C# 实现SM2国密加密帮助类
本人在了解对接国家医疗保障信息平台中定点医药机构接口文档中，传输加密方式使用国密算法之SM2.然后本人在隔离期间研究了一下，将内容进行总结，本文主要讲解“国密加密算法”SM系列之SM2的C#实现方法，加密规则请详阅国密局发布的文档。
首先需第三方Nuget包：Portable.BouncyCastle
1.SM2密码计算
using Org.BouncyCastle.Crypto;
using Org.BouncyCastle.Crypto.Digests;
using Org.BouncyCastle.Crypto.Parameters;
using Org.BouncyCastle.Math;
using Org.BouncyCastle.Math.EC;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace Core.Common
{
/// <summary>
/// 密码计算
/// </summary>
public class Cipher
{
private int ct = 1;
/// <summary>
/// 椭圆曲线E上点P2
/// </summary>
private ECPoint p2;
private SM3Digest sm3keybase;
private SM3Digest sm3c3;
private readonly byte[] key = new byte[32];
private byte keyOff = 0;
public Cipher()
{
}
private void Reset()
{
sm3keybase = new SM3Digest();
sm3c3 = new SM3Digest();
byte[] p;
p = p2.Normalize().XCoord.ToBigInteger().ToByteArray();
sm3keybase.BlockUpdate(p, 0, p.Length);
sm3c3.BlockUpdate(p, 0, p.Length);
p = p2.Normalize().YCoord.ToBigInteger().ToByteArray();
sm3keybase.BlockUpdate(p, 0, p.Length);
ct = 1;
NextKey();
}
private void NextKey()
{
SM3Digest sm3keycur = new SM3Digest(sm3keybase);
sm3keycur.Update((byte)(ct >> 24 & 0x00ff));
sm3keycur.Update((byte)(ct >> 16 & 0x00ff));
sm3keycur.Update((byte)(ct >> 8 & 0x00ff));
sm3keycur.Update((byte)(ct & 0x00ff));
sm3keycur.DoFinal(key, 0);
keyOff = 0;
ct++;
}
public virtual ECPoint InitEnc(SM2 sm2, ECPoint userKey)
{
AsymmetricCipherKeyPair key = sm2.EccKeyPairGenerator.GenerateKeyPair();
ECPrivateKeyParameters ecpriv = (ECPrivateKeyParameters)key.Private;
ECPublicKeyParameters ecpub = (ECPublicKeyParameters)key.Public;
BigInteger k = ecpriv.D;
ECPoint c1 = ecpub.Q;
p2 = userKey.Multiply(k);
Reset();
return c1;
}
public virtual void Encrypt(byte[] data)
{
//p2.Normalize();
sm3c3.BlockUpdate(data, 0, data.Length);
for (int i = 0; i < data.Length; i++)
{
if (keyOff == key.Length)
NextKey();
data[i] ^= key[keyOff++];
}
}
public virtual void InitDec(BigInteger userD, ECPoint c1)
{
p2 = c1.Multiply(userD);
Reset();
}
public virtual void Decrypt(byte[] data)
{
for (int i = 0; i < data.Length; i++)
{
if (keyOff == key.Length)
NextKey();
data[i] ^= key[keyOff++];
}
sm3c3.BlockUpdate(data, 0, data.Length);
}
public virtual void Dofinal(byte[] c3)
{
byte[] p = p2.Normalize().YCoord.ToBigInteger().ToByteArray();
sm3c3.BlockUpdate(p, 0, p.Length);
sm3c3.DoFinal(c3, 0);
Reset();
}
}
}
2. 加密处理中心
using System;
using Org.BouncyCastle.Crypto.Generators;
using Org.BouncyCastle.Math.EC;
using Org.BouncyCastle.Math;
using Org.BouncyCastle.Crypto;
using Org.BouncyCastle.Crypto.Parameters;
using Org.BouncyCastle.Security;
using System.Text;
using Org.BouncyCastle.Crypto.Digests;
namespace Core.Common
{
/// <summary>
/// SM2主类
/// </summary>
/// <summary>
/// 加密处理中心
/// </summary>
public class SM2
{
public static SM2 Instance
{
get
{
return new SM2();
}
}
public static SM2 InstanceTest
{
get
{
return new SM2();
}
}
#region 曲线参数
/// <summary>
/// 曲线参数
/// </summary>
public static readonly string[] CurveParameter = {
"FFFFFFFEFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF00000000FFFFFFFFFFFFFFFF",// p,0
"FFFFFFFEFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF00000000FFFFFFFFFFFFFFFC",// a,1
"28E9FA9E9D9F5E344D5A9E4BCF6509A7F39789F515AB8F92DDBCBD414D940E93",// b,2
"FFFFFFFEFFFFFFFFFFFFFFFFFFFFFFFF7203DF6B21C6052B53BBF40939D54123",// n,3
