Changed: Move termux apps properties file list to TermuxConstants and do not follow symlinks

app/src/main/java/com/termux/app/TermuxOpenReceiver.java

@@ -184,25 +184,25 @@ public class TermuxOpenReceiver extends BroadcastReceiver {
             File file = new File(uri.getPath());
             try {
                 String path = file.getCanonicalPath();
-                Logger.logDebug(LOG_TAG, "Open file request received for \"" + path + "\" with mode \"" + mode + "\"");
+                String callingPackage = getCallingPackage();
+                Logger.logDebug(LOG_TAG, "Open file request received from " + callingPackage + " for \"" + path + "\" with mode \"" + mode + "\"");
                 String storagePath = Environment.getExternalStorageDirectory().getCanonicalPath();
                 // See https://support.google.com/faqs/answer/7496913:
                 if (!(path.startsWith(TermuxConstants.TERMUX_FILES_DIR_PATH) || path.startsWith(storagePath))) {
                     throw new IllegalArgumentException("Invalid path: " + path);
                 }
 
-                // If "allow-external-apps" property to not set to "true", then throw exception
+                // If TermuxConstants.PROP_ALLOW_EXTERNAL_APPS property to not set to "true", then throw exception
                 String errmsg = PluginUtils.checkIfAllowExternalAppsPolicyIsViolated(getContext(), LOG_TAG);
                 if (errmsg != null) {
                     throw new IllegalArgumentException(errmsg);
                 }
 
-                // Do not allow apps with RUN_COMMAND permission to modify termux apps properties files,
+                // **DO NOT** allow these files to be modified by ContentProvider exposed to external
-                // including allow-external-apps
+                // apps, since they may silently modify the values for security properties like
-                if (TermuxConstants.TERMUX_PROPERTIES_PRIMARY_FILE_PATH.equals(path) ||
+                // TermuxConstants.PROP_ALLOW_EXTERNAL_APPS set by users without their explicit consent.
-                    TermuxConstants.TERMUX_PROPERTIES_SECONDARY_FILE_PATH.equals(path) ||
+                if (TermuxConstants.TERMUX_PROPERTIES_FILE_PATHS_LIST.contains(path) ||
-                    TermuxConstants.TERMUX_FLOAT_PROPERTIES_PRIMARY_FILE_PATH.equals(path) ||
+                    TermuxConstants.TERMUX_FLOAT_PROPERTIES_FILE_PATHS_LIST.contains(path)) {
-                    TermuxConstants.TERMUX_FLOAT_PROPERTIES_SECONDARY_FILE_PATH.equals(path)) {
                     mode = "r";
                 }
 

termux-shared/src/main/java/com/termux/shared/settings/properties/TermuxPropertyConstants.java

@@ -1,8 +1,8 @@
 package com.termux.shared.settings.properties;
 
-import androidx.annotation.NonNull;
-
 import com.google.common.collect.ImmutableBiMap;
+import com.termux.shared.file.FileUtils;
+import com.termux.shared.file.filesystem.FileType;
 import com.termux.shared.termux.TermuxConstants;
 import com.termux.shared.logger.Logger;
 import com.termux.terminal.TerminalEmulator;
@@ -11,6 +11,7 @@ import com.termux.view.TerminalView;
 import java.io.File;
 import java.util.Arrays;
 import java.util.HashSet;
+import java.util.List;
 import java.util.Set;
 
 /*
@@ -81,6 +82,8 @@ import java.util.Set;
  */
 public final class TermuxPropertyConstants {
 
+    private static final String LOG_TAG = "TermuxPropertyConstants";
+
     /* boolean */
 
     /** Defines the key for whether hardware keyboard shortcuts are enabled. */
@@ -413,50 +416,54 @@ public final class TermuxPropertyConstants {
 
 
 
-    /** Returns the first {@link File} found at
+    /** Returns the first {@link File} found in
-     * {@link TermuxConstants#TERMUX_PROPERTIES_PRIMARY_FILE_PATH} or
+     * {@link TermuxConstants#TERMUX_PROPERTIES_FILE_PATHS_LIST} via a call to
-     * {@link TermuxConstants#TERMUX_PROPERTIES_SECONDARY_FILE_PATH}
+     * {@link #getPropertiesFile(List)}.
-     * from which termux properties can be loaded.
-     * If the {@link File} found is not a regular file or is not readable then null is returned.
      *
-     * @return Returns the {@link File} object for termux properties.
+     * @return Returns the {@link File} object for Termux app properties.
      */
     public static File getTermuxPropertiesFile() {
-        return getPropertiesFile(new String[]{
+        return getPropertiesFile(TermuxConstants.TERMUX_PROPERTIES_FILE_PATHS_LIST);
-            TermuxConstants.TERMUX_PROPERTIES_PRIMARY_FILE_PATH,
-            TermuxConstants.TERMUX_PROPERTIES_SECONDARY_FILE_PATH
-        });
     }
 
