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

   1 /*
   2  * Copyright © 2016-2020 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.pm.PackageInfo;
  25 import android.content.pm.PackageManager;
  26 import android.content.pm.Signature;
  27 import android.content.res.Configuration;
  28 import android.os.Build;
  29 import android.os.Bundle;
  30 import android.text.SpannableStringBuilder;
  31 import android.text.Spanned;
  32 import android.text.style.ForegroundColorSpan;
  33 import android.view.LayoutInflater;
  34 import android.view.View;
  35 import android.view.ViewGroup;
  36 import android.webkit.WebView;
  37 import android.widget.TextView;
  38
  39 import androidx.annotation.NonNull;
  40 import androidx.fragment.app.Fragment;
  41 import androidx.webkit.WebViewCompat;
  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     // Define the class variables.
  58     private int tabNumber;
  59     private String[] blocklistVersions;
  60     private View tabLayout;
  61
  62     public static AboutTabFragment createTab(int tabNumber, String[] blocklistVersions) {
  63         // Create a bundle.
  64         Bundle argumentsBundle = new Bundle();
  65
  66         // Store the tab number in the bundle.
  67         argumentsBundle.putInt("tab_number", tabNumber);
  68         argumentsBundle.putStringArray("blocklist_versions", blocklistVersions);
  69
  70         // Create a new instance of the tab fragment.
  71         AboutTabFragment aboutTabFragment = new AboutTabFragment();
  72
  73         // Add the arguments bundle to the fragment.
  74         aboutTabFragment.setArguments(argumentsBundle);
  75
  76         // Return the new fragment.
  77         return aboutTabFragment;
  78     }
  79
  80     @Override
  81     public void onCreate(Bundle savedInstanceState) {
  82         // Run the default commands.
  83         super.onCreate(savedInstanceState);
  84
  85         // Get a handle for the arguments.
  86         Bundle arguments = getArguments();
  87
  88         // Remove the incorrect lint warning below that arguments might be null.
  89         assert arguments != null;
  90
  91         // Store the arguments in class variables.
  92         tabNumber = getArguments().getInt("tab_number");
  93         blocklistVersions = getArguments().getStringArray("blocklist_versions");
  94     }
  95
  96     @Override
  97     public View onCreateView(@NonNull LayoutInflater layoutInflater, ViewGroup container, Bundle savedInstanceState) {
  98         // Get a handle for the context and assert that it isn't null.
  99         Context context = getContext();
 100         assert context != null;
 101
 102         // Get the current theme status.
 103         int currentThemeStatus = getResources().getConfiguration().uiMode & Configuration.UI_MODE_NIGHT_MASK;
 104
 105         // Load the tabs.  Tab numbers start at 0.
 106         if (tabNumber == 0) {  // Load the about tab.
 107             // 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.
 108             tabLayout = layoutInflater.inflate(R.layout.about_tab_version, container, false);
 109
 110             // Get handles for the text views.
