C# 填充无效，无法被移除

1.本文采用微软的

RijndaelManaged

命名空间:

System.Security.Cryptography

Assemblies:

mscorlib.dll, netstandard.dll, System.Security.Cryptography.Algorithms.dll

访问的托管的版本Rijndael算法。 此类不能被继承。

实现加密解密，

查看代码：

using System;
using System.IO;
using System.Security.Cryptography;

namespace RijndaelManaged_Example
{
    class RijndaelExample
    {
        public static void Main()
        {
            try
            {

                string original = "Here is some data to encrypt!";

                // Create a new instance of the RijndaelManaged
                // class.  This generates a new key and initialization
                // vector (IV).
                using (RijndaelManaged myRijndael = new RijndaelManaged())
                {

                    myRijndael.GenerateKey();
                    myRijndael.GenerateIV();
                    // Encrypt the string to an array of bytes.
                    byte[] encrypted = EncryptStringToBytes(original, myRijndael.Key, myRijndael.IV);

                    // Decrypt the bytes to a string.
                    string roundtrip = DecryptStringFromBytes(encrypted, myRijndael.Key, myRijndael.IV);

                    //Display the original data and the decrypted data.
                    Console.WriteLine("Original:   {0}", original);
                    Console.WriteLine("Round Trip: {0}", roundtrip);
                }

            }
            catch (Exception e)
            {
                Console.WriteLine("Error: {0}", e.Message);
            }
        }
        static byte[] EncryptStringToBytes(string plainText, byte[] Key, byte[] IV)
        {
            // Check arguments.
            if (plainText == null || plainText.Length <= )
                throw new ArgumentNullException("plainText");
            if (Key == null || Key.Length <= )
                throw new ArgumentNullException("Key");
            if (IV == null || IV.Length <= )
                throw new ArgumentNullException("IV");
            byte[] encrypted;
            // Create an RijndaelManaged object
            // with the specified key and IV.
            using (RijndaelManaged rijAlg = new RijndaelManaged())
            {
                rijAlg.Key = Key;
                rijAlg.IV = IV;

                // Create an encryptor to perform the stream transform.
                ICryptoTransform encryptor = rijAlg.CreateEncryptor(rijAlg.Key, rijAlg.IV);

                // Create the streams used for encryption.
                using (MemoryStream msEncrypt = new MemoryStream())
                {
                    using (CryptoStream csEncrypt = new CryptoStream(msEncrypt, encryptor, CryptoStreamMode.Write))
                    {
                        using (StreamWriter swEncrypt = new StreamWriter(csEncrypt))
                        {

                            //Write all data to the stream.
                            swEncrypt.Write(plainText);
                        }
                        encrypted = msEncrypt.ToArray();
                    }
                }
            }

            // Return the encrypted bytes from the memory stream.
            return encrypted;

        }

        static string DecryptStringFromBytes(byte[] cipherText, byte[] Key, byte[] IV)
        {
            // Check arguments.
            if (cipherText == null || cipherText.Length <= )
                throw new ArgumentNullException("cipherText");
            if (Key == null || Key.Length <= )
                throw new ArgumentNullException("Key");
            if (IV == null || IV.Length <= )
                throw new ArgumentNullException("IV");

            // Declare the string used to hold
            // the decrypted text.
            string plaintext = null;

            // Create an RijndaelManaged object
            // with the specified key and IV.
            using (RijndaelManaged rijAlg = new RijndaelManaged())
            {
                rijAlg.Key = Key;
                rijAlg.IV = IV;

                // Create a decryptor to perform the stream transform.
                ICryptoTransform decryptor = rijAlg.CreateDecryptor(rijAlg.Key, rijAlg.IV);

                // Create the streams used for decryption.
                using (MemoryStream msDecrypt = new MemoryStream(cipherText))
                {
                    using (CryptoStream csDecrypt = new CryptoStream(msDecrypt, decryptor, CryptoStreamMode.Read))
                    {
                        using (StreamReader srDecrypt = new StreamReader(csDecrypt))
                        {
                            // Read the decrypted bytes from the decrypting stream
                            // and place them in a string.
                            plaintext = srDecrypt.ReadToEnd();
                        }
                    }
                }

            }

            return plaintext;

