refactor: added function to open secrets store by checking env var

pkg/secrets/example/main.go

@@ -0,0 +1,212 @@
+package main
+
+// This example demonstrates the usage of the LocalSecretStore to store and retrieve secrets.
+// It provides a command-line interface to generate a master key, store secrets, and retrieve them.
+// The master key is assumed to be stored in the environment variable MASTER_KEY and while it can
+// anything you want, we recommend a 32 bit key for AES-256 encryption.  The master key is used
+// as part of a Key Derivation Function (KDF) to generate a unique AES key for each secret.
+// The algorithm of choice is HMAC-based Extract-and-Expand Key Derivation Function (HKDF).
+// Each secret is separately encrypted using AES-GCM and stored in a JSON file.
+// The JSON file is loaded into memory when the LocalSecretStore is created and saved back to the file
+// when a secret is stored or removed.
+//
+
+import (
+	"encoding/base64"
+	"fmt"
+	"os"
+
+	"github.com/OpenCHAMI/magellan/pkg/secrets"
+)
+
+func usage() {
+	fmt.Println("Usage:")
+	fmt.Println("  go run main.go generatekey")
+	fmt.Println("    - Generates a new 32-byte master key (in hex).")
+	fmt.Println()
+	fmt.Println("  Export MASTER_KEY=<your master key> to use the same key in the next commands.")
+	fmt.Println()
+	fmt.Println("  go run main.go store <secretID> <secretValue> [filename]")
+	fmt.Println("    - Stores the given string value under secretID.")
+	fmt.Println()
+	fmt.Println("  go run main.go storebase64 <secretID> <base64String> [filename]")
+	fmt.Println("    - Decodes the base64-encoded string before storing.")
+	fmt.Println()
+	fmt.Println("  go run main.go storejson <secretID> <jsonString> [filename]")
+	fmt.Println("    - Stores the provided JSON for the specified secretID.")
+	fmt.Println()
+	fmt.Println("  go run main.go retrieve <secretID> [filename]")
+	fmt.Println("    - Retrieves and prints the secret value for the given secretID.")
+	fmt.Println()
+	fmt.Println("  go run main.go list [filename]")
+	fmt.Println("    - Lists all the secret IDs and their values.")
+	fmt.Println()
+}
+
+// openStore tries to create or open the LocalSecretStore based on the environment
+// variable MASTER_KEY. If not found, it prints an error.
+func openStore(filename string) (*secrets.LocalSecretStore, error) {
+	masterKey := os.Getenv("MASTER_KEY")
+	if masterKey == "" {
+		return nil, fmt.Errorf("MASTER_KEY environment variable not set")
+	}
+
+	store, err := secrets.NewLocalSecretStore(masterKey, filename, true)
+	if err != nil {
+		return nil, fmt.Errorf("cannot open secrets store: %v", err)
+	}
+	return store, nil
+}
+
+func main() {
+	if len(os.Args) < 2 {
+		usage()
+		os.Exit(1)
+	}
+
+	cmd := os.Args[1]
+
+	switch cmd {
+	case "generatekey":
+		key, err := secrets.GenerateMasterKey()
+		if err != nil {
+			fmt.Printf("Error generating master key: %v\n", err)
+			os.Exit(1)
+		}
+		fmt.Printf("%s\n", key)
+
+	case "store":
+		if len(os.Args) < 4 {
+			fmt.Println("Not enough arguments. Usage: go run main.go store <secretID> <secretValue> [filename]")
+			os.Exit(1)
+		}
+		secretID := os.Args[2]
+		secretValue := os.Args[3]
+		filename := "mysecrets.json"
+		if len(os.Args) == 5 {
+			filename = os.Args[4]
+		}
+
+		store, err := openStore(filename)
+		if err != nil {
+			fmt.Println(err)
+			os.Exit(1)
+		}
+
+		if err := store.StoreSecretByID(secretID, secretValue); err != nil {
+			fmt.Printf("Error storing secret: %v\n", err)
+			os.Exit(1)
+		}
+		fmt.Println("Secret stored successfully.")
+
+	case "storebase64":
+		if len(os.Args) < 4 {
+			fmt.Println("Not enough arguments. Usage: go run main.go storebase64 <secretID> <base64String> [filename]")
+			os.Exit(1)
+		}
+		secretID := os.Args[2]
+		base64Value := os.Args[3]
+		filename := "mysecrets.json"
+		if len(os.Args) == 5 {
+			filename = os.Args[4]
+		}
+
+		decoded, err := base64.StdEncoding.DecodeString(base64Value)
+		if err != nil {
+			fmt.Printf("Error decoding base64 data: %v\n", err)
+			os.Exit(1)
+		}
+
+		store, err := openStore(filename)
+		if err != nil {
+			fmt.Println(err)
+			os.Exit(1)
+		}
+
+		if err := store.StoreSecretByID(secretID, string(decoded)); err != nil {
+			fmt.Printf("Error storing base64-decoded secret: %v\n", err)
+			os.Exit(1)
+		}
+		fmt.Println("Base64-decoded secret stored successfully.")
+
+	case "storejson":
+		if len(os.Args) < 4 {
+			fmt.Println(`Not enough arguments. Usage: go run main.go storejson <secretID> '{"key":"value"}' [filename]`)
+			os.Exit(1)
+		}
+		secretID := os.Args[2]
+		jsonValue := os.Args[3]
+		filename := "mysecrets.json"
+		if len(os.Args) == 5 {
+			filename = os.Args[4]
+		}
+
+		store, err := openStore(filename)
+		if err != nil {
+			fmt.Println(err)
+			os.Exit(1)
+		}
+
+		if err := store.StoreSecretByID(secretID, jsonValue); err != nil {
+			fmt.Printf("Error storing JSON secret: %v\n", err)
+			os.Exit(1)
+		}
+		fmt.Println("JSON secret stored successfully.")
+
+	case "retrieve":
+		if len(os.Args) < 3 {
+			fmt.Println("Not enough arguments. Usage: go run main.go retrieve <secretID> [filename]")
+			os.Exit(1)
+		}
+		secretID := os.Args[2]
+		filename := "mysecrets.json"
+		if len(os.Args) == 4 {
+			filename = os.Args[3]
+		}
+
+		store, err := openStore(filename)
+		if err != nil {
+			fmt.Println(err)
+			os.Exit(1)
+		}
+
+		secretValue, err := store.GetSecretByID(secretID)
+		if err != nil {
+			fmt.Printf("Error retrieving secret: %v\n", err)
+			os.Exit(1)
+		}
+		fmt.Printf("Secret for %s: %s\n", secretID, secretValue)
+
+	case "list":
+		if len(os.Args) < 2 {
+			fmt.Println("Not enough arguments. Usage: go run main.go list [filename]")
+			os.Exit(1)
+		}
+
+		filename := "mysecrets.json"
+		if len(os.Args) == 3 {
+			filename = os.Args[2]
+		}
+
+		store, err := openStore(filename)
+		if err != nil {
+			fmt.Println(err)
+			os.Exit(1)
+		}
+
+		secrets, err := store.ListSecrets()
+		if err != nil {
+			fmt.Printf("Error listing secrets: %v\n", err)
+			os.Exit(1)
+		}
+
+		fmt.Println("Secrets:")
+		for key, value := range secrets {
+			fmt.Printf("%s: %s\n", key, value)
+		}
+
+	default:
+		usage()
+	}
+
+}

