We have a simple User API including "GET /user" to request user information. When processing the request we store the current datetime as "lastVisit" in our database. As a result we have a GET request updating the user in our database, which seems to be bad practice.
As we don't handle the login process on ourselves, GET /user is the first request to our backend. We cannot use /login to retrieve and store "lastVisit".
Is it bad practice? How to solve the issue?
There's nothing wrong with updating your database when you receive a GET request - the uniform interface of HTTP constrains what the GET method token means, but you have a lot of freedom in how your server implements the handling of that request.
So that much is fine.
"lastVisit", however, may be a problem - which is to say, your interpretation of what it means that somebody asked for a copy of the page ignores various edge cases: a web spider following links to index the documents (think Google), or a smart browser that is trying to reduce latency by downloading a link before the user clicks on it.
You don't know, from the request, whether the fetch was triggered by the client, or by the general purpose agent acting in the client's stead. Similarly, you don't know about any requests for the resource that were intercepted and handled by a cache that had a valid copy of the resource.
It may be that using request handling time as a proxy for last visit is a good enough cost effective approximation of what you want to get by, but you should keep in mind that it is an estimate, not a truth.
I'm in the process of writing a testing framework for an application, and I am not allowed to update, delete, move, or basically do anything with the data used by this application. For GET requests I need to test this is no problem, but PUT, POST and DELETE methods that change data this obviously is not the case.
Is there any way to send a POST request without any body, and still get a response that shows the url can take a request? Or in other words, how can I show that a url that is a POST is up and able to take requests, without actually sending the POST request and changing something in the database? (unfortunately its not possible to add a test object to database and run requests on that).
I need to do this programmatically in either Java or C# as well.
There is no general way to 'test' if a POST request will work.
Most servers will likely emit a 400 error for these endpoints, which doesn't tell you a lot.
The most standard way to see if something is able to accept a POST request at all, is probably by doing an OPTIONS request and using the Allow header in the response to get the list of supported methods.
There is no guarantee that this is going to be correct, but many modern frameworks do a decent job populating this list. This is likely going to give you the most accurate, but still imperfect results.
You should not send an empty POST request anywhere because it could have a meaning and you could make unexpected changes to a server. For this kind of introspection stuff, stick to the 'safe' methods.
I'll start this question with 'this is not the same as the previous one'. I can see straightaway that an almost identical question has been asked but the answer is not what I'm after. I will explain...
I need to test an autocomplete search box in a web page. Normally I'd just do a series of requests with the HTML containing one extra letter each time (which is the answer to the other question similar to this). Problem is, that's not how the page behaves. It does submit a new request each time I type a letter, but it's cancelling the previous one instead of letting it continue. Therefore the only one that actually gets to a HTTP 200 response is the very last one.
This blog contains an example of what I'm seeing;
Autocomplete and request cancellation
But about halfway down it shows our test condition;
Client cancellation must also be supported by the search backend. Backend that doesn’t support cancellation continues processing request even after client disconnects.
I need to write a jmeter script that replicates a series of cancelled requests, followed by a single successful request, such that when I look on the backend I either see multiple running queries (bad) or just the last one (good).
Edit: I've also hit a follow up issue, how to identify canceled requests in web server logs. It looks like I'm only seeing single requests if they are allowed to complete (IE if I pause between letters). If the requests are cancelled, they don't get logged in the log. So, how do I verify that they happened at all? If we import the logs into a visualization tool, are we going to be missing the 'canceled' requests.
"Request cancellation" is nothing more than closing the connection from the client side
The easiest way of implementing it in JMeter is setting the response timeout, the setting lives under "Advanced" tab of the HTTP Request sampler or even better HTTP Request Defaults)
Just set this timeout to be lower than the threshold configured in your frontend and JMeter will close the connection making the backend "think" that the autocomplete request has been aborted because the user is still typing.
Demo:
Currently as it stands, if a user reads the source of my web application, they'd be able to determine the direct URIs of all the RESTful services my web application utilizes.
The problem I see is this: My web application knows how to correctly use the API, and I might not have thought of every single validation known to man to prevent bad data from being sent through the API.
And so with that is there a method to prevent "direct" access to the API and limit it only to my web application?
P.S. As an FYI: API calls concerning a user are protected by the presence of a user-specific cookie which is only issued upon login. This means I'm not too afraid of User X being able to directly modify User Y's data through the API.
No.