 111             TextView versionTextView = tabLayout.findViewById(R.id.version);
 112             TextView brandTextView = tabLayout.findViewById(R.id.brand);
 113             TextView manufacturerTextView = tabLayout.findViewById(R.id.manufacturer);
 114             TextView modelTextView = tabLayout.findViewById(R.id.model);
 115             TextView deviceTextView = tabLayout.findViewById(R.id.device);
 116             TextView bootloaderTextView = tabLayout.findViewById(R.id.bootloader);
 117             TextView radioTextView = tabLayout.findViewById(R.id.radio);
 118             TextView androidTextView = tabLayout.findViewById(R.id.android);
 119             TextView securityPatchTextView = tabLayout.findViewById(R.id.security_patch);
 120             TextView buildTextView = tabLayout.findViewById(R.id.build);
 121             TextView webViewProviderTextView = tabLayout.findViewById(R.id.webview_provider);
 122             TextView webViewVersionTextView = tabLayout.findViewById(R.id.webview_version);
 123             TextView orbotTextView = tabLayout.findViewById(R.id.orbot);
 124             TextView i2pTextView = tabLayout.findViewById(R.id.i2p);
 125             TextView openKeychainTextView = tabLayout.findViewById(R.id.open_keychain);
 126             TextView easyListTextView = tabLayout.findViewById(R.id.easylist);
 127             TextView easyPrivacyTextView = tabLayout.findViewById(R.id.easyprivacy);
 128             TextView fanboyAnnoyanceTextView = tabLayout.findViewById(R.id.fanboy_annoyance);
 129             TextView fanboySocialTextView = tabLayout.findViewById(R.id.fanboy_social);
 130             TextView ultraListTextView = tabLayout.findViewById(R.id.ultralist);
 131             TextView ultraPrivacyTextView = tabLayout.findViewById(R.id.ultraprivacy);
 132             TextView certificateIssuerDNTextView = tabLayout.findViewById(R.id.certificate_issuer_dn);
 133             TextView certificateSubjectDNTextView = tabLayout.findViewById(R.id.certificate_subject_dn);
 134             TextView certificateStartDateTextView = tabLayout.findViewById(R.id.certificate_start_date);
 135             TextView certificateEndDateTextView = tabLayout.findViewById(R.id.certificate_end_date);
 136             TextView certificateVersionTextView = tabLayout.findViewById(R.id.certificate_version);
 137             TextView certificateSerialNumberTextView = tabLayout.findViewById(R.id.certificate_serial_number);
 138             TextView certificateSignatureAlgorithmTextView = tabLayout.findViewById(R.id.certificate_signature_algorithm);
 139
 140             // Setup the labels.
 141             String version = getString(R.string.version) + " " + BuildConfig.VERSION_NAME + " (" + getString(R.string.version_code) + " " + BuildConfig.VERSION_CODE + ")";
 142             String brandLabel = getString(R.string.brand) + "  ";
 143             String manufacturerLabel = getString(R.string.manufacturer) + "  ";
 144             String modelLabel = getString(R.string.model) + "  ";
 145             String deviceLabel = getString(R.string.device) + "  ";
 146             String bootloaderLabel = getString(R.string.bootloader) + "  ";
 147             String androidLabel = getString(R.string.android) + "  ";
 148             String buildLabel = getString(R.string.build) + "  ";
 149             String webViewVersionLabel = getString(R.string.webview_version) + "  ";
 150             String easyListLabel = getString(R.string.easylist_label) + "  ";
 151             String easyPrivacyLabel = getString(R.string.easyprivacy_label) + "  ";
 152             String fanboyAnnoyanceLabel = getString(R.string.fanboy_annoyance_label) + "  ";
 153             String fanboySocialLabel = getString(R.string.fanboy_social_label) + "  ";
 154             String ultraListLabel = getString(R.string.ultralist_label) + "  ";
 155             String ultraPrivacyLabel = getString(R.string.ultraprivacy_label) + "  ";
 156             String issuerDNLabel = getString(R.string.issuer_dn) + "  ";
 157             String subjectDNLabel = getString(R.string.subject_dn) + "  ";
 158             String startDateLabel = getString(R.string.start_date) + "  ";
 159             String endDateLabel = getString(R.string.end_date) + "  ";
 160             String certificateVersionLabel = getString(R.string.certificate_version) + "  ";
 161             String serialNumberLabel = getString(R.string.serial_number) + "  ";
 162             String signatureAlgorithmLabel = getString(R.string.signature_algorithm) + "  ";
 163
 164             // The WebView layout is only used to get the default user agent from `bare_webview`.  It is not used to render content on the screen.
 165             // Once the minimum API >= 26 this can be accomplished with the WebView package info.
 166             View webViewLayout = layoutInflater.inflate(R.layout.bare_webview, container, false);
 167             WebView tabLayoutWebView = webViewLayout.findViewById(R.id.bare_webview);
 168             String userAgentString =  tabLayoutWebView.getSettings().getUserAgentString();
 169
 170             // Get the device's information and store it in strings.
