feat(secrets): implement SecretStore interface and StaticStore/LocalStore for credential management

This commit is contained in:
Alex Lovell-Troy 2025-03-07 17:10:31 -05:00
parent 76b9d35ec7
commit 1f2e72dab6
No known key found for this signature in database
13 changed files with 525 additions and 29 deletions

75
pkg/secrets/encryption.go Normal file
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package secrets
import (
"crypto/aes"
"crypto/cipher"
"crypto/rand"
"crypto/sha256"
"encoding/hex"
"fmt"
"io"
"golang.org/x/crypto/hkdf"
)
// Derive a unique AES key per SecretID using HKDF
func deriveAESKey(masterKey []byte, secretID string) []byte {
salt := []byte(secretID)
hkdf := hkdf.New(sha256.New, masterKey, salt, nil)
derivedKey := make([]byte, 32) // AES-256 key
io.ReadFull(hkdf, derivedKey)
return derivedKey
}
// Encrypt data using AES-GCM
func encryptAESGCM(key, plaintext []byte) (string, error) {
block, err := aes.NewCipher(key)
if err != nil {
return "", err
}
aesGCM, err := cipher.NewGCM(block)
if err != nil {
return "", err
}
nonce := make([]byte, aesGCM.NonceSize())
_, err = io.ReadFull(rand.Reader, nonce)
if err != nil {
return "", err
}
ciphertext := aesGCM.Seal(nonce, nonce, plaintext, nil)
return hex.EncodeToString(ciphertext), nil
}
// Decrypt data using AES-GCM
func decryptAESGCM(key []byte, encryptedData string) (string, error) {
data, err := hex.DecodeString(encryptedData)
if err != nil {
return "", err
}
block, err := aes.NewCipher(key)
if err != nil {
return "", err
}
aesGCM, err := cipher.NewGCM(block)
if err != nil {
return "", err
}
nonceSize := aesGCM.NonceSize()
if len(data) < nonceSize {
return "", fmt.Errorf("ciphertext too short")
}
nonce, ciphertext := data[:nonceSize], data[nonceSize:]
plaintext, err := aesGCM.Open(nil, nonce, ciphertext, nil)
if err != nil {
return "", err
}
return string(plaintext), nil
}

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package secrets
import (
"testing"
)
func TestDeriveAESKey(t *testing.T) {
masterKey := []byte("testmasterkey")
secretID := "mySecretID"
key1 := deriveAESKey(masterKey, secretID)
key2 := deriveAESKey(masterKey, secretID)
if len(key1) != 32 {
t.Errorf("derived key should be 32 bytes, got %d", len(key1))
}
if string(key1) != string(key2) {
t.Errorf("keys derived from same secretID should match")
}
}
func TestEncryptDecryptAESGCM(t *testing.T) {
masterKey := []byte("anotherTestMasterKey")
secretID := "testSecret"
plaintext := "Hello, secrets!"
key := deriveAESKey(masterKey, secretID)
encrypted, err := encryptAESGCM(key, []byte(plaintext))
if err != nil {
t.Fatalf("encryption failed: %v", err)
}
decrypted, err := decryptAESGCM(key, encrypted)
if err != nil {
t.Fatalf("decryption failed: %v", err)
}
if decrypted != plaintext {
t.Errorf("expected %q, got %q", plaintext, decrypted)
}
}

