MedicalInsurance/BeiJingMI/Lib/SM4Crypto.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace SM4Crypto.Lib
{
    class SM4Crypto
    {
        private static readonly uint[] FK = { 0xa3b1bac6, 0x56aa3350, 0x677d9197, 0xb27022dc };
        private static readonly uint[] CK = {
        0x00070e15, 0x1c232a31, 0x383f464d, 0x545b6269,
        0x70777e85, 0x8c939aa1, 0xa8afb6bd, 0xc4cbd2d9,
        0xe0e7eef5, 0xfc030a11, 0x181f262d, 0x343b4249,
        0x50575e65, 0x6c737a81, 0x888f969d, 0xa4abb2b9,
        0xc0c7ced5, 0xdce3eaf1, 0xf8ff060d, 0x141b2229,
        0x30373e45, 0x4c535a61, 0x686f767d, 0x848b9299,
        0xa0a7aeb5, 0xbcc3cad1, 0xd8dfe6ed, 0xf4fb0209,
        0x10171e25, 0x2c333a41, 0x484f565d, 0x646b7279
    };

        public static string Encrypt(string plainText, string keyHex)
        {
            byte[] key = HexStringToByteArray(keyHex);
            byte[] data = Encoding.UTF8.GetBytes(plainText);

            // 添加PKCS7填充
            data = PKCS7Padding(data);

            byte[] encrypted = SM4Encrypt(data, key);
            return Convert.ToBase64String(encrypted);
        }

        private static byte[] SM4Encrypt(byte[] input, byte[] key)
        {
            uint[] roundKeys = GenerateRoundKeys(key);
            byte[] output = new byte[input.Length];

            for (int i = 0; i < input.Length; i += 16)
            {
                byte[] block = new byte[16];
                Array.Copy(input, i, block, 0, 16);
                byte[] encryptedBlock = EncryptBlock(block, roundKeys);
                Array.Copy(encryptedBlock, 0, output, i, 16);
            }

            return output;
        }

        private static byte[] EncryptBlock(byte[] input, uint[] roundKeys)
        {
            uint x0 = BytesToUint(input, 0);
            uint x1 = BytesToUint(input, 4);
            uint x2 = BytesToUint(input, 8);
            uint x3 = BytesToUint(input, 12);

            for (int i = 0; i < 32; i++)
            {
                uint temp = x1 ^ x2 ^ x3 ^ roundKeys[i];
                temp = SBox(temp);
                temp = temp ^ LeftRotate(temp, 13) ^ LeftRotate(temp, 23);
                temp = temp ^ x0;

                x0 = x1;
                x1 = x2;
                x2 = x3;
                x3 = temp;
            }

            byte[] output = new byte[16];
            UintToBytes(x3, output, 0);
            UintToBytes(x2, output, 4);
            UintToBytes(x1, output, 8);
            UintToBytes(x0, output, 12);

            return output;
        }

        private static uint[] GenerateRoundKeys(byte[] key)
        {
            uint[] mk = new uint[4];
            for (int i = 0; i < 4; i++)
            {
                mk[i] = BytesToUint(key, i * 4);
            }

            uint[] k = new uint[36];
            k[0] = mk[0] ^ FK[0];
            k[1] = mk[1] ^ FK[1];
            k[2] = mk[2] ^ FK[2];
            k[3] = mk[3] ^ FK[3];

            uint[] roundKeys = new uint[32];
            for (int i = 0; i < 32; i++)
            {
                k[i + 4] = k[i] ^ TTransform(k[i + 1] ^ k[i + 2] ^ k[i + 3] ^ CK[i]);
                roundKeys[i] = k[i + 4];
            }

            return roundKeys;
        }

        private static uint TTransform(uint value)
        {
            value = SBox(value);
            return value ^ LeftRotate(value, 13) ^ LeftRotate(value, 23);
        }

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

            uint result = 0;
            for (int i = 0; i < 4; i++)
            {
                byte b = (byte)((value >> (24 - i * 8)) & 0xFF);
                result = (result << 8) | sbox[b];
            }
            return result;
        }

        private static uint LeftRotate(uint value, int shift)
        {
            return (value << shift) | (value >> (32 - shift));
        }

        private static uint BytesToUint(byte[] bytes, int offset)
        {
            return (uint)((bytes[offset] << 24) | (bytes[offset + 1] << 16) | (bytes[offset + 2] << 8) | bytes[offset + 3]);
        }

        private static void UintToBytes(uint value, byte[] bytes, int offset)
        {
            bytes[offset] = (byte)(value >> 24);
            bytes[offset + 1] = (byte)(value >> 16);
            bytes[offset + 2] = (byte)(value >> 8);
            bytes[offset + 3] = (byte)value;
        }

        private static byte[] PKCS7Padding(byte[] data)
        {
            int padding = 16 - (data.Length % 16);
            byte[] result = new byte[data.Length + padding];
            Array.Copy(data, result, data.Length);
            for (int i = data.Length; i < result.Length; i++)
            {
                result[i] = (byte)padding;
            }
            return result;
        }

        private static byte[] HexStringToByteArray(string hex)
        {
            if (hex.Length % 2 != 0)
                throw new ArgumentException("十六进制字符串长度必须是偶数");

            byte[] bytes = new byte[hex.Length / 2];
            for (int i = 0; i < hex.Length; i += 2)
            {
                bytes[i / 2] = Convert.ToByte(hex.Substring(i, 2), 16);
            }
            return bytes;
        }
    }
}