Ask for the mnemonic and passphrase before taking the state directory lock (closes #152)

init, vault create, unlocker add, and add, import and generate secret
with --force asked for the mnemonic or passphrase, or unlocked the
vault, while holding the state directory lock, so every other command
that changes anything waited at the prompt. They now ask and unlock
first and lock after. What they checked before asking is checked again
under the lock: unlocker add fails if the vault was removed meanwhile
and refuses a GPG key added meanwhile. A forced add of a secret that
another command created meanwhile lets go of the lock, gets the key,
and takes the lock again. secret.CreatePGPUnlocker now takes the vault,
already unlocked; SetMnemonic and SetUnlockPassphrase, used only by it,
are gone.

Not done: secret move between vaults still unlocks both under the lock;
the issue does not name it.

Model: opus-5-5

internal/vault/errors_test.go

@@ -132,7 +132,7 @@ func TestGetSecretWithWrongMnemonic(t *testing.T) {
 	t.Cleanup(mnemonic.Destroy)
 
 	vlt := vault.NewVault(created.GetFilesystem(), testStateDir, testVaultName)
-	vlt.SetMnemonic(mnemonic)
+	vlt.Mnemonic = mnemonic
 
 	_, err := vlt.GetSecret(testSecretName)
 	require.ErrorIs(t, err, vault.ErrMnemonicMismatch)

internal/vault/management.go

@@ -235,9 +235,9 @@ func processMnemonicForVault(
 // vault: one wrapping ErrInvalidVaultName when it is not a valid vault name,
 // and one wrapping ErrVaultExists when that vault already exists. Creating an
 // existing vault again would replace its keys, and its secrets could no
-// longer be decrypted. CreateVault checks this before writing anything; the
-// commands that create a vault also check it before they ask for the
-// mnemonic or passphrase, holding the state directory lock.
+// longer be decrypted. The commands that create a vault check it before they
+// ask for the mnemonic or passphrase, and CreateVault checks it again, under
+// the state directory lock, before writing anything.
 func CheckNewVaultName(fs afero.Fs, stateDir string, name string) error {
 	err := ValidateVaultName(name)
 	if err != nil {

internal/vault/secrets_version_test.go

@@ -336,7 +336,7 @@ func TestVaultVersionTimestampsAfterUnlock(t *testing.T) {
 
 	// A new instance is locked; AddSecret unlocks it with the passphrase
 	vault := NewVault(fs, testStateDir, "test")
-	vault.SetUnlockPassphrase(passphrase)
+	vault.UnlockPassphrase = passphrase
 
 	addTestSecretToVault(t, vault, testSecretPath, []byte("version-2"), true)
 	require.False(t, fs.readAt.IsZero(), "AddSecret did not unlock the vault")

internal/vault/vault.go

@@ -64,18 +64,6 @@ func (v *Vault) ClearLongTermKey() {
 	v.longTermKey = nil
 }
 
-// SetMnemonic sets v.Mnemonic, for code that has v only as a
-// secret.VaultInterface.
-func (v *Vault) SetMnemonic(mnemonic *memguard.LockedBuffer) {
-	v.Mnemonic = mnemonic
-}
-
-// SetUnlockPassphrase sets v.UnlockPassphrase, for code that has v only as
-// a secret.VaultInterface.
-func (v *Vault) SetUnlockPassphrase(passphrase *memguard.LockedBuffer) {
-	v.UnlockPassphrase = passphrase
-}
-
 // GetOrDeriveLongTermKey gets the long-term key from memory or derives it
 // from available sources
 func (v *Vault) GetOrDeriveLongTermKey() (*age.X25519Identity, error) {

internal/vault/vault_error_test.go

@@ -128,7 +128,7 @@ func TestAddSecretForceWithWrongPassphraseChangesNothing(t *testing.T) {
 	t.Cleanup(wrong.Destroy)
 
 	vlt := vault.NewVault(fs, testStateDir, testVaultName)
-	vlt.SetUnlockPassphrase(wrong)
+	vlt.UnlockPassphrase = wrong
 
 	secretDir := filepath.Join(testStateDir, "vaults.d", testVaultName,
 		"secrets.d", testSecretName)