Several Twilio services can be accessed from a web application running on the browser, but given that this is an inherently insecure platform, the authentication flow is different than for server-based applications.

1. Generate Jwt Secret Key Python Online
2. Generate Jwt Secret Key Python Programming
3. Jwt Secret Key Generator Python
4. Generate Jwt Token With Private Key Python

Under Token configuration, select JWT with shared secret as the Token type. Under Parameters for signing public key, choose the Type of secret. You can use an existing AWS Secrets Manager shared secret or create a new shared secret. Table of Contents. Hide Passwords and Secret Keys in Environment Variables. If you are into python, there is a fair chance that you would have contributed to open-source or had your code snippets/projects on Github or BitBucket.Some time your code involves some important credentials like passwords or secret keys etc. Like the code for our post on how to send emails using python uses google/app. Project: django-oauth-toolkit-jwt Author: Humanitec File: utils.py License: MIT License. Reading Headers without Validation¶. Some APIs require you to read a JWT header without validation. For example, in situations where the token issuer uses multiple keys and you have no way of knowing in advance which one of the issuer’s public keys or shared secrets to use for validation, the issuer may include an identifier for the key in the header.

An application running on the browser needs to obtain an Access Token from your server, and then use this token to authenticate. This is more secure because it prevents you from having to expose your Twilio account credentials in the browser, and also because access tokens have a short lifespan. In this tutorial you are going to learn how this authentication flow works and how to generate access tokens for Twilio services using Python and the Flask framework.

Tutorial requirements

To follow this tutorial you will need:

• Python 3.6 or newer. If your operating system does not provide a Python interpreter, you can go to python.org to download an installer.
• A free or paid Twilio account. If you are new to Twilio get your free account now! This link will give you $10 when you upgrade.

Using Twilio on the Browser

Before we begin, I thought it would be a good idea to review the list of Twilio services that have JavaScript SDKs for the browser. At the time I’m writing this, this is the complete list:

• Programmable Voice: twilio.js Documentation
• Programmable Video: twilio-video.js Documentation
• Conversations: twilio-conversations.js Documentation
• Sync: twilio-sync.js Documentation
• Programmable Chat: twilio-chat.js Documentation

Authentication for these services from the browser requires your application to implement a server-side component that generates access tokens. At a high level, the process works as follows:

1. The application running on the browser sends a request to your server for an access token. The request must include any information that your server needs to verify the identity of the user making the request, such as a username and a password.
2. The access token endpoint in your server receives the request and verifies that the user credentials are valid.
3. Using the Twilio Python Helper Library, it then generates an access token for the user, and provisions it with one or more grants, which give granular access to Twilio API features. The token is also given a validity period, which can be no longer than 24 hours.
4. The generated access token, which is a string, is returned to the browser in the response of the endpoint. The client can then use it with any of the JavaScript SDKs listed above.

In this tutorial we will concentrate on the server-side component that generates tokens.

Project structure

Let’s begin by creating the directory where we will store our server files. Open a terminal window, find a suitable parent directory, and then enter the following commands:

Following best practices, we are going to create a Python virtual environment where we will install our Python dependencies.

If you are using a Unix or MacOS system, open a terminal and enter the following commands to do the tasks described above:

For those of you following the tutorial on Windows, enter the following commands in a command prompt window:

The pip command installs the three Python packages that we are going to use in this project, which are:

• The Twilio Python Helper library, to generate access tokens for Twilio services
• The Flask framework, to create the web application
• Python-dotenv, to import environment variables with configuration information
• httpie, to send test requests to the server from the command line.

For your reference, at the time this tutorial was released these were the versions of the above packages and their dependencies:

Setting up your Twilio account

Log in to your Twilio account to access the Console. In the main dashboard page you can see the “Account SID” assigned to your account. This is important, as it identifies your account.

Because we are going to need the Account SID later, click the “Copy to Clipboard” button on the right side. Then create a new file named .env in your text editor (note the leading dot) and write the following contents to it, carefully pasting the SID where indicated:

To generate access tokens you also need to have a Twilio API Key, so the next step is to add one to your Twilio account. Navigate to the API Keys section of the Twilio Console. If you’ve never created an API Key before, you will see a “Create new API Key” button. If you already have one or more API Keys created, you will instead see a red “+” button to add one more. Either way, click to create a new API Key.

