Android(java)与C#，DES加解密

最新推荐文章于 2023-07-12 14:31:44 发布

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本文介绍如何在C#与Android平台之间实现DES加密解密的互操作性，包括不同填充模式下的实现细节。

C#进行加密，Android进行解密。或者，Android进行加密，C#进行解密。

C#加密：

        /// C# DES加密
        /// </summary>
        /// <param name="originalValue"></param>
        /// <param name="key">key长度必须为8位的倍数</param>
        /// <returns></returns>
        public string DESEncrypt(string originalValue, string key)
        {
            DESCryptoServiceProvider sa = new DESCryptoServiceProvider();
            sa.Key = Encoding.ASCII.GetBytes(key);
            sa.Mode = CipherMode.ECB;
            //sa.Padding = PaddingMode.None;
            //sa.Padding = PaddingMode.Zeros;
            sa.Padding = PaddingMode.PKCS7;

            byte[] bysData = Encoding.UTF8.GetBytes(originalValue);
            byte[] bysEncrypted = sa.CreateEncryptor().TransformFinalBlock(bysData, 0, bysData.Length);

            return Convert.ToBase64String(bysEncrypted);
        }

C#解密：

        /// C# DES解密
        /// </summary>
        /// <param name="encryptedValue"></param>
        /// <param name="key">key长度必须为8位的倍数</param>
        /// <returns></returns>
        public string DESDecrypt(string encryptedValue, string key)
        {
            SymmetricAlgorithm sa;
            ICryptoTransform ct;
            MemoryStream ms;
            CryptoStream cs;
            byte[] byt;

            sa = new DESCryptoServiceProvider();
            sa.Key = Encoding.ASCII.GetBytes(key);
            sa.Mode = CipherMode.ECB;
            //sa.Padding = PaddingMode.None;
            //sa.Padding = PaddingMode.Zeros;
            sa.Padding = PaddingMode.PKCS7;
            ct = sa.CreateDecryptor();

            byt = Convert.FromBase64String(encryptedValue);

            ms = new MemoryStream();
            cs = new CryptoStream(ms, ct, CryptoStreamMode.Write);
            cs.Write(byt, 0, byt.Length);
            cs.FlushFinalBlock();

            cs.Close();

            return Encoding.UTF8.GetString(ms.ToArray());
        }

Android解密：

public String desDecrypt(String str, String key)
{
try 
{
    byte[] bysDecoded = Base64.decode(str, Base64.DEFAULT);
    DESKeySpec objDesKeySpec = new DESKeySpec(key.getBytes("ASCII"));
    SecretKeyFactory objKeyFactory = SecretKeyFactory.getInstance("DES");
    SecretKey objSecretKey = objKeyFactory.generateSecret(objDesKeySpec);
   //Cipher objCipher = Cipher.getInstance("DES/ECB/NoPadding");
    Cipher objCipher = Cipher.getInstance("DES/ECB/PKCS5Padding");
    objCipher.init(Cipher.DECRYPT_MODE, objSecretKey);
    String strDecrypted = new String(objCipher.doFinal(bysDecoded), "utf-8").trim();
   return strDecrypted;
} 
catch (Exception e) 
{
    e.printStackTrace(System.out);
    return "";
}
}

Android加密：

public String desDecrypt(String str, String key)
{
try 
{
    byte[] bysDecoded = Base64.decode(str, Base64.DEFAULT);
    DESKeySpec objDesKeySpec = new DESKeySpec(key.getBytes("ASCII"));
    SecretKeyFactory objKeyFactory = SecretKeyFactory.getInstance("DES");
    SecretKey objSecretKey = objKeyFactory.generateSecret(objDesKeySpec);
   //Cipher objCipher = Cipher.getInstance("DES/ECB/NoPadding");
    Cipher objCipher = Cipher.getInstance("DES/ECB/PKCS5Padding");
   objCipher.init(Cipher.DECRYPT_MODE, objSecretKey);
   String strDecrypted = new String(objCipher.doFinal(bysDecoded), "utf-8").trim();
    return strDecrypted;
} 
catch (Exception e) 
{
    e.printStackTrace(System.out);
    return "";
}
}

如果C#使用的是PaddingMode.None或者PaddingMode.Zeros，那么Android对应的就是DES/ECB/NoPadding。