-    /** Returns the first {@link File} found at
+    /** Returns the first {@link File} found in
-     * {@link TermuxConstants#TERMUX_FLOAT_PROPERTIES_PRIMARY_FILE_PATH} or
+     * {@link TermuxConstants#TERMUX_FLOAT_PROPERTIES_FILE_PATHS_LIST} via a call to
-     * {@link TermuxConstants#TERMUX_FLOAT_PROPERTIES_SECONDARY_FILE_PATH}
+     * {@link #getPropertiesFile(List)}.
-     * from which termux properties can be loaded.
-     * If the {@link File} found is not a regular file or is not readable then null is returned.
      *
-     * @return Returns the {@link File} object for termux properties.
+     * @return Returns the {@link File} object for Termux:Float app properties.
      */
     public static File getTermuxFloatPropertiesFile() {
-        return getPropertiesFile(new String[]{
+        return getPropertiesFile(TermuxConstants.TERMUX_FLOAT_PROPERTIES_FILE_PATHS_LIST);
-            TermuxConstants.TERMUX_FLOAT_PROPERTIES_PRIMARY_FILE_PATH,
-            TermuxConstants.TERMUX_FLOAT_PROPERTIES_SECONDARY_FILE_PATH
-        });
     }
 
-    public static File getPropertiesFile(@NonNull String[] possiblePropertiesFileLocations) {
+    /** Returns the first {@link File} found in
-        File propertiesFile = new File(possiblePropertiesFileLocations[0]);
+     * {@code propertiesFilePaths} from which app properties can be loaded. If the {@link File} found
-        int i = 0;
+     * is not a regular file or is not readable, then {@code null} is returned. Symlinks **will not**
-        while (!propertiesFile.exists() && i < possiblePropertiesFileLocations.length) {
+     * be followed for potential security reasons.
-            propertiesFile = new File(possiblePropertiesFileLocations[i]);
+     *
-            i += 1;
+     * @return Returns the {@link File} object for Termux:Float app properties.
+     */
+    public static File getPropertiesFile(List<String> propertiesFilePaths) {
+        if (propertiesFilePaths == null || propertiesFilePaths.size() == 0)
+            return null;
+
+        for(String propertiesFilePath : propertiesFilePaths) {
+            File propertiesFile = new File(propertiesFilePath);
+
+            // Symlinks **will not** be followed.
+            FileType fileType = FileUtils.getFileType(propertiesFilePath, false);
+            if (fileType == FileType.REGULAR) {
+                if (propertiesFile.canRead())
+                    return propertiesFile;
+                else
+                    Logger.logWarn(LOG_TAG, "Ignoring properties file at \"" + propertiesFilePath + "\" since it is not readable");
+            } else if (fileType != FileType.NO_EXIST) {
+                Logger.logWarn(LOG_TAG, "Ignoring properties file at \"" + propertiesFilePath + "\" of type: \"" + fileType.getName() + "\"");
+            }
         }
 
-        if (propertiesFile.isFile() && propertiesFile.canRead()) {
+        Logger.logDebug(LOG_TAG, "No readable properties file found at: " + propertiesFilePaths);
-            return propertiesFile;
+        return null;
-        } else {
-            Logger.logDebug("No readable properties file found at: " + Arrays.toString(possiblePropertiesFileLocations));
-            return null;
-        }
     }
 
 }

termux-shared/src/main/java/com/termux/shared/termux/TermuxConstants.java

@@ -12,7 +12,7 @@ import java.util.IllegalFormatException;
 import java.util.List;
 
 /*
- * Version: v0.32.0
+ * Version: v0.33.0
  *
  * Changelog
  *
@@ -211,6 +211,9 @@ import java.util.List;
  * - 0.32.0 (2021-09-23)
  *      - Added `TERMUX_API.TERMUX_API_ACTIVITY_NAME`, `TERMUX_TASKER.TERMUX_TASKER_ACTIVITY_NAME`
  *          and `TERMUX_WIDGET.TERMUX_WIDGET_ACTIVITY_NAME`.
+ *
+ * - 0.33.0 (2021-10-08)
+ *      - Added `TERMUX_PROPERTIES_FILE_PATHS_LIST` and `TERMUX_FLOAT_PROPERTIES_FILE_PATHS_LIST`.
  */
 
