How can one use HttpClient with a pipeline of multiple proxies?
A single proxy can be handled via HttpClientHandler:
HttpClient client1 = new HttpClient(new HttpClientHandler()
{
Proxy = new WebProxy()
{
Address = new Uri($"http://{proxyIp}:{proxyPort}"),
BypassProxyOnLocal = false,
UseDefaultCredentials = false
}
});
I want the requests to pass through multiple proxies.
I already tried subclassing DelegatingHandler like this:
public class ProxyDelegatingHandler : DelegatingHandler
{
public ProxyDelegatingHandler(string proxyIp, int proxyPort):
base(new HttpClientHandler()
{
Proxy = new WebProxy()
{
Address = new Uri($"http://{proxyIp}:{proxyPort}"),
BypassProxyOnLocal = false,
UseDefaultCredentials = false
}
})
{
}
protected override Task<HttpResponseMessage> SendAsync(
HttpRequestMessage request, CancellationToken cancellationToken)
{
return base.SendAsync(request, cancellationToken);
}
}
And passing the list to factory, but it throws an exception which is probably caused by incorrect implementation of ProxyDelegatingHandler:
var handlers = new List<DelegatingHandler>();
handlers.Add(new ProxyDelegatingHandler(ip1, port2));
handlers.Add(new ProxyDelegatingHandler(ip2, port2));
HttpClient client = HttpClientFactory.Create(handlers.ToArray())
HttpRequestMessage requestMessage = new HttpRequestMessage(HttpMethod.Get, url);
var res = await client.SendAsync(requestMessage);
Exception:
The 'DelegatingHandler' list is invalid because the property 'InnerHandler' of 'CustomHandler' is not null. Parametername: handlers
Related Post: link
Related
I currently have webservice calls that create a proxy interface for a URL. I have a requirement to update the application to accept Oauth 2.0. Is it possible to use Oauth 2.0 with WCF Webservice calls?
This is my proxy interface initialization. I use it just like a regular class initialization.
var client = ServiceClient.CreateProxyInterface<MyWebServiceClass>(WebServiceUrl);
inside the proxy interface I do some authorization checks and create an instance of the requested object and return it back to the client
public static TInterface CreateProxyInterface<TInterface>(string ServiceUrl) where TInterface : class
{
var UseClientCertificate = true;
if (ServiceClient.IsUnsecuredHttpService(ServiceUrl, UseClientCertificate))
ServiceUrl = new UriBuilder(ServiceUrl)
{
Scheme = Uri.UriSchemeHttps,
Port = -1
}.Uri.ToString();
var key = TInterface.ToString() + ServiceUrl + UseClientCertificate.ToString();
ChannelFactory myChannelFactory = ServiceClient.FactoryCache[key];
proxy = ((ChannelFactory<TInterface>) mlifChannelFactory1.Factory).CreateChannel();
return proxyInterface;
}
the client can then call a method within that class
var address = client.GetAddress(personId);
On the server side, you can customize a class to inherit ServiceAuthorizationManager, and then override the CheckAccessCore method in ServiceAuthorizationManager to implement it.
Below is an example I found from previous answers：OAuth and WCF SOAP service. After my attempts, his example is effective, so I think it should help you.
public class OAuthAuthorizationManager : ServiceAuthorizationManager
{
protected override bool CheckAccessCore(OperationContext operationContext)
{
// Extract the action URI from the OperationContext. Match this against the claims
// in the AuthorizationContext.
string action = operationContext.RequestContext.RequestMessage.Headers.Action;
try
{
//get the message
var message = operationContext.RequestContext.RequestMessage;
//get the http headers
var httpHeaders = ((System.ServiceModel.Channels.HttpRequestMessageProperty)message.Properties.Values.ElementAt(message.Properties.Keys.ToList().IndexOf("httpRequest"))).Headers;
//get authorization header
var authHeader = httpHeaders.GetValues("Authorization");
if (authHeader != null)
{
var parts = authHeader[0].Split(' ');
if (parts[0] == "Bearer")
{
var tokenClaims = ValidateJwt(parts[1]);
foreach (System.Security.Claims.Claim c in tokenClaims.Where(c => c.Type == "http://www.contoso.com/claims/allowedoperation"))
{
var authorized = true;
//other claims authorization logic etc....
