I have a program that asks the user to type in a URL, and click download. Then the program downloads the webpage.
However, some websites use SSL, and in that case the user has to prefix his URL with https:// for this to work.
The problem is that the user may not know whether the website uses SSL, and may type http://... instead of https://....
Is there some way to send a preliminary message to the website (from vb.net) asking whether the URL should start with https or just http? If there is, I can correct the user URL before attempting to retrieve the web page.
(I should say there it is not enough to use something like this:
request.RequestUri.Scheme - this looks at the URL the user submitted, not the URL coming back from the server, as far as I know)
For websites that uses SSL, usually they will force the request to use HTTPS. That is when you send a request in HTTP, for example, http://www.example.com, the website will send a redirect response with HTTP status code 302 as well as the URL the client side that initiate the request should redirect user to.
So, you can try HTTP first and check the response to see if there is a redirect. So, you will need to handle that in your code.
Related
I am using cloudflare's "flexible ssl" as an intermediary between client and my site.
After setting this up, I went to the browser and tried accessing my site via https:
https://example.com/login
and everything works. I fill in my login info and log in successfully and am not on http://example.com . I manually enter https://example.com/* where * is many other pages and it all works fine.
Now I want to redirect all requests to use the seemingly working https. So i go to my cloudflare account on their website and create a page rule : http://example.com/* to always use https.
Now I go to example.com/login and successfully redirected to https://example.com/login, I fill in my log in information and submit the login form , the page refreshes and I am back to https://example.com/login with an empty login form.
Anyone know what the problem is or how to help troubleshoot?
I am using laravel as a framework for the site and apache as the webserver.
create a page rule : http://example.com/* to always use https
Noted. Be aware that CloudFlare does this by accepting every HTTP request on http://example.com/* and returning a 301 redirect to the equivalent HTTPS request. The browser completes the redirect by sending a GET request to the HTTPS URL.
I fill in my log in information and submit the login form
Check the login form source carefully and check what URL the login form is submitted to. My guess is that the form is submitted to http://example.com/login or something similar. CloudFlare will accept the POST request to http://example.com/login and return a 301 redirect to https://example.com/login -- which your browser will complete as a GET request and hence not sending the login data.
So your best solution is to make sure that your login form POSTs to the correct HTTPS URL not to the HTTP URL.
That's my best guess anyway.
how to help troubleshoot?
Ensure that you are using different log files to distinguish between HTTP and HTTPS requests on your server.
Some other suggestions:
Get a Let's Encrypt SSL certificate and put that on your site so that the communication between CloudFlare and your site is all SSL. https://letsencrypt.org/
Ensure that HSTS is turned on for all of your HTTPS requests so that the browser will know not to send any requests to any HTTP URLs.
Create a development server where you can test all of this working with HTTPS between the browser and the web server without CloudFlare. Once you've got it all working in HTTPS mode without CloudFlare then you can try it with CloudFlare and you should get essentially the same results. Your problem is with the HTTP -> HTTPS switch, not specifically with CloudFlare.
Basically if somebody is already on an HTTPS page, I don't want them to be capable of being redirected to/accidentally clicking an HTTP one (on the same site at least). It seems to me like you would use the referer as a RewriteCond to accomplish this, except for the fact that it is apparently browser policy not to send referers when going from HTTPS pages to HTTP ones. So if a user loads an HTTP page, how can I detect if they came from an HTTPS one and make sure they are redirected to the secure version of the page they are trying to access?
Unfortunately the software we are using has many hardcoded HTTP links so it is necessary to use some sort of redirection.
I want to use an Apache proxy server (mod_proxy) to intercept all requests and responses to a web server. However I want to change requests and responses before redirecting them. Simply rewriting URLs is easy and documented, but the changes I want to make are more sophisticated, namely they need to inspect the request for user credentials as well as conditionally make redirects.
Is this possible in Apache's mod_rewrite, possibly in combination with other modules?
While the main goal is to implement this in Apache, I would also be happy with an alternative solution which doesn't necessarily use Apache.
