFinalBlock(bysFixSizeData, 0, bysFixSizeData.Length);

//將byte[]轉為Base64的字串

Console.WriteLine(Convert.ToBase64String(bysEncrypted));

//輸出: xnygZZ+WkN4pmDVDjBJ41o9LePFibMJkfvLkf9phS9mW2tbtS6JcMSiwX2N1KbGp

Java 解密的程式如下：: 使用 org.apache.commons.codec.binary.Base64 這個類別做 Base64 字串的解碼.

try {

  //解密的Key

  String strKey = "12345678";

  //已加密的Base64字串

  String strEncrypted = "xnygZZ+WkN4pmDVDjBJ41o9LePFibMJkfvLkf9phS9mW2tbtS6JcMSiwX2N1KbGp";  

  //先將Base64字串轉碼為byte[]

  Base64 objBase64 = new Base64();

  byte[] bysDecoded = objBase64.decode(strEncrypted.getBytes());  

  //建立解密所需的Key. 因為加密時的key是用ASCII轉換, 所以這邊也用ASCII做

  DESKeySpec objDesKeySpec = new DESKeySpec(strKey.getBytes("ASCII"));

  SecretKeyFactory objKeyFactory = SecretKeyFactory.getInstance("DES");

  SecretKey objSecretKey = objKeyFactory.generateSecret(objDesKeySpec);  

  //設定一個DES/ECB/NoPadding的Cipher

  //ECB對應到.Net的CipherMode.ECB

  //NoPadding對應到.Net的PaddingMode.None

  Cipher objCipher = Cipher.getInstance("DES/ECB/NoPadding");

  //設定為解密模式, 並設定解密的key

  objCipher.init(Cipher.DECRYPT_MODE, objSecretKey);  

  //輸出解密後的字串. 因為加密是用UTF-8將字串轉為byte[], 所以這邊要用UTF-8轉回去

  //注意後面會多一些空字元. 因為加密前有因為資料長度的關係補上一些空的bytes

  //這邊用String的trim()將這些空字元刪掉

  String strDecrypted = new String(objCipher.doFinal(bysDecoded), "utf-8").trim();

  System.out.println("[" + strDecrypted + "]");

  //輸出:[我是一個PaddingMode.None的測試字串！]

} catch (Exception e) {

  e.printStackTrace(System.out);

}

接下來測試一下 .Net 中的 PaddingMode.Zeros:

//建立一個Mode=ECB, Padding=None, Key為12345678的DESCryptoServiceProvider

DESCryptoServiceProvider objDESCryptoServiceProvider = new DESCryptoServiceProvider();

//Key的長度要64bits -> 8bytes

objDESCryptoServiceProvider.Key = Encoding.ASCII.GetBytes("12345678");

objDESCryptoServiceProvider.Mode = CipherMode.ECB;

objDESCryptoServiceProvider.Padding = PaddingMode.Zeros;  

//用UTF-8編碼, 將字串轉為byte[]

//因為PaddingMode.Zeros的關係, 不用像上一個Sample一樣, 另外弄一個byte[]去將資料補到8的倍數

byte[] bysData = Encoding.UTF8.GetBytes("我是一個PaddingMode.Zeros的測試字串！");  

//進行加密

byte[] bysEncrypted = objDESCryptoServiceProvider.CreateEncryptor()

  .TransformFinalBlock(bysData, 0, bysData.Length);

//將byte[]轉為Base64的字串

Console.WriteLine(Convert.ToBase64String(bysEncrypted));

//輸出: xnygZZ+WkN4pmDVDjBJ41o9LePFibMJkYe6Sq5Y3mpq2JD91DLtxC/66itziI0rD

Java 的程式不用改變, 維持原狀即可.

try {

  //解密的Key

  String strKey = "12345678";

  //已加密的Base64字串

  String strEncrypted = "xnygZZ+WkN4pmDVDjBJ41o9LePFibMJkfvLkf9phS9mW2tbtS6JcMSiwX2N1KbGp";  

  //先將Base64字串轉碼為byte[]

  Base64 objBase64 = new Base64();

  byte[] bysDecoded = objBase64.decode(strEncrypted.getBytes());  

  //建立解密所需的Key. 因為加密時的key是用ASCII轉換, 所以這邊也用ASCII做

  DESKeySpec objDesKeySpec = new DESKeySpec(strKey.getBytes("ASCII"));

