using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Security.Cryptography;
using System.Text;
using System.Web;

namespace DSWeb.Areas.Dispatch.Helper
{
    public class AesHelper
    {
        /// <summary>
        /// AES加密
        /// </summary>
        /// <param name="Data">被加密的明文</param>
        /// <param name="Key">密钥</param>
        /// <param name="Vector">向量</param>
        /// <returns>密文</returns>
        public static Byte[] AESEncrypt(Byte[] Data, String Key, String Vector)
        {
            Byte[] bKey = new Byte[32];
            Array.Copy(Encoding.UTF8.GetBytes(Key.PadRight(bKey.Length)), bKey, bKey.Length);
            Byte[] bVector = new Byte[16];
            Array.Copy(Encoding.UTF8.GetBytes(Vector.PadRight(bVector.Length)), bVector, bVector.Length);

            Byte[] Cryptograph = null; // 加密后的密文

            Rijndael Aes = Rijndael.Create();
            try
            {
                // 开辟一块内存流
                using (MemoryStream Memory = new MemoryStream())
                {
                    // 把内存流对象包装成加密流对象
                    using (CryptoStream Encryptor = new CryptoStream(Memory,
                     Aes.CreateEncryptor(bKey, bVector),
                     CryptoStreamMode.Write))
                    {
                        // 明文数据写入加密流
                        Encryptor.Write(Data, 0, Data.Length);
                        Encryptor.FlushFinalBlock();

                        Cryptograph = Memory.ToArray();
                    }
                }
            }
            catch
            {
                Cryptograph = null;
            }

            return Cryptograph;
        }

        /// <summary>
        /// AES解密
        /// </summary>
        /// <param name="Data">被解密的密文</param>
        /// <param name="Key">密钥</param>
        /// <param name="Vector">向量</param>
        /// <returns>明文</returns>
        public static Byte[] AESDecrypt(Byte[] Data, String Key, String Vector)
        {
            Byte[] bKey = new Byte[32];
            Array.Copy(Encoding.UTF8.GetBytes(Key.PadRight(bKey.Length)), bKey, bKey.Length);
            Byte[] bVector = new Byte[16];
            Array.Copy(Encoding.UTF8.GetBytes(Vector.PadRight(bVector.Length)), bVector, bVector.Length);

            Byte[] original = null; // 解密后的明文

            Rijndael Aes = Rijndael.Create();
            try
            {
                // 开辟一块内存流，存储密文
                using (MemoryStream Memory = new MemoryStream(Data))
                {
                    // 把内存流对象包装成加密流对象
                    using (CryptoStream Decryptor = new CryptoStream(Memory,
                    Aes.CreateDecryptor(bKey, bVector),
                    CryptoStreamMode.Read))
                    {
                        // 明文存储区
                        using (MemoryStream originalMemory = new MemoryStream())
                        {
                            Byte[] Buffer = new Byte[1024];
                            Int32 readBytes = 0;
                            while ((readBytes = Decryptor.Read(Buffer, 0, Buffer.Length)) > 0)
                            {
                                originalMemory.Write(Buffer, 0, readBytes);
                            }

                            original = originalMemory.ToArray();
                        }
                    }
                }
            }
            catch
            {
                original = null;
            }

            return original;
        }

        public static byte[] AESDecrypt(byte[] Data, byte[] Key, byte[] vector)
        {
            byte[] original = null; // 解密后的明文

            Rijndael Aes = Rijndael.Create();
            try
            {
                // 开辟一块内存流，存储密文
                using (MemoryStream Memory = new MemoryStream(Data))
                {
                    // 把内存流对象包装成加密流对象
                    using (CryptoStream Decryptor = new CryptoStream(Memory,
                    Aes.CreateDecryptor(Key, vector),
                    CryptoStreamMode.Read))
                    {
                        // 明文存储区
                        using (MemoryStream originalMemory = new MemoryStream())
                        {
                            byte[] Buffer = new byte[1024];
                            int readBytes = 0;
                            while ((readBytes = Decryptor.Read(Buffer, 0, Buffer.Length)) > 0)
                            {
                                originalMemory.Write(Buffer, 0, readBytes);
                            }

                            original = originalMemory.ToArray();
                        }
                    }
                }
            }
            catch
            {
                original = null;
            }

            return original;
        }
    }
}