app/src/main/java/com/stoutner/privacybrowser/fragments/AboutTabFragment.java

   1 /*
   2  * Copyright © 2016-2019 Soren Stoutner <soren@stoutner.com>.
   3  *
   4  * This file is part of Privacy Browser <https://www.stoutner.com/privacy-browser>.
   5  *
   6  * Privacy Browser is free software: you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation, either version 3 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * Privacy Browser is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with Privacy Browser.  If not, see <http://www.gnu.org/licenses/>.
  18  */
  19
  20 package com.stoutner.privacybrowser.fragments;
  21
  22 import android.annotation.SuppressLint;
  23 import android.content.Context;
  24 import android.content.SharedPreferences;
  25 import android.content.pm.PackageInfo;
  26 import android.content.pm.PackageManager;
  27 import android.content.pm.Signature;
  28 import android.os.Build;
  29 import android.os.Bundle;
  30 import android.preference.PreferenceManager;
  31 import android.text.SpannableStringBuilder;
  32 import android.text.Spanned;
  33 import android.text.style.ForegroundColorSpan;
  34 import android.view.LayoutInflater;
  35 import android.view.View;
  36 import android.view.ViewGroup;
  37 import android.webkit.WebView;
  38 import android.widget.TextView;
  39
  40 import androidx.annotation.NonNull;
  41 import androidx.fragment.app.Fragment;
  42
  43 import com.stoutner.privacybrowser.BuildConfig;
  44 import com.stoutner.privacybrowser.R;
  45
  46 import java.io.ByteArrayInputStream;
  47 import java.io.InputStream;
  48 import java.math.BigInteger;
  49 import java.security.Principal;
  50 import java.security.cert.CertificateException;
  51 import java.security.cert.CertificateFactory;
  52 import java.security.cert.X509Certificate;
  53 import java.text.DateFormat;
  54 import java.util.Date;
  55
  56 public class AboutTabFragment extends Fragment {
  57     // Declare the class variables.
  58     private int tabNumber;
  59     private String[] blocklistVersions;
  60
  61     public static AboutTabFragment createTab(int tabNumber, String[] blocklistVersions) {
  62         // Create a bundle.
  63         Bundle argumentsBundle = new Bundle();
  64
  65         // Store the tab number in the bundle.
  66         argumentsBundle.putInt("tab_number", tabNumber);
  67         argumentsBundle.putStringArray("blocklist_versions", blocklistVersions);
  68
  69         // Create a new instance of the tab fragment.
  70         AboutTabFragment aboutTabFragment = new AboutTabFragment();
  71
  72         // Add the arguments bundle to the fragment.
  73         aboutTabFragment.setArguments(argumentsBundle);
  74
  75         // Return the new fragment.
  76         return aboutTabFragment;
  77     }
  78
  79     @Override
  80     public void onCreate(Bundle savedInstanceState) {
  81         // Run the default commands.
  82         super.onCreate(savedInstanceState);
  83
  84         // Get a handle for the arguments.
  85         Bundle arguments = getArguments();
  86
  87         // Remove the incorrect lint warning below that arguments might be null.
  88         assert arguments != null;
  89
  90         // Store the arguments in class variables.
  91         tabNumber = getArguments().getInt("tab_number");
  92         blocklistVersions = getArguments().getStringArray("blocklist_versions");
  93     }
  94
  95     @Override
  96     public View onCreateView(@NonNull LayoutInflater layoutInflater, ViewGroup container, Bundle savedInstanceState) {
  97         // Create a tab layout view.
  98         View tabLayout;
  99
 100         // Get a handle for the context and assert that it isn't null.
 101         Context context = getContext();
 102         assert context != null;
 103
 104         // Get a handle for the shared preferences.
 105         SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(context);
 106
 107         // Get the theme preference.
 108         boolean darkTheme = sharedPreferences.getBoolean("dark_theme", false);
 109
 110         // Load the tabs.  Tab numbers start at 0.
