C# SM4加密

最新推荐文章于 2025-04-07 17:26:44 发布
我还是那么诚实
最新推荐文章于 2025-04-07 17:26:44 发布
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文章标签： c# 加密解密
本文链接：https://blog.youkuaiyun.com/qq_20392837/article/details/119461230
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这个代码实现了一个名为SM4的加密算法，它包含加密和解密功能。SM4算法使用了S盒、轮常数和线性变换等操作。代码中定义了加密和解密的静态方法，以及密钥设置、轮密钥计算和ECB、CBC模式的加密解密过程。此外，还提供了密钥长度检查和填充功能。
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using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace ConsoleApp1
{
public class SM4
{
public static int SM4_ENCRYPT = 1;
    public static int SM4_DECRYPT = 0;

    private long GET_ULONG_BE(byte[] b, int i)
    {
        long n = (long)(b[i] & 0xff) << 24 | (long)((b[i + 1] & 0xff) << 16) | (long)((b[i + 2] & 0xff) << 8)
                | (long)(b[i + 3] & 0xff) & 0xffffffffL;
        return n;
    }

    private void PUT_ULONG_BE(long n, byte[] b, int i)
    {
        b[i] = (byte)(int)(0xFF & n >> 24);
        b[i + 1] = (byte)(int)(0xFF & n >> 16);
        b[i + 2] = (byte)(int)(0xFF & n >> 8);
        b[i + 3] = (byte)(int)(0xFF & n);
    }

    private long SHL(long x, int n)
    {
        return (x & 0xFFFFFFFF) << n;
    }

    private long ROTL(long x, int n)
    {
        return SHL(x, n) | x >> (32 - n);
    }

    private void SWAP(long[] sk, int i)
    {
        long t = sk[i];
        sk[i] = sk[(31 - i)];
        sk[(31 - i)] = t;
    }

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

    public static int[] FK = { -1548633402, 0x56aa3350, 0x677d9197, -1301273892 };

    public static int[] CK = { 462357, 472066609, 943670861, 1415275113, 1886879365, -1936483679, 
        -1464879427, -993275175, -521670923, -66909679, 404694573, 876298825, 1347903077, 1819507329, 
        -2003855715, -1532251463, -1060647211, -589042959, -117504499, 337322537, 808926789, 1280531041, 
        1752135293, -2071227751, -1599623499, -1128019247, -656414995, -184876535, 269950501, 741554753, 1213159005, 1684763257 };

    private byte sm4Sbox(byte inch)
    {
        int i = inch & 0xFF;
        byte retVal = SboxTable[i];
        return retVal;
    }

    private long sm4Lt(long ka)
    {
        long bb = 0L;
        long c = 0L;
        byte[] a = new byte[4];
        byte[] b = new byte[4];
        PUT_ULONG_BE(ka, a, 0);
        b[0] = sm4Sbox(a[0]);
        b[1] = sm4Sbox(a[1]);
        b[2] = sm4Sbox(a[2]);
        b[3] = sm4Sbox(a[3]);
        bb = GET_ULONG_BE(b, 0);
        c = bb ^ ROTL(bb, 2) ^ ROTL(bb, 10) ^ ROTL(bb, 18) ^ ROTL(bb, 24);
        return c;
    }

    private long sm4F(long x0, long x1, long x2, long x3, long rk)
    {
        return x0 ^ sm4Lt(x1 ^ x2 ^ x3 ^ rk);
    }

    private long sm4CalciRK(long ka)
    {
        long bb = 0L;
        long rk = 0L;
        byte[] a = new byte[4];
        byte[] b = new byte[4];
        PUT_ULONG_BE(ka, a, 0);
        b[0] = sm4Sbox(a[0]);
        b[1] = sm4Sbox(a[1]);
        b[2] = sm4Sbox(a[2]);
        b[3] = sm4Sbox(a[3]);
        bb = GET_ULONG_BE(b, 0);
        rk = bb ^ ROTL(bb, 13) ^ ROTL(bb, 23);
        return rk;

    }

    private void sm4_setkey(long[] SK, byte[] key)
    {
        long[] MK = new long[4];
        long[] k = new long[36];
        int i = 0;
        MK[0] = GET_ULONG_BE(key, 0);
        MK[1] = GET_ULONG_BE(key, 4);
        MK[2] = GET_ULONG_BE(key, 8);
        MK[3] = GET_ULONG_BE(key, 12);
        k[0] = MK[0] ^ (long)FK[0];
        k[1] = MK[1] ^ (long)FK[1];
        k[2] = MK[2] ^ (long)FK[2];
        k[3] = MK[3] ^ (long)FK[3];
        for (; i < 32; i++)
        {
            k[(i + 4)] = (k[i] ^ sm4CalciRK(k[(i + 1)] ^ k[(i + 2)] ^ k[(i + 3)] ^ (long)CK[i]));
            SK[i] = k[(i + 4)];
        }
    }