129
pkg/secrets/localstore.go Normal file
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package secrets
import (
"crypto/rand"
"encoding/hex"
"encoding/json"
"fmt"
"os"
"sync"
)
// Structure to store encrypted secrets in a JSON file
type LocalSecretStore struct {
mu sync.RWMutex
masterKey []byte
filename string
Secrets map[string]string `json:"secrets"`
}
func NewLocalSecretStore(masterKeyHex, filename string, create bool) (*LocalSecretStore, error) {
var secrets map[string]string
masterKey, err := hex.DecodeString(masterKeyHex)
if err != nil {
return nil, fmt.Errorf("unable to generate masterkey from hex representation: %v", err)
}
if _, err := os.Stat(filename); os.IsNotExist(err) {
if !create {
return nil, fmt.Errorf("file %s does not exist", filename)
}
file, err := os.Create(filename)
if err != nil {
return nil, fmt.Errorf("unable to create file %s: %v", filename, err)
}
file.Close()
secrets = make(map[string]string)
}
if secrets == nil {
secrets, err = loadSecrets(filename)
if err != nil {
return nil, fmt.Errorf("unable to load secrets from file: %v", err)
}
}
return &LocalSecretStore{
masterKey: masterKey,
filename: filename,
Secrets: secrets,
}, nil
}
// GenerateMasterKey creates a 32-byte random key and returns it as a hex string.
func GenerateMasterKey() (string, error) {
key := make([]byte, 32) // 32 bytes for AES-256
_, err := rand.Read(key)
if err != nil {
return "", err
}
return hex.EncodeToString(key), nil
}
// GetSecretByID decrypts the secret using the master key and returns it
func (l *LocalSecretStore) GetSecretByID(secretID string) (string, error) {
l.mu.RLock()
encrypted, exists := l.Secrets[secretID]
l.mu.RUnlock()
if !exists {
return "", fmt.Errorf("no secret found for %s", secretID)
}
derivedKey := deriveAESKey(l.masterKey, secretID)
return decryptAESGCM(derivedKey, encrypted)
}
// StoreSecretByID encrypts the secret using the master key and stores it in the JSON file
func (l *LocalSecretStore) StoreSecretByID(secretID, secret string) error {
derivedKey := deriveAESKey(l.masterKey, secretID)
encryptedSecret, err := encryptAESGCM(derivedKey, []byte(secret))
if err != nil {
return err
}
l.mu.Lock()
l.Secrets[secretID] = encryptedSecret
err = saveSecrets(l.filename, l.Secrets)
l.mu.Unlock()
return err
}
// ListSecrets returns a copy of secret IDs to secrets stored in memory
func (l *LocalSecretStore) ListSecrets() (map[string]string, error) {
l.mu.RLock()
defer l.mu.RUnlock()
secretsCopy := make(map[string]string)
for key, value := range l.Secrets {
secretsCopy[key] = value
}
return secretsCopy, 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)
if err != nil {
return err
}
defer file.Close()
encoder := json.NewEncoder(file)
encoder.SetIndent("", " ")
return encoder.Encode(store)
}
// Loads the secrets JSON file
func loadSecrets(jsonFile string) (map[string]string, error) {
file, err := os.Open(jsonFile)
if err != nil {
return nil, fmt.Errorf("unable to open secret file %s:%v", jsonFile, err)
}
defer file.Close()
store := make(map[string]string)
decoder := json.NewDecoder(file)
err = decoder.Decode(&store)
return store, err
}

