William William - 1 month ago 16
C# Question

Redirect to HTTPS

What is the recommend way to redirect to HTTPS all incoming requests that are not secure. Do I need to write a middleware component? If so, I couldn't figure out how to get the server name.

public class RedirectHttpMiddleware
{
RequestDelegate _next;

public RedirectHttpMiddleware(RequestDelegate next)
{
_next = next;
}

public async Task Invoke(HttpContext context)
{
if (context.Request.IsSecure)
await _next(context);
else
{
var server = ""; // How do I get the server name?
context.Response.Redirect("https://" + server + context.Request.Path);
}
}
}

Answer

You can use your own middleware class, but typically I just do something like this in my Startup configuration:

app.Use(async (context, next) =>
{
    if (context.Request.IsHttps)
    {
        await next();
    }
    else
    {
        var withHttps = Uri.UriSchemeHttps + Uri.SchemeDelimiter + context.Request.Uri.GetComponents(UriComponents.AbsoluteUri & ~UriComponents.Scheme, UriFormat.SafeUnescaped);
        context.Response.Redirect(withHttps);
    }
});

What this does is just grab the entire URL, query string and all, and use GetComponents to get everything except the scheme in the URL. Then the HTTPS scheme gets prepended to the components URL.

This will work with the full .NET Framework, for ASP.NET Core, you can do something like this:

app.Use(async (context, next) =>
{
    if (context.Request.IsHttps)
    {
        await next();
    }
    else
    {
        var withHttps = "https://" + context.Request.Host + context.Request.Path;
        context.Response.Redirect(withHttps);
    }
});

This appends the host and the path to the HTTPS scheme. You may want to add other components such as the query and hash, too.