While I was reading about interaction with Amazon S3, I came to know that request authentication with Amazon AWS is done in 2 ways
HTTP Authorization:
Using the HTTP Authorization header is the most common method of providing authentication information
Query string parameters:
Using query parameters to authenticate requests is useful when you want to express a request entirely in a URL. This method is also referred as presigning a URL.
The question is in which situation should I prefer one method over the other. Do these two authentication methods have their own advantages and disadvantages? As a developer, by using query string parameters method I can presign the URL which enables the end users to temporarily access the Amazon S3 resources by entering the presigned URL in the web browser. Can I use HTTP Authorization method to achieve the same thing? If so which method is better to use and what are their respective limitations?
Can I use HTTP Authorization method to achieve the same thing?
Sometimes. The key difference is that, as a developer, you don't always have enough control over the user agent to inject a header. The most obvious example of this is a simple GET request launched by a web browser in response to the user clicking a link. In that situation, you don't have the a ability to inject an Authorization: header for the browser to send ... so pre-signing the URL is all you can do.
Importantly, there's no information in a signed URL that is considered sensitive, so there's no particularly strong motivation to use the header instead of a signed URL. Your AWS Access Key ID is not secret, and your AWS Secret can't be derived from the other elements and the signature in a computationally-feasible time frame, particularly if you use Signature Version 4, which you should. Signature Version 2 is not officially deprecated in older regions, but newer S3 never supported it and likely never will.
When you do control the user agent, such as in back-end server code, adding the header may be preferable, because you don't need to do any manipulation of the URL string you already have in-hand.
The overview in the first AWS page says what the difference is:
Except for POST requests and requests that are signed by using query parameters, all Amazon S3 bucket operations and object operations use the Authorization request header to provide authentication information.
Basically a POST is used for HTML forms (discussed at length in the Mozilla page). You would use forms whenever the request involves passing data to the remote server, versus just checking status. As noted in HTML method Attribute (W3Schools),
Never use GET to send sensitive data! (will be visible in the URL)
as distinguished from POST:
Appends form-data inside the body of the HTTP request (data is not shown is in URL)
Related
I've been doing some HTTP methods and header research recently if we should use GET with basic authorization instead of POST when submitting?
HTTP Methods
The GET method requests a representation of the specified resource. Requests using GET should only retrieve data.
The POST method submits an entity to the specified resource, often causing a change in state or side effects on the server.
As we see here, the POST method normally changes the state of the server. If sending out JWTs/HTTP cookies, we are not modifying the state of the server. Nor are we creating a new resource in the server.
I understand that we should not not send the username and password as a GET parameter but should we use the authorization header instead?
Basic authentication
For "Basic" authentication the credentials are constructed by first combining the username and the password with a colon (aladdin:opensesame), and then by encoding the resulting string in base64 (YWxhZGRpbjpvcGVuc2VzYW1l).
Authorization: Basic YWxhZGRpbjpvcGVuc2VzYW1l
The only advantage I see to using POST over GET is that we need no extra code in the HTML/JS on the client side to send headers via the fetch API. To send headers, we would need an onsubmit and then check if status code is 200. If 200, we will need to redirect to the page after the login screen. Then again, if using the fetch API, this means the server does not need to send a new HTML page to the client all the time either.
Should we use GET with basic auth or POST when logging in since we don't create a resource/modify the server state?
Would this change if say we enable 2FA since we would need to generate a code for that user?
Doing basic authentication in the browser and using GET is not that recommended.
To do your own login form it is better to always do it using HTTPS and POST. Do post the username/password in the body of the request and secure it with proper CSRF protection.
If you want to level up, you can always look at the OpenIDConnect approach, but that is more advanced depending on your needs.
Also, a good approach is to explore how existing site implement a login form and look at the HTTP(s) traffic in a tool like Fiddler.