if(authorized)
{
return true;
}
}
}
}
return false;
}
catch (Exception)
{
throw;
}
}
private static IEnumerable<System.Security.Claims.Claim> ValidateJwt(string jwt)
{
var handler = new JwtSecurityTokenHandler();
var validationParameters = new TokenValidationParameters()
{
ValidAudience = "urn://your.audience",
IssuerSigningKey = new InMemorySymmetricSecurityKey(Convert.FromBase64String("base64encoded symmetric key")),
ValidIssuer = "urn://your.issuer",
CertificateValidator = X509CertificateValidator.None,
RequireExpirationTime = true
};
try
{
SecurityToken validatedToken;
var principal = handler.ValidateToken(jwt, validationParameters, out validatedToken);
return principal.Claims;
}
catch (Exception e)
{
return new List<System.Security.Claims.Claim>();
}
}
}
I have implemented httpClientFactory but can't connect to the backend api using broken ssl.I tried a lot and i just got the task cancelled error -> HttpClient - A task was cancelled?
I have tried to set this
public static HttpClient getHttpClient()
{
if (_httpClient == null)
{
Uri baseUri = new Uri(Url.baseUrl);
if (baseUri.Scheme == "http")
{
var handler = new HttpClientHandler();
handler.ClientCertificateOptions = ClientCertificateOption.Manual;
handler.ServerCertificateCustomValidationCallback =
(httpRequestMessage, cert, cetChain, policyErrors) =>
{
return true;
};
_httpClient = new HttpClient(handler);
}
else
{
_httpClient = new HttpClient();
}
_httpClient.DefaultRequestHeaders.Accept.Clear();
_httpClient.DefaultRequestHeaders.Accept.Add(new
MediaTypeWithQualityHeaderValue("application/json"));
_httpClient.BaseAddress = baseUri;
}
return _httpClient;
}
My app requirements is to authenticate using client credentials AND another code (hash).
I followed this link to create and use custom IExtensionGrantValidator.
I manged to invoke the custom IExtensionGrantValidator with approved grant, but client always gets invalid_grant error.
For some reason the set operation ofd Result (property of ExtensionGrantValidationContext) always fails (overriding the Error value returns the overrided value to client).
This is CustomGrantValidator Code:
public class CustomGrantValidator : IExtensionGrantValidator
{
public string GrantType => "grant-name";
public Task ValidateAsync(ExtensionGrantValidationContext context)
{
var hash = context.Request.Raw["hash"]; //extract hash from request
var result = string.IsNullOrEmpty(hash) ?
new GrantValidationResult(TokenRequestErrors.InvalidRequest) :
new GrantValidationResult(hash, GrantType);
context.Result = result
}
}
Startup.cs contains this line:
services.AddTransient<IExtensionGrantValidator, CustomGrantValidator>();
And finally client's code:
var httpClient = new HttpClient() { BaseAddress = new Uri("http://localhost:5000") };
var disco = await httpClient.GetDiscoveryDocumentAsync("http://localhost:5000");
var cReq = await httpClient.RequestTokenAsync(new TokenRequest
{
GrantType = "grant-name",
Address = disco.TokenEndpoint,
ClientId = clientId,// client Id taken from appsetting.json
ClientSecret = clientSecret, //client secret taken from appsetting.json
Parameters = new Dictionary<string, string> { { "hash", hash } }
});
if (cReq.IsError)
//always getting 'invalid_grant' error
throw InvalidOperationException($"{cReq.Error}: {cReq.ErrorDescription}");
The below codes works on my environment :
public async Task ValidateAsync(ExtensionGrantValidationContext context)
{
var hash = context.Request.Raw["hash"]; //extract hash from request
var result = string.IsNullOrEmpty(hash) ?
new GrantValidationResult(TokenRequestErrors.InvalidRequest) :
new GrantValidationResult(hash, GrantType);
context.Result = result;
return;
}
Don't forget to register the client to allow the custom grant :
return new List<Client>
{
new Client
{
ClientId = "client",
// no interactive user, use the clientid/secret for authentication
AllowedGrantTypes = { "grant-name" },
// secret for authentication
ClientSecrets =
{
new Secret("secret".Sha256())
},
// scopes that client has access to
AllowedScopes = { "api1" }
}
};
I got the same issue and found the answer from #Sarah Lissachell, turn out that I need to implement the IProfileService. This interface has a method called IsActiveAsync. If you don't implement this method, the answer of ValidateAsync will always be false.
