SymmetricAlgorithmHelper对称加密辅助类，支持DES，3DES，AES，RC2

理论上只要继承自SymmetricAlgorithm的对称加密算法，该辅助类都支持加密解密，另外为了方便与JAVA互通，默认提供了ECB和CBC两种加密模式、填充方式均为PKCS7的静态方法

using System.Security.Cryptography;
public class SymmetricAlgorithmHelper<T>
where T : SymmetricAlgorithm, new()
{
/// <summary>
/// 加密 ECB PKCS7模式
/// </summary>
/// <param name="str">要加密的数据</param>
/// <param name="key">秘钥（base64格式）</param>
/// <returns>加密后的结果（base64格式）</returns>
public static string EncryptWithECB(string str, string key)
{
return EncryptWithECB(str, Convert.FromBase64String(key));
}
/// <summary>
/// 加密 ECB PKCS7模式
/// </summary>
/// <param name="str">要加密的数据</param>
/// <param name="key">秘钥</param>
/// <returns>加密后的结果（base64格式）</returns>
public static string EncryptWithECB(string str, byte[] key)
{
var toEncryptArray = Encoding.UTF8.GetBytes(str);
return Convert.ToBase64String(Encrypt(toEncryptArray, key, null, CipherMode.ECB, PaddingMode.PKCS7));
}
/// <summary>
/// 解密 ECB PKCS7模式
/// </summary>
/// <param name="str">要解密的数据（base64格式）</param>
/// <param name="key">秘钥（base64格式）</param>
/// <returns>utf-8编码返回解密后得数据</returns>
public static string DecryptWithECB(string str, string key)
{
return DecryptWithECB(str, Convert.FromBase64String(key));
}
/// <summary>
///  3DES 解密 ECB PKCS7模式
/// </summary>
/// <param name="str">要解密的数据（base64格式）</param>
/// <param name="key">秘钥</param>
/// <returns>utf-8编码返回解密后得数据</returns>
public static string DecryptWithECB(string str, byte[] key)
{
var toDecryptArray = Convert.FromBase64String(str);
return Encoding.UTF8.GetString(Decrypt(toDecryptArray, key, null, CipherMode.ECB, PaddingMode.PKCS7));
}
/// <summary>
/// 加密 CBC PKCS7模式
/// </summary>
/// <param name="str">要加密的数据</param>
/// <param name="key">秘钥（base64格式）</param>
/// <param name="iv">向量（base64格式）</param>
/// <returns>加密后的结果（base64格式）</returns>
public static string EncryptWithCBC(string str, string key, string iv)
{
return EncryptWithCBC(str, Convert.FromBase64String(key), Convert.FromBase64String(iv));
}
/// <summary>
/// 加密 CBC PKCS7模式
/// </summary>
/// <param name="str">要加密的数据</param>
/// <param name="key">秘钥</param>
/// <param name="iv">向量</param>
/// <returns>加密后的结果（base64格式）</returns>
public static string EncryptWithCBC(string str, byte[] key, byte[] iv)
{
var toEncryptArray = Encoding.UTF8.GetBytes(str);
return Convert.ToBase64String(Encrypt(toEncryptArray, key, iv, CipherMode.CBC, PaddingMode.PKCS7));
}
/// <summary>
/// 解密 CBC PKCS7模式
/// </summary>
/// <param name="str">要解密的数据（base64格式）</param>
/// <param name="key">秘钥（base64格式）</param>
/// <param name="iv">向量（base64格式）</param>
/// <returns>utf-8编码返回解密后得数据</returns>
public static string DecryptWithCBC(string str, string key, string iv)
{
return DecryptWithCBC(str, Convert.FromBase64String(key), Convert.FromBase64String(iv));
}
/// <summary>
///  解密 CBC PKCS7模式
/// </summary>
/// <param name="str">要解密的数据（base64格式）</param>
/// <param name="key">秘钥</param>
/// <param name="iv">向量</param>
/// <returns>utf-8编码返回解密后得数据</returns>
public static string DecryptWithCBC(string str, byte[] key, byte[] iv)
{
var toDecryptArray = Convert.FromBase64String(str);
return Encoding.UTF8.GetString(Decrypt(toDecryptArray, key, iv, CipherMode.CBC, PaddingMode.PKCS7));
}
/// <summary>
/// 加密
/// </summary>
/// <param name="data">要加密的数据</param>
/// <param name="key">秘钥</param>