        }
    }
}

这个加密乃 微软官方案例。毛的问题

下面这个是错误的代码

       [Fact(DisplayName ="")]
        public void stat()
        {
            string original = "Here is some data to encrypt!";

            // Create a new instance of the RijndaelManaged
            // class.  This generates a new key and initialization
            // vector (IV).
            using (RijndaelManaged myRijndael = new RijndaelManaged())
            {

                myRijndael.GenerateKey();
                myRijndael.GenerateIV();
                // Encrypt the string to an array of bytes.
                byte[] encrypted = EncryptStringToBytes(original, myRijndael.Key, myRijndael.IV);
                myRijndael.GenerateKey();
                myRijndael.GenerateIV();
                // Decrypt the bytes to a string.
                string roundtrip = DecryptStringFromBytes(encrypted, myRijndael.Key, myRijndael.IV);

                //Display the original data and the decrypted data.
                Console.WriteLine("Original:   {0}", original);
                Console.WriteLine("Round Trip: {0}", roundtrip);
            }
        }

        /// <summary>
        ///
        /// </summary>
        /// <param name="plainText"></param>
        /// <param name="Key"></param>
        /// <param name="IV"></param>
        /// <returns></returns>
        static byte[] EncryptStringToBytes(string plainText, byte[] Key, byte[] IV)
        {
            // Check arguments.
            if (plainText == null || plainText.Length <= )
                throw new ArgumentNullException("plainText");
            if (Key == null || Key.Length <= )
                throw new ArgumentNullException("Key");
            if (IV == null || IV.Length <= )
                throw new ArgumentNullException("IV");
            byte[] encrypted;
            // Create an RijndaelManaged object
            // with the specified key and IV.
            using (RijndaelManaged rijAlg = new RijndaelManaged())
            {
                rijAlg.Key = Key;
                rijAlg.IV = IV;

                // Create an encryptor to perform the stream transform.
                ICryptoTransform encryptor = rijAlg.CreateEncryptor(rijAlg.Key, rijAlg.IV);

                // Create the streams used for encryption.
                using (MemoryStream msEncrypt = new MemoryStream())
                {
                    using (CryptoStream csEncrypt = new CryptoStream(msEncrypt, encryptor, CryptoStreamMode.Write))
                    {
                        using (StreamWriter swEncrypt = new StreamWriter(csEncrypt))
                        {

                            //Write all data to the stream.
                            swEncrypt.Write(plainText);
                        }
                        encrypted = msEncrypt.ToArray();
                    }
                }
            }

            // Return the encrypted bytes from the memory stream.
            return encrypted;

        }

        /// <summary>
        ///
        /// </summary>
        /// <param name="cipherText"></param>
        /// <param name="Key"></param>
        /// <param name="IV"></param>
        /// <returns></returns>
        static string DecryptStringFromBytes(byte[] cipherText, byte[] Key, byte[] IV)
        {
            // Check arguments.
            if (cipherText == null || cipherText.Length <= )
                throw new ArgumentNullException("cipherText");
            if (Key == null || Key.Length <= )
                throw new ArgumentNullException("Key");
            if (IV == null || IV.Length <= )
                throw new ArgumentNullException("IV");

            // Declare the string used to hold
            // the decrypted text.
            string plaintext = null;

            // Create an RijndaelManaged object
            // with the specified key and IV.
            using (RijndaelManaged rijAlg = new RijndaelManaged())
            {
                rijAlg.Key = Key;
                rijAlg.IV = IV;

                // Create a decryptor to perform the stream transform.
                ICryptoTransform decryptor = rijAlg.CreateDecryptor(rijAlg.Key, rijAlg.IV);

                // Create the streams used for decryption.
                using (MemoryStream msDecrypt = new MemoryStream(cipherText))
                {
                    using (CryptoStream csDecrypt = new CryptoStream(msDecrypt, decryptor, CryptoStreamMode.Read))
                    {
                        using (StreamReader srDecrypt = new StreamReader(csDecrypt))
                        {
                            // Read the decrypted bytes from the decrypting stream
                            // and place them in a string.
                            plaintext = srDecrypt.ReadToEnd();
                        }
                    }
                }

            }

            return plaintext;

        }

我把唯一改动测试的地方做了个标记。因为加密前随机的key 跟解密后的key 不一致，所以导致了这个错误

防止踩坑，以及知道这个玩意的原理。