public class IdentityProfileService : IProfileService
{
//This method comes second
public async Task GetProfileDataAsync(ProfileDataRequestContext context)
{
//IsActiveAsync turns out to be true
//Here you add the claims that you want in the access token
var claims = new List<Claim>();
claims.Add(new Claim("ThisIsNotAGoodClaim", "MyCrapClaim"));
context.IssuedClaims = claims;
}
//This method comes first
public async Task IsActiveAsync(IsActiveContext context)
{
bool isActive = false;
/*
Implement some code to determine that the user is actually active
and set isActive to true
*/
context.IsActive = isActive;
}
}
Then you have to add this implementation in your startup page.
public void ConfigureServices(IServiceCollection services)
{
// Some other code
services.AddIdentityServer()
.AddDeveloperSigningCredential()
.AddAspNetIdentity<Users>()
.AddInMemoryApiResources(config.GetApiResources())
.AddExtensionGrantValidator<CustomGrantValidator>()
.AddProfileService<IdentityProfileService>();
// More code
}
I wanto to forward an incoming POST request to my asp.net core controller "as is" (including headers, body, from-data) to a different URL without using a middleware.
I found an example for doing that for asp.net: https://philsversion.com/2012/09/06/creating-a-proxy-with-apicontroller/
But this does not work for asp.net core, since the call to
return await http.SendAsync(this.Request);
in asp.net core accepts an HttpRequestMessage and the Request object is of type HttpRequest.
I also found some code, which creates a HttpRequestMessage from an HttpRequest, see: Convert Microsoft.AspNetCore.Http.HttpRequest to HttpRequestMessage
Using this code, the receiving endpoint (to which I forward to) gets the Body, but it does not get Form fields.
Checking the class HttpRequestMessage I saw that it does not contain a property for FormFields.
[Microsoft.AspNetCore.Mvc.HttpPost]
[NrgsRoute("api/redirect-v1/{key}")]
public async Task<HttpResponseMessage> Forward(
[FromUri] string key,
CancellationToken cancellationToken)
{
// the URL was shortened, we need to get the original URL to which we want to forward the POST request
var url = await _shortenUrlService.GetUrlFromToken(key, cancellationToken).ConfigureAwait(false);
using (var httpClient = new HttpClient())
{
var forwardUrl = new Uri(url);
Request.Path = new PathString(forwardUrl.PathAndQuery);
// see: https://stackoverflow.com/questions/45759417/convert-microsoft-aspnetcore-http-httprequest-to-httprequestmessage
var requestMessage = Request.ToHttpRequestMessage();
return await httpClient.SendAsync(requestMessage, cancellationToken);
// Problem: Forwards header and body but NOT form fields
}
}
Expected result would be that at my receiving endpoint I have the same
- headers
- body
- form fields
as in the original POST request.
