Class BoundedMetadataHttpMessageHandler

Namespace

MailFathom.Infrastructure.Security.OAuth

Assembly

MailFathom.Infrastructure.dll

Keeps the retrieval of an authorization server's metadata inside stated bounds.

public sealed class BoundedMetadataHttpMessageHandler : DelegatingHandler, IDisposable

Inheritance

object

HttpMessageHandler

DelegatingHandler

BoundedMetadataHttpMessageHandler

Implements

IDisposable

Inherited Members

DelegatingHandler.InnerHandler

HttpMessageHandler.Dispose()

object.Equals(object)

object.Equals(object, object)

object.GetHashCode()

object.GetType()

object.ReferenceEquals(object, object)

object.ToString()

Remarks

Discovery documents and key sets are the one thing this process fetches from a machine it does not own, and it fetches them on a schedule nobody watches. A server that has been replaced, misconfigured, or taken over is therefore in a position to answer a key refresh with something other than a few kilobytes of JSON, and the refresh happens inside a request's authentication path.

Two bounds are enforced here and two are set where the client is composed. This handler refuses a response larger than the limit and a request that is not https; the client that owns it carries the timeout and follows no redirect, so a server cannot answer slowly forever and cannot send the retrieval somewhere the configuration never named.

A declared length over the limit is refused before the body is read at all, and a body without one is read through a buffer that stops at the same limit. Both fail as an ordinary retrieval failure, which the caller already treats as "the metadata could not be read" rather than as a reason to accept a token.

Constructors

BoundedMetadataHttpMessageHandler(int)

Initializes a new bounded metadata handler.

Methods

SendAsync(HttpRequestMessage, CancellationToken)

Sends an HTTP request to the inner handler to send to the server as an asynchronous operation.