ca = "https://sshca.example.com"  // Address of the cashierd CA
key_type = "rsa"  // Type of ssh key to generate - rsa, ecdsa, ed25519
key_size = 2048  // Size of key to generate. ecdsa must be one of 256, 384, 521. This value is ignored for ed25519 keys.
validity = "24h"  // How long the cert will be valid for. Must be a valid go time.Duration.