private static SymmetricAlgorithm GetSymmetricAlgorithm(CryptoKind kind)
{
SymmetricAlgorithm algorithm = null;
switch (kind)
{
case CryptoKind.DES:
algorithm = DES.Create();
break;
case CryptoKind.TripleDES:
algorithm = TripleDES.Create();
break;
case CryptoKind.RC2:
algorithm = RC2.Create();
break;
case CryptoKind.Rijndael:
algorithm = Rijndael.Create();
break;
case CryptoKind.AES:
algorithm = Aes.Create();
break;
}
return(algorithm);
}
/// <summary>
/// 对称减密。
/// </summary>
/// <param name="data">内容。</param>
/// <param name="key">键。</param>
/// <param name="iv">初始化向量。</param>
/// <param name="kind">减密方式。</param>
/// <returns></returns>
public static string Decrypt(this string data, string key, string iv, CryptoKind kind = CryptoKind.DES)
{
if (data is null)
{
throw new ArgumentNullException(nameof(data));
}
if (key is null)
{
throw new ArgumentNullException(nameof(key));
}
if (iv is null)
{
throw new ArgumentNullException(nameof(iv));
}
ICryptoTransform crypto = null;
using (var algorithm = GetSymmetricAlgorithm(kind))
{
var rgbKey = Encoding.ASCII.GetBytes(key);
var rgbIV = Encoding.ASCII.GetBytes(iv);
if (!algorithm.ValidKeySize(rgbKey.Length * 8))
{
throw new ArgumentOutOfRangeException(nameof(key));
}
if (algorithm.IV.Length != rgbIV.Length)
{
throw new ArgumentOutOfRangeException(nameof(iv));
}
crypto = algorithm.CreateDecryptor(rgbKey, rgbIV);
}
using (var ms = new MemoryStream())
{
using (var cs = new CryptoStream(ms, crypto, CryptoStreamMode.Write))
{
var buffer = Convert.FromBase64String(data);
cs.Write(buffer, 0, buffer.Length);
cs.FlushFinalBlock();
cs.Close();
}
return(Encoding.UTF8.GetString(ms.ToArray()));
}
}
/// <summary>
/// 对称加密（<see cref="CipherMode.ECB"/>，<seealso cref="PaddingMode.PKCS7"/>）。
/// </summary>
/// <param name="data">内容。</param>
/// <param name="key">键。</param>
/// <param name="kind">加密方式。</param>
/// <returns></returns>
public static string Encrypt(this string data, string key, CryptoKind kind = CryptoKind.DES)
{
if (data is null)
{
throw new ArgumentNullException(nameof(data));
}
if (key is null)
{
throw new ArgumentNullException(nameof(key));
}
ICryptoTransform crypto = null;
using (var algorithm = GetSymmetricAlgorithm(kind))
{
var rgbKey = Encoding.ASCII.GetBytes(key);
if (!algorithm.ValidKeySize(rgbKey.Length * 8))
{
throw new ArgumentOutOfRangeException(nameof(key));
}
algorithm.Key = rgbKey;
algorithm.Mode = CipherMode.ECB;
algorithm.Padding = PaddingMode.PKCS7;
crypto = algorithm.CreateEncryptor();
}
using (var ms = new MemoryStream())
{
using (var cs = new CryptoStream(ms, crypto, CryptoStreamMode.Write))
{
var buffer = Encoding.UTF8.GetBytes(data);
cs.Write(buffer, 0, buffer.Length);
cs.FlushFinalBlock();
cs.Close();
}
return(Convert.ToBase64String(ms.ToArray()));
}
}
