using System;
using System.Security.Cryptography;
using System.Text;

namespace TEAMModelOS.SDK.Helper.Security.AESCrypt
{

    /// <summary>
    /// Describe：AES 加密算法
    /// </summary>
    public class AESCrypt
    {
        public const string RET_ERROR = "x07x07x07x07x07";
        private byte[] _IV = { 0x12, 0x34, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF, 0x12, 0x34, 0x56, 0x78, 0x90, 0xAB, 0xCD, 0xEF };
        private byte[] _Key = { 0x63, 0x7c, 0x77, 0x7b, 0xf2, 0x6b, 0x6f, 0xc5, 0x30, 0x01, 0x67, 0x2b, 0xfe, 0xd7, 0xab, 0x76, 0xca, 0x82, 0xc9, 0x7d, 0xfa, 0x59, 0x47, 0xf0, 0xad, 0xd4, 0xa2, 0xaf, 0x9c, 0xa4, 0x72, 0xc0, 0xb7, 0xfd, 0x93, 0x26, 0x36, 0x3f, 0xf7, 0xcc, 0x34, 0xa5, 0xe5, 0xf1, 0x71, 0xd8, 0x31, 0x15, 0x04, 0xc7, 0x23, 0xc3, 0x18, 0x96, 0x05, 0x9a, 0x07, 0x12, 0x80, 0xe2, 0xeb, 0x27, 0xb2, 0x75, 0x09, 0x83, 0x2c, 0x1a, 0x1b, 0x6e, 0x5a, 0xa0, 0x52, 0x3b, 0xd6, 0xb3, 0x29, 0xe3, 0x2f, 0x84, 0x53, 0xd1, 0x00, 0xed, 0x20, 0xfc, 0xb1, 0x5b, 0x6a, 0xcb, 0xbe, 0x39, 0x4a, 0x4c, 0x58, 0xcf, 0xd0, 0xef, 0xaa, 0xfb, 0x43, 0x4d, 0x33, 0x85, 0x45, 0xf9, 0x02, 0x7f, 0x50, 0x3c, 0x9f, 0xa8, 0x51, 0xa3, 0x40, 0x8f, 0x92, 0x9d, 0x38, 0xf5, 0xbc, 0xb6, 0xda, 0x21, 0x10, 0xff, 0xf3, 0xd2, 0xcd, 0x0c, 0x13, 0xec, 0x5f, 0x97, 0x44, 0x17, 0xc4, 0xa7, 0x7e, 0x3d, 0x64, 0x5d, 0x19, 0x73, 0x60, 0x81, 0x4f, 0xdc, 0x22, 0x2a, 0x90, 0x88, 0x46, 0xee, 0xb8, 0x14, 0xde, 0x5e, 0x0b, 0xdb, 0xe0, 0x32, 0x3a, 0x0a, 0x49, 0x06, 0x24, 0x5c, 0xc2, 0xd3, 0xac, 0x62, 0x91, 0x95, 0xe4, 0x79, 0xe7, 0xc8, 0x37, 0x6d, 0x8d, 0xd5, 0x4e, 0xa9, 0x6c, 0x56, 0xf4, 0xea, 0x65, 0x7a, 0xae, 0x08, 0xba, 0x78, 0x25, 0x2e, 0x1c, 0xa6, 0xb4, 0xc6, 0xe8, 0xdd, 0x74, 0x1f, 0x4b, 0xbd, 0x8b, 0x8a, 0x70, 0x3e, 0xb5, 0x66, 0x48, 0x03, 0xf6, 0x0e, 0x61, 0x35, 0x57, 0xb9, 0x86, 0xc1, 0x1d, 0x9e, 0xe1, 0xf8, 0x98, 0x11, 0x69, 0xd9, 0x8e, 0x94, 0x9b, 0x1e, 0x87, 0xe9, 0xce, 0x55, 0x28, 0xdf, 0x8c, 0xa1, 0x89, 0x0d, 0xbf, 0xe6, 0x42, 0x68, 0x41, 0x99, 0x2d, 0x0f, 0xb0, 0x54, 0xbb, 0x16 };
        private const string CRYPTO_KEY = "ENCRYPTIONALGORITHMBYYUANGANG";
        private int CRYPTO_KEY_LENGTH = 32;

        private Aes m_aesCryptoServiceProvider;
        private string m_message;
        public string Message
        {
            get { return m_message; }
            set { m_message = value; }
        }
        private bool m_containKey;
        /// <summary>
        /// True：密文中包含密钥
        /// False：密文中不包含密钥
        /// </summary>
        public bool ContainKey
        {
            get { return m_containKey; }
            set { m_containKey = value; }
        }
        public AESCrypt()
        {
            m_aesCryptoServiceProvider = Aes.Create();
            m_containKey = true;
            m_message = string.Empty;
        }
        public AESCrypt(bool containKey)
            : this()
        {
            m_containKey = containKey;
        }
        private string Encrypt(string s_crypto, byte[] key)
        {
            string s_encryped = string.Empty;
            byte[] crypto, encrypted;
            ICryptoTransform ct;