Here is a more precise explanation of what I want to achieve, to give a little more context:
Check each incoming request for user credentials. If credentials are present, they are replaced by the user information which the web server can use to identify the user (Ideally in the Authorization header)
For example, let's assume a request contains a cookie which authenticates the request as beeing sent from the user "John", this cookie is removed, and the Authorization header is changed to Authorization Authenticated_by_proxy {"id":12345,"name":"John"}
Check each answer to see if it's an Error 403. If this is the case and the user is not logged in, redirect the user to a login page instead of forwarding the error
From Google Developer Console page, it explains the meaning of "Google Redirect URI" is :
Determines where the response is sent. The value of this parameter
must exactly match one of the values registered in the APIs Console
(including the http or https schemes, case, and trailing '/').
Not sure, whether this explanation is same as my think or not:
On my app (web application), it allow user to sign-in via Google (Assume, I registered a Google project with ClientID/secrete configured on my web-app, and on Google COnsole page the redirectURI is "http://bbc.co.uk" ).
After I login to Google successfully by my Google account, my Web-app login page will be redirected to "http://bbc.co.uk" as on Google RedirectURI ?
That last sentence is a bit ambiguous. A better description is:
After I login to my Google Account successfully with my Google
credentials, Google will redirect my browser back to
Redirect URI http://bbc.co.uk that is registered for the web app in the Google > API Console.
Just to be sure: this means that the Redirect URI should be part of your web app. It is not actually Google's Redirect URI but it is the Redirect URI that you've configured in the Google API Console for your web app.
Let me see if i cant explain this in a different way.
What would happen if you didn't have a redirect URI?
If you go to the Developer console and create a Client ID for native application by default the redirect URI
This will redirect the Authentication back to where ever it was request from. In the case of native installed applications this is needed because there is no way to know where the user is that has installed the application.
Lets look at this in action
Request authentication:
https://accounts.google.com/o/oauth2/auth?client_id={clientid}.apps.googleusercontent.com&redirect_uri=urn:ietf:wg:oauth:2.0:oob&scope=https://www.googleapis.com/auth/analytics.readonly&response_type=code
If you place the above line in a web browser the user will see something like this
Assuming they select ok then they get this displayed back at them.
That is the Authentication code, not to be confused with the access token. This is just the first step. Once your application has the Authentication code it can then exchanged that for a refresh token and a access token. Most client library handle this step internally. You and your users never see this Authentication code.
Back Redirect URI:
In the case if a web application your web application needs to be able to get a hold of that authentication code. Now I probably shouldn't be telling you this but you could just use a native application client in your web application and it will work. Why because the authentication server will just return the Authentication code back to where ever it was that requested it. For security reasons this is probably a bad practice.
So what do you need to place in the redirect uri. It is the file that you have ready to handle this authentication code. Normally its just the same as the login page, but you can have several. Just put each of them on separate lines.
http://localhost/login.php
http://www.daimto.com/login.php
I like to do this because then it works when i am testing locally vs when its up on the server.
I think the wording "Determines where the response is sent" confuses a lot of beginners as it implies that Google will somehow call that URL directly. Then the word "redirect" leads people to confuse the URL with the page of the app that the user will get to once he's authenticated.
http://bbc.co.uk is definitely NOT the redirect URL. A redirect URL would normally look like https://myapp.com/servlet_or_php_that_i_wrote_to_process_tokens.php
Google will "call" servlet_or_php_that_i_wrote_to_process_tokens.php by redirecting the browser to it. Once servlet_or_php_that_i_wrote_to_process_tokens.php as done whatever is needed with the token, it will then issue its own redirect to (say) bbc.co.uk
Is it possible to send a jsonp-Request from domain http://www.a.com (not under my control) to domain www.b.com (under my control) through https? If so, are the parameter values in the GET-Request encrypted or do they be logged in access-logs in plain text?
I'm searching a secure way to do cross domain request. Unfortunately POST-Statements through CORS requests / SSL doesn't work with Internet Explorer. It doesn't support setting cookies by Access-Control-Allow-Credentials. Is there another way to achieve this goal?
For the second part of the question , HTTPS will only encrypt the channel the request uses to transfer the data. Once it arrives at the web server all the request params will be logged in your access log in plain text.
You would need to use a POST request to prevent the data being written to the access log. However you cant use JSONP over a POST request (not possible to send a POST request using a tag).