APIs at Cloudflare

Today we are announcing the general availability of API Tokens - a scalable and more secure way to interact with the Cloudflare API. As part of making a better Internet, Cloudflare strives to simplify manageability of a customer’s presence at the edge. Part of the way we do this is by ensuring that all of our products and services are configurable by API. Customers ranging from partners to enterprises to developers want to automate management of Cloudflare. Sometimes that is done via our API directly, and other times it is done via open source software we help maintain like our Terraform provider or Cloudflare-Go library. It is critical that customers who are automating management of Cloudflare can keep their Cloudflare services as secure as possible.

Least Privilege and Why it Matters

Securing software systems is hard. Limiting what a piece of software can do is a good defense to prevent mistakes or malicious actions from having greater impact than they could. The principle of least privilege helps guide how much access a given system should have to perform actions. Originally formulated by Jerome Saltzer, “Every program and every privileged user of the system should operate using the least amount of privilege necessary to complete the job.” In the case of Cloudflare, many customers have various domains routing traffic leveraging many different services. If a bad actor gets unauthorized access to a system they can use whatever access that system has to cause further damage or steal additional information.

Let’s see how the capabilities of API Tokens fit into the principle of least privilege.

About API Tokens

API Tokens provide three main capabilities:

1. Scoping API Tokens by Cloudflare resource

2. Scoping API Tokens by permission

3. The ability to provision multiple API Tokens

Let’s break down each of these capabilities.

Scoping API Tokens by Cloudflare Resource

Cloudflare separates service configuration by zone which typically equates to a domain. Additionally, some customers have multiple accounts each with many zones. It is important that when granting API access to a service it only has access to the accounts resources and zones that are pertinent for the job at hand. API Tokens can be scoped to only cover specific accounts and specific zones. One common use case is if you have a staging zone and a production zone, then an API Token can be limited to only be able to affect the staging zone and not have access to the production zone.

Scoping API Tokens by Permission

Being able to scope an API Token to a specific zone is great, but in one zone there are many different services that can be configured: firewall rules, page rules, and load balancers just to name a few. If a customer has a service that should only be able to create new firewall rules in response to traffic patterns, then also allowing that service to change DNS records is a violation of least privilege. API Tokens allow you to scope each token to specific permission. Multiple permissions can be combined to create custom tokens to fit specific use cases.

Multiple API Tokens

If you use Cloudflare to protect and accelerate multiple services, then may be making API changes to Cloudflare from multiple locations - different servers, VMs, containers, or workers. Being able to create an API Token per service means each service is insulated to changes from another. If one API Token is leaked or needs to be rolled, there won’t be any impact to the other services’ API Tokens. Also the capabilities mentioned previously mean that each service can be scoped to exactly what actions and resources necessary. This allows customers to better realize the practice of least privilege for accessing Cloudflare by API.

Now let’s walk through how to create an API Token and use it.

Using API Tokens

To create your first API Token go to the ‘API Tokens’ section of your user profile which can be found here: dash.cloudflare.com/profile/api-tokens

1. On this page, you will find both a list of all of your API Tokens in addition to your Global API Key and Origin CA Key.

API Tokens Getting Started - Create Token

To create your first API Token, select ‘Create Token’.

---

2. On the create screen there are two ways to create your token. You can create it from scratch through the ‘Custom’ option or you can start with a predefined template by selecting ‘Start with a template’.

API Token Template Selection

For this case, we will use the ‘Edit zone DNS’ template to create an API Token that can edit a single zone’s DNS records.

---

3. Once the template is selected, we need to pick a zone for the API Token to be scoped to. Notice that the DNS Edit permission was already pre-selected.

Specifying the zone for which the token will be able to control DNS

In this case, ‘garrettgalow.com’ is selected as the Cloudflare zone that the API Token will be able to edit DNS records for.

---

4. Once I select continue to summary, I’m given a chance to review my selection. In this case the resources and permissions are quite simple, but this gives you a change to make sure you are giving the API Token exactly the correct amount of privilege before creating it.

Token Summary - confirmation

---

5. Once created, we are presented with the API Token. This screen is the only time you will be presented with the secret so be sure to put the secret in a safe place! Anyone with this secret can perform the granted actions on the resources specified so protect it like a password. In the below screenshot I have black boxed the secret for obvious reasons. If you happen to lose the secret, you can always regenerate it from the API Tokens table so you don’t have to configure all the permissions again.

Token creation completion screen with the token secret

In addition to the secret itself this screen provides an example curl request that can be used to verify that the token was successfully created. It also provides an example of how the token should be used for any direct HTTP requests. With API Tokens we now follow the RFC Authorization Bearer standard. Calling that API we see a successful response telling us that the token is valid and active

~$ curl -X GET "https://api.cloudflare.com/client/v4/user/tokens/verify" \
>      -H "Authorization: Bearer vh9awGupxxxxxxxxxxxxxxxxxxx" \
>      -H "Content-Type:application/json" | jq

{
  "result": {
    "id": "ad599f2b67cdccf24a160f5dcd7bc57b",
    "status": "active"
  },
  "success": true,
  "errors": [],
  "messages": [
    {
      "code": 10000,
      "message": "This API Token is valid and active",
      "type": null
    }
  ]
}

What’s coming next

For anyone using the Cloudflare API, we recommend moving to using API Tokens over their predecessor API Keys going forward. With this announcement, our Terraform provider, Cloudflare-Go library, and WordPress plugin are all updated for API Token compatibility. Other libraries will receive updates soon. Both API Tokens and API Keys will be supported for the time being for customers to be able to safely migrate. We have more planned capabilities for API Tokens to further safeguard how and when tokens are used, so stay tuned for future announcements!

Let us know what you think and what you'd like to see next regarding API security on the Cloudflare Community.