I have recorded a login flow of an application and found some URIs like below:
/api/oauth2/initiate GET
/oauth2/authorize GET
/api/v1/oauth2/authorize GET
/api/v1/oauth2/authenticate POST
{"username":"${Username}","password":"${Password}","client_id":"${client_Id}","response_type":"code","redirect_uri":"${scheme}://${host}/api/oauth2/callback","server_id":"${server_Id}"}
When I am hitting above in sequence via JMeter I am getting 200 response. Just like JMeter I tried recording in Postman and it worked same, but instead of JSON it gave response in XML format.
It doesn't generate a access_token, it works via session cookies.
My question is - Do I really have API access or it is just browser record n play? If Yes, Does this mean I can get access to any API, if I am a registered user of that application? For ex: Facebook, YouTube or any startup website.
JMeter works on the protocol level. This means that whatever request you are generating. Say a simple browser request or an API call, you can do that easily.
Now the thing is replicating requests. You don't need to record the requests necessarily using the browser. You need to analyze the few things that are required. Say Postman is generating a request. You specify the things you want to send and you use the API Token there. The same things can be specified there as well. It all depends on how you are understanding the concept of request generation.
You simply need to replicate the samplers and the parameters. And the request headers in postman can be replicated here in the same way.
For each HTTP Request Sampler make sure you add a corresponding child HTTP Header Manager config element.
Headers basically tell the server that what client we are using and in what form data is being sent and then server responds accordingly with the information.
What you're recorded is OAuth2 flow and you won't be able to replay it without correlating the dynamic values.
You can have access to Google API or Facebook Graph API given you have proper access_token but I don't think you should be testing them directly, you should focus on solely your application.
My application has a microsoft authentication on it before logging into it & I have recorded script but when I am running it, it is showing me access denied error everytime.I have set authentication manager but still same error. See image attached.
I have tried HTTP Authentication Manager & provided login username & password.
Most probably your application uses OAuth therefore it is neither something you can really record and replay nor handle with the HTTP Authorization Manager.
Depending on your application setup you will either need:
To perform correlation of the query parameters
Or to pass the relevant Authorization Bearer token via HTTP Header Manager. The process of obtaining the token can be different depending on your application login chain implementation, check out How to Run Performance Tests on OAuth Secured Apps with JMeter article to get a couple of ideas regarding bypassing 3rd-party provider login challenge in JMeter tests.
Check if you can provide the auth credentials as parameter of the requests.
for example www.abc.com?username=abc&password=abc. Replicate the same with Jmeter
Use Fiddler (or you can get away with browser dev tools if you don't mind searching manually) and log in manually via your browser.
Check the request(s) that are submitted to Microsoft for tokens/GUIDs and search for where the browser got those strings from (it'll be in one of the previous requests' responses' bodies or redirect URLs. In Fiddler you can use the find function on responses, browser dev tools you'll have to find it manually).
You can then use a JMeter Regular Expression Extractor post-processor (or any of the other post processors you prefer) to extract that string from the earlier request into a variable.
In your login request you can then use the value of that variable (if you used regular expression post-processor with a capture group the first group's value will be ${variable_g1}
You'll probably have an anti-forgery value that you can extract from the HTML of the login page which needs to be submitted with the username and password and then in the response you'll get a cookie set and potentially JWT token in the response body/URL.
Situation: I run a Django app in the web, where logged-in users can also download .pdf files (non-public, with specific restrictions, depending on user rights). The most convenient way to do so (e.g. in S3) is to use a time-restricted, pre-signed URL because they open immediately in the browser, plus the app server does not have to handle additional traffic.
Problem: Backblaze B2 oviously does not offer an explicit method for creating presigned URLs to download non-public files directly in the browser.
Generating the api URL and the authorization token, and fetching the file from the object store happens at the app server level and the process is not exposed to the "ordinary" user.
But in the end, the API operation "b2_download_file_by_name" just uses a GET request, which means I can add the authorization token to the request's URL using "?Authorization=123xyz........". This way I get a presigned URL that works perfectly fine in the browser to allow access to a specific non-public file for a limited time. (Please note: B2 downloads can be restricted to files with specific prefixes [like s3 pseudo-folders], but if the specified "prefix" is long enough, I can make the auth token specific for one file.)