 111         if (tabNumber == 0) {  // Load the about tab.
 112             // Setting false at the end of inflater.inflate does not attach the inflated layout as a child of container.  The fragment will take care of attaching the root automatically.
 113             tabLayout = layoutInflater.inflate(R.layout.about_tab_version, container, false);
 114
 115             // Get handles for the `TextViews`.
 116             TextView versionTextView = tabLayout.findViewById(R.id.version);
 117             TextView brandTextView = tabLayout.findViewById(R.id.brand);
 118             TextView manufacturerTextView = tabLayout.findViewById(R.id.manufacturer);
 119             TextView modelTextView = tabLayout.findViewById(R.id.model);
 120             TextView deviceTextView = tabLayout.findViewById(R.id.device);
 121             TextView bootloaderTextView = tabLayout.findViewById(R.id.bootloader);
 122             TextView radioTextView = tabLayout.findViewById(R.id.radio);
 123             TextView androidTextView = tabLayout.findViewById(R.id.android);
 124             TextView securityPatchTextView = tabLayout.findViewById(R.id.security_patch);
 125             TextView buildTextView = tabLayout.findViewById(R.id.build);
 126             TextView webViewProviderTextView = tabLayout.findViewById(R.id.webview_provider);
 127             TextView webViewVersionTextView = tabLayout.findViewById(R.id.webview_version);
 128             TextView orbotTextView = tabLayout.findViewById(R.id.orbot);
 129             TextView openKeychainTextView = tabLayout.findViewById(R.id.open_keychain);
 130             TextView easyListTextView = tabLayout.findViewById(R.id.easylist);
 131             TextView easyPrivacyTextView = tabLayout.findViewById(R.id.easyprivacy);
 132             TextView fanboyAnnoyanceTextView = tabLayout.findViewById(R.id.fanboy_annoyance);
 133             TextView fanboySocialTextView = tabLayout.findViewById(R.id.fanboy_social);
 134             TextView ultraPrivacyTextView = tabLayout.findViewById(R.id.ultraprivacy);
 135             TextView certificateIssuerDNTextView = tabLayout.findViewById(R.id.certificate_issuer_dn);
 136             TextView certificateSubjectDNTextView = tabLayout.findViewById(R.id.certificate_subject_dn);
 137             TextView certificateStartDateTextView = tabLayout.findViewById(R.id.certificate_start_date);
 138             TextView certificateEndDateTextView = tabLayout.findViewById(R.id.certificate_end_date);
 139             TextView certificateVersionTextView = tabLayout.findViewById(R.id.certificate_version);
 140             TextView certificateSerialNumberTextView = tabLayout.findViewById(R.id.certificate_serial_number);
 141             TextView certificateSignatureAlgorithmTextView = tabLayout.findViewById(R.id.certificate_signature_algorithm);
 142
 143             // Setup the labels.
 144             String version = getString(R.string.version) + " " + BuildConfig.VERSION_NAME + " (" + getString(R.string.version_code) + " " + BuildConfig.VERSION_CODE + ")";
 145             String brandLabel = getString(R.string.brand) + "  ";
 146             String manufacturerLabel = getString(R.string.manufacturer) + "  ";
 147             String modelLabel = getString(R.string.model) + "  ";
 148             String deviceLabel = getString(R.string.device) + "  ";
 149             String bootloaderLabel = getString(R.string.bootloader) + "  ";
 150             String androidLabel = getString(R.string.android) + "  ";
 151             String buildLabel = getString(R.string.build) + "  ";
 152             String webViewVersionLabel = getString(R.string.webview_version) + "  ";
 153             String easyListLabel = getString(R.string.easylist_label) + "  ";
 154             String easyPrivacyLabel = getString(R.string.easyprivacy_label) + "  ";
 155             String fanboyAnnoyanceLabel = getString(R.string.fanboy_annoyance_label) + "  ";
 156             String fanboySocialLabel = getString(R.string.fanboy_social_label) + "  ";
 157             String ultraPrivacyLabel = getString(R.string.ultraprivacy_label) + "  ";
 158             String issuerDNLabel = getString(R.string.issuer_dn) + "  ";
 159             String subjectDNLabel = getString(R.string.subject_dn) + "  ";
 160             String startDateLabel = getString(R.string.start_date) + "  ";
 161             String endDateLabel = getString(R.string.end_date) + "  ";
 162             String certificateVersionLabel = getString(R.string.certificate_version) + "  ";
 163             String serialNumberLabel = getString(R.string.serial_number) + "  ";
 164             String signatureAlgorithmLabel = getString(R.string.signature_algorithm) + "  ";
 165
 166             // `webViewLayout` is only used to get the default user agent from `bare_webview`.  It is not used to render content on the screen.
