Repository password change support (#1197)

* repo: added 'enable password change' flag (defaults to true for new repositories), which prevents embedding replicas of kopia.repository in pack blobs

* cli: added 'repo change-password' which can change the password of a connected repository

* repo: nit - renamed variables and functions dealing with key derivation

* repo: fixed cache validation HMAC secret to use stored HMAC secret instead of password-derived one

* cli: added test for repo change-password

* repo: negative cases for attempting to change password in an old repository

* Update cli/command_repository_change_password.go

Co-authored-by: Julio Lopez <julio+gh@kasten.io>

Co-authored-by: Julio Lopez <julio+gh@kasten.io>

internal/repotesting/repotesting.go

@@ -17,13 +17,15 @@
 	"github.com/kopia/kopia/repo/object"
 )
 
-const masterPassword = "foobarbazfoobarbaz"
+const defaultPassword = "foobarbazfoobarbaz"
 
 // Environment encapsulates details of a test environment.
 type Environment struct {
 	Repository       repo.Repository
 	RepositoryWriter repo.DirectRepositoryWriter
 
+	Password string
+
 	configDir  string
 	storageDir string
 	connected  bool
@@ -46,9 +48,10 @@ func (e *Environment) setup(t *testing.T, opts ...Options) *Environment {
 
 	opt := &repo.NewRepositoryOptions{
 		BlockFormat: content.FormattingOptions{
-			HMACSecret: []byte{},
-			Hash:       "HMAC-SHA256",
-			Encryption: encryption.DefaultAlgorithm,
+			HMACSecret:           []byte{},
+			Hash:                 "HMAC-SHA256",
+			Encryption:           encryption.DefaultAlgorithm,
+			EnablePasswordChange: true,
 		},
 		ObjectFormat: object.Format{
 			Splitter: "FIXED-1M",
@@ -72,17 +75,21 @@ func (e *Environment) setup(t *testing.T, opts ...Options) *Environment {
 		t.Fatalf("err: %v", err)
 	}
 
-	if err = repo.Initialize(ctx, st, opt, masterPassword); err != nil {
+	if e.Password == "" {
+		e.Password = defaultPassword
+	}
+
+	if err = repo.Initialize(ctx, st, opt, e.Password); err != nil {
 		t.Fatalf("err: %v", err)
 	}
 
-	if err = repo.Connect(ctx, e.ConfigFile(), st, masterPassword, nil); err != nil {
+	if err = repo.Connect(ctx, e.ConfigFile(), st, e.Password, nil); err != nil {
 		t.Fatalf("can't connect: %v", err)
 	}
 
 	e.connected = true
 
-	rep, err := repo.Open(ctx, e.ConfigFile(), masterPassword, openOpt)
+	rep, err := repo.Open(ctx, e.ConfigFile(), e.Password, openOpt)
 	if err != nil {
 		t.Fatalf("can't open: %v", err)
 	}
@@ -135,7 +142,7 @@ func (e *Environment) MustReopen(t *testing.T, openOpts ...func(*repo.Options))
 		t.Fatalf("close error: %v", err)
 	}
 
-	rep, err := repo.Open(ctx, e.ConfigFile(), masterPassword, repoOptions(openOpts))
+	rep, err := repo.Open(ctx, e.ConfigFile(), e.Password, repoOptions(openOpts))
 	if err != nil {
 		t.Fatalf("err: %v", err)
 	}
@@ -154,7 +161,7 @@ func (e *Environment) MustOpenAnother(t *testing.T) repo.RepositoryWriter {
 
 	ctx := testlogging.Context(t)
 
-	rep2, err := repo.Open(ctx, e.ConfigFile(), masterPassword, &repo.Options{})
+	rep2, err := repo.Open(ctx, e.ConfigFile(), e.Password, &repo.Options{})
 	if err != nil {
 		t.Fatalf("err: %v", err)
 	}
@@ -192,11 +199,11 @@ func (e *Environment) MustConnectOpenAnother(t *testing.T, openOpts ...func(*rep
 		},
 	}
 
-	if err = repo.Connect(ctx, config, st, masterPassword, connOpts); err != nil {
+	if err = repo.Connect(ctx, config, st, e.Password, connOpts); err != nil {
 		t.Fatal("can't connect:", err)
 	}
 
-	rep, err := repo.Open(ctx, e.ConfigFile(), masterPassword, repoOptions(openOpts))
+	rep, err := repo.Open(ctx, e.ConfigFile(), e.Password, repoOptions(openOpts))
 	if err != nil {
 		t.Fatal("can't open:", err)
 	}

internal/repotesting/repotesting_test.go

@@ -19,7 +19,7 @@ func TestTimeFuncWiring(t *testing.T) {
 	ft := faketime.NewTimeAdvance(time.Date(2018, time.February, 6, 0, 0, 0, 0, time.UTC), 0)
 
 	// Re open with injected time
-	rep, err := repo.Open(ctx, env.RepositoryWriter.ConfigFilename(), masterPassword, &repo.Options{TimeNowFunc: ft.NowFunc()})
+	rep, err := repo.Open(ctx, env.RepositoryWriter.ConfigFilename(), env.Password, &repo.Options{TimeNowFunc: ft.NowFunc()})
 	if err != nil {
 		t.Fatal("Failed to open repo:", err)
 	}