使用AES加密的帮助类

public class EncryptionHelper
{
//默认密钥向量
private static readonly byte[] DefaultKey = {0x12, 0x34, 0x56, 120, 0x90, 0xab, 0xcd, 0xef};

/// <summary>
///     解密字节数组
/// </summary>
/// <param name="cipherBytes">密文字节数组</param>
/// <param name="password">密钥</param>
/// <returns>解密后字节数组</returns>
public static byte[] DecryptBytes(byte[] cipherBytes, string password)
{
byte[] buffer;
try
{
using (Aes aes = new AesManaged())
{
//设置密钥及密钥向量
aes.Key = new Rfc2898DeriveBytes(password, DefaultKey).GetBytes(0x10);
aes.IV = aes.Key;
using (var memoryStream = new MemoryStream())
{
using (
var cryptoStream = new CryptoStream(memoryStream, aes.CreateDecryptor(),
CryptoStreamMode.Write))
{
cryptoStream.Write(cipherBytes, 0, cipherBytes.Length);
cryptoStream.Flush();
}
//得到解密后的字节数组
buffer = memoryStream.ToArray();
}
}
}
catch
{
buffer = null;
}
return buffer;
}

/// <summary>
///     解密字符串
/// </summary>
/// <param name="cipherText">密文</param>
/// <param name="password">密钥</param>
/// <returns>解密后字符串</returns>
public static string DecryptString(string cipherText, string password)
{
byte[] decryptBytes = DecryptBytes(Convert.FromBase64String(cipherText), password);
if (decryptBytes == null)
{
return null;
}
return Encoding.UTF8.GetString(decryptBytes, 0, decryptBytes.Length);
}

/// <summary>
///     加密字节数组
/// </summary>
/// <param name="plainBytes">明文字节数组</param>
/// <param name="password">密钥</param>
/// <returns>加密后字节数组</returns>
public static byte[] EncryptBytes(byte[] plainBytes, string password)
{
byte[] buffer;
try
{
using (Aes aes = new AesManaged())
{
//设置密钥及密钥向量
aes.Key = new Rfc2898DeriveBytes(password, DefaultKey).GetBytes(0x10);
aes.IV = aes.Key;
using (var memoryStream = new MemoryStream())
{
using (
var cryptoStream = new CryptoStream(memoryStream, aes.CreateEncryptor(),
CryptoStreamMode.Write))
{
cryptoStream.Write(plainBytes, 0, plainBytes.Length);
cryptoStream.FlushFinalBlock();
}
//得到加密后的字节数组
buffer = memoryStream.ToArray();
}
}
}
catch
{
buffer = null;
}
return buffer;
}

/// <summary>
///     加密字符串
/// </summary>
/// <param name="plainText">明文</param>
/// <param name="password">密钥</param>
/// <returns>加密后字符串</returns>
public static string EncryptString(string plainText, string password)
{
byte[] cipherBytes = EncryptBytes(Encoding.UTF8.GetBytes(plainText), password);
if (cipherBytes == null)
{
return null;
}
return Convert.ToBase64String(cipherBytes);
}
}