 167             // Once the minimum API >= 26 this can be accomplished with the WebView package info.
 168             View webViewLayout = layoutInflater.inflate(R.layout.bare_webview, container, false);
 169             WebView tabLayoutWebView = webViewLayout.findViewById(R.id.bare_webview);
 170             String userAgentString =  tabLayoutWebView.getSettings().getUserAgentString();
 171
 172             // Get the device's information and store it in strings.
 173             String brand = Build.BRAND;
 174             String manufacturer = Build.MANUFACTURER;
 175             String model = Build.MODEL;
 176             String device = Build.DEVICE;
 177             String bootloader = Build.BOOTLOADER;
 178             String radio = Build.getRadioVersion();
 179             String android = Build.VERSION.RELEASE + " (" + getString(R.string.api) + " " + Build.VERSION.SDK_INT + ")";
 180             String build = Build.DISPLAY;
 181             // Select the substring that begins after `Chrome/` and goes until the next ` `.
 182             String webView = userAgentString.substring(userAgentString.indexOf("Chrome/") + 7, userAgentString.indexOf(" ", userAgentString.indexOf("Chrome/")));
 183
 184             // Get the Orbot version name if Orbot is installed.
 185             String orbot;
 186             try {
 187                 // Store the version name.
 188                 orbot = context.getPackageManager().getPackageInfo("org.torproject.android", 0).versionName;
 189             } catch (PackageManager.NameNotFoundException exception) {  // Orbot is not installed.
 190                 orbot = "";
 191             }
 192
 193             // Get the OpenKeychain version name if it is installed.
 194             String openKeychain;
 195             try {
 196                 // Store the version name.
 197                 openKeychain = context.getPackageManager().getPackageInfo("org.sufficientlysecure.keychain", 0).versionName;
 198             } catch (PackageManager.NameNotFoundException exception) {  // OpenKeychain is not installed.
 199                 openKeychain = "";
 200             }
 201
 202             // Create a `SpannableStringBuilder` for the hardware and software `TextViews` that needs multiple colors of text.
 203             SpannableStringBuilder brandStringBuilder = new SpannableStringBuilder(brandLabel + brand);
 204             SpannableStringBuilder manufacturerStringBuilder = new SpannableStringBuilder(manufacturerLabel + manufacturer);
 205             SpannableStringBuilder modelStringBuilder = new SpannableStringBuilder(modelLabel + model);
 206             SpannableStringBuilder deviceStringBuilder = new SpannableStringBuilder(deviceLabel + device);
 207             SpannableStringBuilder bootloaderStringBuilder = new SpannableStringBuilder(bootloaderLabel + bootloader);
 208             SpannableStringBuilder androidStringBuilder = new SpannableStringBuilder(androidLabel + android);
 209             SpannableStringBuilder buildStringBuilder = new SpannableStringBuilder(buildLabel + build);
 210             SpannableStringBuilder webViewVersionStringBuilder = new SpannableStringBuilder(webViewVersionLabel + webView);
 211             SpannableStringBuilder easyListStringBuilder = new SpannableStringBuilder(easyListLabel + blocklistVersions[0]);
 212             SpannableStringBuilder easyPrivacyStringBuilder = new SpannableStringBuilder(easyPrivacyLabel + blocklistVersions[1]);
 213             SpannableStringBuilder fanboyAnnoyanceStringBuilder = new SpannableStringBuilder(fanboyAnnoyanceLabel + blocklistVersions[2]);
 214             SpannableStringBuilder fanboySocialStringBuilder = new SpannableStringBuilder(fanboySocialLabel + blocklistVersions[3]);
 215             SpannableStringBuilder ultraPrivacyStringBuilder = new SpannableStringBuilder(ultraPrivacyLabel + blocklistVersions[4]);
 216
 217             // Create the `blueColorSpan` variable.
