AES加密和解密

/// <summary>
/// AES 加密与java特殊处理秘钥后结果一致
/// </summary>
/// <param name="str">明文（待加密）</param>
/// <param name="key">密文</param>
/// <returns></returns>
private static string AESEncrypt(string str, string key)
{
if (string.IsNullOrEmpty(str)) return null;
Byte[] toEncryptArray = Encoding.UTF8.GetBytes(str);

byte[] keyArray = null;
using (var sha1 = new SHA1CryptoServiceProvider())
{
byte[] hash = sha1.ComputeHash(Encoding.UTF8.GetBytes(key));
var rd = sha1.ComputeHash(hash);
keyArray = rd.Take(16).ToArray();
}

RijndaelManaged rm = new RijndaelManaged
{
Key = keyArray,
Mode = CipherMode.ECB,
Padding = PaddingMode.PKCS7
};

ICryptoTransform cTransform = rm.CreateEncryptor();
Byte[] resultArray = cTransform.TransformFinalBlock(toEncryptArray, 0, toEncryptArray.Length);

return Convert.ToBase64String(resultArray, 0, resultArray.Length);
}
/// <summary>
/// AES 解密
/// </summary>
/// <param name="str">明文（待解密）</param>
/// <param name="key">密文</param>
/// <returns></returns>
private static string AESDecrypt(string str, string key)
{
if (string.IsNullOrEmpty(str)) return null;
Byte[] toEncryptArray = Convert.FromBase64String(str);

byte[] keyArray = null;
using (var sha1 = new SHA1CryptoServiceProvider())
{
byte[] hash = sha1.ComputeHash(Encoding.UTF8.GetBytes(key));
var rd = sha1.ComputeHash(hash);
keyArray = rd.Take(16).ToArray();
}

RijndaelManaged rm = new RijndaelManaged
{
Key = keyArray,
Mode = CipherMode.ECB,
Padding = PaddingMode.PKCS7
};

ICryptoTransform cTransform = rm.CreateDecryptor();
Byte[] resultArray = cTransform.TransformFinalBlock(toEncryptArray, 0, toEncryptArray.Length);

return Encoding.UTF8.GetString(resultArray);
}