If the browser is making the request, the user can spoof the request. Period.
My web application knows how to correctly use the API
That's good, but that's leading you down the path of assuming client-side functionality executed as intended. Never make that assumption.
I might not have thought of every single validation known to man to prevent bad data from being sent through the API
This statement leads me to believe that the API itself is more complex than it needs to be. The best thing you can do is simplify. It's difficult to be more specific without seeing specific code, but API requests should be fairly simple and straightforward and the same techniques to prevent malicious code from getting through should be applied universally. The same general rules apply here as in any web application interaction...
Never trust anything that came from the client
Never assume client-side code executed as intended
Never execute input as code, always treat it as a raw value
and so on...
As you mention toward the end, you've already taken care of authentication and authorization for the requests. Given that, if User X is permitted to make a given API call, then what you're essentially asking is, "How do I allow User X to make an API call without allowing User X to make an API call?" The server can't tell the difference. A request is a request.
Sure, there are things you can try, such as always including some custom header in requests made from code. But anybody can inspect that request and spoof that header. The user's browser isn't part of your application and isn't under your control.
What's the difference when using GET or POST method? Which one is more secure? What are (dis)advantages of each of them?
(similar question)
It's not a matter of security. The HTTP protocol defines GET-type requests as being idempotent, while POSTs may have side effects. In plain English, that means that GET is used for viewing something, without changing it, while POST is used for changing something. For example, a search page should use GET, while a form that changes your password should use POST.
Also, note that PHP confuses the concepts a bit. A POST request gets input from the query string and through the request body. A GET request just gets input from the query string. So a POST request is a superset of a GET request; you can use $_GET in a POST request, and it may even make sense to have parameters with the same name in $_POST and $_GET that mean different things.
For example, let's say you have a form for editing an article. The article-id may be in the query string (and, so, available through $_GET['id']), but let's say that you want to change the article-id. The new id may then be present in the request body ($_POST['id']). OK, perhaps that's not the best example, but I hope it illustrates the difference between the two.
When the user enters information in a form and clicks Submit , there are two ways the information can be sent from the browser to the server: in the URL, or within the body of the HTTP request.
The GET method, which was used in the example earlier, appends name/value pairs to the URL. Unfortunately, the length of a URL is limited, so this method only works if there are only a few parameters. The URL could be truncated if the form uses a large number of parameters, or if the parameters contain large amounts of data. Also, parameters passed on the URL are visible in the address field of the browser not the best place for a password to be displayed.
The alternative to the GET method is the POST method. This method packages the name/value pairs inside the body of the HTTP request, which makes for a cleaner URL and imposes no size limitations on the forms output. It is also more secure.
The best answer was the first one.
You are using:
GET when you want to retrieve data (GET DATA).
POST when you want to send data (POST DATA).
There are two common "security" implications to using GET. Since data appears in the URL string its possible someone looking over your shoulder at Address Bar/URL may be able to view something they should not be privy to such as a session cookie that could potentially be used to hijack your session. Keep in mind everyone has camera phones.
The other security implication of GET has to do with GET variables being logged to most web servers access log as part of the requesting URL. Depending on the situation, regulatory climate and general sensitivity of the data this can potentially raise concerns.
Some clients/firewalls/IDS systems may frown upon GET requests containing an excessive amount of data and may therefore provide unreliable results.
POST supports advanced functionality such as support for multi-part binary input used for file uploads to web servers.
POST requires a content-length header which may increase the complexity of an application specific client implementation as the size of data submitted must be known in advance preventing a client request from being formed in an exclusively single-pass incremental mode. Perhaps a minor issue for those choosing to abuse HTTP by using it as an RPC (Remote Procedure Call) transport.
Others have already done a good job in covering the semantic differences and the "when" part of this question.
I use GET when I'm retrieving information from a URL and POST when I'm sending information to a URL.
You should use POST if there is a lot of data, or sort-of sensitive information (really sensitive stuff needs a secure connection as well).
Use GET if you want people to be able to bookmark your page, because all the data is included with the bookmark.
Just be careful of people hitting REFRESH with the GET method, because the data will be sent again every time without warning the user (POST sometimes warns the user about resending data).
This W3C document explains the use of HTTP GET and POST.
I think it is an authoritative source.
The summary is (section 1.3 of the document):
Use GET if the interaction is more like a question (i.e., it is a safe operation such as a query, read operation, or lookup).
