Knox -- the high level overview

Knox is a service for storing and rotation of secrets, keys, and passwords used by other services.

The Problem Knox is Meant to Solve

Pinterest has a plethora of keys or secrets doing things like signing cookies, encrypting data, protecting our network via TLS, accessing our AWS machines, communicating with our third parties, and many more. If these keys become compromised, rotating (or changing our keys) used to be a difficult process generally involving a deploy and likely a code change. Keys/secrets within Pinterest were stored in git repositories. This means they were copied all over our company's infrastructure and present on many of our employees laptops. There was no way to audit who accessed or who has access to the keys. Knox was built to solve these problems.

The goals of Knox are:

Ease of use for developers to access/use confidential secrets, keys, and credentials
Confidentiality for secrets, keys, and credentials
Provide mechanisms for key rotation in case of compromise
Create audit log to keep track of what systems and users access confidential data

Getting knox set up

The first step is to install Go (or use Docker, see below). We require Go >= 1.6 or Go 1.5 with the vendor flag enabled (GO15VENDOREXPERIMENT=1). For instructions on setting up Go, please visit https://golang.org/doc/install

After Go is set up (including a $GOPATH directory that will store your workspace), please run go get -d github.com/pinterest/knox to get the latest version of the knox code.

To compile the devserver and devclient binaries, run go install github.com/pinterest/knox/cmd/dev_server and go install github.com/pinterest/knox/cmd/dev_client. These can be directly executed, the dev_client expects the server to be running on a localhost. By default, the client uses mTLS with a hardcoded signed cert given for example.com for machine authentication and had github authentication enabled for users.

To start your server run:

$GOPATH/bin/dev_server

For using this client as a user, generate a token via these instructions https://help.github.com/articles/creating-an-access-token-for-command-line-use/ with read:org permissions. This token will be able to get your username and the organization you belong to. With the dev_server running you can now create your first knox key.

export KNOX_USER_AUTH=<insert generated github token here>
echo -n "My first knox secret" | $GOPATH/bin/dev_client create test_service:first_secret

You can retrieve the secret using:

$GOPATH/bin/dev_client get test_service:first_secret

You can see all key IDs using:

$GOPATH/bin/dev_client keys

To see all available commands run:

$GOPATH/bin/dev_client help

For production usage, I recommend making your own client, renaming it knox, and moving it into you $PATH for ease of use.

For more information on interacting with knox, use knox help or go to https://github.com/pinterest/knox/wiki/Knox-Client

Knox with Docker

You can run a Docker container to get knox set up, instead of installing Go on your host.

git clone https://github.com/pinterest/knox.git
cd knox
docker run --name knox --rm -v "$PWD":/go/src/github.com/pinterest/knox -it golang /bin/bash

This will run a bash shell into the container, mounting a local copy of knox in the go source path.

You can refer back to the section "Getting knox set up" to set up knox.