fix(server): encrypt jwt secret at rest

Signed-off-by: Deluan <deluan@navidrome.org>

core/auth/auth.go

@@ -1,7 +1,9 @@
 package auth
 
 import (
+	"cmp"
 	"context"
+	"crypto/sha256"
 	"sync"
 	"time"
 
@@ -13,24 +15,32 @@ import (
 	"github.com/navidrome/navidrome/log"
 	"github.com/navidrome/navidrome/model"
 	"github.com/navidrome/navidrome/model/request"
+	"github.com/navidrome/navidrome/utils"
 )
 
 var (
 	once      sync.Once
-	Secret    []byte
 	TokenAuth *jwtauth.JWTAuth
 )
 
+// Init creates a JWTAuth object from the secret stored in the DB.
+// If the secret is not found, it will create a new one and store it in the DB.
 func Init(ds model.DataStore) {
 	once.Do(func() {
+		ctx := context.TODO()
 		log.Info("Setting Session Timeout", "value", conf.Server.SessionTimeout)
-		secret, err := ds.Property(context.TODO()).Get(consts.JWTSecretKey)
+
+		secret, err := ds.Property(ctx).Get(consts.JWTSecretKey)
 		if err != nil || secret == "" {
-			log.Error("No JWT secret found in DB. Setting a temp one, but please report this error", err)
-			secret = uuid.NewString()
+			secret = createNewSecret(ctx, ds)
+		} else {
+			if secret, err = utils.Decrypt(ctx, getEncKey(), secret); err != nil {
+				log.Error(ctx, "Could not decrypt JWT secret, creating a new one", err)
+				secret = createNewSecret(ctx, ds)
+			}
 		}
-		Secret = []byte(secret)
-		TokenAuth = jwtauth.New("HS256", Secret, nil)
+
+		TokenAuth = jwtauth.New("HS256", []byte(secret), nil)
 	})
 }
 
@@ -112,3 +122,27 @@ func WithAdminUser(ctx context.Context, ds model.DataStore) context.Context {
 	ctx = request.WithUsername(ctx, u.UserName)
 	return request.WithUser(ctx, *u)
 }
+
+func createNewSecret(ctx context.Context, ds model.DataStore) string {
+	log.Info(ctx, "Creating new JWT secret, used for encrypting UI sessions")
+	secret := uuid.NewString()
+	encSecret, err := utils.Encrypt(ctx, getEncKey(), secret)
+	if err != nil {
+		log.Error(ctx, "Could not encrypt JWT secret", err)
+	}
+
+	if err := ds.Property(ctx).Put(consts.JWTSecretKey, encSecret); err != nil {
+		log.Error(ctx, "Could not save JWT secret in DB", err)
+	}
+
+	return secret
+}
+
+func getEncKey() []byte {
+	key := cmp.Or(
+		conf.Server.PasswordEncryptionKey,
+		consts.DefaultEncryptionKey,
+	)
+	sum := sha256.Sum256([]byte(key))
+	return sum[:]
+}

core/auth/auth_test.go

@@ -4,12 +4,12 @@ import (
 	"testing"
 	"time"
 
-	"github.com/go-chi/jwtauth/v5"
 	"github.com/navidrome/navidrome/conf"
 	"github.com/navidrome/navidrome/consts"
 	"github.com/navidrome/navidrome/core/auth"
 	"github.com/navidrome/navidrome/log"
 	"github.com/navidrome/navidrome/model"
+	"github.com/navidrome/navidrome/tests"
 	. "github.com/onsi/ginkgo/v2"
 	. "github.com/onsi/gomega"
 )
@@ -32,8 +32,10 @@ var _ = BeforeSuite(func() {
 var _ = Describe("Auth", func() {
 
 	BeforeEach(func() {
-		auth.Secret = []byte(testJWTSecret)
-		auth.TokenAuth = jwtauth.New("HS256", auth.Secret, nil)
+		ds := &tests.MockDataStore{
+			MockedProperty: &tests.MockedPropertyRepo{},
+		}
+		auth.Init(ds)
 	})
 
 	Describe("Validate", func() {

server/initial_setup.go

@@ -27,10 +27,6 @@ func initialSetup(ds model.DataStore) {
 			return nil
 		}
 		log.Info("Running initial setup")
-		if err = createJWTSecret(tx); err != nil {
-			return err
-		}
-
 		if conf.Server.DevAutoCreateAdminPassword != "" {
 			if err = createInitialAdminUser(tx, conf.Server.DevAutoCreateAdminPassword); err != nil {
 				return err
@@ -69,20 +65,6 @@ func createInitialAdminUser(ds model.DataStore, initialPassword string) error {
 	return err
 }
 
-func createJWTSecret(ds model.DataStore) error {
-	properties := ds.Property(context.TODO())
-	_, err := properties.Get(consts.JWTSecretKey)
-	if err == nil {
-		return nil
-	}
-	log.Info("Creating new JWT secret, used for encrypting UI sessions")
-	err = properties.Put(consts.JWTSecretKey, uuid.NewString())
-	if err != nil {
-		log.Error("Could not save JWT secret in DB", err)
-	}
-	return err
-}
-
 func checkFFmpegInstallation() {
 	f := ffmpeg.New()
 	_, err := f.CmdPath()

utils/encrypt.go

@@ -6,6 +6,7 @@ import (
 	"crypto/cipher"
 	"crypto/rand"
 	"encoding/base64"
+	"errors"
 	"io"
 
 	"github.com/navidrome/navidrome/log"
@@ -36,7 +37,15 @@ func Encrypt(ctx context.Context, encKey []byte, data string) (string, error) {
 	return base64.StdEncoding.EncodeToString(ciphertext), nil
 }
 
-func Decrypt(ctx context.Context, encKey []byte, encData string) (string, error) {
+func Decrypt(ctx context.Context, encKey []byte, encData string) (value string, err error) {
+	// Recover from any panics
+	defer func() {
+		if r := recover(); r != nil {
+			log.Error(ctx, "Panic during decryption", r)
+			err = errors.New("decryption panicked")
+		}
+	}()
+
 	enc, _ := base64.StdEncoding.DecodeString(encData)
 
 	block, err := aes.NewCipher(encKey)