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package secrets
import (
"encoding/hex"
"os"
"testing"
)
func TestNewLocalSecretStore(t *testing.T) {
masterKey, err := GenerateMasterKey()
if err != nil {
t.Fatalf("Failed to generate master key: %v", err)
}
filename := "test_secrets.json"
defer os.Remove(filename)
store, err := NewLocalSecretStore(masterKey, filename, true)
if err != nil {
t.Fatalf("Failed to create LocalSecretStore: %v", err)
}
if store.filename != filename {
t.Errorf("Expected filename %s, got %s", filename, store.filename)
}
if hex.EncodeToString(store.masterKey) != masterKey {
t.Errorf("Expected master key %s, got %s", masterKey, hex.EncodeToString(store.masterKey))
}
}
func TestGenerateMasterKey(t *testing.T) {
key, err := GenerateMasterKey()
if err != nil {
t.Fatalf("Failed to generate master key: %v", err)
}
if len(key) != 64 { // 32 bytes in hex representation
t.Errorf("Expected key length 64, got %d", len(key))
}
}
func TestStoreAndGetSecretByID(t *testing.T) {
masterKey, err := GenerateMasterKey()
if err != nil {
t.Fatalf("Failed to generate master key: %v", err)
}
filename := "test_secrets.json"
defer os.Remove(filename)
store, err := NewLocalSecretStore(masterKey, filename, true)
if err != nil {
t.Fatalf("Failed to create LocalSecretStore: %v", err)
}
secretID := "test_secret"
secretValue := "my_secret_value"
err = store.StoreSecretByID(secretID, secretValue)
if err != nil {
t.Fatalf("Failed to store secret: %v", err)
}
retrievedSecret, err := store.GetSecretByID(secretID)
if err != nil {
t.Fatalf("Failed to get secret: %v", err)
}
if retrievedSecret != secretValue {
t.Errorf("Expected secret value %s, got %s", secretValue, retrievedSecret)
}
}
func TestStoreAndGetSecretJSON(t *testing.T) {
masterKey, err := GenerateMasterKey()
if err != nil {
t.Fatalf("Failed to generate master key: %v", err)
}
filename := "test_secrets.json"
defer os.Remove(filename)
store, err := NewLocalSecretStore(masterKey, filename, true)
if err != nil {
t.Fatalf("Failed to create LocalSecretStore: %v", err)
}
secretID := "json_creds"
jsonSecret := `{"username":"testUser","password":"testPass"}`
if err := store.StoreSecretByID(secretID, jsonSecret); err != nil {
t.Fatalf("Failed to store JSON secret: %v", err)
}
retrieved, err := store.GetSecretByID(secretID)
if err != nil {
t.Fatalf("Failed to get JSON secret by ID: %v", err)
}
if retrieved != jsonSecret {
t.Errorf("Expected %s, got %s", jsonSecret, retrieved)
}
}
func TestListSecrets(t *testing.T) {
masterKey, err := GenerateMasterKey()
if err != nil {
t.Fatalf("Failed to generate master key: %v", err)
}
filename := "test_secrets.json"
defer os.Remove(filename)
store, err := NewLocalSecretStore(masterKey, filename, true)
if err != nil {
t.Fatalf("Failed to create LocalSecretStore: %v", err)
}
secretID1 := "test_secret_1"
secretValue1 := "my_secret_value_1"
secretID2 := "test_secret_2"
secretValue2 := "my_secret_value_2"
err = store.StoreSecretByID(secretID1, secretValue1)
if err != nil {
t.Fatalf("Failed to store secret: %v", err)
}
err = store.StoreSecretByID(secretID2, secretValue2)
if err != nil {
t.Fatalf("Failed to store secret: %v", err)
}
secrets, err := store.ListSecrets()
if err != nil {
t.Fatalf("Failed to list secrets: %v", err)
}
if len(secrets) != 2 {
t.Errorf("Expected 2 secrets, got %d", len(secrets))
}
if secrets[secretID1] != store.Secrets[secretID1] {
t.Errorf("Expected secret value %s, got %s", store.Secrets[secretID1], secrets[secretID1])
}
if secrets[secretID2] != store.Secrets[secretID2] {
t.Errorf("Expected secret value %s, got %s", store.Secrets[secretID2], secrets[secretID2])
}
}

7
pkg/secrets/main.go Normal file
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package secrets
type SecretStore interface {
GetSecretByID(secretID string) (string, error)
StoreSecretByID(secretID, secret string) error
ListSecrets() (map[string]string, error)
}

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package secrets
import "fmt"
type StaticStore struct {
Username string
Password string
}
// NewStaticStore creates a new StaticStore with the given username and password.
func NewStaticStore(username, password string) *StaticStore {
return &StaticStore{
Username: username,
Password: password,
}
}
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),
}, nil
}