 218             ForegroundColorSpan blueColorSpan;
 219
 220             // Set `blueColorSpan` according to the theme.  We have to use the deprecated `getColor()` until API >= 23.
 221             if (darkTheme) {
 222                 blueColorSpan = new ForegroundColorSpan(getResources().getColor(R.color.blue_400));
 223             } else {
 224                 blueColorSpan = new ForegroundColorSpan(getResources().getColor(R.color.blue_700));
 225             }
 226
 227             // Setup the spans to display the device information in blue.  `SPAN_INCLUSIVE_INCLUSIVE` allows the span to grow in either direction.
 228             brandStringBuilder.setSpan(blueColorSpan, brandLabel.length(), brandStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 229             manufacturerStringBuilder.setSpan(blueColorSpan, manufacturerLabel.length(), manufacturerStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 230             modelStringBuilder.setSpan(blueColorSpan, modelLabel.length(), modelStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 231             deviceStringBuilder.setSpan(blueColorSpan, deviceLabel.length(), deviceStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 232             bootloaderStringBuilder.setSpan(blueColorSpan, bootloaderLabel.length(), bootloaderStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 233             androidStringBuilder.setSpan(blueColorSpan, androidLabel.length(), androidStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 234             buildStringBuilder.setSpan(blueColorSpan, buildLabel.length(), buildStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 235             webViewVersionStringBuilder.setSpan(blueColorSpan, webViewVersionLabel.length(), webViewVersionStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 236             easyListStringBuilder.setSpan(blueColorSpan, easyListLabel.length(), easyListStringBuilder.length(), Spanned.SPAN_INCLUSIVE_EXCLUSIVE);
 237             easyPrivacyStringBuilder.setSpan(blueColorSpan, easyPrivacyLabel.length(), easyPrivacyStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 238             fanboyAnnoyanceStringBuilder.setSpan(blueColorSpan, fanboyAnnoyanceLabel.length(), fanboyAnnoyanceStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 239             fanboySocialStringBuilder.setSpan(blueColorSpan, fanboySocialLabel.length(), fanboySocialStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 240             ultraPrivacyStringBuilder.setSpan(blueColorSpan, ultraPrivacyLabel.length(), ultraPrivacyStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 241
 242             // Display the strings in the text boxes.
 243             versionTextView.setText(version);
 244             brandTextView.setText(brandStringBuilder);
 245             manufacturerTextView.setText(manufacturerStringBuilder);
 246             modelTextView.setText(modelStringBuilder);
 247             deviceTextView.setText(deviceStringBuilder);
 248             bootloaderTextView.setText(bootloaderStringBuilder);
 249             androidTextView.setText(androidStringBuilder);
 250             buildTextView.setText(buildStringBuilder);
 251             webViewVersionTextView.setText(webViewVersionStringBuilder);
 252             easyListTextView.setText(easyListStringBuilder);
 253             easyPrivacyTextView.setText(easyPrivacyStringBuilder);
 254             fanboyAnnoyanceTextView.setText(fanboyAnnoyanceStringBuilder);
 255             fanboySocialTextView.setText(fanboySocialStringBuilder);
 256             ultraPrivacyTextView.setText(ultraPrivacyStringBuilder);
 257
 258             // Only populate the radio text view if there is a radio in the device.
