Http status code for bad params in post request - client-server

I have a server in which the client can register itself as a device (like a mobile device). For the registration, the device must be associated with another resource (say an user) which is already registered on the server. To do that, the client sends a Http Post request to the server, with two params, its own ID and the associated resource ID.
I need to choose an Http Status code to return when the client ask the server to do some procedure and one of the resources indicated in the parameters are not found.
I suggested 404, but my professor said that 404 is used the resource associated to the URI is not found, not when you submit a well-formed request with bad parameters.
What is the most suitable http status and why would you choose?

In my opinion, it fits to:
400 - Bad Request
The request could not be understood by the server due to malformed syntax. The client SHOULD NOT repeat the request without modifications.
OR
403 - Forbidden
The server understood the request, but is refusing to fulfill it. Authorization will not help and the request SHOULD NOT be repeated. If the request method was not HEAD and the server wishes to make public why the request has not been fulfilled, it SHOULD describe the reason for the refusal in the entity. If the server does not wish to make this information available to the client, the status code 404 (Not Found) can be used instead.
Ref: fc2616

I would use 403 'Forbidden' - meaning, you are forbidden from accessing the page with the request you have sent

Related

JMeter view results tree requests showing error

Why is this second request happening (Request2-1) here and how to solve it.
Your request is redirected and there is not permission to access the resource.
The HTTP 403 Forbidden client error status response code indicates that the server understands the request but refuses to authorize it.
Please check the request details in the view result tree by clicking Request->Request Body and Request->Request Headers
You need to ensure that the request is permitted.
Most probably the resources, you're trying to access require authentication and you're not supplying valid authentication context.
If you do HTTP Status Code 403 means that the user is not allowed to access the endpoint.
See How to use JMeter for Login Authentication article for more information on example bypassing login challenge in JMeter tests.
If "Follow Redirects" is selected in HTTP Request, it will follow the redirects and groups each redirect under the original request as in the image you posted.
Some APIs can redirect, this is normal. Response failure is caused by the request content sent. Check the parameters and body values you sent.

Should WebSocket server only handle GET requests?

I have a WebSocket server written which only handles upgrade requests which are GET requests. If a POST or any other kind of request with the required headers comes it is handled by a HTTP server.
In the specification it is not stated explicitly that the WebSocket upgrade request should be a GET request.
If the upgrade request is not a GET request should the server handle it as a WebSocket upgrade request, should it pass it to be handled by the HTTP server or should it respond to it with a status code like 400 Bad Request ?
Could this be a design decision where the server decides not to handle methods which are not GET requests?
From section 4.1 (Client Requirements) of the webSocket specification, it says this:
The method of the request MUST be GET, and the HTTP version MUST
be at least 1.1
And, then later in section 4.2.1 (Reading the Client's Opening Handshake) of the webSocket specification, it says this:
The client's opening handshake consists of the following parts. If
the server, while reading the handshake, finds that the client did
not send a handshake that matches the description below (note that as
per [RFC2616], the order of the header fields is not important),
including but not limited to any violations of the ABNF grammar
specified for the components of the handshake, the server MUST stop
processing the client's handshake and return an HTTP response with an
appropriate error code (such as 400 Bad Request).
An HTTP/1.1 or higher GET request, including a "Request-URI"
[RFC2616] that should be interpreted as a /resource name/
defined in Section 3 (or an absolute HTTP/HTTPS URI containing
the /resource name/).
So, there are multiple places where it says the http request must be a GET.
As for your specific questions:
Should WebSocket server only handle GET requests?
Yes, a webSocket connection will always start with a GET request, not a POST or any other method.
If the upgrade request is not a GET request should the server handle it as a WebSocket upgrade request, should it pass it to be handled by the HTTP server or should it respond to it with a status code like 400 Bad Request ?
As described in the above reference portion of the specfication, the server should respond with a status code like 400 Bad Request.
Could this be a design decision where the server decides not to handle methods which are not GET requests?
Yes.