Give the key a name that represents the use you intend to give to your access tokens, leave the key type as “Standard” and then click the “Create API Key” button.

Now you will be presented with the details of your newly created API Key. The “SID” and “SECRET” values for your key are used when generating access tokens along with the Account SID value that we saved earlier.

Open the .env file you created earlier in your text editor, and add two more lines to it to record the details of your API key:

Once you have your API key safely written to the .env file you can leave the API Keys page. Note that if you ever lose your API Key secret you will need to generate a new key, as Twilio does not keep this value for security reasons.

Before we move on, remember that the information that you’ve written to your .env file is private. Make sure you don’t share this file with anyone. If you plan on storing your project under source control it would be a good idea to configure this file so that it is ignored, because you do not want to ever commit this file by mistake.

Creating the web server

As mentioned in the requirements section, we will be using the Flask framework to implement the logic in our web server. Since this is going to be a simple project we will code the entire server in a single file named app.py.

Below you can see the implementation of our web server. Copy the code into a new file named app.py file in the twilio-access-tokens directory.

The first thing that we do in this application is to call the load_dotenv() function from the python-dotenv package. This function will read the contents of the .env file and incorporate all the variables to the environment. Once the environment is populated, we can retrieve our three authentication variables, twilio_account_sid, twilio_api_key_sid and twilio_api_key_secret.

The app variable is called the “Flask application instance”. Its purpose is to provide the support functions we need to implement our web server using the Flask framework. The @app.route decorator is used to define a mapping between URLs and Python functions. In this application we are associating the /token URL with the token() function, so whenever a client sends a POST request this URL, Flask will run the function and return its response to the client.

The implementation of the token() function begins by extracting the username and password sent by the client from the request payload, which would allow your application to know which user is making the request.

There are several ways in which the client can submit user credentials, so keep in mind that this is just one of many available options. Another common way to do this is according to the HTTP Basic Authentication specification, via theAuthorization header.

The application server is now in a position to validate that the user credentials are valid. This needs to be done according to the requirements of your application, by accessing your user database. For this simplified example, validation only checks that both the username and password fields were sent by the client and if one or both are missing a 401 status code is returned to tell the client that the user could not be authenticated. In a real application the password has to be checked as well.

Once the user has been validated, an access token can be generated. The AccessToken class from the Twilio helper library for Python is used for this. The first three arguments to this class are the three secrets that we retrieved from the environment.

The identity argument sets a unique name for the user, which will be included in the token. If your application does not use unique usernames, then you can use the user IDs stored in the user database.

The final argument is ttl or “time-to-live”, which specifies for how long the token is going to be valid, in seconds. If ttl is omitted, the token will be generated with a validity of one hour, or 3600 seconds. You can increase or decrease this time according to your application needs. The maximum value for ttl is 24 hours, which must be given as 86400 seconds.

The generated token needs to be given grants for the services we are allowing this client to access. In the example above, a grant to a Programmable Video room called “My Room” is added to the token, which means that the client will only be able to access this video room with the token. There are different grant classes for the different Twilio services, as follows:

• VoiceGrant for Programmable Voice
• VideoGrant for Programmable Video
• ConversationsGrant for Conversations
• SyncGrant for Twilio Sync
• ChatGrant for Programmable Chat

Note that a single token can include multiple grants by invoking the add_grant method as many times as needed.

Once the token has the desired grants it is ready to be returned to the client. The to_jwt() method renders it as a JSON Web Token to be returned to the client. The token is returned in a JSON payload in the format:

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Running the web server

We are now ready to run our web server. If you are using a Linux or MacOS computer, use the following command:

If you use a Windows computer, use the following commands instead:

You should see something like the following output once the server starts:

At this point you have the web server running and ready to receive requests. We have also enabled Flask’s debug mode, which will trigger the web server to restart itself whenever changes are made to the application, so you can now leave this terminal window alone and when/if you make changes to the server the application will restart on its own.

Generating Access Tokens

To ensure that you have the server running properly, we can test the access token generation by sending a request, in a way similar to how a real client would do it.