    private void sm4_one_round(long[] sk, byte[] input, byte[] output)
    {
        int i = 0;
        long[] ulbuf = new long[36];
        ulbuf[0] = GET_ULONG_BE(input, 0);
        ulbuf[1] = GET_ULONG_BE(input, 4);
        ulbuf[2] = GET_ULONG_BE(input, 8);
        ulbuf[3] = GET_ULONG_BE(input, 12);
        while (i < 32)
        {
            ulbuf[(i + 4)] = sm4F(ulbuf[i], ulbuf[(i + 1)], ulbuf[(i + 2)], ulbuf[(i + 3)], sk[i]);
            i++;
        }
        PUT_ULONG_BE(ulbuf[35], output, 0);
        PUT_ULONG_BE(ulbuf[34], output, 4);
        PUT_ULONG_BE(ulbuf[33], output, 8);
        PUT_ULONG_BE(ulbuf[32], output, 12);
    }

    private byte[] padding(byte[] input, int mode)
    {
        if (input == null)
        {
            return null;
        }

        byte[] ret = (byte[])null;
        if (mode == SM4_ENCRYPT)
        {
            int p = 16 - input.Length % 16;
            ret = new byte[input.Length + p];
            Array.Copy(input, 0, ret, 0, input.Length);
            for (int i = 0; i < p; i++)
            {
                ret[input.Length + i] = (byte)p;
            }
        }
        else
        {
            int p = input[input.Length - 1];
            ret = new byte[input.Length - p];
            Array.Copy(input, 0, ret, 0, input.Length - p);
        }
        return ret;
    }

    public void sm4_setkey_enc(SM4_Context ctx, byte[] key)
    {
        if (ctx == null)
        {
            throw new Exception("ctx is null!");
        }

        /*if (key == null || key.length != 16) {
            throw new Exception("key error!");
        }*/
        if (key == null || key.Length != 32)
        {
            throw new Exception("key error!");
        }

        ctx.mode = SM4_ENCRYPT;
        sm4_setkey(ctx.sk, key);
    }

    public void sm4_setkey_dec(SM4_Context ctx, byte[] key)
    {
        if (ctx == null)
        {
            throw new Exception("ctx is null!");
        }

        /*if (key == null || key.length != 16) {
            throw new Exception("key error!");
        }*/
        if (key == null || key.Length != 32)
        {
            throw new Exception("key error!");
        }

        int i = 0;
        ctx.mode = SM4_DECRYPT;
        sm4_setkey(ctx.sk, key);
        for (i = 0; i < 16; i++)
        {
            SWAP(ctx.sk, i);
        }
    }

    public byte[] sm4_crypt_ecb(SM4_Context ctx, byte[] input)
    {
        if (input == null)
        {
            throw new Exception("input is null!");
        }

        if ((ctx.isPadding) && (ctx.mode == SM4_ENCRYPT))
        {
            input = padding(input, SM4_ENCRYPT);
        }

        int length = input.Length;
        MemoryStream bins = new MemoryStream(input);
        MemoryStream bous = new MemoryStream();
        for (; length > 0; length -= 16)
        {
            byte[] inByte = new byte[16];
            byte[] outByte = new byte[16];
            bins.Read(inByte, 0, inByte.Length);
            sm4_one_round(ctx.sk, inByte, outByte);
            bous.Write(outByte, 0, outByte.Length);
        }

        byte[] output = bous.ToArray();
        if (ctx.isPadding && ctx.mode == SM4_DECRYPT)
        {
            output = padding(output, SM4_DECRYPT);
        }
        bins.Dispose();
        bous.Dispose();
        return output;
    }

    public byte[] sm4_crypt_cbc(SM4_Context ctx, byte[] iv, byte[] input)
    {
        if (iv == null || iv.Length != 16)
        {
            throw new Exception("iv error!");
        }

        if (input == null)
        {
            throw new Exception("input is null!");
        }

        if (ctx.isPadding && ctx.mode == SM4_ENCRYPT)
        {
            input = padding(input, SM4_ENCRYPT);
        }

        int i = 0;
        int length = input.Length;
        MemoryStream bins = new MemoryStream(input);
        MemoryStream bous = new MemoryStream();
        if (ctx.mode == SM4_ENCRYPT)
        {
            for (; length > 0; length -= 16)
            {
                byte[] inByte = new byte[16];
                byte[] outByte = new byte[16];
                byte[] out1 = new byte[16];

                bins.Read(inByte, 0, inByte.Length);
                for (i = 0; i < 16; i++)
                {
                    outByte[i] = ((byte)(inByte[i] ^ iv[i]));
                }
                sm4_one_round(ctx.sk, outByte, out1);
                Array.Copy(out1, 0, iv, 0, 16);
                bous.Write(out1, 0, out1.Length);
            }
        }
        else
        {
            byte[] temp = new byte[16];
            for (; length > 0; length -= 16)
            {
                byte[] inByte = new byte[16];
                byte[] outByte = new byte[16];
                byte[] out1 = new byte[16];

                bins.Read(inByte, 0, inByte.Length);
                Array.Copy(inByte, 0, temp, 0, 16);
                sm4_one_round(ctx.sk, inByte, outByte);
                for (i = 0; i < 16; i++)
                {
                    out1[i] = ((byte)(outByte[i] ^ iv[i]));
                }
                Array.Copy(temp, 0, iv, 0, 16);
                bous.Write(out1,0,out1.Length);
            }
        }

        byte[] output = bous.ToArray();
        if (ctx.isPadding && ctx.mode == SM4_DECRYPT)
        {
            output = padding(output, SM4_DECRYPT);
        }
        bins.Dispose();
        bous.Dispose();
        return output;
    }
}
}