  SecretKeyFactory objKeyFactory = SecretKeyFactory.getInstance("DES");

  SecretKey objSecretKey = objKeyFactory.generateSecret(objDesKeySpec);  

  //設定一個DES/ECB/NoPadding的Cipher

  //ECB對應到.Net的CipherMode.ECB

  //NoPadding對應到.Net的PaddingMode.None

  Cipher objCipher = Cipher.getInstance("DES/ECB/NoPadding");

  //設定為解密模式, 並設定解密的key

  objCipher.init(Cipher.DECRYPT_MODE, objSecretKey);  

  //輸出解密後的字串. 因為加密是用UTF-8將字串轉為byte[], 所以這邊要用UTF-8轉回去

  //注意後面會多一些空字元. 因為加密前有因為資料長度的關係補上一些空的bytes

  //這邊用String的trim()將這些空字元刪掉

  String strDecrypted = new String(objCipher.doFinal(bysDecoded), "utf-8").trim();

  System.out.println("[" + strDecrypted + "]");

  //輸出:[我是一個PaddingMode.None的測試字串！]

} catch (Exception e) {

  e.printStackTrace(System.out);

}

最後測試 .Net 中的 PaddingMode.PKCS7:

//建立一個Mode=ECB, Padding=None, Key為12345678的DESCryptoServiceProvider

DESCryptoServiceProvider objDESCryptoServiceProvider = new DESCryptoServiceProvider();

//Key的長度要64bits -> 8bytes

objDESCryptoServiceProvider.Key = Encoding.ASCII.GetBytes("12345678");

objDESCryptoServiceProvider.Mode = CipherMode.ECB;

objDESCryptoServiceProvider.Padding = PaddingMode.PKCS7;  

//用UTF-8編碼, 將字串轉為byte[]

//這邊也不用另外做補資料的動作

byte[] bysData = Encoding.UTF8.GetBytes("我是一個PaddingMode.PKCS7的測試字串！");  

//進行加密

byte[] bysEncrypted = objDESCryptoServiceProvider.CreateEncryptor()

  .TransformFinalBlock(bysData, 0, bysData.Length);

//將byte[]轉為Base64的字串

Console.WriteLine(Convert.ToBase64String(bysEncrypted));

//輸出: xnygZZ+WkN4pmDVDjBJ41o9LePFibMJkt86hRLUM4/m2JD91DLtxC5+8Tqc7iB2f

Java 程式的差別就在於把 DES / ECB / NoPadding 改為 DES / ECB / PKCS5Padding.

try {

  //解密的Key

  String strKey = "12345678";

  //已加密的Base64字串

  String strEncrypted = "xnygZZ+WkN4pmDVDjBJ41o9LePFibMJkt86hRLUM4/m2JD91DLtxC5+8Tqc7iB2f";  

  //先將Base64字串轉碼為byte[]

  Base64 objBase64 = new Base64();

  byte[] bysDecoded = objBase64.decode(strEncrypted.getBytes());  

  //建立解密所需的Key. 因為加密時的key是用ASCII轉換, 所以這邊也用ASCII做

  DESKeySpec objDesKeySpec = new DESKeySpec(strKey.getBytes("ASCII"));

  SecretKeyFactory objKeyFactory = SecretKeyFactory.getInstance("DES");

  SecretKey objSecretKey = objKeyFactory.generateSecret(objDesKeySpec);  

  //設定一個DES/ECB/PKCS5Padding的Cipher

  //ECB對應到.Net的CipherMode.ECB

  //用PKCS5Padding對應到.Net的PaddingMode.PKCS7

  Cipher objCipher = Cipher.getInstance("DES/ECB/PKCS5Padding");

  //設定為解密模式, 並設定解密的key

  objCipher.init(Cipher.DECRYPT_MODE, objSecretKey);  

  //輸出解密後的字串. 因為加密時指定PaddingMode.PKCS7, 所以可以不用處理空字元

  //不過若想保險點, 也是可以用trim()去處理過一遍

  String strDecrypted = new String(objCipher.doFinal(bysDecoded), "utf-8").trim();

  System.out.println("[" + strDecrypted + "]");

  //輸出:[我是一個PaddingMode.PKCS7的測試字串！]

} catch (Exception e) {

  e.printStackTrace(System.out);

}