Added: Add SELinuxUtils to get process and file paths security contexts

termux-shared/src/main/java/com/termux/shared/android/SELinuxUtils.java

@@ -0,0 +1,96 @@
+package com.termux.shared.android;
+
+import android.annotation.SuppressLint;
+
+import androidx.annotation.NonNull;
+import androidx.annotation.Nullable;
+
+import com.termux.shared.logger.Logger;
+import com.termux.shared.reflection.ReflectionUtils;
+
+import java.lang.reflect.Method;
+
+public class SELinuxUtils {
+
+    public static final String ANDROID_OS_SELINUX_CLASS = "android.os.SELinux";
+
+    private static final String LOG_TAG = "SELinuxUtils";
+
+    /**
+     * Gets the security context of the current process.
+     *
+     * @return Returns a {@link String} representing the security context of the current process.
+     * This will be {@code null} if an exception is raised.
+     */
+    @Nullable
+    public static String getContext() {
+        ReflectionUtils.bypassHiddenAPIReflectionRestrictions();
+        String methodName = "getContext";
+        try {
+            @SuppressLint("PrivateApi") Class<?> clazz = Class.forName(ANDROID_OS_SELINUX_CLASS);
+            Method method = ReflectionUtils.getDeclaredMethod(clazz, methodName);
+            if (method == null) {
+                Logger.logError(LOG_TAG, "Failed to get " + methodName + "() method of " + ANDROID_OS_SELINUX_CLASS + " class");
+                return null;
+            }
+
+            return (String) ReflectionUtils.invokeMethod(method, null).value;
+        } catch (Exception e) {
+            Logger.logStackTraceWithMessage(LOG_TAG, "Failed to call " + methodName + "() method of " + ANDROID_OS_SELINUX_CLASS + " class", e);
+            return null;
+        }
+    }
+
+    /**
+     * Get the security context of a given process id.
+     *
+     * @param pid The pid of process.
+     * @return Returns a {@link String} representing the security context of the given pid.
+     * This will be {@code null} if an exception is raised.
+     */
+    @Nullable
+    public static String getPidContext(int pid) {
+        ReflectionUtils.bypassHiddenAPIReflectionRestrictions();
+        String methodName = "getPidContext";
+        try {
+            @SuppressLint("PrivateApi") Class<?> clazz = Class.forName(ANDROID_OS_SELINUX_CLASS);
+            Method method = ReflectionUtils.getDeclaredMethod(clazz, methodName, int.class);
+            if (method == null) {
+                Logger.logError(LOG_TAG, "Failed to get " + methodName + "() method of " + ANDROID_OS_SELINUX_CLASS + " class");
+                return null;
+            }
+
+            return (String) ReflectionUtils.invokeMethod(method, null, pid).value;
+        } catch (Exception e) {
+            Logger.logStackTraceWithMessage(LOG_TAG, "Failed to call " + methodName + "() method of " + ANDROID_OS_SELINUX_CLASS + " class", e);
+            return null;
+        }
+    }
+
+    /**
+     * Get the security context of a file object.
+     *
+     * @param path The pathname of the file object.
+     * @return Returns a {@link String} representing the security context of the file.
+     * This will be {@code null} if an exception is raised.
+     */
+    @Nullable
+    public static String getFileContext(@NonNull String path) {
+        ReflectionUtils.bypassHiddenAPIReflectionRestrictions();
+        String methodName = "getFileContext";
+        try {
+            @SuppressLint("PrivateApi") Class<?> clazz = Class.forName(ANDROID_OS_SELINUX_CLASS);
+            Method method = ReflectionUtils.getDeclaredMethod(clazz, methodName, String.class);
+            if (method == null) {
+                Logger.logError(LOG_TAG, "Failed to get " + methodName + "() method of " + ANDROID_OS_SELINUX_CLASS + " class");
+                return null;
+            }
+
+            return (String) ReflectionUtils.invokeMethod(method, null, path).value;
+        } catch (Exception e) {
+            Logger.logStackTraceWithMessage(LOG_TAG, "Failed to call " + methodName + "() method of " + ANDROID_OS_SELINUX_CLASS + " class", e);
+            return null;
+        }
+    }
+
+}