针对日常加密算法，大致分为对称加密，非对称加密，哈希函数(MD5)，其中对称加密比较常见的，如AES、DES、3DES，对称加密算法是指加密和解密采用相同的密钥口，是可逆的， 实习那会用的就是DES，网上很多现成的轮子。此外非对称加密算法， 常用的如 RSA算法、ECC算法、DSA等算法， 非对称不可逆，安全性更高，相对应加密效率稍微低一些， 国产加密如今崛起，SM系列中很多加密算法，结合自身业务场景经过比较选取最优解SM4，本文用来记录具体SM4的使用对接。
（测试版本Net6），直接 安装BouncyCastle.Cryptography 包即可， 写个帮助类，直接贴代码
#region SM4解密解密
public static void GenerateKeyHex(out string key, out string iv)
{
//用于生成对称加密算法
var keyGenerator = new CipherKeyGenerator();
keyGenerator.Init(new KeyGenerationParameters(new SecureRandom(), 128));
var a = keyGenerator.GenerateKey();
key = Hex.ToHexString(a);
SecureRandom random = new SecureRandom();
byte[] b = new byte[16]; // IV长度为16字节
random.NextBytes(b);
iv = Hex.ToHexString(b);
}
//随机生成密钥
public static string GetRandomIV()
{
SecureRandom random = new();
byte[] b = new byte[16]; // IV长度为16字节
random.NextBytes(b);
return Hex.ToHexString(b);
}
//CBC模式加密
public static byte[] CBCEncrypt(this string appkey)
{
byte[] plaintext = Encoding.UTF8.GetBytes(appkey);
IBufferedCipher cipher = new PaddedBufferedBlockCipher(new CbcBlockCipher(new SM4Engine()), new Pkcs7Padding());
cipher.Init(true, new ParametersWithIV(new KeyParameter(Decode(AppSetting.Secret.SMKey)), Decode(AppSetting.Secret.SMIV)));
byte[] output = new byte[cipher.GetOutputSize(plaintext.Length)];
int bytesProcessed = cipher.ProcessBytes(plaintext, 0, plaintext.Length, output, 0);
cipher.DoFinal(output, bytesProcessed);
return output;
}
//CBC模式解密
public static byte[] CBCDecrypt(this string appkey)
{
try
{
byte[] ciphertext = Convert.FromBase64String(appkey);
IBufferedCipher cipher = new PaddedBufferedBlockCipher(new CbcBlockCipher(new SM4Engine()), new Pkcs7Padding());
cipher.Init(false, new ParametersWithIV(new KeyParameter(Decode(AppSetting.Secret.SMKey)), Decode(AppSetting.Secret.SMIV)));
byte[] output = new byte[cipher.GetOutputSize(ciphertext.Length)];
int bytesProcessed = cipher.ProcessBytes(ciphertext, 0, ciphertext.Length, output, 0);
cipher.DoFinal(output, bytesProcessed);
return RemovePadding(output);
}
catch
{
Comm.NLogHelper.WriteError($"登录校验-解密失败:{appkey}");
return null;
}
}
static byte[] Decode(string key)
{
return Regex.IsMatch(key, "^[0-9a-f]+$", RegexOptions.IgnoreCase) ? Hex.Decode(key) : Convert.FromBase64String(key);
}
// 去除填充字符
public static byte[] RemovePadding(byte[] data)
{
int lastNonZeroByte = data.Length - 1;
while (data[lastNonZeroByte] == 0)
{
lastNonZeroByte--;
}
// 截取非零字节之前的所有字节
byte[] result = new byte[lastNonZeroByte + 1];
Array.Copy(data, result, lastNonZeroByte + 1);
return result;
}
#endregion
其中密钥和偏移量，可以根据上面生成的方法自行生成, 调用方法简单
//加密 var encrypted = "加密字段XXXXX".CBCEncrypt(); string base64 = Convert.ToBase64String(encrypted); //解密 var original =base64.CBCDecrypt();
但是对于老旧项目的低版本，比如FrameWork4.5 一下, 使用BouncyCastle.Crypto 包，所以需要手动书写一下SM4 的帮助类, 代码如下，需要保证 密码Key 和 偏移量 IV
public const string CBCKey = "XXXX";
public const string CBCIV = "xxxx";
//CBC模式加密
public static string EncryptCBC(string plainText, bool hexstring = true)
{
var ctx = new SM4Context();
ctx.isPadding = true;
ctx.mode = SM4CryptoServiceProvider.SM4_ENCRYPT;
byte[] keyBytes;
byte[] ivBytes;
if (hexstring)
{
keyBytes = Hex.Decode(CBCKey);
ivBytes = Hex.Decode(CBCIV);
}
else
{
keyBytes = Encoding.UTF8.GetBytes(CBCKey);
ivBytes = Encoding.UTF8.GetBytes(CBCIV);
}
var sm4 = new SM4CryptoServiceProvider();
sm4.sm4_setkey_enc(ctx, keyBytes);
byte[] encrypted = sm4.sm4_crypt_cbc(ctx, ivBytes, Encoding.UTF8.GetBytes(plainText));
string cipherText = Convert.ToBase64String(encrypted);
return cipherText;
}
