Description
Learning Goals of this Project:
summer 2023 solution link CLICKHERE
You will be learning about modern web-based API security principles in this project. These APIs are extremely popular ways of sharing data and integrating enterprise software systems. Understanding how they work and best security practices are paramount to a well rounded security expert.
In particular we will cover these learning topics:
- Web-based RESTful http services
- JSON, XML and Yaml serialization formats
- API documentation and test harnesses, Swagger & Postman
- OAUTH based security protocols
- JWT security tokens
- CORS browser protection
The final deliverables:
A single JSON formatted file will be submitted to Gradescope. This file should be named project_apisecurity.json. A template can be found in the /home/apisec/Desktop folder. See Submission Details for more information
Important Reference Material:
- https://en.wikipedia.org/wiki/Representational_state_transfer
- https://en.wikipedia.org/wiki/JSON
- https://swagger.io/
- https://www.postman.com/
- https://oauth.net/
- https://jwt.io/
- https://developer.mozilla.org/en-US/docs/Web/HTTP/CORS
Submission:
Gradescope (autograded) – see Submission Details
BACKGROUND:
You’ve been hired by the IPLRA (International Programming Language Review Association) to conduct a security audit for their newly released API. They are excited to finally release an API to the community for developers across the world to leverage. In fact, they see this API as a way to increase their amount of reviews by 800%. The only thing standing in their way is a final audit and approval, by you. Unfortunately, after only 5 minutes of looking at the API, you’ve found issues and need to report them. Your goal is to bring visibility to these vulnerabilities in their API by finding the flags for each scenario. Good luck on your flag hunt and we hope you enjoy learning all about modern web APIs.
Note: The IPLRA is not real and we made it up.
SETUP:
To get set up for the flags, carefully follow the steps below.
You will need switch users. Log into the VM with the following user.
Username: apisec Password: this_is_fun
Run this at the terminal to start the API $ sudo ./StartContainer.sh
project_apisecurity.json is available in the /home/apisec/Desktop folder. Put all flags in this file and submit it as your final deliverable.
To access the Web API open Chrome in the VM and navigate to this URL. This is the Swagger documentation page that describes the API and allows for testing: http://localhost:5001/swagger/index.html
*Note: You can also click the “Swagger UI” bookmark in Chrome
*****************GATECH_ID IS A REQUIRED HEADER***************
NOTE: This is not the Georgia Tech Username, it is the gtId that you can find on your Buzzcard or here: https://public.webapps.gatech.edu/cfeis/gtid/.
Be very careful! When you copy and paste be sure to strip off all leading spaces or special characters.
FLAG 1: Swagger Intro (20 pts)
This flag will introduce you to basic API functionality using a documentation and test harness tool called Swagger. Swagger is a very popular tool used to develop and test web APIs and has plugins/modules in most programming languages. You can learn more about Swagger here: https://swagger.io/
You’ll need to leverage Swagger (or any other http tool you desire such as curl or Postman) to determine how the API is configured and what endpoints to invoke to earn this flag.
Warning: The site doesn’t use file storage or a database, all data is stored in memory. If you crash the web API or restart the VM, any data you have created/modified will have been lost and you’ll need to begin at step 1.
To earn your flag you must perform the following actions by making API calls.
- Create a new Programming Language that IS featured and is named “White Walkers”
- Create a review of the new White Walker language. The title should be “Winter is Coming”, rating is 5 and the reviewer is “Night King”
- Reply to the new review by Night King. The replier should be “Arya Stark” and the body “Not great, do not recommend”
- Finally, delete the new programming language you created and your flag will be revealed.
Hints:
- Study the API endpoints available to you. Notice the responses, these may be useful to understand what is going on.
- The GATECH_ID header is required and enforced as such by the Swagger UI test harness.
- Choose any value for fields not explicitly stated above.
- Do not include extra quotes or double quotes embedded within the actual value.
FLAG 2: Stolen Credentials (20 pts)
In order to get this flag you need to create a new reviewer in the system. Unfortunately, the developers locked down this functionality some time ago so you’ll need an auth token in order to perform it. You read in the newspaper last week that Programming Reviews LLC had a big data breach so there is a good chance you can come across some credentials.
To earn your flag you must perform the following actions.
- Use Swagger to find and call/invoke a suitable API endpoint that you feel can create new reviewers.
- The API requires a token but in order to get a token you need to find suitable credentials. Use the APIs available to you to find these.
- Now that you’ve found the credentials you need to get that token. Be sure to call/invoke the “flag2token” to get your token.
- Armed with your token, call the API endpoint once more. Create a new reviewer with user name = “sparrow1” and full name = “The High Sparrow” and your flag will be revealed.
Hints:
- Remember there was a data breach. I bet you can find suitable credentials somewhere.
- Once you find the credentials you may need to do some decoding to get the actual values.
- Looking for that ClientID? Be sure to follow all directions and inspect any response that the API is sending back.
- In order to pass in the token you’ll need to set the Authorization Bearer header. Swagger has not been configured to do this. We suggest you use a tool called Postman. This is a very popular web API testing client. You can find more information here:
https://learning.postman.com/docs/getting-started/introduction/
○ You can also use Curl if you’re more comfortable with the command line. We do recommend you at least look at Postman since it will make your life much easier for this project and it’s very popular.
Include your flag2 into the json file and now onto Flag 3!
