secret/internal/cli/unlock_failure_test.go

// Unlock Failure Tests
//
// When a vault cannot be opened through its current unlocker, because a
// file the unlocker needs is missing or the passphrase is wrong, the error
// keeps its cause and ends by saying that the mnemonic still opens that
// vault, but only for a vault that the mnemonic does open, and not when the
// passphrase could not be read at all. When a secret's current file is
// missing, the error says how to make a version current again. Each test
// that pins such advice also follows it.

package cli_test

import (
	"bytes"
	"io"
	"os"
	"os/exec"
	"path/filepath"
	"testing"

	"filippo.io/age"
	"github.com/awnumar/memguard"
	"github.com/spf13/afero"
	"github.com/spf13/cobra"
	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
	"sneak.berlin/go/secret/internal/cli"
	"sneak.berlin/go/secret/internal/secret"
	"sneak.berlin/go/secret/internal/vault"
)

const (
	// mnemonicAdvice ends the error when the current vault "default", which
	// its mnemonic opens, cannot be opened through its current unlocker.
	mnemonicAdvice = "; the vault 'default' still opens with its mnemonic: " +
		"run 'secret unlocker add passphrase' with SB_SECRET_MNEMONIC set " +
		"to the mnemonic to give it a new unlocker"

	// versionAdvice ends the error when a secret's current file cannot be
	// read.
	versionAdvice = "; this file only names the current version: " +
		"'secret version list' lists the secret's versions, and " +
		"'secret version promote' makes one of them current"

	// unlockTestVaultDir is the directory of the vault "default" of
	// newTwoVaultFs, the current vault, whose secret "x" is "value".
	unlockTestVaultDir = testStateDir + "/vaults.d/default"
)

// currentUnlockerDir returns the directory of the current unlocker of the
// vault in vaultDir on fs.
func currentUnlockerDir(t *testing.T, fs afero.Fs, vaultDir string) string {
	t.Helper()

	unlockerName, err := afero.ReadFile(fs,
		filepath.Join(vaultDir, "current-unlocker"))
	require.NoError(t, err)

	return filepath.Join(vaultDir, "unlockers.d", string(unlockerName))
}

// newUnlockTestCLI returns the directory of the current unlocker of the
// vault "default" on fs, a copy of the vaults of newTwoVaultFs, and a CLI
// instance on fs that has the unlock passphrase, as from the environment,
// but not the mnemonic.
func newUnlockTestCLI(t *testing.T, fs afero.Fs) (string, *cli.Instance) {
	t.Helper()

	c := cli.NewCLIInstanceWithStateDir(fs, testStateDir)
	c.UnlockPassphrase = memguard.NewBufferFromBytes([]byte(testPassphrase))
	t.Cleanup(c.UnlockPassphrase.Destroy)

	return currentUnlockerDir(t, fs, unlockTestVaultDir), c
}

// discardCmd returns a command whose output is discarded.
func discardCmd() *cobra.Command {
	cmd := &cobra.Command{}
	cmd.SetOut(io.Discard)

	return cmd
}

// getSecret returns what `secret get name` prints.
func getSecret(t *testing.T, c *cli.Instance, name string) string {
	t.Helper()

	var out bytes.Buffer

	cmd := &cobra.Command{}
	cmd.SetOut(&out)
	require.NoError(t, c.GetSecret(cmd, name))

	return out.String()
}

// TestUnlockFailureNamesMnemonic checks the error of `secret get` when a
// file that opening the vault through its current unlocker needs is
// missing: it keeps the cause, which names the file, and ends with the
// advice that the mnemonic still opens the vault. The test then follows
// that advice: `secret unlocker add passphrase`, with the mnemonic, gives
// the vault a new unlocker, which opens it.
func TestUnlockFailureNamesMnemonic(t *testing.T) {
	t.Parallel()

	tests := []struct {
		file       string // the file removed
		inVaultDir bool   // the file is the vault's, not the unlocker's
		want       string // the message before the cause
	}{
		{
			file:       "current-unlocker",
			inVaultDir: true,
			want: "failed to unlock vault: failed to get long-term key: " +
				"failed to get current unlocker: " +
				"failed to read current unlocker: ",
		},
		{
			file: "priv.age",
			want: "failed to unlock vault: failed to get long-term key: " +
				"failed to get unlocker identity: " +
				"failed to read unlocker private key: ",
		},
		{
			file: "longterm.age",
			want: "failed to unlock vault: failed to get long-term key: " +
				"failed to read encrypted long-term private key: ",
		},
	}

	for _, tt := range tests {
		t.Run(tt.file, func(t *testing.T) {
			t.Parallel()