/// <param name="iv">向量</param>
/// <param name="cipherMode">块模式</param>
/// <param name="paddingMode">填充模式</param>
/// <returns>加密后得到的数组</returns>
public static byte[] Encrypt(byte[] data, byte[] key, byte[] iv, CipherMode cipherMode, PaddingMode paddingMode)
{
return Transform(data, cipherMode, paddingMode, algorithm => algorithm.CreateEncryptor(key, iv));
}
/// <summary>
/// 解密
/// </summary>
/// <param name="data">要解密的数据</param>
/// <param name="key">秘钥</param>
/// <param name="iv">向量</param>
/// <param name="cipherMode">块模式</param>
/// <param name="paddingMode">填充模式</param>
/// <returns>解密后的到的数组</returns>
public static byte[] Decrypt(byte[] data, byte[] key, byte[] iv, CipherMode cipherMode, PaddingMode paddingMode)
{
return Transform(data, cipherMode, paddingMode, algorithm => algorithm.CreateDecryptor(key, iv));
}
private static byte[] Transform(byte[] data, CipherMode cipherMode, PaddingMode paddingMode, Func<T, ICryptoTransform> func)
{
using (T algorithm = new T
{
Mode = cipherMode,
Padding = paddingMode
})
{
using (ICryptoTransform cTransform = func(algorithm))
{
return cTransform.TransformFinalBlock(data, 0, data.Length);
}
}
}
/// <summary>
/// 生成秘钥
/// </summary>
/// <param name="key">秘钥(base64格式)</param>
/// <param name="iv">iv向量(base64格式)</param>
/// <param name="keySize">要生成的KeySize</param>
public static void Create(out string key, out string iv, int keySize)
{
KeyGenerator.CreateSymmetricAlgorithmKey<T>(out key, out iv, keySize);
}
}
public class TripleDESHelper : SymmetricAlgorithmHelper<TripleDESCryptoServiceProvider>
{
/// <summary>
/// 生成秘钥
/// </summary>
/// <param name="key">秘钥(base64格式)</param>
/// <param name="iv">iv向量(base64格式)</param>
/// <param name="keySize">要生成的KeySize，只支持128、192</param>
public static new void Create(out string key, out string iv, int keySize = 192)
{
KeyGenerator.CreateSymmetricAlgorithmKey<TripleDESCryptoServiceProvider>(out key, out iv, keySize);
}
}
public class AESHelper : SymmetricAlgorithmHelper<AesCryptoServiceProvider>//RijndaelManaged
{
/// <summary>
/// 生成秘钥
/// </summary>
/// <param name="key">秘钥(base64格式)</param>
/// <param name="iv">iv向量(base64格式)</param>
/// <param name="keySize">要生成的KeySize，只支持128、192、256，java一般生成的秘钥长度为128，所以这里默认也采用128</param>
public static new void Create(out string key, out string iv, int keySize = 128)
{
KeyGenerator.CreateSymmetricAlgorithmKey<AesCryptoServiceProvider>(out key, out iv, keySize);
}
}
public class DESHelper : SymmetricAlgorithmHelper<DESCryptoServiceProvider>
{
/// <summary>
/// 生成秘钥
/// </summary>
/// <param name="key">秘钥(base64格式)</param>
/// <param name="iv">iv向量(base64格式)</param>
/// <param name="keySize">要生成的KeySize，DES只支持64，所以此处切勿传其它值</param>
public static new void Create(out string key, out string iv, int keySize = 64)
{
KeyGenerator.CreateSymmetricAlgorithmKey<DESCryptoServiceProvider>(out key, out iv, keySize);
}
}
public class RC2Helper : SymmetricAlgorithmHelper<RC2CryptoServiceProvider>
{
/// <summary>
/// 生成秘钥
/// </summary>
/// <param name="key">秘钥(base64格式)</param>
/// <param name="iv">iv向量(base64格式)</param>
/// <param name="keySize">要生成的KeySize，支持的MinSize:40 MaxSize:128 SkipSize:8</param>
public static new void Create(out string key, out string iv, int keySize = 96)
{
KeyGenerator.CreateSymmetricAlgorithmKey<RC2CryptoServiceProvider>(out key, out iv, keySize);
}
}

