I'm trying to automate a process so I want to connect to an external API, first just to log in (can't use the API Key since I'm not an admin user).
I basically copied the request the browser does when it logs in, but when doing this from Postman I get a 400 responde, with the body "Not allowed by CORS".
Is there any way through code, that I can bypass that and work with such API?
Cors means Cross-Origin Resource Sharing. Basically browsers help web servers a way to protect themselves for data change requests.
Remove Origin Header (or) replace Origin value to server hostname (in this case api.kenjo.io)
Add referer header.
With dothttp it would look like below.
POST 'https://api.kenjo.io/auth/token'
origin: 'https://www.kenjo.io'
referer: 'https://www.kenjo.io/'
Have a single entry service which is acting like a facade/proxy service for downstream services. The service will need able to detect if the request is a "page request" or "api/xhr" request to perform error handling (302 redirection or 401).
So far have considered:
To use Accept header and detect text/html follow the following reference, can't tell if this is a good indicator to detect a page request
To introduce a custom header for all "api/xhr" request
To enforce all the "api/xhr" requests to follow a "/api" pattern (troublesome as for certain application the xhr is not a restful api)
Any good suggestions are welcome
Ended up using Option 1
Detect page request using Accept header with value "text/html"
As we do not use ajax for partial view
Usually the non-standard HTTP header X-Requested-With is used. Just the presence of the header should be enough. It has at least one advantage over Accept: It cannot be set on a cross-site request, which helps preventing CSRF.
I have two web pages hosted on a.example.com and b.example. Each web page is including a script with a <script> tag, hosted on another domain and served with correct CORS headers.
At a certain point, user navigates from a.example.com to b.example.com.
Safari has here a strange behavior: the referrer and origin headers in preflight request are filled with a.example.com, making the server sending a bad value in Access-Control-Allow-Origin (and so the script can't be executed).
Is there a way to force Safari browser to send correct origin header in that kind of scenario ?
Does the cache policy for the script include Vary: Origin?
Respectively is there actually a second request after navigating to b.example.com?
If not, there is a chance that Safari is actually serving the script from cache - despite the Access-Control-Allow-Origin policy forbidding it to access the resource. Which is a conforming behavior, if the cache policy isn't configured correctly.
It seemed to be indeed a Safari bug.
The issue is not reproductible on Safari 10.0. It repro only on Safari 9.1.1 / 9.1.3.
I'm currently working on an HTTP based API. Our terms of use require the user to send an appropriate user-agent header (e.g. "-" is considered invalid). Now I'm not quite sure which would be the correct HTTP status the server should be responding with, if the request is rejected. Any suggestions?
400 Bad Request or 403 Forbidden would be the two I'd pick
I'm working on a webserver that I didn't totally set up and I'm trying to figure out which parts of a web page are being sent encrypted and which aren't. Firefox tells me that parts of the page are encrypted, but I want to know what, specifically, is encrypted.
The problem is not always bad links in your page.
If you link to iresources at an external site using https://, and then the external site does its own HTTP redirect to non-SSL pages, that will break the SSL lock on your page.
BUT, when you viewing the source or the information in the media tab, you will not see any http://, becuase your page is properly using only https:// links.
As suggested above, the firebug Net tab will show this and any other problems. Follow these steps:
Install Firebug add-on into firefox if you don't already have it, and restart FF when prompted.
Open Firebug (F12 or the little insect menu to the right of your search box).
In firebug, choose the "Net" tab. Hit "Enable" (text link) to turn it on
Refresh your problem page without using the cache by hitting Ctrl-Shift-R (or Command-shift-R in OSX). You will see the "Net" tab in firefox fill up with a list of each HTTP request made.
Once the page is done loading, hover your mouse over the left colum of each HTTP request shown in the net tab. A tooltip will appear showing you the actual link used. it will be easy to spot any that are http:// instead of https://.
If any of your links resulted in an HTTP redirect, you will see "301 Moved Permanently" in the HTTP status column, and another HTTP request will be just below for the new location. If the problem was due to an external redirect, that's where the evidence will be - the new location's request will be HTTP.
If your problem is due to redirections from an external site, you will see "301 Moved permanently" status codes for the requests that point them to their new location.
Exapnd any of those 301 relocations with the plus sign at the left, and review the response headers to see what is going on. the Location: header will tell you the new location the external server is requesting browsers use.
Make note of this info in the redirect, then send a friendly polite email to the external site in question and ask them to remove the https:// -> http:// redirects for you. Explain how it's breaking the SSL on your site, and ideally include a link to the page that is broken if possible, so that they can see the error for themselves. (this will spur faster action than if you just tell them about the error).
Here is sample output from Firebug for the the external redirect issue.. In my case I found a page calling https:// data feeds was getting the feeds rewritten by the external server to http://.
I've renamed my site to "mysite.example.com" and the external site to "external.example.com", but otherwise left the heders intact. The request headers are shown at the bottom, below the response headers. Note that I"m requesting an https:// link from my site, but getting redirected to an http:// link, which is what was breaking my SSL lock:
Response Headers
Server nginx/0.8.54
Date Fri, 07 Oct 2011 17:35:16 GMT
Content-Type text/html
Content-Length 185
Connection keep-alive
Location http://external.example.com/embed/?key=t6Qu2&width=940&height=300&interval=week&baseAtZero=false
Request Headers
Host external.example.com
User-Agent Mozilla/5.0 (Windows NT 6.1; WOW64; rv:7.0.1) Gecko/20100101 Firefox/7.0.1
Accept */*
Accept-Language en-gb,en;q=0.5
Accept-Encoding gzip, deflate
Accept-Charset ISO-8859-1,utf-8;q=0.7,*;q=0.7
Connection keep-alive
Referer https://mysite.example.com/real-time-data
Cookie JSESSIONID=B33FF1C1F1B732E7F05A547A9CB76ED3
Pragma no-cache
Cache-Control no-cache
So, the important thing to note is that in the Response Headers (above), you are seeing a Location: that starts with http://, not https://. Your browser will take this into account when figuring out if the lock is valid or not, and report only partially encrypted content! (This is actually an important browser security feature to alert users to a potential XSRF and/or phishing attacks).
The solution in this case is not something you can fix on your site - you have to ask the external site to stop their redirect to http. Often this was done on their side for convenience, without realizing this consequence, and a well written, polite email can get it fixed.
For each element loaded in page, check their scheme:
it starts with HTTPS: it is encrypted.
it starts with HTTP: it's not encrypted.
(you can see a relatively complete list on firefox by right-clicking on the page and selecting "View Page Info" then the "medias"tab.
EDIT: FF only shows images and multimedia elements. They are also javascript files & CSS ones which have to be checked. And Firebug is a good tool to find what you need.
Some elements may not list http or https, in this case whichever was used for the page will be used for these items, i.e. if the page request is under SSL then these images will come encrypted while if the page request is not under SSL then these will come unencrypted. Fiddler in Internet Explorer may also be useful in tracking down some of this information.
Sniff the packets - that'll tell you really quick. WireShark is a good program for such a task.
Can firebug do this?
Edit: Looks like firebug will also do this using the "Net" panel, which also gives you some other interesting statistics.
The best tool I have found for detecting http links on a https connection is Fiddler. It's also great for many other troubleshooting efforts.
I use FF plugin HTTPFox for this.
https://addons.mozilla.org/en-us/firefox/addon/httpfox/