            try
            {
                crypto = string2Byte(s_crypto);
                m_aesCryptoServiceProvider.Key = key;
                m_aesCryptoServiceProvider.IV = _IV;
                ct = m_aesCryptoServiceProvider.CreateEncryptor();
                encrypted = ct.TransformFinalBlock(crypto, 0, crypto.Length);
                if (m_containKey)
                {
                    s_encryped += byte2HexString(key);
                }
                s_encryped += byte2HexString(encrypted);
                return s_encryped;
            }
            catch (Exception ex)
            {
                m_message = ex.ToString();
                return RET_ERROR;
            }
        }
        private string Decrypt(string s_encrypted, byte[] key)
        {
            string s_decrypted = string.Empty;
            byte[] encrypted, decrypted;
            ICryptoTransform ct;

            try
            {
                encrypted = hexString2Byte(s_encrypted);
                m_aesCryptoServiceProvider.Key = key;
                m_aesCryptoServiceProvider.IV = _IV;
                ct = m_aesCryptoServiceProvider.CreateDecryptor();
                decrypted = ct.TransformFinalBlock(encrypted, 0, encrypted.Length);
                s_decrypted += byte2String(decrypted);
                return s_decrypted;
            }
            catch (Exception ex)
            {
                m_message = ex.ToString();
                m_message = "Decrypt fail.";
                return RET_ERROR;
            }
        }

        #region 加密

        /// <summary>
        /// 指定密钥对明文进行AES加密
        /// </summary>
        /// <param name="s_crypto">明文</param>
        /// <param name="s_key">加密密钥</param>
        /// <returns></returns>
        public string Encrypt(string s_crypto, string s_key)
        {
            byte[] key = new byte[CRYPTO_KEY_LENGTH];

            byte[] temp = string2Byte(s_key);
            if (temp.Length > key.Length)
            {
                m_message = "Key too long,need less than 32 Bytes key.";
                return RET_ERROR;
            }
            key = string2Byte(s_key.PadRight(key.Length));
            return Encrypt(s_crypto, key);
        }
        /// <summary>
        /// 动态生成密钥，并对明文进行AES加密
        /// </summary>
        /// <param name="s_crypto">明文</param>
        /// <returns></returns>
        public string Encrypt(string s_crypto)
        {
            byte[] key = new byte[CRYPTO_KEY_LENGTH];

            m_aesCryptoServiceProvider.GenerateKey();
            key = m_aesCryptoServiceProvider.Key;
            return Encrypt(s_crypto, key);
        }

        #endregion

        #region 解密

        /// <summary>
        /// 从密文中解析出密钥，并对密文进行解密
        /// </summary>
        /// <param name="s_encrypted">密文</param>
        /// <returns></returns>
        public string Decrypt(string s_encrypted)
        {
            string s_key = string.Empty;
            byte[] key = new byte[CRYPTO_KEY_LENGTH];

            if (s_encrypted.Length <= CRYPTO_KEY_LENGTH * 2)
            {
                m_message = "Encrypted string invalid.";
                return RET_ERROR;
            }
            if (m_containKey)
            {
                s_key = s_encrypted.Substring(0, CRYPTO_KEY_LENGTH * 2);
                s_encrypted = s_encrypted.Substring(CRYPTO_KEY_LENGTH * 2);
            }
            key = hexString2Byte(s_key);
            return Decrypt(s_encrypted, key);
        }
        /// <summary>
        /// 指定密钥，并对密文进行解密
        /// </summary>
        /// <param name="s_encrypted">密文</param>
        /// <param name="s_key">密钥</param>
        /// <returns></returns>
        public string Decrypt(string s_encrypted, string s_key)
        {
            byte[] key = new byte[CRYPTO_KEY_LENGTH];

            byte[] temp = string2Byte(s_key);
            if (temp.Length > key.Length)
            {
                m_message = "Key invalid.too long,need less than 32 Bytes";
                return RET_ERROR;
            }
            key = string2Byte(s_key.PadRight(key.Length));
            if (m_containKey)
            {
                s_encrypted = s_encrypted.Substring(CRYPTO_KEY_LENGTH * 2);
            }
            return Decrypt(s_encrypted, key);
        }

        #endregion

        #region 私有方法

        private string byte2HexString(byte[] bytes)
        {
            StringBuilder sb = new StringBuilder();
            foreach (byte b in bytes)
            {
                sb.AppendFormat("{0:X2}", b);
            }
            return sb.ToString();
        }
        private byte[] hexString2Byte(string hex)
        {
            int len = hex.Length / 2;
            byte[] bytes = new byte[len];
            for (int i = 0; i < len; i++)
            {
                bytes[i] = (byte)(Convert.ToInt32(hex.Substring(i * 2, 2), 16));
            }
            return bytes;
        }
        private byte[] string2Byte(string str)
        {
            return Encoding.UTF8.GetBytes(str);
        }
        private string byte2String(byte[] bytes)
        {
            return Encoding.UTF8.GetString(bytes);
        }

        #endregion

    }
}