因为每种加密方式对Key长度的支持不一样，所以除SymmetricAlgorithmHelper外，还通过继承的方式覆盖了创建秘钥的Create方法，分别为TripleDESHelper、AESHelper、DESHelper、RC2Helper，KeyGenerator的代码在这里，而测试代码如下

static void SymmetricAlgorithmDemo<T>(int keySize = 128)
where T : SymmetricAlgorithm, new()
{
string key, iv;
SymmetricAlgorithmHelper<T>.Create(out key, out iv, keySize);
Console.WriteLine("Key:" + key);
Console.WriteLine("IV:" + iv);
SymmetricAlgorithmDemo<T>(key, iv);
}
static void SymmetricAlgorithmDemo<T>(string key, string iv)
where T : SymmetricAlgorithm, new()
{
string content = "测试数据";
string name = typeof(T).Name;
string encTxt = SymmetricAlgorithmHelper<T>.EncryptWithECB(content, key);
Console.WriteLine(name + " ECB PKCS7加密结果：" + encTxt);
Console.WriteLine(name + " ECB PKCS7解密结果：" + SymmetricAlgorithmHelper<T>.DecryptWithECB(encTxt, key));
encTxt = SymmetricAlgorithmHelper<T>.EncryptWithCBC(content, key, iv);
Console.WriteLine(name + " CBC PKCS7加密结果：" + encTxt);
Console.WriteLine(name + " CBC PKCS7解密结果：" + SymmetricAlgorithmHelper<T>.DecryptWithCBC(encTxt, key, iv));
encTxt = Convert.ToBase64String(SymmetricAlgorithmHelper<T>.Encrypt(Encoding.UTF8.GetBytes(content), Convert.FromBase64String(key), Convert.FromBase64String(iv), CipherMode.CFB, PaddingMode.Zeros));
Console.WriteLine(name + " CFB Zeros加密结果：" + encTxt);
Console.WriteLine(name + " CFB Zeros解密结果：" + Encoding.UTF8.GetString(SymmetricAlgorithmHelper<T>.Decrypt(Convert.FromBase64String(encTxt), Convert.FromBase64String(key), Convert.FromBase64String(iv), CipherMode.CFB, PaddingMode.Zeros)));
}

static void Main(string[] args)
{
SymmetricAlgorithmDemo<TripleDESCryptoServiceProvider>();
SymmetricAlgorithmDemo<AesCryptoServiceProvider>();
SymmetricAlgorithmDemo<RijndaelManaged>();//AES
SymmetricAlgorithmDemo<DESCryptoServiceProvider>(64);
SymmetricAlgorithmDemo<RC2CryptoServiceProvider>();

string key, iv;
SymmetricAlgorithmHelper<RijndaelManaged>.Create(out key, out iv, 256);
Console.WriteLine("Key:" + key);
Console.WriteLine("IV:" + iv);
//验证AesCryptoServiceProvider和RijndaelManaged加密结果是否一致
SymmetricAlgorithmDemo<AesCryptoServiceProvider>(key, iv);
SymmetricAlgorithmDemo<RijndaelManaged>(key, iv);//AES
//测试AESHelper加密结果是否与上面一致
string encTxt = AESHelper.EncryptWithECB("测试数据", key);
Console.WriteLine("AESHelper ECB PKCS7加密结果：" + encTxt);
Console.WriteLine("AESHelper ECB PKCS7解密结果：" + AESHelper.DecryptWithECB(encTxt, key));
}