 /**
@@ -653,27 +656,46 @@ public final class TermuxConstants {
     public static final String TERMUX_WIDGET_DEFAULT_PREFERENCES_FILE_BASENAME_WITHOUT_EXTENSION = TERMUX_WIDGET_PACKAGE_NAME + "_preferences"; // Default: "com.termux.widget_preferences"
 
 
-    /** Termux app termux.properties primary file path */
+
+    /** Termux app properties primary file path */
     public static final String TERMUX_PROPERTIES_PRIMARY_FILE_PATH = TERMUX_DATA_HOME_DIR_PATH + "/termux.properties"; // Default: "/data/data/com.termux/files/home/.termux/termux.properties"
-    /** Termux app termux.properties primary file */
+    /** Termux app properties primary file */
     public static final File TERMUX_PROPERTIES_PRIMARY_FILE = new File(TERMUX_PROPERTIES_PRIMARY_FILE_PATH);
 
-    /** Termux app termux.properties secondary file path */
+    /** Termux app properties secondary file path */
     public static final String TERMUX_PROPERTIES_SECONDARY_FILE_PATH = TERMUX_CONFIG_HOME_DIR_PATH + "/termux.properties"; // Default: "/data/data/com.termux/files/home/.config/termux/termux.properties"
-    /** Termux app termux.properties secondary file */
+    /** Termux app properties secondary file */
     public static final File TERMUX_PROPERTIES_SECONDARY_FILE = new File(TERMUX_PROPERTIES_SECONDARY_FILE_PATH);
 
+    /** Termux app properties file paths list. **DO NOT** allow these files to be modified by
+     * {@link android.content.ContentProvider} exposed to external apps, since they may silently
+     * modify the values for security properties like {@link #PROP_ALLOW_EXTERNAL_APPS} set by users
+     * without their explicit consent. */
+    public static final List<String> TERMUX_PROPERTIES_FILE_PATHS_LIST = Arrays.asList(
+        TERMUX_PROPERTIES_PRIMARY_FILE_PATH,
+        TERMUX_PROPERTIES_SECONDARY_FILE_PATH);
 
-    /** Termux:Float app termux.properties primary file path */
+
+
+    /** Termux:Float app properties primary file path */
     public static final String TERMUX_FLOAT_PROPERTIES_PRIMARY_FILE_PATH = TERMUX_DATA_HOME_DIR_PATH + "/termux.float.properties"; // Default: "/data/data/com.termux/files/home/.termux/termux.float.properties"
-    /** Termux:Float app termux.properties primary file */
+    /** Termux:Float app properties primary file */
     public static final File TERMUX_FLOAT_PROPERTIES_PRIMARY_FILE = new File(TERMUX_FLOAT_PROPERTIES_PRIMARY_FILE_PATH);
 
-    /** Termux:Float app termux.properties secondary file path */
+    /** Termux:Float app properties secondary file path */
     public static final String TERMUX_FLOAT_PROPERTIES_SECONDARY_FILE_PATH = TERMUX_CONFIG_HOME_DIR_PATH + "/termux.float.properties"; // Default: "/data/data/com.termux/files/home/.config/termux/termux.float.properties"
-    /** Termux:Float app termux.properties secondary file */
+    /** Termux:Float app properties secondary file */
     public static final File TERMUX_FLOAT_PROPERTIES_SECONDARY_FILE = new File(TERMUX_FLOAT_PROPERTIES_SECONDARY_FILE_PATH);
 
+    /** Termux:Float app properties file paths list. **DO NOT** allow these files to be modified by
+     * {@link android.content.ContentProvider} exposed to external apps, since they may silently
+     * modify the values for security properties like {@link #PROP_ALLOW_EXTERNAL_APPS} set by users
+     * without their explicit consent. */
+    public static final List<String> TERMUX_FLOAT_PROPERTIES_FILE_PATHS_LIST = Arrays.asList(
+        TERMUX_FLOAT_PROPERTIES_PRIMARY_FILE_PATH,
+        TERMUX_FLOAT_PROPERTIES_SECONDARY_FILE_PATH);
+
+
 
     /** Termux app and Termux:Styling colors.properties file path */
     public static final String TERMUX_COLOR_PROPERTIES_FILE_PATH = TERMUX_DATA_HOME_DIR_PATH + "/colors.properties"; // Default: "/data/data/com.termux/files/home/.termux/colors.properties"