1、RSA非对称加密算法
RSA加密算法是最常用的非对称加密算法，由罗纳德·李维斯特（Ron Rivest）、阿迪·萨莫尔（Adi Shamir）和伦纳德·阿德曼（Leonard Adleman）于1977年一起提出，RSA就是他们三人姓氏开头字母拼在一起组成的。非对称加密算法的特点就是加密秘钥和解密秘钥不同，秘钥分为公钥和私钥，用私钥加密的明文，只能用公钥解密；用公钥加密的明文，只能用私钥解密。
RSA是第一个比较完善的公开密钥算法，它既能用于加密，也能用于数字签名。这个算法经受住了多年深入的密码分析，虽然密码分析者既不能证明也不能否定RSA的安全性，但这恰恰说明该算法有一定的可信性，目前它已经成为最流行的公开密钥算法。RSA的安全基于大数分解的难度。其公钥和私钥是一对大素数（100到200位十进制数或更大）的函数。从一个公钥和密文恢复出明文的难度，等价于分解两个大素数之积。
2、通过扩展方法写入和读取xml配置文件参数
using System;using System.Collections.Generic;using System.Linq;using System.Security.Cryptography;using System.Threading.Tasks;using System.Xml;namespace CJavaPy.Encrypt{ public static class RSACryptoServiceProviderExtensions { public static void FromXmlString(this RSACryptoServiceProvider rsa, string xmlString) { RSAParameters parameters = new RSAParameters(); XmlDocument xmlDoc = new XmlDocument(); xmlDoc.LoadXml(xmlString); if (xmlDoc.DocumentElement.Name.Equals("RSAKeyValue")) { foreach (XmlNode node in xmlDoc.DocumentElement.ChildNodes) { switch (node.Name) { case "Modulus": parameters.Modulus = Convert.FromBase64String(node.InnerText); break; case "Exponent": parameters.Exponent = Convert.FromBase64String(node.InnerText); break; case "P": parameters.P = Convert.FromBase64String(node.InnerText); break; case "Q": parameters.Q = Convert.FromBase64String(node.InnerText); break; case "DP": parameters.DP = Convert.FromBase64String(node.InnerText); break; case "DQ": parameters.DQ = Convert.FromBase64String(node.InnerText); break; case "InverseQ": parameters.InverseQ = Convert.FromBase64String(node.InnerText); break; case "D": parameters.D = Convert.FromBase64String(node.InnerText); break; } } } else { throw new Exception("Invalid XML RSA key."); } rsa.ImportParameters(parameters); } public static string ToXmlString(this RSACryptoServiceProvider rsa, bool includePrivateParameters) { RSAParameters parameters = rsa.ExportParameters(includePrivateParameters); return string.Format("{0} {1} {2}
{3}
{4} {5} {6} {7}
3、实现公钥和私钥加解密工具类
using System;using System.IO;using System.Reflection;using System.Security.Cryptography;using Microsoft.AspNetCore.Hosting;namespace CJavaPy.Encrypt{ public class EncryptService { private const string Path = "Encrypt/"; private const string PrivateKeyFile = "Private.config"; private const string PublicKeyFile = "Public.config"; private readonly string _folder; private readonly string _privateKeyFileName; private readonly string _publicKeyFileName; public EncryptService(IWebHostEnvironment hostingEnvironment) { _folder = System.IO.Path.Combine(hostingEnvironment.ContentRootPath, Path); _privateKeyFileName = System.IO.Path.Combine(_folder, PrivateKeyFile); _publicKeyFileName = System.IO.Path.Combine(_folder, PublicKeyFile); } public byte[] Encrypt(byte[] source) { Func encrypt = sou => { using (RSACryptoServiceProvider rsa = new RSACryptoServiceProvider()) { if (!Directory.Exists(_folder)) { Directory.CreateDirectory(_folder); } if (!File.Exists(_privateKeyFileName)) { File.WriteAllText(_privateKeyFileName, rsa.ToXmlString(true)); File.WriteAllText(_publicKeyFileName, rsa.ToXmlString(false)); } rsa.FromXmlString(File.ReadAllText(_publicKeyFileName)); int maxBlockSize = rsa.KeySize / 8 - 11; if (sou.Length <= maxBlockSize) return rsa.Encrypt(sou, false); using (MemoryStream plaiStream = new MemoryStream(sou)) { using (MemoryStream crypStream = new MemoryStream()) { byte[] buffer = new byte[maxBlockSize]; int blockSize = plaiStream.Read(buffer, 