.NET Core 3 Web Api Cors fetch 一直 307 Temporary Redirect
继上一篇 .net core 3 web api jwt 一直 401 为添加JWT-BearerToken认证所述的坑后，
本次为添加CORS跨域，又踩坑了。
自从 .NET Core 2.2 之后，CORS跨域配置代码发生了很大变化。
在 .NET Core 3.1 中，本作者碰到各种HTTP错误，诸如 500、307、401 等错误代码...
在必应Bing和不断Debug调整配置代码位置后，得知：
AllowAnyOrigin方法，在新的 CORS 中间件已经被阻止使用允许任意 Origin，所以该方法无效。AllowCredentials方法，自从 .NET Core 2.2 之后，不允许和AllowAnyOrigin同时调用。WithOrigins方法，在 .NET Core 3.1 中有bug，具体原因未知，暂时只能用SetIsOriginAllowed(t=> true)代替，等效.AllowAnyOrigin方法。- 创建项目默认的模板中，
app.UseHttpsRedirection()在前面，所以我将app.UseCors()放在它后面，这是导致HTTP 307 Temporary Redirect福报的根本原因之一。 - 度娘告诉我，
app.UseCors()方法要在app.UseAuthentication()之后，是误人子弟的，其实放在它前面也可以，并且app.UseCors()要在app.UseRouting()之后，app.UseEndpoints()和app.UseHttpsRedirection()之前 - 使用fetch跨域请求时，要注意controller的action是否有设置除了
HttpOptions之外的其它Http Method方法，如果有要加上HttpOptions标记特性，因为fetch跨域请求会先执行OPTIONS预请求。 - 使用fetch请求需要JWT认证的接口时，除了在HTTP Headers设置
Authorization之外，还需要设置'credentials': 'include'。 - 写
app.UseXxxxxx方法，引入中间件时，要注意管道(Middleware)注册顺序。
参考：
- CORS配置：https://docs.microsoft.com/zh-cn/aspnet/core/security/cors?view=aspnetcore-3.1
- JWT认证：https://docs.microsoft.com/zh-cn/aspnet/core/security/authentication/?view=aspnetcore-3.1
- Cors Issue: https://github.com/dotnet/aspnetcore/issues/16672
- Forum: https://forums.asp.net/t/2160821.aspx?CORS+in+ASP+NET+Core+3+x
源代码
以下是在 .NET Core 3.1下经过严谨测试，可以JWT认证、CORS跨域、IIS托管、自寄主运行的源代码，仅供参考。
WebApi.csproj
<Project Sdk="Microsoft.NET.Sdk.Web">
<PropertyGroup>
<TargetFramework>netcoreapp3.1</TargetFramework>
<RootNamespace>WebApi</RootNamespace>
</PropertyGroup>
<ItemGroup>
<PackageReference Include="Microsoft.AspNetCore.Authentication.JwtBearer" Version="3.1.2" />
<PackageReference Include="Microsoft.Extensions.Logging.Console" Version="3.1.2" />
<PackageReference Include="Microsoft.Extensions.Logging.Debug" Version="3.1.2" />
<PackageReference Include="Microsoft.Extensions.Logging.EventSource" Version="3.1.2" />
<PackageReference Include="Microsoft.Extensions.Logging.TraceSource" Version="3.1.2" />
<PackageReference Include="Microsoft.Extensions.Options.ConfigurationExtensions" Version="3.1.2" />
<PackageReference Include="Microsoft.TeamFoundationServer.Client" Version="16.153.0" />
<PackageReference Include="Microsoft.VisualStudio.Services.Client" Version="16.153.0" />
<PackageReference Include="Microsoft.VisualStudio.Services.InteractiveClient" Version="16.153.0" />
<PackageReference Include="NLog.Web.AspNetCore" Version="4.9.0" />
</ItemGroup>
</Project>
Program.cs
using Microsoft.AspNetCore.Hosting;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Logging;
using NLog.Extensions.Logging;
using System.Diagnostics;
using System.IO;
namespace WebApi
{
public class Program
{
public static void Main(string[] args)
{
CreateHostBuilder(args).Build().Run();
}
public static IHostBuilder CreateHostBuilder(string[] args)
{
return Host.CreateDefaultBuilder(args)
.ConfigureLogging((context, logging) =>
{
logging.ClearProviders()
#if DEBUG
.AddConsole()
.AddDebug()
.AddEventLog()
.AddTraceSource(new SourceSwitch(nameof(Program), "Warning"), new ConsoleTraceListener())
#endif
.AddNLog();
})
.ConfigureWebHostDefaults(webBuilder =>
{
webBuilder.UseContentRoot(Directory.GetCurrentDirectory())
.UseKestrel()
.UseIISIntegration()
.UseIIS()
.UseStartup<Startup>();
});
}
}
}
Startup.cs
using MCS.Vsts.Options;
using MCS.Vsts.Services;
using Microsoft.AspNetCore.Authentication.JwtBearer;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.HttpOverrides;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using Microsoft.IdentityModel.Tokens;
using System.Text;
namespace WebApi
{
public class Startup
{
public IConfiguration Configuration { get; }
public Startup(IConfiguration configuration)
{
Configuration = configuration;
}
public void ConfigureServices(IServiceCollection services)
{
services.AddControllers();
//认证
services.AddAuthentication(JwtBearerDefaults.AuthenticationScheme)
.AddJwtBearer(options =>
{
var secretBytes = Encoding.UTF8.GetBytes(Configuration["ServerConfig:Secret"]);
options.TokenValidationParameters = new TokenValidationParameters()
{
IssuerSigningKey = new SymmetricSecurityKey(secretBytes),
ValidateIssuer = false,
ValidateAudience = false,
ValidateActor = false,
RequireSignedTokens = true,
RequireExpirationTime = true,
ValidateLifetime = true
};
});
//跨域
services.AddCors(options =>
{
options.AddDefaultPolicy(builder =>
{
builder
//允许任何来源的主机访问
//TODO: 新的 CORS 中间件已经阻止允许任意 Origin，即设置 AllowAnyOrigin 也不会生效
//AllowAnyOrigin()
//设置允许访问的域
//TODO: 目前.NET Core 3.1 有 bug, 暂时通过 SetIsOriginAllowed 解决
//.WithOrigins(Configuration["CorsConfig:Origin"])
.SetIsOriginAllowed(t=> true)
.AllowAnyMethod()
.AllowAnyHeader()
.AllowCredentials();
});
});
//TODO: do something...
}
public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
{
if (env.IsDevelopment())
{
app.UseDeveloperExceptionPage();
}
else
{
//Enabled HSTS
app.UseHsts();
}
//TODO: 要放在UseCors之后
//app.UseHttpsRedirection();
app.UseRouting();
app.UseForwardedHeaders(new ForwardedHeadersOptions
{
ForwardedHeaders = ForwardedHeaders.XForwardedFor | ForwardedHeaders.XForwardedProto
});
//TODO: UseCors要在UseRouting之后，UseEndpoints 和 UseHttpsRedirection 之前
app.UseCors();
app.UseAuthentication();
app.UseAuthorization();
app.UseHttpsRedirection();
app.UseEndpoints(endpoints =>
{
endpoints.MapControllers();
});
}
}
}
appsettings.json
{
"Logging": {
"LogLevel": {
"Default": "Information",
"Microsoft": "Warning",
"Microsoft.Hosting.Lifetime": "Information"
}
},
"AllowedHosts": "*",
"https_port": 44370,
"urls": "http://*:50867",
"ServerConfig": {
"Secret": "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
},
"CorsConfig": {
"BaseUri": "http://myserver"
}
}