package linode import ( "context" "crypto/rand" "crypto/rsa" "crypto/x509" "encoding/pem" "fmt" "io/ioutil" "os" "github.com/hashicorp/packer/helper/multistep" "github.com/hashicorp/packer/packer" "golang.org/x/crypto/ssh" ) // StepCreateSSHKey represents a Packer build step that generates SSH key pairs. type StepCreateSSHKey struct { Debug bool DebugKeyPath string } // Run executes the Packer build step that generates SSH key pairs. // The key pairs are added to the ssh config func (s *StepCreateSSHKey) Run(_ context.Context, state multistep.StateBag) multistep.StepAction { ui := state.Get("ui").(packer.Ui) config := state.Get("config").(*Config) if config.Comm.SSHPrivateKeyFile != "" { ui.Say("Using existing SSH private key") privateKeyBytes, err := ioutil.ReadFile(config.Comm.SSHPrivateKeyFile) if err != nil { state.Put("error", fmt.Errorf( "Error loading configured private key file: %s", err)) return multistep.ActionHalt } config.Comm.SSHPrivateKey = privateKeyBytes config.Comm.SSHPublicKey = nil return multistep.ActionContinue } ui.Say("Creating temporary SSH key for instance...") priv, err := rsa.GenerateKey(rand.Reader, 2048) if err != nil { err := fmt.Errorf("Error creating temporary ssh key: %s", err) state.Put("error", err) ui.Error(err.Error()) return multistep.ActionHalt } priv_blk := pem.Block{ Type: "RSA PRIVATE KEY", Headers: nil, Bytes: x509.MarshalPKCS1PrivateKey(priv), } pub, err := ssh.NewPublicKey(&priv.PublicKey) if err != nil { err := fmt.Errorf("Error creating temporary ssh key: %s", err) state.Put("error", err) ui.Error(err.Error()) return multistep.ActionHalt } config.Comm.SSHPrivateKey = pem.EncodeToMemory(&priv_blk) config.Comm.SSHPublicKey = ssh.MarshalAuthorizedKey(pub) // Linode has a serious issue with the newline that the ssh package appends to the end of the key. if config.Comm.SSHPublicKey[len(config.Comm.SSHPublicKey)-1] == '\n' { config.Comm.SSHPublicKey = config.Comm.SSHPublicKey[:len(config.Comm.SSHPublicKey)-1] } if s.Debug { ui.Message(fmt.Sprintf("Saving key for debug purposes: %s", s.DebugKeyPath)) f, err := os.Create(s.DebugKeyPath) if err != nil { state.Put("error", fmt.Errorf("Error saving debug key: %s", err)) return multistep.ActionHalt } // Write out the key err = pem.Encode(f, &priv_blk) f.Close() if err != nil { state.Put("error", fmt.Errorf("Error saving debug key: %s", err)) return multistep.ActionHalt } } return multistep.ActionContinue } // Nothing to clean up. SSH keys are associated with a single Linode instance. func (s *StepCreateSSHKey) Cleanup(state multistep.StateBag) {}