Escalator: Add new method to privilege escalate within GUI

1 files changed, 114 insertions, 0 deletions

diff --git a/Userland/Applications/Escalator/EscalatorWindow.cpp b/Userland/Applications/Escalator/EscalatorWindow.cpp
new file mode 100644
index 0000000000..9b2927fe63
--- /dev/null
+++ b/Userland/Applications/Escalator/EscalatorWindow.cpp
@@ -0,0 +1,114 @@
+/*
+ * Copyright (c) 2022, Ashley N. <dev-serenity@ne0ndrag0n.com>
+ * Copyright (c) 2022, the SerenityOS developers.
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include "EscalatorWindow.h"
+#include <AK/Assertions.h>
+#include <Applications/Escalator/EscalatorGML.h>
+#include <LibCore/SecretString.h>
+#include <LibCore/System.h>
+#include <LibGUI/FileIconProvider.h>
+#include <LibGUI/Icon.h>
+#include <LibGUI/Label.h>
+#include <LibGUI/MessageBox.h>
+#include <LibGUI/Widget.h>
+#include <unistd.h>
+
+EscalatorWindow::EscalatorWindow(StringView executable, Vector<StringView> arguments, EscalatorWindow::Options const& options)
+    : m_arguments(arguments)
+    , m_executable(executable)
+    , m_current_user(options.current_user)
+    , m_preserve_env(options.preserve_env)
+{
+    auto app_icon = GUI::FileIconProvider::icon_for_executable(m_executable);
+
+    set_title("Run as Root");
+    set_icon(app_icon.bitmap_for_size(16));
+    resize(345, 100);
+    set_resizable(false);
+    set_minimizable(false);
+
+    auto& main_widget = set_main_widget<GUI::Widget>();
+    main_widget.load_from_gml(escalator_gml);
+
+    RefPtr<GUI::Label> app_label = *main_widget.find_descendant_of_type_named<GUI::Label>("description");
+
+    String prompt;
+    if (options.description.is_empty())
+        prompt = String::formatted("{} requires root access. Please enter password for user \"{}\".", m_arguments[0], m_current_user.username());
+    else
+        prompt = options.description;
+
+    app_label->set_text(prompt);
+
+    m_icon_image_widget = *main_widget.find_descendant_of_type_named<GUI::ImageWidget>("icon");
+    m_icon_image_widget->set_bitmap(app_icon.bitmap_for_size(32));
+
+    m_ok_button = *main_widget.find_descendant_of_type_named<GUI::DialogButton>("ok_button");
+    m_ok_button->on_click = [this](auto) {
+        auto result = check_password();
+        if (result.is_error()) {
+            GUI::MessageBox::show_error(this, String::formatted("Failed to execute command: {}", result.error()));
+            close();
+        }
+    };
+    m_ok_button->set_default(true);
+
+    m_cancel_button = *main_widget.find_descendant_of_type_named<GUI::DialogButton>("cancel_button");
+    m_cancel_button->on_click = [this](auto) {
+        close();
+    };
+
+    m_password_input = *main_widget.find_descendant_of_type_named<GUI::PasswordBox>("password");
+}
+
+ErrorOr<void> EscalatorWindow::check_password()
+{
+    String password = m_password_input->text();
+    if (password.is_empty()) {
+        GUI::MessageBox::show_error(this, "Please enter a password."sv);
+        return {};
+    }
+
+    // FIXME: PasswordBox really should store its input directly as a SecretString.
+    Core::SecretString password_secret = Core::SecretString::take_ownership(password.to_byte_buffer());
+    if (!m_current_user.authenticate(password_secret)) {
+        GUI::MessageBox::show_error(this, "Incorrect or disabled password."sv);
+        m_password_input->select_all();
+        return {};
+    }
+
+    // Caller will close Escalator if error is returned.
+    TRY(execute_command());
+    VERIFY_NOT_REACHED();
+}
+
+ErrorOr<void> EscalatorWindow::execute_command()
+{
+    // Translate environ to format for Core::System::exec.
+    Vector<StringView> exec_environment;
+    for (size_t i = 0; environ[i]; ++i) {
+        StringView env_view { environ[i], strlen(environ[i]) };
+        auto maybe_needle = env_view.find('=');
+
+        if (!maybe_needle.has_value())
+            continue;
+
+        if (!m_preserve_env && env_view.substring_view(0, maybe_needle.value()) != "TERM"sv)
+            continue;
+
+        exec_environment.append(env_view);
+    }
+
+    // Escalate process privilege to root user.
+    TRY(Core::System::seteuid(0));
+    auto root_user = TRY(Core::Account::from_uid(0));
+    TRY(root_user.login());
+
+    TRY(Core::System::pledge("stdio sendfd rpath exec"));
+    TRY(Core::System::exec(m_executable, m_arguments, Core::System::SearchInPath::No, exec_environment));
+    VERIFY_NOT_REACHED();
+}