在Asp.net SignalR与Angular通信添加身份认证（通过jwt）

这是一个复杂的东西，我查找了一些混乱的资料，最终在混乱的状态成功了，然后我尝试阅读代码，并删除了一些重复的东西，并以一种较为简洁的方式成功。

示例hubs端点

app.MapHub<MessageHub>("/hubs/message");

我假设你已经知道如何添加SignalR和通常的使用jwt的验证。

这包括

处理跨域， 添加身份，数据库，账户，驱动，身份验证。

在这种情况下，只需要额外添加

builder.Services.AddAuthentication(options =>
    {
        options.DefaultAuthenticateScheme = JwtBearerDefaults.AuthenticationScheme;
        options.DefaultScheme = JwtBearerDefaults.AuthenticationScheme;
        options.DefaultChallengeScheme = JwtBearerDefaults.AuthenticationScheme;
    })
    .AddJwtBearer(options =>
    {
        options.TokenValidationParameters = new TokenValidationParameters
        {
            ValidateIssuer = true,
            ValidateAudience = true,
            ValidateLifetime = true,
            ValidateIssuerSigningKey = true,
            ValidIssuer = jswSettings.Issuer,
            ValidAudience = jswSettings.Audience,
            IssuerSigningKey = new SymmetricSecurityKey(secretKey)
        };
        options.Events = new JwtBearerEvents();
    });
builder.Services.TryAddEnumerable(
    ServiceDescriptor.Singleton<IPostConfigureOptions<JwtBearerOptions>,
        ConfigureJwtBearerOptions>());

其中 

ConfigureJwtBearerOptions 是自定义的类，这个设计思路来自于微软的指南，是通过添加类似于中间件的形式实现。

如果不添加

options.Events = new JwtBearerEvents();

会在后面的（上面的）组件中提示空对象。

using Microsoft.IdentityModel.Tokens;

using Microsoft.AspNetCore.Authentication.JwtBearer;
using Microsoft.Extensions.Options;
public class ConfigureJwtBearerOptions : IPostConfigureOptions<JwtBearerOptions>
{
    public void PostConfigure(string? name, JwtBearerOptions options)
    {
        var originalOnMessageReceived = options.Events.OnMessageReceived;
        options.Events.OnMessageReceived = async context =>
        {
            await originalOnMessageReceived(context);

            if (string.IsNullOrEmpty(context.Token))
            {
                var accessToken = context.Request.Query["access_token"];
                var path = context.HttpContext.Request.Path;

                if (!string.IsNullOrEmpty(accessToken) &&
                    path.StartsWithSegments("/hubs/message"))
                {
                    context.Token = accessToken;
                }
            }
        };
        options.Events.OnAuthenticationFailed = context =>
        {
            if (context.Exception.GetType() == typeof(SecurityTokenExpiredException))
            {
                context.Response.Headers.Append("Token-Expired", "true");
            }
            else if (context.Exception.GetType() == typeof(SecurityTokenInvalidLifetimeException))
            {
                context.Response.Headers.Append("Token-Expired", "true");
            }

            return Task.CompletedTask;
        };
    }
}

 这个可以忽略

options.Events.OnAuthenticationFailed

主要的逻辑是 设置上下文的 token。

最后在中心上设置相应的要求

[Authorize(Policy = "user")]
public class MessageHub: Hub

这里使用的是之前配置的身份验证。

builder.Services.AddAuthorization(options =>
{
    options.AddPolicy("admin", policy => policy.RequireRole(["admin"]));
    options.AddPolicy("user", policy => policy.RequireRole(["user"]));
    options.AddPolicy("vip", policy => policy.RequireRole(["vip"]));
});

token中包含身份信息。在分发的token中包含。

private string GenerateToken(string username, int id)
    {
        var securityKey = new SymmetricSecurityKey(Encoding.UTF8.GetBytes(_configuration["Jwt:SecretKey"]!));
        var credentials = new SigningCredentials(securityKey, SecurityAlgorithms.HmacSha256);
        var roles = _context.AccountRoles!.Where(a => a.AccountId == id)
            .Include(r=>r.Role).ToList();
        var claims = new List<Claim> { new Claim(ClaimTypes.Name, username) };
        roles.ForEach(role =>
        {
            claims.Add(new Claim(ClaimTypes.Role,role.Role!.Name!));
        });
        var token = new JwtSecurityToken(
            issuer: _configuration["Jwt:Issuer"],
            audience: _configuration["Jwt:Audience"],
            claims: claims,
            expires: DateTime.Now.AddDays(3),
            signingCredentials: credentials);
        return new JwtSecurityTokenHandler().WriteToken(token);
    }