 259             if (!radio.isEmpty()) {
 260                 String radioLabel = getString(R.string.radio) + "  ";
 261                 SpannableStringBuilder radioStringBuilder = new SpannableStringBuilder(radioLabel + radio);
 262                 radioStringBuilder.setSpan(blueColorSpan, radioLabel.length(), radioStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 263                 radioTextView.setText(radioStringBuilder);
 264             } else {  // This device does not have a radio.
 265                 radioTextView.setVisibility(View.GONE);
 266             }
 267
 268             // Build.VERSION.SECURITY_PATCH is only available for SDK_INT >= 23.
 269             if (Build.VERSION.SDK_INT >= 23) {
 270                 String securityPatchLabel = getString(R.string.security_patch) + "  ";
 271                 String securityPatch = Build.VERSION.SECURITY_PATCH;
 272                 SpannableStringBuilder securityPatchStringBuilder = new SpannableStringBuilder(securityPatchLabel + securityPatch);
 273                 securityPatchStringBuilder.setSpan(blueColorSpan, securityPatchLabel.length(), securityPatchStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 274                 securityPatchTextView.setText(securityPatchStringBuilder);
 275             } else {  // The API < 23.
 276                 // Hide the security patch text view.
 277                 securityPatchTextView.setVisibility(View.GONE);
 278             }
 279
 280             // Only populate the WebView provider if the SDK >= 26.
 281             if (Build.VERSION.SDK_INT >= 26) {
 282                 // Create the WebView provider label.
 283                 String webViewProviderLabel = getString(R.string.webview_provider) + "  ";
 284
 285                 // Get the current WebView package info.
 286                 PackageInfo webViewPackageInfo = WebView.getCurrentWebViewPackage();
 287
 288                 // Remove the warning below that the package info might be null.
 289                 assert webViewPackageInfo != null;
 290
 291                 // Get the WebView provider name.
 292                 String webViewPackageName = webViewPackageInfo.packageName;
 293
 294                 // Create the spannable string builder.
 295                 SpannableStringBuilder webViewProviderStringBuilder = new SpannableStringBuilder(webViewProviderLabel + webViewPackageName);
 296
 297                 // Apply the coloration.
 298                 webViewProviderStringBuilder.setSpan(blueColorSpan, webViewProviderLabel.length(), webViewProviderStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 299
 300                 // Display the WebView provider.
 301                 webViewProviderTextView.setText(webViewProviderStringBuilder);
 302             } else {  // The API < 26.
 303                 // Hide the WebView provider text view.
 304                 webViewProviderTextView.setVisibility(View.GONE);
 305             }
 306
 307             // Only populate the Orbot text view if it is installed.
 308             if (!orbot.isEmpty()) {
 309                 String orbotLabel = getString(R.string.orbot) + "  ";
 310                 SpannableStringBuilder orbotStringBuilder = new SpannableStringBuilder(orbotLabel + orbot);
 311                 orbotStringBuilder.setSpan(blueColorSpan, orbotLabel.length(), orbotStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 312                 orbotTextView.setText(orbotStringBuilder);
 313             } else {  // Orbot is not installed.
 314                 orbotTextView.setVisibility(View.GONE);
 315             }
 316
 317             // Only populate the OpenKeychain text view if it is installed.
 318             if (!openKeychain.isEmpty()) {
 319                 String openKeychainLabel = getString(R.string.openkeychain) + "  ";
 320                 SpannableStringBuilder openKeychainStringBuilder = new SpannableStringBuilder(openKeychainLabel + openKeychain);
 321                 openKeychainStringBuilder.setSpan(blueColorSpan, openKeychainLabel.length(), openKeychainStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 322                 openKeychainTextView.setText(openKeychainStringBuilder);
 323             } else {  //OpenKeychain is not installed.
 324                 openKeychainTextView.setVisibility(View.GONE);
 325             }
 326
 327             // Display the package signature.
 328             try {
 329                 // Get the first package signature.  Suppress the lint warning about the need to be careful in implementing comparison of certificates for security purposes.
