fix(auth): prompt for --with-token without echo on a terminal

With stdin on a terminal, auth login --with-token read the pasted token
from the raw terminal, which echoed it in clear text without a prompt.
It now asks with a hidden "Paste an access token" prompt, and refuses
to read the terminal when prompting is disabled. Piped stdin is read as
before.

Signed-off-by: bircni <bircni@icloud.com>

internal/app/auth.go

@@ -185,6 +185,18 @@ func (a *application) authCommand() *cobra.Command {
 				return err
 			}
 			method = settings.AuthOAuth
+		} else if a.deps.Streams.InTTY {
+			if !a.policy(snapshot).CanPrompt(a.deps.Streams) {
+				return clierr.Wrap(clierr.Usage, errors.New("--with-token reads the token from stdin; pipe it in, for example: tea auth login --with-token < token.txt"))
+			}
+			token, err := a.deps.Prompter.SecretInput(cmd.Context(), "Paste an access token")
+			if err != nil {
+				return err
+			}
+			credential.AccessToken = strings.TrimSpace(token)
+			if credential.AccessToken == "" {
+				return clierr.Wrap(clierr.Usage, errors.New("access token cannot be empty"))
+			}
 		} else {
 			data, err := io.ReadAll(io.LimitReader(a.deps.Streams.In, 65537))
 			if err != nil {
@@ -214,7 +226,7 @@ func (a *application) authCommand() *cobra.Command {
 	login.Flags().BoolVar(&oauth, "oauth", false, "Authorize through a browser using OAuth PKCE")
 	login.Flags().StringVar(&clientID, "client-id", "", "OAuth client ID registered on the instance (default: the instance's stored ID, then tea's)")
 	login.Flags().BoolVar(&insecure, "insecure", false, "Skip TLS certificate verification for this instance")
-	login.Flags().BoolVar(&withToken, "with-token", false, "Read a personal access token from stdin")
+	login.Flags().BoolVar(&withToken, "with-token", false, "Read a personal access token from stdin, or prompt for it on a terminal")
 	login.Flags().StringVar(&sshKey, "ssh-key", "", "Authenticate with an SSH private key via HTTP signatures")
 	login.Flags().StringVar(&sshAgentPrincipal, "ssh-agent-principal", "", "Authenticate with an ssh-agent certificate principal via HTTP signatures")
 	login.Flags().StringVar(&sshAgentKey, "ssh-agent-key", "", "Authenticate with an ssh-agent public key fingerprint via HTTP signatures")

internal/app/auth_test.go

@@ -87,6 +87,26 @@ func TestLoginValidatesUserEnvironmentWithFlagPrecedence(t *testing.T) {
 	}
 }
 
+func TestLoginWithTokenPromptsWithoutEchoOnATerminal(t *testing.T) {
+	server := newAuthenticatedServer(http.NotFoundHandler())
+	defer server.Close()
+	args := []string{"auth", "login", "--host", server.URL, "--with-token", "--credential-store", "file"}
+	deps, _, _ := testDeps(t)
+	deps.Streams.In = strings.NewReader("echoed-token\n")
+	deps.Streams.InTTY, deps.Streams.ErrTTY = true, true
+	prompt := &scriptedPrompter{secret: " private-login-token "}
+	deps.Prompter = prompt
+	err := Execute(context.Background(), deps, append(args, "--no-input"))
+	require.Equal(t, clierr.Usage, clierr.ExitCode(err), "%v", err)
+	require.ErrorContains(t, err, "tea auth login --with-token < token.txt")
+	require.Empty(t, prompt.secrets)
+	require.NoError(t, Execute(context.Background(), deps, args))
+	require.Equal(t, []string{"Paste an access token"}, prompt.secrets)
+	credential, err := deps.Credentials.Load(server.URL, "alice", settings.StoreFile)
+	require.NoError(t, err)
+	require.Equal(t, "private-login-token", credential.AccessToken)
+}
+
 func TestLoginInsecureInstance(t *testing.T) {
 	server := httptest.NewUnstartedServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
 		_, _ = w.Write([]byte(`{"login":"alice"}`))