"32C4AE2C1F1981195F9904466A39C9948FE30BBFF2660BE1715A4589334C74C7",// gx,4
"BC3736A2F4F6779C59BDCEE36B692153D0A9877CC62A474002DF32E52139F0A0" // gy,5
};
/// <summary>
/// 椭圆曲线参数
/// </summary>
public string[] EccParam = CurveParameter;
/// <summary>
/// 椭圆曲线参数P
/// </summary>
public readonly BigInteger EccP;
/// <summary>
/// 椭圆曲线参数A
/// </summary>
public readonly BigInteger EccA;
/// <summary>
/// 椭圆曲线参数B
/// </summary>
public readonly BigInteger EccB;
/// <summary>
/// 椭圆曲线参数N
/// </summary>
public readonly BigInteger EccN;
/// <summary>
/// 椭圆曲线参数Gx
/// </summary>
public readonly BigInteger EccGx;
/// <summary>
/// 椭圆曲线参数Gy
/// </summary>
public readonly BigInteger EccGy;
#endregion
/// <summary>
/// 椭圆曲线
/// </summary>
public readonly ECCurve EccCurve;
/// <summary>
/// 椭圆曲线的点G
/// </summary>
public readonly ECPoint EccPointG;
/// <summary>
/// 椭圆曲线 bc规范
/// </summary>
public readonly ECDomainParameters EccBcSpec;
/// <summary>
/// 椭圆曲线密钥对生成器
/// </summary>
public readonly ECKeyPairGenerator EccKeyPairGenerator;
private SM2()
{
EccParam = CurveParameter;
EccP = new BigInteger(EccParam[0], 16);
EccA = new BigInteger(EccParam[1], 16);
EccB = new BigInteger(EccParam[2], 16);
EccN = new BigInteger(EccParam[3], 16);
EccGx = new BigInteger(EccParam[4], 16);
EccGy = new BigInteger(EccParam[5], 16);
ECFieldElement ecc_gx_fieldelement = new FpFieldElement(EccP, EccGx);
ECFieldElement ecc_gy_fieldelement = new FpFieldElement(EccP, EccGy);
EccCurve = new FpCurve(EccP, EccA, EccB);
EccPointG = new FpPoint(EccCurve, ecc_gx_fieldelement, ecc_gy_fieldelement);
EccBcSpec = new ECDomainParameters(EccCurve, EccPointG, EccN);
ECKeyGenerationParameters ecc_ecgenparam;
ecc_ecgenparam = new ECKeyGenerationParameters(EccBcSpec, new SecureRandom());
EccKeyPairGenerator = new ECKeyPairGenerator();
EccKeyPairGenerator.Init(ecc_ecgenparam);
}
/// <summary>
/// 获取杂凑值H
/// </summary>
/// <param name="z">Z值</param>
/// <param name="data">待签名消息</param>
/// <returns></returns>
public virtual byte[] Sm2GetH(byte[] z, byte[] data)
{
SM3Digest sm3 = new SM3Digest();
//Z
sm3.BlockUpdate(z, 0, z.Length);
//待签名消息
sm3.BlockUpdate(data, 0, data.Length);
// H
byte[] md = new byte[sm3.GetDigestSize()];
sm3.DoFinal(md, 0);
return md;
}
/// <summary>
/// 获取Z值
/// Z=SM3(ENTL∣∣userId∣∣a∣∣b∣∣gx∣∣gy ∣∣x∣∣y)
/// </summary>
/// <param name="userId">签名方的用户身份标识</param>
/// <param name="userKey">签名方公钥</param>
/// <returns></returns>
public virtual byte[] Sm2GetZ(byte[] userId, ECPoint userKey)
{
SM3Digest sm3 = new SM3Digest();
byte[] p;
// ENTL由2个字节标识的ID的比特长度
int len = userId.Length * 8;
sm3.Update((byte)(len >> 8 & 0x00ff));
sm3.Update((byte)(len & 0x00ff));
// userId用户身份标识ID
sm3.BlockUpdate(userId, 0, userId.Length);
// a,b为系统曲线参数；
p = EccA.ToByteArray();
sm3.BlockUpdate(p, 0, p.Length);
p = EccB.ToByteArray();
sm3.BlockUpdate(p, 0, p.Length);
// gx、gy为基点
p = EccGx.ToByteArray();
sm3.BlockUpdate(p, 0, p.Length);
p = EccGy.ToByteArray();
sm3.BlockUpdate(p, 0, p.Length);
// x,y用户的公钥的X和Y
p = userKey.Normalize().XCoord.ToBigInteger().ToByteArray();
sm3.BlockUpdate(p, 0, p.Length);
p = userKey.Normalize().YCoord.ToBigInteger().ToByteArray();
sm3.BlockUpdate(p, 0, p.Length);
// Z
byte[] md = new byte[sm3.GetDigestSize()];
sm3.DoFinal(md, 0);
return md;
}
}
}
3 加密调用
using Org.BouncyCastle.Crypto;
using Org.BouncyCastle.Crypto.Parameters;
using Org.BouncyCastle.Math;
using Org.BouncyCastle.Math.EC;