 330                 @SuppressLint("PackageManagerGetSignatures") Signature packageSignature = getContext().getPackageManager().getPackageInfo(getContext().getPackageName(), PackageManager.GET_SIGNATURES).signatures[0];
 331
 332                 // Convert the signature to a `byte[]` `InputStream`.
 333                 InputStream certificateByteArrayInputStream = new ByteArrayInputStream(packageSignature.toByteArray());
 334
 335                 // Display the certificate information on the screen.
 336                 try {
 337                     // Instantiate a `CertificateFactory`.
 338                     CertificateFactory certificateFactory = CertificateFactory.getInstance("X509");
 339
 340                     // Generate an `X509Certificate`.
 341                     X509Certificate x509Certificate = (X509Certificate) certificateFactory.generateCertificate(certificateByteArrayInputStream);
 342
 343                     // Store the individual sections of the certificate that we are interested in.
 344                     Principal issuerDNPrincipal = x509Certificate.getIssuerDN();
 345                     Principal subjectDNPrincipal = x509Certificate.getSubjectDN();
 346                     Date startDate = x509Certificate.getNotBefore();
 347                     Date endDate = x509Certificate.getNotAfter();
 348                     int certificateVersion = x509Certificate.getVersion();
 349                     BigInteger serialNumberBigInteger = x509Certificate.getSerialNumber();
 350                     String signatureAlgorithmNameString = x509Certificate.getSigAlgName();
 351
 352                     // Create a `SpannableStringBuilder` for each `TextView` that needs multiple colors of text.
 353                     SpannableStringBuilder issuerDNStringBuilder = new SpannableStringBuilder(issuerDNLabel + issuerDNPrincipal.toString());
 354                     SpannableStringBuilder subjectDNStringBuilder = new SpannableStringBuilder(subjectDNLabel + subjectDNPrincipal.toString());
 355                     SpannableStringBuilder startDateStringBuilder = new SpannableStringBuilder(startDateLabel + DateFormat.getDateTimeInstance(DateFormat.MEDIUM, DateFormat.LONG).format(startDate));
 356                     SpannableStringBuilder endDataStringBuilder = new SpannableStringBuilder(endDateLabel + DateFormat.getDateTimeInstance(DateFormat.MEDIUM, DateFormat.LONG).format(endDate));
 357                     SpannableStringBuilder certificateVersionStringBuilder = new SpannableStringBuilder(certificateVersionLabel + certificateVersion);
 358                     SpannableStringBuilder serialNumberStringBuilder = new SpannableStringBuilder(serialNumberLabel + serialNumberBigInteger);
 359                     SpannableStringBuilder signatureAlgorithmStringBuilder = new SpannableStringBuilder(signatureAlgorithmLabel + signatureAlgorithmNameString);
 360
 361                     // Setup the spans to display the device information in blue.  `SPAN_INCLUSIVE_INCLUSIVE` allows the span to grow in either direction.
 362                     issuerDNStringBuilder.setSpan(blueColorSpan, issuerDNLabel.length(), issuerDNStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 363                     subjectDNStringBuilder.setSpan(blueColorSpan, subjectDNLabel.length(), subjectDNStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 364                     startDateStringBuilder.setSpan(blueColorSpan, startDateLabel.length(), startDateStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 365                     endDataStringBuilder.setSpan(blueColorSpan, endDateLabel.length(), endDataStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 366                     certificateVersionStringBuilder.setSpan(blueColorSpan, certificateVersionLabel.length(), certificateVersionStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 367                     serialNumberStringBuilder.setSpan(blueColorSpan, serialNumberLabel.length(), serialNumberStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 368                     signatureAlgorithmStringBuilder.setSpan(blueColorSpan, signatureAlgorithmLabel.length(), signatureAlgorithmStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 369
 370                     // Display the strings in the text boxes.