Use POST if:
The interaction is more like an order, or
The interaction changes the state of the resource in a way that the
user would perceive (e.g., a subscription to a service), or
The user be held accountable for the results of the interaction.
Get and Post methods have nothing to do with the server technology you are using, it works the same in php, asp.net or ruby. GET and POST are part of HTTP protocol.
As mark noted, POST is more secure. POST forms are also not cached by the browser.
POST is also used to transfer large quantities of data.
The reason for using POST when making changes to data:
A web accelerator like Google Web Accelerator will click all (GET) links on a page and cache them. This is very bad if the links make changes to things.
A browser caches GET requests so even if the user clicks the link it may not send a request to the server to execute the change.
To protect your site/application against CSRF you must use POST. To completely secure your app you must then also generate a unique identifier on the server and send that along in the request.
Also, don't put sensitive information in the query string (only option with GET) because it shows up in the address bar, bookmarks and server logs.
Hopefully this explains why people say POST is 'secure'. If you are transmitting sensitive data you must use SSL.
GET and POST are HTTP methods which can achieve similar goals
GET is basically for just getting (retrieving) data, A GET should not have a body, so aside from cookies, the only place to pass info is in the URL and URLs are limited in length , GET is less secure compared to POST because data sent is part of the URL
Never use GET when sending passwords, credit card or other sensitive information!, Data is visible to everyone in the URL, Can be cached data .
GET is harmless when we are reloading or calling back button, it will be book marked, parameters remain in browser history, only ASCII characters allowed.
POST may involve anything, like storing or updating data, or ordering a product, or sending e-mail. POST method has a body.
POST method is secured for passing sensitive and confidential information to server it will not visible in query parameters in URL and parameters are not saved in browser history. There are no restrictions on data length. When we are reloading the browser should alert the user that the data are about to be re-submitted. POST method cannot be bookmarked
All or perhaps most of the answers in this question and in other questions on SO relating to GET and POST are misguided. They are technically correct and they explain the standards correctly, but in practice it's completely different. Let me explain:
GET is considered to be idempotent, but it doesn't have to be. You can pass parameters in a GET to a server script that makes permanent changes to data. Conversely, POST is considered not idempotent, but you can POST to a script that makes no changes to the server. So this is a false dichotomy and irrelevant in practice.
Further, it is a mistake to say that GET cannot harm anything if reloaded - of course it can if the script it calls and the parameters it passes are making a permanent change (like deleting data for example). And so can POST!
Now, we know that POST is (by far) more secure because it doesn't expose the parameters being passed, and it is not cached. Plus you can pass more data with POST and it also gives you a clean, non-confusing URL. And it does everything that GET can do. So it is simply better. At least in production.
So in practice, when should you use GET vs. POST? I use GET during development so I can see and tweak the parameters I am passing. I use it to quickly try different values (to test conditions for example) or even different parameters. I can do that without having to build a form and having to modify it if I need a different set of parameters. I simply edit the URL in my browser as needed.
Once development is done, or at least stable, I switch everything to POST.
If you can think of any technical reason that this is incorrect, I would be very happy to learn.
GET method is use to send the less sensitive data whereas POST method is use to send the sensitive data.
Using the POST method you can send large amount of data compared to GET method.
Data sent by GET method is visible in browser header bar whereas data send by POST method is invisible.
Use GET method if you want to retrieve the resources from URL. You could always see the last page if you hit the back button of your browser, and it could be bookmarked, so it is not as secure as POST method.
Use POST method if you want to 'submit' something to the URL. For example you want to create a google account and you may need to fill in all the detailed information, then you hit 'submit' button (POST method is called here), once you submit successfully, and try to hit back button of your browser, you will get error or a new blank form, instead of last page with filled form.
I find this list pretty helpful
GET
GET requests can be cached
GET requests remain in the browser history
GET requests can be bookmarked
GET requests should (almost) never be used when dealing with sensitive data
GET requests have length restrictions
GET requests should be used only to retrieve data
POST
POST requests are not cached
POST requests do not remain in the browser history
POST requests cannot be bookmarked
POST requests have no restrictions on data length
The GET method:
It is used only for sending 256 character date
When using this method, the information can be seen on the browser
It is the default method used by forms
It is not so secured.
The POST method:
It is used for sending unlimited data.
With this method, the information cannot be seen on the browser
You can explicitly mention the POST method
It is more secured than the GET method
It provides more advanced features