using Org.BouncyCastle.Utilities.Encoders;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace Core.Common
{
/// <summary>
/// Sm2算法
/// 对标国际RSA算法
/// </summary>
public class Sm2Crypto
{
/// <summary>
/// 数据
/// </summary>
public string Str { get; set; }
/// <summary>
/// 数据
/// </summary>
public byte[] Data { get; set; }
/// <summary>
/// 公钥
/// </summary>
public string PublicKey { get; set; }
/// <summary>
/// 私钥
/// </summary>
public string PrivateKey { get; set; }
/// <summary>
/// 获取密钥
/// </summary>
/// <param name="privateKey">私钥</param>
/// <param name="publicKey">公钥</param>
public static void GetKey(out string privateKey, out string publicKey)
{
SM2 sm2 = SM2.Instance;
AsymmetricCipherKeyPair key = sm2.EccKeyPairGenerator.GenerateKeyPair();
ECPrivateKeyParameters ecpriv = (ECPrivateKeyParameters)key.Private;
ECPublicKeyParameters ecpub = (ECPublicKeyParameters)key.Public;
publicKey = Encoding.Default.GetString(Hex.Encode(ecpub.Q.GetEncoded())).ToUpper();
privateKey = Encoding.Default.GetString(Hex.Encode(ecpriv.D.ToByteArray())).ToUpper();
}
#region 解密
public object Decrypt(Sm2Crypto entity)
{
var data = !string.IsNullOrEmpty(entity.Str) ?
Hex.Decode(entity.Str) :
entity.Data;
return Encoding.Default.GetString(Decrypt(Hex.Decode(entity.PrivateKey), data));
}
/// <summary>
/// 解密
/// </summary>
/// <param name="privateKey"></param>
/// <param name="encryptedData"></param>
/// <returns></returns>
private static byte[] Decrypt(byte[] privateKey, byte[] encryptedData)
{
if (null == privateKey || privateKey.Length == 0)
{
return null;
}
if (encryptedData == null || encryptedData.Length == 0)
{
return null;
}
String data = Encoding.Default.GetString(Hex.Encode(encryptedData));
byte[] c1Bytes = Hex.Decode(Encoding.Default.GetBytes(data.Substring(0, 130)));
int c2Len = encryptedData.Length - 97;
byte[] c2 = Hex.Decode(Encoding.Default.GetBytes(data.Substring(130, 2 * c2Len)));
byte[] c3 = Hex.Decode(Encoding.Default.GetBytes(data.Substring(130 + 2 * c2Len, 64)));
SM2 sm2 = SM2.Instance;
BigInteger userD = new BigInteger(1, privateKey);
ECPoint c1 = sm2.EccCurve.DecodePoint(c1Bytes);
//c1.Normalize();
Cipher cipher = new Cipher();
cipher.InitDec(userD, c1);
cipher.Decrypt(c2);
cipher.Dofinal(c3);
return c2;
}
#endregion
#region 加密
public string Encrypt(Sm2Crypto entity)
{
var data = !string.IsNullOrEmpty(entity.Str) ?
Encoding.Default.GetBytes(entity.Str) :
entity.Data;
return Encrypt(Hex.Decode(entity.PublicKey), data);
}
/// <summary>
/// 加密
/// </summary>
/// <param name="publicKey"></param>
/// <param name="data"></param>
/// <returns></returns>
private static string Encrypt(byte[] publicKey, byte[] data)
{
if (null == publicKey || publicKey.Length == 0)
{
return null;
}
if (data == null || data.Length == 0)
{
return null;
}
byte[] source = new byte[data.Length];
Array.Copy(data, 0, source, 0, data.Length);
Cipher cipher = new Cipher();
SM2 sm = SM2.Instance;
ECPoint userKey = sm.EccCurve.DecodePoint(publicKey);
//userKey.Normalize();
ECPoint c1 = cipher.InitEnc(sm, userKey);
cipher.Encrypt(source);
byte[] c3 = new byte[32];
cipher.Dofinal(c3);
String sc1 = Encoding.Default.GetString(Hex.Encode(c1.GetEncoded()));
String sc2 = Encoding.Default.GetString(Hex.Encode(source));
String sc3 = Encoding.Default.GetString(Hex.Encode(c3));
return (sc1 + sc2 + sc3).ToUpper();
}
#endregion
}
}
4.最终调用结果
希望这边文章能帮助相关人员，欢迎评论+转发，谢谢所有水友们！！！