To send requests to our server we are going to use the httpie Python package. Open a second terminal window (leave the first running the Flask server as shown in the previous section), cd into the project directory, and activate the virtual environment. On a Mac or Unix computer that would be done as follows:

On Windows, the commands are these:

You can send a token request to the server with the following command:

The command sends a POST request to the /token URL of our server, passing the username and password fields that the server expects. The response contains a single entry under the key token, which is the generated Twilio access token. Depending on the JavaScript SDK that you are using, there will be a function that connects to Twilio that accepts this token as an argument.

Now try to send a request with missing information to confirm that the server rejects the request with a 401 error. For example, do not send a password:

Conclusion

Congratulations, you now have a secure access token generation server that you can use with your browser-based Twilio applications!

I hope this tutorial gave you the tools that you need to implement good security practices. I can’t wait to see what you build with Twilio!

Miguel Grinberg is a Python Developer for Technical Content at Twilio. Reach out to him at mgrinberg [at] twilio [dot] com if you have a cool Python project you’d like to share on the Twilio blog!

From Introduction to JSON Web Tokens : JSON Web Token (JWT) is an open standard (RFC 7519) that defines a compact and self-contained way for securely transmitting information between parties as a JSON object. This information can be verified and trusted because it is digitally signed. JWTs can be signed using a secret (with HMAC algorithm) or a public/private key pair using RSA.

Introduction to JSON Web Tokens is great by itself, so here I'll show how to implement trivial JWT authentication in Python.

This article assumes Python 3.5 to use nice asyncio coroutine syntax.

We will use aiohttp as http library, gunicorn as development server with --reload. pyjwt is python implementation of JWT standard. Requirements for the tutorial are listed at requirements.txt on github page. Install it in virtualenv with:

As it is a demo application, there is not much error handling, but only essential code to show how to use JWT.

Initial setup

At first, lets create a wrapper for aiohttp.web.Response where we dumps body to json and assign the suitable content type:

There is a User model in the helper module models. It makes it possible to get and create users in the memory to meet our need for a simple storage mechanism. We will need to import it and create the user to work with it further:

Login

Next, create a handler to allow the client to login, i.e. acquire authentication token.

Here is a step-by-step breakdown of the process:

1. Get data from post query.
2. Fetch user by email from storage.
3. Check if passwords match.
4. If the user with the email does not exist or the password doesn't match, return response with error message.
5. Next, create token payload, where we store data we'd like to have when authorized clients perform certain actions. There are reserved keys, like exp, which JWT standard defines and its implementations use internally to provide additional features. In our case, we store the user ID to identify user and expiration date, after which the token becomes invalid. Description of exp and other reserved keys provided in corresponding RFC section
6. Finally, we encode our payload with a secret string and specified algorithm and the return response with a token in the JSON body.

In order to ask aiohttp to use this handler, we should create Application and add_route with login handler.

The code at this point is available here. If you follow along, clone the repo, and rungit checkout login-url

Now, to check if everything OK, run gunicorn:

And issue request to /login url:

You should see something like this:

Auth middleware

Now we can acquire the token. We can store it in client and use it to get access to the user's resources. Next we create middleware that will fetch a user and add it to the response object.

Here is the code (add it to web.py):

Let’s go through it step-by-step:

1. Define the aiohttp middleware.
2. Get token from AUTHORIZATION header, if there is one.
3. Try to decode it with the same secret and encoding algorithm as it was created.
4. If token expired or decoding error occurs, return response with error message.
5. If everything OK, fetch user by with user_id in payload and assign it to request.user.
6. Note that middlewares=[auth_middleware] added to Application instance creation.
7. Also, url handler to check request.user.

Code is in the commit. Or git checkout auth-middleware if have cloned repo.

Ensure, that gunicorn is running, get token from /login url, and use it in /get-user url:

If token is invalid or expired, you'll get an error message. If successful, you'll see user info printed in the console:

OK, that’s great! Now we can use the user in our views.

In essence, all further actions are not related to the authentication mechanism. For example, it is common to have something to ensure, that only logged in users have access to specific handlers. Let’s write a simple decorator to accomplish this task:

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Here, we just check if request.user is a truthy value. If it is not, it should return a response with an error message.

Jwt Secret Key Generator Python

Continue reading the second part: JWT authorization in python: Part 2, Theory

Generate Jwt Token With Private Key Python

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