Vault is a high security secret store. At Mattermost, its primary purpose is to sign SSH keys.
If you’re on macOS and have Brew installed, you can just
brew install vault. Otherwise, see the Vault installation instructions.
Once installed, you’ll need to configure it. Add the following to your .bash_profile or .zshrc:
Authentication is done via OneLogin and RADIUS:
$ vault login -method=radius email@example.com
OneLogin users must have the “Developers” role in order to authenticate.
Note: If authentication times out or fails for any reason other than “access denied by the authentication server”, have a OneLogin admin verify that the Vault server IP addresses are whitelisted in the OneLogin RADIUS configuration.
You can use a command like the following to sign your SSH key and connect to a machine:
$ vault ssh -mount-point=dev-ssh-signer -mode=ca -role=default -private-key-path=~/.ssh/id_ed25519 -public-key-path=~/.ssh/id_ed25519.pub firstname.lastname@example.org
Creating a wrapper or alias for this command is recommended.
ed25519 SSH key with:
$ ssh-keygen -o -a 100 -t ed25519 -f ~/.ssh/id_ed25519 -C "email@example.com"
To configure SSH on a host machine, you need to copy Vault’s CA certificate to that machine and point the “TrustedUserCAKeys” option to it in /etc/ssh/sshd_config.
The certificate can be obtained via…
vault read dev-ssh-signer/config/ca
When launching a machine on EC2 that you want to make accessible to all developers, you can simply use this as “user data” when launching the machine:
#cloud-config bootcmd: - cloud-init-per once ssh-users-ca echo "TrustedUserCAKeys /etc/ssh/trusted_ca_keys.pub" >> /etc/ssh/sshd_config write_files: - path: /etc/ssh/trusted_ca_keys.pub content: ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAACAQDHDwQhQ3eRiW4CV5RKAJb0n9P/07aHrku5hAVc+M59ejZHPVD/4sEfSaKvIXNTcY5TsrudzEhY3nVBsJDcJjb5qC5ayy+JNGFNnF05JoZ4E3tggJm5HQv3Znm/N6s65ZMA0HsZojCvEf+K8P0AKdJWiZbZGF095+N3WL9bUQIxBmCIBVPAOQSTCo8QKeorFfxhw/XcmH3s/KDV52/hEt6RWTxaDup03r7y8fbVo81F4QJ2ItmHgL3vGSpJk/nkLB2RWxT6zp4JIEo7PZ6S2Gm/2jaW+B5DftUd0gI8GKo9+vhtWjEEbOdu/mz92/GHLHW+s3TnftLeXVs7a8UYwdh/qJ4P64U3wlA//igo7ToXONsZ4TwmcKg6FD9JAq+LKTC0+prx/Gulx5esiPS+bgnkM/CMuoWMtucLoXaNz9ELBmeb6QSj1a7T/4LFzBiefT977OIhglORnEsKvY0HXvzX66a73Lm3bC9mUXxi1HSJNTDdLOmnVK+ipVjViy2/C9KJmKL3ePwBQSJ9d9IK76W4SGXTGT4mTVBSSF6j+/2a4tXq9c3NCuEWyXgPJRP1t6Iib42oAosxPoZ4zeBZM05BHbveD2b0G/bmeaZRgsEaZ3Qjnr50a6Wke7Vr9q3QGjn3+8QEdUdrnCTN8dlloLYhwY9pgh1JEYDaCdPHSP1ppw==
When the Vault instance starts up, it needs to be “unsealed” in order to decrypt its storage and become functional. At the time of writing, there are 8 keyholders. Two of them must work together to unseal Vault using this command:
VAULT_ADDR='https://vault-sealed.mattermost.com' vault unseal