HTTP status code for a resource infected by virus

I'm developing an application which acts as an Http-Proxy for serving files from an external resource. It actually downloads the file from the external resource, checks for viruses and if the file is not infected, returns the file to the client.
My problem is, in case of the file is infected, what HTTP Status code my service should return? I suppose that any type of 4xx error codes is not appropriate for that situation because this class of code is intended for Client errors.
Is a 502 (Bad Gateway) error more appropriate?
Is there any kind of Standard that covers this situation?
I think you are right maestromarko : 502 Bad Gateway. Read the specifications here:
The 502 (Bad Gateway) status code indicates that the server, while
acting as a gateway or proxy, received an invalid response from an
inbound server it accessed while attempting to fulfill the request.
Your proxy is acting as a Gateway and he received what it conciders is invalid as there are virus in it.
It is not a 4xx class error, because whatever the client changes in the request, the result will still be an error.
See also this decision diagram
Http response codes are only meant to handle http specific conditions so I don't think there is a correct answer as such. But some possibilities...
204 - "The server successfully processed the request and is not returning any content"
403 - "The request was valid, but the server is refusing action"
https://en.m.wikipedia.org/wiki/List_of_HTTP_status_codes

What's the appropriate HTTP status code to return if a user tries logging in with an incorrect username / password, but correct format?