FLAG 3: JWT Intro (20 pts)
Now that you’ve used an Auth token we’re going to dig a bit deeper into JWT (JSON Web Tokens). This flag is simple and designed only to get you acquainted with how JWTs are constructed. There are numerous resources to help you work with JWTs, one we recommend is https://jwt.io/ but you are not required to use this site for the project. Choose any library, tool or site you wish to inspect and construct JWT tokens.
To earn your flag you must perform the following actions.
- Call/invoke the “flag3token” GET API to get your token.
- Parse the token using a tool of your choice.
- Use values from the token to craft the correct payload and POST that to the “flag3token” API for your flag.
Hints:
- The intent of this flag is to get you familiar with the JWT token structure. You will need to understand what it is and how to construct/deconstruct these. This will likely require some outside research on your part.
The next few flags will require some trial and error and a bit of research on your part to succeed. Your task is to craft JWT tokens such that you can use the token to successfully authenticate and earn your flag.
FLAG 4: Hack JWTs – #1 (20 pts)
You are a PHP ninja! You can’t get enough of this language. When you learned that others hate it and gave it bad reviews you felt the need to “correct the situation”. You’ve learned of an API that allows you to delete reviews. Muhahahah! The problem is that only the site moderator can do this and you don’t have his credentials. This has not stopped you in the past.
To earn your flag you must perform the following actions.
- Find the suitable API that will allow you to accomplish your goal above.
- You have previously registered with the site as a “reviewer” and remember your username is “php_guru1” and password is “The_sql_injection_vulnerabilities_are_a_lie”. Use these to get your token from the “flag4token” API.
- Analyze the token and do research to find a way to “upgrade” your token so that you can fool the API into thinking you are a “moderator”.
- Leverage your newly crafted token to delete all of those incriminating PHP reviews and earn your flag.
Hints:
- Maybe inspecting your token will give you a clue of how the server is handling authorization.
FLAG 5: Hack JWTs – #2 (20 pts)
You’ve learned about a new experimental programming language that is TOP SECRET! This language only requires 1 single keyword to find a polynomial time algorithm to solve any NP-hard problem! You want the 1 million dollar reward for solving this problem and thus need access to this programming language. Find the language.
To earn your flag you must perform the following actions.
- The programming language is not returned in normal API calls. In order to see this magical new language you need to leverage the “Top Secret” GET request.
- Grab your normal JWT token from the “flag5token” API. Use these credentials: username is “IheartC#” and password is “csharp”
- You have the token so why not try to give it a shot? Try to use this token to view Top Secret languages.
- 403 – Forbidden. You need more help…
- Inspect this token. You’ve learned through “insider program language trading” that in order to see TOP SECRET languages you need to provide the following JWT Claim.
- Claim Name: TOP_SECRET ii. Claim Value: allowed
- Alter your token and try it again
- Hmm, it appears that the server is correctly verifying the signature to ensure it hasn’t been tampered with. Rats!
- Good news, the developers of this API are pretty bad at securing safe things like secret keys. Find the secret key.
- With the key in hand, properly construct the JWT token with the TOP_SECRET claim.
- Leverage your token to finally view the source code of the experimental programming language to earn your 1 million dollars and the flag.
Hints:
- You need to find the key that’s used to verify the JWT signature. Search through the APIs to see if you can find a trail that leads to it.
- You need to construct a valid JWT token. You can leverage tools and websites such as jwt.io to perform this or handle it manually. This choice is up to you.
Submission Details:
File submission instructions:
This project needs to be submitted via gradescope. Navigate to the course in Canvas, click ‘Gradescope’, click ‘Project API Security’ and submit there.
The contents of the submission file should be the following. There is a project_apisecurity.json file in your vm with a template set up, or you can copy-paste this to your newly created project_apisecurity.json file elsewhere and replace the placeholders with the flags you retrieve from each relevant task.
Note: You can use TextEdit or Vim to create and edit this file. Do not use LibreOffice or any Word Document editor. It must be in proper JSON format with no special characters in order to pass the autograder and these Word Document editors are likely to introduce special characters.
If you can’t find the file in the VM just copy this format below:
| {
“flag1”: “<copy flag 1 here>”, “flag2”: “<copy flag 2 here>”, “flag3”: “<copy flag 3 here>”, “flag4”: “<copy flag 4 here>”, “flag5”: “<copy flag 5 here>” } |
An example of what the submitted file content should look like:
{
“flag1”:
“4ec60c3e084d8387f0f33916e9b08b99d5264a486c29130dd4a5a530b958c5c0f1faeaca2ce30b478 281ec546a4729f629b531a86cb27d86c089f0c542”, “flag2”:
“f496d9514c01e8019cd2bc21edfeb8e33f4a29af14a8bf92f7b3c14b5e06c5c0f1faeaca2ce30b478 281ec546a4729f629b531a86cb27d86c089f0c442”, “flag3”:
“b621bba0bb535f2f7a222bd32994d3875bcfcad651160c543de0a01dbe2e0c5c0f1faeaca2ce30b47 8281ec546a4729f629b531a86cb27d86cf0c49542”, “flag4”:
“f38e2cafb43ab4a0a647a8b08fc97bca25aa7cfb517029d5dd02faf49bff5c5c0f1faeaca2ce30b47 8281ec546a4729f629b531a86cb27d86c08c49542”, “flag5”:
“1711ee5eb85b9020d1f4193ee6d884abd12a2eadc4890d28c490ae0c36446c5c0f1faeaca2ce30b47
8281ec546a4729f629b531a86cb27d86c08949542”
}