			fs := newTwoVaultFs(t)
			unlockerDir, c := newUnlockTestCLI(t, fs)

			path := filepath.Join(unlockerDir, tt.file)

			if tt.inVaultDir {
				path = filepath.Join(unlockTestVaultDir, tt.file)
			}

			require.NoError(t, fs.Remove(path))

			err := c.GetSecret(discardCmd(), "x")

			var cause *os.PathError

			require.ErrorAs(t, err, &cause)
			require.ErrorIs(t, err, os.ErrNotExist)
			assert.Equal(t, path, cause.Path)

			require.EqualError(t, err, tt.want+cause.Error()+mnemonicAdvice)

			c.Mnemonic = testMnemonicBuffer(t)
			require.NoError(t, c.UnlockersAdd("passphrase", discardCmd()))

			c.Mnemonic = nil
			assert.Equal(t, "value", getSecret(t, c, "x"))
		})
	}
}

// TestWrongPassphraseNamesMnemonic checks the error of `secret get` given a
// passphrase that does not decrypt the passphrase unlocker: it keeps age's
// error and ends with the advice that the mnemonic still opens the vault.
func TestWrongPassphraseNamesMnemonic(t *testing.T) {
	t.Parallel()

	_, c := newUnlockTestCLI(t, newTwoVaultFs(t))
	c.UnlockPassphrase = memguard.NewBufferFromBytes([]byte("wrong passphrase"))
	t.Cleanup(c.UnlockPassphrase.Destroy)

	err := c.GetSecret(discardCmd(), "x")

	var noMatch *age.NoIdentityMatchError

	require.ErrorAs(t, err, &noMatch)

	require.EqualError(t, err, "failed to unlock vault: "+
		"failed to get long-term key: failed to get unlocker identity: "+
		"failed to decrypt unlocker private key: failed to create decryptor: "+
		noMatch.Error()+mnemonicAdvice)
}

// TestMoveUnlockFailureNamesVault checks the error of `secret move` into
// the vault "work", which is not the current vault, when "work" cannot be
// opened through its current unlocker: the advice names "work" and says to
// select it first, since `secret unlocker add` acts on the current vault.
// The test then follows that advice, and the move succeeds.
func TestMoveUnlockFailureNamesVault(t *testing.T) {
	t.Parallel()

	fs := newTwoVaultFs(t)
	_, c := newUnlockTestCLI(t, fs)

	path := filepath.Join(
		currentUnlockerDir(t, fs, testStateDir+"/vaults.d/work"), "priv.age")
	require.NoError(t, fs.Remove(path))

	err := c.MoveSecret(discardCmd(), "default:x", "work:y", false)

	var cause *os.PathError

	require.ErrorAs(t, err, &cause)
	assert.Equal(t, path, cause.Path)

	require.EqualError(t, err, "failed to unlock destination vault 'work': "+
		"failed to get unlocker identity: failed to read unlocker private key: "+
		cause.Error()+"; the vault 'work' still opens with its mnemonic: "+
		"run 'secret vault select work', then 'secret unlocker add passphrase' "+
		"with SB_SECRET_MNEMONIC set to the mnemonic to give it a new unlocker")

	require.NoError(t, c.SelectVault(discardCmd(), "work"))

	c.Mnemonic = testMnemonicBuffer(t)
	require.NoError(t, c.UnlockersAdd("passphrase", discardCmd()))

	c.Mnemonic = nil
	require.NoError(t, c.MoveSecret(discardCmd(), "default:x", "work:y", false))
	assert.Equal(t, "value", getSecret(t, c, "y"))
}

// TestPassphraseNotReadNamesNoMnemonic runs `secret get x` on the built
// binary without SB_UNLOCK_PASSPHRASE and with a stdin that is not a
// terminal, so the passphrase cannot be read. The unlocker was not tried,
// and adding one would need a passphrase read the same way, so the error
// is the cause alone, without the advice to use the mnemonic.
func TestPassphraseNotReadNamesNoMnemonic(t *testing.T) {
	t.Parallel()

	stateDir := t.TempDir()

	mnemonic := memguard.NewBufferFromBytes([]byte(testMnemonic))
	defer mnemonic.Destroy()

	passphrase := memguard.NewBufferFromBytes([]byte(testPassphrase))
	defer passphrase.Destroy()

	vlt, err := vault.CreateVault(
		afero.NewOsFs(), stateDir, "default", mnemonic, passphrase)
	require.NoError(t, err)

	value := memguard.NewBufferFromBytes([]byte("value"))
	defer value.Destroy()

	require.NoError(t, vlt.AddSecret("x", value, false))