A similar question is posted here: What's an appropriate HTTP status code to return by a REST API service for a validation failure?
The answer in the thread above states that "For instance if the URI is supposed to have an ISO-8601 date and you find that it's in the wrong format or refers to February 31st, then you would return an HTTP 400. Ditto if you expect well-formed XML in an entity body and it fails to parse."
However, what happens if the user submitted correctly formatted data? By this I mean, the user submitted a plain alphabetical string / text for the username and password (which is perfectly valid for my application). The only issue is that the password did not match with the username. In this case, 400 will be incorrect because it is perfectly valid syntax and well-formed.
A 401 would be incorrect (as suggested here: Which HTTP status code to say username or password were incorrect?) because the user is not trying to access any page, he is simply trying to login and entered data which does not match.
If you look back at the first post I linked to, the second answer states that 422 is the correct response (and it looks correct to me), however, I am using Django Rest Framework and 422 is not part of the status codes (a list of the status codes which are part of DRF can be found here: http://www.django-rest-framework.org/api-guide/status-codes/#client-error-4xx)
404 also doesn't look right because the data is successfully accepted and not refused.
With that said, what is the real correct response which should be used?
If you are strictly using the HTTP authentication framework provided by RFC 7235 for your REST API, the correct HTTP code would actually be 401. From the RFC:
The 401 (Unauthorized) status code indicates that the request has not been applied because it lacks valid authentication credentials for the target resource. The server generating a 401 response MUST send a WWW-Authenticate header field (Section 4.1) containing at least one challenge applicable to the target resource.
If the request included authentication credentials, then the 401 response indicates that authorization has been refused for those credentials. The user agent MAY repeat the request with a new or replaced Authorization header field (Section 4.2).
Your REST API should employ an authentication scheme of some sort in order to return a valid 401 response to your client.
Another pertinent section from RFC 7235, page 4:
Upon receipt of a request for a protected resource that omits
credentials, contains invalid credentials (e.g., a bad password) or
partial credentials (e.g., when the authentication scheme requires
more than one round trip), an origin server SHOULD send a 401
(Unauthorized) response that contains a WWW-Authenticate header field
with at least one (possibly new) challenge applicable to the
requested resource.
A higher-level response, such as a rendered login page for a visual user (redirected from a protected resource via 302), would be better served with the 200 status code (per #KernelDeimos' answer, for example). Since login pages are typically their own resource (e.g. /login?redirect=original-resource), the unauthenticated user is still authorized to see this page, even if they provide an incorrect username/password. Then, you redirect the authenticated user back to the resource, at which point would show 200 if allowed, or 403 if the user is forbidden to view the resource.
The area where 401 could come into play with a visual login page is a front-end library that leverages the REST API using XHR requests, then relay the 401 response from the REST API back into a meaningful format on the login page.
If login is handled at a higher-level (ex: sending a POST to the server with a username and password), use the appropriate status code in 2xx for a successfully handled login request with the wrong password. If using the HTTP authentication framework provided by RFC 7235, send 401 (see answer by #sjagr for further detail).
Below the line is the rest of my original answer, which explains my train of thought. Also note the thread on sjagr's answer which includes a debate which improved both our answers and a comment from Julian Reschke (one of the RFC's authors).
Before asking "what is the correct HTTP status code", it's important to consider this question: "Should success or failure of login be reflected in the HTTP status code of the response?"
In #sjagr's answer the first part of this section is highlighted. I'm going to highlight the second part and explain why:
If the request included authentication credentials, then the 401 response indicates that authorization has been refused for those credentials. The user agent MAY repeat the request with a new or replaced Authorization header field (Section 4.2).
This refers to an Authorization header, rather than a request body containing login credentials. The phrasing of the first part, unfortunately, could be misinterpreted to refer to a request body containing login information. This ambiguity can be resolved by considering separation of concerns; (https://en.wikipedia.org/wiki/Separation_of_concerns) the server's response header should not depend on the differences of two valid request bodies, with the exception of when it causes an internal server error, otherwise the concerns of data transfer and appliction login begin to creep into each other.
I would use HTTP response 2xx for a valid login request, where the client has permission to attempt a login, that is handled successfully with a response indicating success or failure.
I also like the way #spectras expressed this in the comments:
Attempting to express an application-level error in a transport-level status code is a design mistake.
401 - Unauthorized
403 - Forbidden
http://www.buggybread.com/2012/11/http-error-codes-401-access-denied-403.html
If you try to log into a Google account with the wrong password, it will return a 200 response containing data that indicates the password was incorrect. For that reason, I just use a 200.
At the end of the day, which status code you use is purely a semantic issue and isn't going to change the functionality of your application. What really matters is that your application displays the correct information to the user.
I think what causes all the confusion is that there are two entities that need to be authenticated. One is the client (front-end app) needs to authenticate itself, that its authorized to make a login request for the user, and then the user needs to authenticate itself with his username/password.
The status code should only be related to the client making the request, not the user.
From https://developer.mozilla.org/en-US/docs/Web/HTTP/Status
HTTP response status codes indicate whether a specific HTTP request has been successfully completed.
200 is correct:
Given that you have a front-end application that talks to the backend, the appropriate respond code should be 200 and the response body should contain the information if password matches or not, but that result has no impact on the status code, because the request itself was authorized and successfully parsed.
401 is wrong:
Assume your front-end authenticates with a token for example, then the response code 401 would mean the front-end token is invalid, not the password of the user inside that request.
403 is wrong: Assume your front-end authenticates with a token for example, then the response code 403 would mean the token is vaild, but that token does not have the access right to ask if password/username match.

Correct response code for wrong request type

Which http response code best notifies a user that an api only ajax and post are accepted?
For example i have a controller that will only allow ajax requests and these must be post and not get.
So if an end user was to request using get or post using non ajax they should get a response to indicate this is not allowed.
Would either of these be the best response for this:
400
403
405
400 - Bad Request, 405 - Method not allowed
I think yours is 405, 403 is forbidden, regarding access permissions, not format or method. Bad Request could be a combination of forbidden parameters
HTTP doesn't have status code to distinguish between requests initiated by XmlHttpRequest (you call it AJAX) and requests made by any other HTTP client or directly by browser.
I guess that by non-ajax request you mean request that is made directly by putting an URL into browser (or by click on a link). It means that browser performs GET request.
HTTP allows you specify set of allowed HTTP methods for particular resource.
To fulfill your use-case you just need status code which allows you specify that just POST method is allowed.
405 - Method not allowed
The method specified in the Request-Line is not allowed for the
resource identified by the Request-URI. The response MUST include an
Allow header containing a list of valid methods for the requested
resource.
http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.4.6
Practically it means that your server will return 405 for GET,PUT,DELETE methods.

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