using System;
using System.Runtime.InteropServices;
using System.Text;
using PTMedicalInsurance.Variables;

namespace PTMedicalInsurance.Common
{
    class YinHaiEncrypt
    {
        //加密
        [DllImport("hsafsiyhsafe.dll", CharSet = CharSet.Ansi, EntryPoint = "gm_ecb_encrypt_key@16", CallingConvention = CallingConvention.StdCall)]
        private static extern int gm_ecb_encrypt_key(byte[] pub_key, byte[] plain, int plain_len, byte[] cipher);
        //解密
        [DllImport("hsafsiyhsafe.dll", CharSet = CharSet.Ansi, EntryPoint = "gm_ecb_decrypt_key@16", CallingConvention = CallingConvention.StdCall)]
        private static extern int gm_ecb_decrypt_key(byte[] pub_key, byte[] cipher, int cipher_len, byte[] plain);
        //生成签名
        [DllImport("hsafsitool.dll", EntryPoint = "gm_sign_key@24", CharSet = CharSet.Ansi, ExactSpelling = false, CallingConvention = CallingConvention.StdCall)]
        private static extern int gm_sign_key(byte[] userid, byte[] prv_key, byte[] pub_key, byte[] msg, int msg_len, byte[] singrs);
        //验签
        [DllImport("hsafsitool.dll", EntryPoint = "gm_verify_key@20", CharSet = CharSet.Ansi, ExactSpelling = false, CallingConvention = CallingConvention.StdCall)]
        private static extern int gm_verify_key(byte[] userid, byte[] pub_key, byte[] msg, int msg_len, byte[] singrs);


        public const string pubKey = "725871EF03A7AA708708615A0B9400C14A9E7E4F0E5E14E911AE39CD9177C17685DED3BBDB1B242F09393BA7A0C852338A0D06D1619B79B70CF3CCD3754FF646";

        public const string prvKey = "BC5E29E032BF908DEB6EB180A0C61ED7F9AA7BF56C35B727A85CD65F79504384";

        public string Signature(string data)
        {
            string rtn = "";
            try
            {
                byte[] pub_key = Encoding.UTF8.GetBytes(pubKey);
                byte[] prv_key = Encoding.UTF8.GetBytes(prvKey);
                byte[] userid = Encoding.UTF8.GetBytes("");
                byte[] msg = Encoding.UTF8.GetBytes(data);
                byte[] singrs = new byte[1024];
                if (gm_sign_key(userid, prv_key, pub_key, msg, msg.Length, singrs) > 0)
                {
                    rtn = Encoding.UTF8.GetString(singrs).Replace("\u0000", "").Trim();
                }
                else
                {
                    rtn = "";
                }
                return rtn;

            }
            catch (Exception ex)
            {
                rtn = "" + ex.Message;
                return rtn;
            }
            finally
            {
                Global.writeLog("", data, rtn);
            }

        }

        public int VerifySignature(string plain, string signature)
        {
            byte[] pub_key = Encoding.UTF8.GetBytes(pubKey);
            byte[] prv_key = Encoding.UTF8.GetBytes(prvKey);
            byte[] userid = Encoding.UTF8.GetBytes("");
            byte[] msg = Encoding.UTF8.GetBytes(plain);
            byte[] singrs = Encoding.UTF8.GetBytes(signature);
            int result = gm_verify_key(userid, pub_key, msg, msg.Length, singrs);
            return result;
        }
        public string Encrypt(string plain)
        {

            byte[] plainB = Encoding.UTF8.GetBytes(plain);
            byte[] cipher = new byte[(plainB.Length + 2048)];
            byte[] pub_key = Encoding.UTF8.GetBytes(pubKey);
            Global.writeLog("Encrypt明文：'" + plain + "'");

            if (gm_ecb_encrypt_key(pub_key, plainB, plainB.Length, cipher) > 0)
            {
                string result = Encoding.UTF8.GetString(cipher).Replace("\u0000", "").Trim();
                Global.writeLog("Encrypt密文：" + result);
                return result;
            }
            else
            {
                return "";
            }
        }

        public string Decrypt(string cipher)
        {
            byte[] pub_key = Encoding.UTF8.GetBytes(pubKey);
            byte[] cipherB = Encoding.UTF8.GetBytes(cipher);
            byte[] plain = new byte[(cipherB.Length)];
            if (gm_ecb_decrypt_key(pub_key, cipherB, cipher.Length, plain) > 0)
            {
                return Encoding.UTF8.GetString(plain);
            }
            else
            {
                return "";
            }
        }
    }
}