public string DecryptCBC(string cipherText)
{
var ctx = new SM4Context();
ctx.isPadding = true;
ctx.mode = SM4CryptoServiceProvider.SM4_DECRYPT;
byte[] keyBytes;
byte[] ivBytes;
if (hexstring)
{
keyBytes = Hex.Decode(secretKey);
ivBytes = Hex.Decode(iv);
}
else
{
keyBytes = Encoding.UTF8.GetBytes(secretKey);
ivBytes = Encoding.UTF8.GetBytes(iv);
}
var sm4 = new SM4CryptoServiceProvider();
sm4.sm4_setkey_dec(ctx, keyBytes);
byte[] decrypted = sm4.sm4_crypt_cbc(ctx, ivBytes, Hex.Decode(cipherText));
return Encoding.UTF8.GetString(decrypted);
}
SM4Context 实现如下：
internal class SM4Context
{
public int mode;
public long[] sk;
public bool isPadding;
public SM4Context()
{
this.mode = 1;
this.isPadding = true;
this.sk = new long[32];
}
}
SM4CryptoServiceProvider 实现如下：
internal class SM4CryptoServiceProvider
{
public const int SM4_ENCRYPT = 1;
public const 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 byte[] SboxTable = new byte[] { (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 uint[] FK = { 0xa3b1bac6, 0x56aa3350, 0x677d9197, 0xb27022dc };
public 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 };
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(SM4Context ctx, byte[] key)
{
ctx.mode = SM4_ENCRYPT;
sm4_setkey(ctx.sk, key);
}
public void sm4_setkey_dec(SM4Context ctx, byte[] key)
{
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(SM4Context ctx, byte[] input)
{
if ((ctx.isPadding) && (ctx.mode == SM4_ENCRYPT))
{
input = padding(input, SM4_ENCRYPT);
}
int length = input.Length;
byte[] bins = new byte[length];
Array.Copy(input, 0, bins, 0, length);
byte[] bous = new byte[length];
for (int i = 0; length > 0; length -= 16, i++)
{
byte[] inBytes = new byte[16];
byte[] outBytes = new byte[16];
Array.Copy(bins, i * 16, inBytes, 0, length > 16 ? 16 : length);
sm4_one_round(ctx.sk, inBytes, outBytes);
Array.Copy(outBytes, 0, bous, i * 16, length > 16 ? 16 : length);
}
if (ctx.isPadding && ctx.mode == SM4_DECRYPT)
{
bous = padding(bous, SM4_DECRYPT);
}
return bous;
}
public byte[] sm4_crypt_cbc(SM4Context ctx, byte[] iv, byte[] input)
{
if (ctx.isPadding && ctx.mode == SM4_ENCRYPT)
{
input = padding(input, SM4_ENCRYPT);
}
int i = 0;
int length = input.Length;
byte[] bins = new byte[length];
Array.Copy(input, 0, bins, 0, length);
byte[] bous = null;
List<byte> bousList = new List<byte>();
if (ctx.mode == SM4_ENCRYPT)
{
for (int j = 0; length > 0; length -= 16, j++)
{
byte[] inBytes = new byte[16];
byte[] outBytes = new byte[16];
byte[] out1 = new byte[16];
Array.Copy(bins, j * 16, inBytes, 0, length > 16 ? 16 : length);
for (i = 0; i < 16; i++)
{
outBytes[i] = ((byte)(inBytes[i] ^ iv[i]));
}
sm4_one_round(ctx.sk, outBytes, out1);
Array.Copy(out1, 0, iv, 0, 16);
for (int k = 0; k < 16; k++)
{
bousList.Add(out1[k]);
}
}
}
else
{
byte[] temp = new byte[16];
for (int j = 0; length > 0; length -= 16, j++)
{
byte[] inBytes = new byte[16];
byte[] outBytes = new byte[16];
byte[] out1 = new byte[16];
Array.Copy(bins, j * 16, inBytes, 0, length > 16 ? 16 : length);
Array.Copy(inBytes, 0, temp, 0, 16);
sm4_one_round(ctx.sk, inBytes, outBytes);
for (i = 0; i < 16; i++)
{
out1[i] = ((byte)(outBytes[i] ^ iv[i]));
}
Array.Copy(temp, 0, iv, 0, 16);
for (int k = 0; k < 16; k++)
{
bousList.Add(out1[k]);
}
}
}
if (ctx.isPadding && ctx.mode == SM4_DECRYPT)
{
bous = padding(bousList.ToArray(), SM4_DECRYPT);
return bous;
}
else
{
return bousList.ToArray();
}
}
}
如此大功告成， 两边可自行攻守，如果保证Key 和 IV一直，则能够互通有无
标签：CBC,16,int,SM4,ctx,long,Framework4.5,new,byte From： https://www.cnblogs.com/Sientuo/p/18282335