 371                     certificateIssuerDNTextView.setText(issuerDNStringBuilder);
 372                     certificateSubjectDNTextView.setText(subjectDNStringBuilder);
 373                     certificateStartDateTextView.setText(startDateStringBuilder);
 374                     certificateEndDateTextView.setText(endDataStringBuilder);
 375                     certificateVersionTextView.setText(certificateVersionStringBuilder);
 376                     certificateSerialNumberTextView.setText(serialNumberStringBuilder);
 377                     certificateSignatureAlgorithmTextView.setText(signatureAlgorithmStringBuilder);
 378                 } catch (CertificateException e) {
 379                     // Do nothing if there is a certificate error.
 380                 }
 381             } catch (PackageManager.NameNotFoundException e) {
 382                 // Do nothing if `PackageManager` says Privacy Browser isn't installed.
 383             }
 384         } else { // load a `WebView` for all the other tabs.  Tab numbers start at 0.
 385             // Setting false at the end of inflater.inflate does not attach the inflated layout as a child of container.  The fragment will take care of attaching the root automatically.
 386             tabLayout = layoutInflater.inflate(R.layout.bare_webview, container, false);
 387
 388             // Get a handle for `tabWebView`.
 389             WebView tabWebView = (WebView) tabLayout;
 390
 391             // Load the tabs according to the theme.
 392             if (darkTheme) {  // The dark theme is applied.
 393                 // Set the background color.  The deprecated `.getColor()` must be used until the minimum API >= 23.
 394                 tabWebView.setBackgroundColor(getResources().getColor(R.color.gray_850));
 395
 396                 switch (tabNumber) {
 397                     case 1:
 398                         tabWebView.loadUrl("file:///android_asset/" + getString(R.string.android_asset_path) + "/about_permissions_dark.html");
 399                         break;
 400
 401                     case 2:
 402                         tabWebView.loadUrl("file:///android_asset/" + getString(R.string.android_asset_path) + "/about_privacy_policy_dark.html");
 403                         break;
 404
 405                     case 3:
 406                         tabWebView.loadUrl("file:///android_asset/" + getString(R.string.android_asset_path) + "/about_changelog_dark.html");
 407                         break;
 408
 409                     case 4:
 410                         tabWebView.loadUrl("file:///android_asset/" + getString(R.string.android_asset_path) + "/about_licenses_dark.html");
 411                         break;
 412
 413                     case 5:
 414                         tabWebView.loadUrl("file:///android_asset/" + getString(R.string.android_asset_path) + "/about_contributors_dark.html");
 415                         break;
 416
 417                     case 6:
 418                         tabWebView.loadUrl("file:///android_asset/" + getString(R.string.android_asset_path) + "/about_links_dark.html");
 419                         break;
 420                 }
 421             } else {  // The light theme is applied.
 422                 switch (tabNumber) {
 423                     case 1:
 424                         tabWebView.loadUrl("file:///android_asset/" + getString(R.string.android_asset_path) + "/about_permissions_light.html");
 425                         break;
 426
 427                     case 2:
 428                         tabWebView.loadUrl("file:///android_asset/" + getString(R.string.android_asset_path) + "/about_privacy_policy_light.html");
 429                         break;
 430
 431                     case 3:
 432                         tabWebView.loadUrl("file:///android_asset/" + getString(R.string.android_asset_path) + "/about_changelog_light.html");
 433                         break;
 434
 435                     case 4:
 436                         tabWebView.loadUrl("file:///android_asset/" + getString(R.string.android_asset_path) + "/about_licenses_light.html");
 437                         break;
 438
 439                     case 5:
 440                         tabWebView.loadUrl("file:///android_asset/" + getString(R.string.android_asset_path) + "/about_contributors_light.html");
 441                         break;
 442
 443                     case 6:
 444                         tabWebView.loadUrl("file:///android_asset/" + getString(R.string.android_asset_path) + "/about_links_light.html");
 445                         break;
 446                 }
 447             }
 448         }
 449
 450         // Return the formatted `tabLayout`.
 451         return tabLayout;
 452     }
 453 }