commit c05d1ddcc64c1650ed79f006397f2245c04e1848
Author: Knut Ahlers <knut@ahlers.me>
Date:   Tue Jan 3 13:14:59 2017 +0100

    Initial version

diff --git a/.gitignore b/.gitignore
new file mode 100644
index 0000000..8bda1d5
--- /dev/null
+++ b/.gitignore
@@ -0,0 +1 @@
+vault-totp
diff --git a/main.go b/main.go
new file mode 100644
index 0000000..1c8a8c3
--- /dev/null
+++ b/main.go
@@ -0,0 +1,136 @@
+package main
+
+import (
+	"fmt"
+	"io/ioutil"
+	"log"
+	"os"
+	"time"
+
+	"github.com/Luzifer/rconfig"
+	"github.com/hashicorp/vault/api"
+	homedir "github.com/mitchellh/go-homedir"
+	"github.com/pquerna/otp/totp"
+)
+
+var (
+	cfg = struct {
+		Field          string `flag:"field" default:"secret" description:"Field inside the key to search the TOTP secret in"`
+		NoTime         bool   `flag:"no-time,n" default:"false" description:"Omit printing the validity time"`
+		OneShot        bool   `flag:"one-shot,1" default:"false" description:"Prints token only once instead continuously"`
+		TestSecret     string `flag:"test" default:"" description:"Use a test secret from CLI instead of using a secret from Vault"`
+		VaultAddress   string `flag:"vault-addr" env:"VAULT_ADDR" default:"https://127.0.0.1:8200" description:"Vault API address"`
+		VaultToken     string `flag:"vault-token" env:"VAULT_TOKEN" vardefault:"vault-token" description:"Vault Token to use for accessing Vault instance"`
+		VersionAndExit bool   `flag:"version" default:"false" description:"Prints current version and exits"`
+	}{}
+
+	version = "dev"
+)
+
+func vaultTokenFromDisk() string {
+	vf, err := homedir.Expand("~/.vault-token")
+	if err != nil {
+		return ""
+	}
+
+	data, err := ioutil.ReadFile(vf)
+	if err != nil {
+		return ""
+	}
+
+	return string(data)
+}
+
+func init() {
+	rconfig.SetVariableDefaults(map[string]string{
+		"vault-token": vaultTokenFromDisk(),
+	})
+
+	if err := rconfig.Parse(&cfg); err != nil {
+		log.Fatalf("Unable to parse commandline options: %s", err)
+	}
+
+	if cfg.VersionAndExit {
+		fmt.Printf("vault-totp %s\n", version)
+		os.Exit(0)
+	}
+
+	if cfg.VaultToken == "" && cfg.TestSecret == "" {
+		log.Fatalf("You need to specify a vault-token")
+	}
+}
+
+func main() {
+	if len(rconfig.Args()) < 2 && cfg.TestSecret == "" {
+		log.Fatalf("Please specify a vault key to read the secret from.\n\nUsage: vault-totp [opts] <vault-key>")
+	}
+
+	var (
+		secret string
+		err    error
+	)
+
+	if cfg.TestSecret == "" {
+		secret, err = getSecretFromVault()
+		if err != nil {
+			log.Fatalf("Error to retrieve secret: %s", err)
+		}
+	} else {
+		secret = cfg.TestSecret
+	}
+
+	for range time.Tick(250 * time.Millisecond) {
+		output, err := buildOutput(secret)
+		if err != nil {
+			log.Fatalf("An error ocurred while generating the code: %s", err)
+		}
+
+		fmt.Printf("\r%s", output)
+
+		if cfg.OneShot {
+			break
+		}
+	}
+
+	fmt.Println("")
+}
+
+func getSecretFromVault() (string, error) {
+	client, err := api.NewClient(&api.Config{
+		Address: cfg.VaultAddress,
+	})
+
+	if err != nil {
+		return "", fmt.Errorf("Unable to create client: %s", err)
+	}
+
+	client.SetToken(cfg.VaultToken)
+
+	data, err := client.Logical().Read(rconfig.Args()[1])
+	if err != nil {
+		return "", fmt.Errorf("Unable to read from key %q: %s", rconfig.Args()[1], err)
+	}
+
+	if data.Data[cfg.Field] == nil {
+		return "", fmt.Errorf("The key %q does not have a field named %q.", rconfig.Args()[1], cfg.Field)
+	}
+
+	return data.Data[cfg.Field].(string), nil
+}
+
+func buildOutput(secret string) (string, error) {
+	// Output: "123456 (Valid 12s)", "123456 (Valid 1s)"
+
+	n := time.Now()
+	code, err := totp.GenerateCode(secret, n)
+	if err != nil {
+		return "", err
+	}
+
+	if cfg.NoTime {
+		return fmt.Sprintf("%s", code), nil
+	}
+
+	remain := 30 - (n.Second() % 30)
+	return fmt.Sprintf("%s (Valid %ds) ", code, remain), nil
+}