pkg/secrets/localstore.go

@@ -101,6 +101,21 @@ func (l *LocalSecretStore) ListSecrets() (map[string]string, error) {
 	return secretsCopy, nil
 }
 
+// openStore tries to create or open the LocalSecretStore based on the environment
+// variable MASTER_KEY. If not found, it prints an error.
+func OpenStore(filename string) (SecretStore, error) {
+	masterKey := os.Getenv("MASTER_KEY")
+	if masterKey == "" {
+		return nil, fmt.Errorf("MASTER_KEY environment variable not set")
+	}
+
+	store, err := NewLocalSecretStore(masterKey, filename, true)
+	if err != nil {
+		return nil, fmt.Errorf("cannot open secrets store: %v", err)
+	}
+	return store, nil
+}
+
 // Saves secrets back to the JSON file
 func saveSecrets(jsonFile string, store map[string]string) error {
 	file, err := os.OpenFile(jsonFile, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0644)

pkg/secrets/staticstore.go

@@ -18,9 +18,11 @@ func NewStaticStore(username, password string) *StaticStore {
 func (s *StaticStore) GetSecretByID(secretID string) (string, error) {
 	return fmt.Sprintf(`{"username":"%s","password":"%s"}`, s.Username, s.Password), nil
 }
+
 func (s *StaticStore) StoreSecretByID(secretID, secret string) error {
 	return nil
 }
+
 func (s *StaticStore) ListSecrets() (map[string]string, error) {
 	return map[string]string{
 		"static_creds": fmt.Sprintf(`{"username":"%s","password":"%s"}`, s.Username, s.Password),