 171             String brand = Build.BRAND;
 172             String manufacturer = Build.MANUFACTURER;
 173             String model = Build.MODEL;
 174             String device = Build.DEVICE;
 175             String bootloader = Build.BOOTLOADER;
 176             String radio = Build.getRadioVersion();
 177             String android = Build.VERSION.RELEASE + " (" + getString(R.string.api) + " " + Build.VERSION.SDK_INT + ")";
 178             String build = Build.DISPLAY;
 179             // Select the substring that begins after `Chrome/` and goes until the next ` `.
 180             String webView = userAgentString.substring(userAgentString.indexOf("Chrome/") + 7, userAgentString.indexOf(" ", userAgentString.indexOf("Chrome/")));
 181
 182             // Get the Orbot version name if Orbot is installed.
 183             String orbot;
 184             try {
 185                 // Store the version name.
 186                 orbot = context.getPackageManager().getPackageInfo("org.torproject.android", 0).versionName;
 187             } catch (PackageManager.NameNotFoundException exception) {  // Orbot is not installed.
 188                 orbot = "";
 189             }
 190
 191             // Get the I2P version name if I2P is installed.
 192             String i2p;
 193             try {
 194                 // Store the version name.
 195                 i2p = context.getPackageManager().getPackageInfo("net.i2p.android.router", 0).versionName;
 196             } catch (PackageManager.NameNotFoundException exception) {  // I2P is not installed.
 197                 i2p = "";
 198             }
 199
 200             // Get the OpenKeychain version name if it is installed.
 201             String openKeychain;
 202             try {
 203                 // Store the version name.
 204                 openKeychain = context.getPackageManager().getPackageInfo("org.sufficientlysecure.keychain", 0).versionName;
 205             } catch (PackageManager.NameNotFoundException exception) {  // OpenKeychain is not installed.
 206                 openKeychain = "";
 207             }
 208
 209             // Create a `SpannableStringBuilder` for the hardware and software `TextViews` that needs multiple colors of text.
 210             SpannableStringBuilder brandStringBuilder = new SpannableStringBuilder(brandLabel + brand);
 211             SpannableStringBuilder manufacturerStringBuilder = new SpannableStringBuilder(manufacturerLabel + manufacturer);
 212             SpannableStringBuilder modelStringBuilder = new SpannableStringBuilder(modelLabel + model);
 213             SpannableStringBuilder deviceStringBuilder = new SpannableStringBuilder(deviceLabel + device);
 214             SpannableStringBuilder bootloaderStringBuilder = new SpannableStringBuilder(bootloaderLabel + bootloader);
 215             SpannableStringBuilder androidStringBuilder = new SpannableStringBuilder(androidLabel + android);
 216             SpannableStringBuilder buildStringBuilder = new SpannableStringBuilder(buildLabel + build);
 217             SpannableStringBuilder webViewVersionStringBuilder = new SpannableStringBuilder(webViewVersionLabel + webView);
 218             SpannableStringBuilder easyListStringBuilder = new SpannableStringBuilder(easyListLabel + blocklistVersions[0]);
 219             SpannableStringBuilder easyPrivacyStringBuilder = new SpannableStringBuilder(easyPrivacyLabel + blocklistVersions[1]);
 220             SpannableStringBuilder fanboyAnnoyanceStringBuilder = new SpannableStringBuilder(fanboyAnnoyanceLabel + blocklistVersions[2]);
 221             SpannableStringBuilder fanboySocialStringBuilder = new SpannableStringBuilder(fanboySocialLabel + blocklistVersions[3]);
 222             SpannableStringBuilder ultraListStringBuilder = new SpannableStringBuilder(ultraListLabel + blocklistVersions[4]);
 223             SpannableStringBuilder ultraPrivacyStringBuilder = new SpannableStringBuilder(ultraPrivacyLabel + blocklistVersions[5]);
 224
 225             // Define the blue color span variable.
 226             ForegroundColorSpan blueColorSpan;
 227
 228             // Set the blue color span according to the theme.  The deprecated `getResources()` must be used until the minimum API >= 23.
 229             if (currentThemeStatus == Configuration.UI_MODE_NIGHT_YES) {
 230                 blueColorSpan = new ForegroundColorSpan(getResources().getColor(R.color.violet_500));
 231             } else {
 232                 blueColorSpan = new ForegroundColorSpan(getResources().getColor(R.color.blue_700));
 233             }
 234
 235             // Setup the spans to display the device information in blue.  `SPAN_INCLUSIVE_INCLUSIVE` allows the span to grow in either direction.