I ended up doing the following:
[HttpPost]
[NrgsRoute("api/redirect-v1/{key}")]
public async Task<RedirectResult> Forward(string key, CancellationToken cancellationToken)
{
var url = await _shortenUrlService.GetUrlFromToken(key, cancellationToken).ConfigureAwait(false);
if (string.IsNullOrEmpty(url))
throw new BadRequestException($"Could not create forward URL from parameter {key}", "redirect-error");
using (var httpClient = new HttpClient())
{
var forwardUrl = new Uri(url);
Request.Path = new PathString(forwardUrl.PathAndQuery);
HttpResponseMessage responseMessage;
if (Request.HasFormContentType)
responseMessage = await ForwardFormData(key, httpClient, forwardUrl, cancellationToken);
else
responseMessage = await ForwardBody(key, httpClient, cancellationToken);
var queryParams = forwardUrl.GetQueryStringParams();
var lUlr = queryParams["lurl"];
return new RedirectResult(lUlr);
}
}
private async Task<HttpResponseMessage> ForwardFormData(string key, HttpClient httpClient, Uri forwardUrl, CancellationToken cancellationToken)
{
var formContent = new List<KeyValuePair<string, string>>();
HttpResponseMessage result;
if (Request.ContentType == "application/x-www-form-urlencoded")
{
foreach (var formKey in Request.Form.Keys)
{
var content = Request.Form[formKey].FirstOrDefault();
if (content != null)
formContent.Add(new KeyValuePair<string, string>(formKey, content));
}
var formUrlEncodedContent = new FormUrlEncodedContent(formContent);
result = await httpClient.PostAsync(forwardUrl, formUrlEncodedContent, cancellationToken);
}
else
{
var multipartFormDataContent = new MultipartFormDataContent();
foreach (var formKey in Request.Form.Keys)
{
var content = Request.Form[formKey].FirstOrDefault();
if (content != null)
multipartFormDataContent.Add(new StringContent(content), formKey);
}
result = await httpClient.PostAsync(forwardUrl, multipartFormDataContent, cancellationToken);
}
return result;
}
private async Task<HttpResponseMessage> ForwardBody(string key, HttpClient httpClient, CancellationToken cancellationToken)
{
// we do not have direct access to Content, see: https://stackoverflow.com/questions/41508664/net-core-forward-a-local-api-form-data-post-request-to-remote-api
var requestMessage = Request.ToHttpRequestMessage();
return await httpClient.SendAsync(requestMessage, cancellationToken);
}
I want to write custom batch handler in my webapi.
Requirement for this : I am not able to identify weather the incoming request is part of batch or independent.
By writing custom batch handler i will be able to add value in header of each request, which i can use later to identify.
First we need to write custom batch hahttps://stackoverflow.blog/2011/07/01/its-ok-to-ask-and-answer-your-own-questions/ndler
For this we need to override HttpMessageHandler. Below is code
public class BatchHandler : HttpMessageHandler
{
HttpMessageInvoker _server;
public BatchHandler(HttpConfiguration config)
{
// BatchServer is a class which overrides
_server = new HttpMessageInvoker(new BatchServer(config));
}
protected override async Task<HttpResponseMessage> SendAsync(
HttpRequestMessage request,
CancellationToken cancellationToken)
{
// Return 400 for the wrong MIME type
// As batch request will always be of MIME type
if ("multipart/mixed" !=
request.Content.Headers.ContentType.MediaType)
{
return request.CreateResponse(HttpStatusCode.BadRequest);
}
// Start a multipart response
var outerContent = new MultipartContent("batch");
var outerResp = request.CreateResponse();
outerResp.Content = outerContent;
// Read the multipart request
var multipart = await request.Content.ReadAsMultipartAsync();
foreach (var httpContent in multipart.Contents)
{
HttpResponseMessage innerResp = null;
try
{
// Decode the request object
var innerReq = await
httpContent.ReadAsHttpRequestMessageAsync();
innerReq.Headers.Add("IsBatch", "true");
// Send the request through the pipeline
innerResp = await _server.SendAsync(
innerReq,
cancellationToken
);
}
catch (Exception ex)
{
// If exceptions are thrown, send back generic 400
innerResp = new HttpResponseMessage(
HttpStatusCode.BadRequest
);
}
// Wrap the response in a message content and put it
// into the multipart response
outerContent.Add(new HttpMessageContent(innerResp));
}
return outerResp;
}
}
in above code their is this line
// BatchServer is a class which overrides HttpServer
_server = new HttpMessageInvoker(new BatchServer(config));
if we don't do this we gets an error
The 'DelegatingHandler' list is invalid because the property
'InnerHandler' of 'xxhandler' is not null.\r\nParameter
name: handlers
Below is the BatchServer class which overrides HttpServer
public class BatchServer : HttpServer
{
private readonly HttpConfiguration _config;
public BatchServer(HttpConfiguration configuration)
: base(configuration)
{
_config = configuration;
}
protected override void Initialize()
{
var firstInPipeline = _config.MessageHandlers.FirstOrDefault();
if (firstInPipeline != null && firstInPipeline.InnerHandler != null)
{
InnerHandler = firstInPipeline;
}
else
{
base.Initialize();
}
}
}
Now we want to hit batch request on BatchHandler
For this we need configure route to BatchHandler
Add below code to your AppStart
var batchHandler = new BatchHandler(config);
config.Routes.MapHttpRoute("batch", "api/batch", null, null, batchHandler);