How to access current HttpContext in ASP.NET Core

Question

How can I access current HttpContext to check for route and parameters inside AuthorizationHandlerContext of Custom Policy-Based Authorization inside ASP.NET Core 2?

Ref example: Custom Policy-Based Authorization

Answer 1

Without injecting, simple solution!

protected override Task HandleRequirementAsync(AuthorizationHandlerContext context, MyRequirement requirement)
        {
                var authFilterCtx = (Microsoft.AspNetCore.Mvc.Filters.AuthorizationFilterContext)context.Resource;
                var httpContext = authFilterCtx.HttpContext;  
        }

Answer 2

You can inject an IHttpContextAccessor into your AuthorizationHandlers constructor.

e.g.

public class MyAuthorizationHandler : AuthorizationHandler<MyRequirement>
{
    private IHttpContextAccessor _contextAccessor;

    public MyAuthorizationHandler (IHttpContextAccessor contextAccessor)
    {
        _contextAccessor = contextAccessor;
    }

    protected override Task HandleRequirementAsync(AuthorizationHandlerContext context,
        MinimumPermissionLevelRequirement requirement) {

        var httpContext = _contextAccessor.HttpContext;
        // do things
    }
}

Answer 3

You should inject an instance of an IHttpContextAccessor into your AuthorizationHandler.

In the context of your example, this may look like the following:

public class BadgeEntryHandler : AuthorizationHandler<EnterBuildingRequirement>
{
    IHttpContextAccessor _httpContextAccessor = null;

    public BadgeEntryHandler(IHttpContextAccessor httpContextAccessor)
    {
        _httpContextAccessor = httpContextAccessor;
    }

    protected override Task HandleRequirementAsync(
        AuthorizationContext context, 
        EnterBuildingRequirement requirement)
    {
        HttpContext httpContext = _httpContextAccessor.HttpContext; // Access context here

        if (context.User.HasClaim(c => c.Type == ClaimTypes.BadgeId &&
                                       c.Issuer == "http://microsoftsecurity"))
        {
            context.Succeed(requirement);
            return Task.FromResult(0);
        }
    }
}

You may need to register this in your DI setup (if one of your dependencies has not already), as follows:

services.AddHttpContextAccessor();