Question: As I wrote above, usually the authorization token is not exposed to the user. Now, if I make the URL visible, does this imply a security risk? In other words, could a user that posesses one or many tokens, extract the general access key from the token, or is the token encrypted well enough to avoid this?
According to the documentation for the b2_download_file_by_name call you can use the download authorization in a URL in the way you describe.
An authorization token can be provided in the URL query string instead of being passed in the HTTP header. An account authorization token obtained from b2_authorize_account will allow access to all files in a private bucket. A download authorization token obtained from b2_get_download_authorization will allow access to files whose names begin with the filename prefix used to generate the download authorization token.
However it seems that the expiry time set in the b2_get_download_authorization call is being ignored so the resulting URL never expires which is not secure of course. I have a support ticket in with B2 about this so hoping for a solution.
I'm writing a REST-ish API service the provides the ability to interact with the end user's data in other 3rd party services (themselves REST APIs) via OAuth. A common example might be publishing data from my service to a third-party service such as Facebook or Twitter.
Suppose, for example, I perform an OAuth dance with the end user and Facebook, resulting in some short-term access token that my service can use to interact with the user's Facebook account. If that access token expires and the user attempts to use my service to publish to Facebook, what sort of error do I return to the user?
401 doesn't seem quite right to me; it seems that 401 would apply to the user's auth state with MY service. 403 seems much more appropriate, but also quite generic.
401 is the way to go. Two excerpts from the RFC2616 which defines the HTTP protocol:
Section 10.4.2 (about 401):
If the request already included Authorization credentials, then the 401
response indicates that authorization has been refused for those
credentials.
This seems to be appropriate for expired tokens. There are authentication credentials, but they're refused, so the user agent must re-authenticate.
Section 10.4.4 (about 403):
The server understood the request, but is refusing to fulfill it.
Authorization will not help and the request SHOULD NOT be repeated.
This should be used when the resource can't be accessed despite the user credentials. Could be a website/API that works only on US being hit by a asian IP or a webpage that has been declared harmful and was deactivated (so the content WAS found, but the server is denying serving it).
On OAuth2, the recommended workflow depends on how the token is being passed. If passed by the Authorization header, the server may return a 401. When passed via query string parameter, the most appropriate response is a 400 Bad Request (unfortunately, the most generic one HTTP has). This is defined by section 5.2 of the OAuth2 spec https://datatracker.ietf.org/doc/html/draft-ietf-oauth-v2-26
There's nothing wrong with being generic, and it sounds like a 403 status would be relevant - there is nothing stopping you from providing a more human readable version that elaborates in a bit more detail why.
I think the following is a comprehensive list if you have some level of ambition when it comes to error responses.
400 Bad Request
For requests that are malformed, for example if a parameter requires an int between 0-9 and 11 has been sent. You can return this, and in the response body specify parameter x requires a value between 0 and 9
401 Unauthorized
Used only for authorization issues. The signature may be wrong, the nonce may have been used before, the timestamp that was sent is not within an acceptable time window, again, use the response body to specify more exactly why you respond with this. For the sake of clarify use this only for OAuth related errors.
403 Forbidden
Expressly to signify that an operation that is well formed, and authorized, is not possible at all (either right now, or ever). Take for example if a resource has been locked for editing by another user: use the response body to say something along the lines of Another person is editing this right now, you'll have to wait mmkay?.
403 Forbidden can also have to do with trying to reach resources. Say for example that a user has access to a resource /resource/101212/properties.json but not to /resource/999/properties.json, then you can simply state: Forbidden due to access rights in the response body.
404 Not Found
The requested resource does not exist. Or the URL simply does not successfully map to an API in your service. Specify in response body.
405 Method Not Allowed
This is to represent that the API can not be called with for example GET but another method must be used. When this is returned also you MUST return the extra response header Allow: POST, PUT, etc.