0, maxBlockSize); while (blockSize > 0) { byte[] toEncrypt = new byte[blockSize]; Array.Copy(buffer, 0, toEncrypt, 0, blockSize); byte[] cryptograph = rsa.Encrypt(toEncrypt, false); crypStream.Write(cryptograph, 0, cryptograph.Length); blockSize = plaiStream.Read(buffer, 0, maxBlockSize); } return crypStream.ToArray(); } } } }; return MarkData(encrypt(source)); } public byte[] Decrypt(byte[] source) { if (IsEncrypt(source)) { Func decrypt = sou => { using (RSACryptoServiceProvider rsa = new RSACryptoServiceProvider()) { if (File.Exists(_folder + PrivateKeyFile)) { rsa.FromXmlString(File.ReadAllText(_privateKeyFileName)); } int maxBlockSize = rsa.KeySize / 8; if (sou.Length <= maxBlockSize) return rsa.Decrypt(sou, false); using (MemoryStream crypStream = new MemoryStream(sou)) { using (MemoryStream plaiStream = new MemoryStream()) { byte[] buffer = new byte[maxBlockSize]; int blockSize = crypStream.Read(buffer, 0, maxBlockSize); while (blockSize > 0) { byte[] toDecrypt = new byte[blockSize]; Array.Copy(buffer, 0, toDecrypt, 0, blockSize); byte[] plaintext = rsa.Decrypt(toDecrypt, false); plaiStream.Write(plaintext, 0, plaintext.Length); blockSize = crypStream.Read(buffer, 0, maxBlockSize); } return plaiStream.ToArray(); } } } }; return decrypt(ClearDataMark(source)); } return source; } private byte[] MarkData(byte[] source) { byte[] newBytes = new byte[source.Length + 200]; for (int i = 0; i < newBytes.Length; i++) { if (i < 100 || i > newBytes.Length - 100 - 1) { newBytes[i] = 0; } else { newBytes[i] = source[i - 100]; } } return newBytes; } private byte[] ClearDataMark(byte[] source) { byte[] newBytes = new byte[source.Length - 200]; for (int i = 100; i < source.Length - 100; i++) { newBytes[i - 100] = source[i]; } return newBytes; } private bool IsEncrypt(byte[] source) { for (int i = 0; i < 100; i++) { if (source[i] != 0 || source[source.Length - i - 1] != 0) { return false; } } return true; } }}
4、使用方法
using System;using System.Collections.Generic;using System.Linq;using System.Threading.Tasks;using Microsoft.AspNetCore.Builder;using Microsoft.AspNetCore.Hosting;using Microsoft.AspNetCore.HttpsPolicy;using Microsoft.Extensions.Configuration;using Microsoft.Extensions.DependencyInjection;using Microsoft.Extensions.Hosting;using CJavaPy.Encrypt;namespace CJavaPy.Encrypt{ public class Startup { public Startup(IConfiguration configuration) { Configuration = configuration; } public IConfiguration Configuration { get; } // This method gets called by the runtime. Use this method to add services to the container. public void ConfigureServices(IServiceCollection services) { services.AddRazorPages(); } // This method gets called by the runtime. Use this method to configure the HTTP request pipeline. public void Configure(IApplicationBuilder app, IWebHostEnvironment env) { if (env.IsDevelopment()) { app.UseDeveloperExceptionPage(); } else { app.UseExceptionHandler("/Error"); app.UseHsts(); } //调用示例代码 EncryptService encryptService = new EncryptService(env); //配置文件不存在会自动生成 byte[] data= encryptService.Encrypt(System.Text.Encoding.UTF8.GetBytes("www.wonhero.com")); string val = System.Text.Encoding.UTF8.GetString(encryptService.Decrypt(data)); string valOrigin = System.Text.Encoding.UTF8.GetString(data); app.UseHttpsRedirection(); app.UseStaticFiles(); app.UseRouting(); app.UseAuthorization(); app.UseEndpoints(endpoints => { endpoints.MapRazorPages(); }); } }}