	//nolint:gosec // G204: test executes the freshly built secret binary
	cmd := exec.CommandContext(t.Context(), secretBinaryPath(t), "get", "x")
	cmd.Env = []string{
		secret.EnvStateDir + "=" + stateDir,
		"PATH=" + os.Getenv("PATH"),
		"HOME=" + os.Getenv("HOME"),
	}

	output, err := cmd.CombinedOutput()
	require.Error(t, err)

	assert.Equal(t, "Error: failed to unlock vault: "+
		"failed to get long-term key: failed to get unlocker identity: "+
		"failed to read passphrase: stdin is not a terminal (piped input or "+
		"script). Please set the SB_UNLOCK_PASSPHRASE environment variable or "+
		"run interactively\n", string(output))
}

// TestCryptoUnlockFailureNamesMnemonic checks that `secret encrypt` and
// `secret decrypt`, reading the key secret, end with the same advice as
// `secret get` when the vault cannot be opened through its current
// unlocker.
func TestCryptoUnlockFailureNamesMnemonic(t *testing.T) {
	t.Parallel()

	tests := []struct {
		command string
		run     func(c *cli.Instance) error
	}{
		{"encrypt", func(c *cli.Instance) error { return c.Encrypt("x", "", "") }},
		{"decrypt", func(c *cli.Instance) error { return c.Decrypt("x", "", "") }},
	}

	for _, tt := range tests {
		t.Run(tt.command, func(t *testing.T) {
			t.Parallel()

			fs := newTwoVaultFs(t)
			unlockerDir, c := newUnlockTestCLI(t, fs)

			path := filepath.Join(unlockerDir, "priv.age")
			require.NoError(t, fs.Remove(path))

			err := tt.run(c)

			var cause *os.PathError

			require.ErrorAs(t, err, &cause)
			assert.Equal(t, path, cause.Path)

			require.EqualError(t, err, "failed to get secret value: "+
				"failed to unlock vault: failed to get long-term key: "+
				"failed to get unlocker identity: "+
				"failed to read unlocker private key: "+cause.Error()+
				mnemonicAdvice)
		})
	}
}

// TestMissingCurrentFileNamesVersionCommands checks the error of `secret
// get` when the secret's current file is missing: it keeps the cause, which
// names the file, and ends with the advice that says how to make a version
// current again. The test then follows that advice.
func TestMissingCurrentFileNamesVersionCommands(t *testing.T) {
	t.Parallel()

	fs := newTwoVaultFs(t)
	_, c := newUnlockTestCLI(t, fs)

	secretDir := filepath.Join(unlockTestVaultDir, "secrets.d", "x")
	path := filepath.Join(secretDir, "current")
	require.NoError(t, fs.Remove(path))

	err := c.GetSecret(discardCmd(), "x")

	var cause *os.PathError

	require.ErrorAs(t, err, &cause)
	require.ErrorIs(t, err, os.ErrNotExist)
	assert.Equal(t, path, cause.Path)

	require.EqualError(t, err, "failed to get current version: "+
		"failed to read current version file: "+cause.Error()+versionAdvice)

	versions, err := afero.ReadDir(fs, filepath.Join(secretDir, "versions"))
	require.NoError(t, err)
	require.Len(t, versions, 1)

	var out bytes.Buffer

	cmd := &cobra.Command{}
	cmd.SetOut(&out)
	require.NoError(t, c.ListVersions(cmd, "x"))
	assert.Contains(t, out.String(), versions[0].Name())

	require.NoError(t, c.PromoteVersion(cmd, "x", versions[0].Name()))
	assert.Equal(t, "value", getSecret(t, c, "x"))
}

// TestUnlockFailureWithoutLongTermKeyNamesNoMnemonic checks that a vault
// created without a mnemonic, which no mnemonic opens, gets no advice to
// use one: `secret unlocker add passphrase` there fails with the cause
// alone.
func TestUnlockFailureWithoutLongTermKeyNamesNoMnemonic(t *testing.T) {
	t.Parallel()

	fs := afero.NewMemMapFs()

	_, err := vault.CreateVault(fs, testStateDir, "keyless", nil, nil)
	require.NoError(t, err)

	c := cli.NewCLIInstanceWithStateDir(fs, testStateDir)
	c.UnlockPassphrase = memguard.NewBufferFromBytes([]byte(testPassphrase))
	t.Cleanup(c.UnlockPassphrase.Destroy)

	err = c.UnlockersAdd("passphrase", discardCmd())

	var cause *os.PathError

	require.ErrorAs(t, err, &cause)

	require.EqualError(t, err, "failed to get long-term key: "+
		"failed to get current unlocker: failed to read current unlocker: "+
		cause.Error())
}