 236             brandStringBuilder.setSpan(blueColorSpan, brandLabel.length(), brandStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 237             manufacturerStringBuilder.setSpan(blueColorSpan, manufacturerLabel.length(), manufacturerStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 238             modelStringBuilder.setSpan(blueColorSpan, modelLabel.length(), modelStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 239             deviceStringBuilder.setSpan(blueColorSpan, deviceLabel.length(), deviceStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 240             bootloaderStringBuilder.setSpan(blueColorSpan, bootloaderLabel.length(), bootloaderStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 241             androidStringBuilder.setSpan(blueColorSpan, androidLabel.length(), androidStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 242             buildStringBuilder.setSpan(blueColorSpan, buildLabel.length(), buildStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 243             webViewVersionStringBuilder.setSpan(blueColorSpan, webViewVersionLabel.length(), webViewVersionStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 244             easyListStringBuilder.setSpan(blueColorSpan, easyListLabel.length(), easyListStringBuilder.length(), Spanned.SPAN_INCLUSIVE_EXCLUSIVE);
 245             easyPrivacyStringBuilder.setSpan(blueColorSpan, easyPrivacyLabel.length(), easyPrivacyStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 246             fanboyAnnoyanceStringBuilder.setSpan(blueColorSpan, fanboyAnnoyanceLabel.length(), fanboyAnnoyanceStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 247             fanboySocialStringBuilder.setSpan(blueColorSpan, fanboySocialLabel.length(), fanboySocialStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 248             ultraListStringBuilder.setSpan(blueColorSpan, ultraListLabel.length(), ultraListStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 249             ultraPrivacyStringBuilder.setSpan(blueColorSpan, ultraPrivacyLabel.length(), ultraPrivacyStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 250
 251             // Display the strings in the text boxes.
 252             versionTextView.setText(version);
 253             brandTextView.setText(brandStringBuilder);
 254             manufacturerTextView.setText(manufacturerStringBuilder);
 255             modelTextView.setText(modelStringBuilder);
 256             deviceTextView.setText(deviceStringBuilder);
 257             bootloaderTextView.setText(bootloaderStringBuilder);
 258             androidTextView.setText(androidStringBuilder);
 259             buildTextView.setText(buildStringBuilder);
 260             webViewVersionTextView.setText(webViewVersionStringBuilder);
 261             easyListTextView.setText(easyListStringBuilder);
 262             easyPrivacyTextView.setText(easyPrivacyStringBuilder);
 263             fanboyAnnoyanceTextView.setText(fanboyAnnoyanceStringBuilder);
 264             fanboySocialTextView.setText(fanboySocialStringBuilder);
 265             ultraListTextView.setText(ultraListStringBuilder);
 266             ultraPrivacyTextView.setText(ultraPrivacyStringBuilder);
 267
 268             // Only populate the radio text view if there is a radio in the device.
 269             if (!radio.isEmpty()) {
 270                 String radioLabel = getString(R.string.radio) + "  ";
 271                 SpannableStringBuilder radioStringBuilder = new SpannableStringBuilder(radioLabel + radio);
 272                 radioStringBuilder.setSpan(blueColorSpan, radioLabel.length(), radioStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 273                 radioTextView.setText(radioStringBuilder);
 274             } else {  // This device does not have a radio.
 275                 radioTextView.setVisibility(View.GONE);
 276             }
 277
 278             // Build.VERSION.SECURITY_PATCH is only available for SDK_INT >= 23.
 279             if (Build.VERSION.SDK_INT >= 23) {
 280                 String securityPatchLabel = getString(R.string.security_patch) + "  ";
 281                 String securityPatch = Build.VERSION.SECURITY_PATCH;
 282                 SpannableStringBuilder securityPatchStringBuilder = new SpannableStringBuilder(securityPatchLabel + securityPatch);
 283                 securityPatchStringBuilder.setSpan(blueColorSpan, securityPatchLabel.length(), securityPatchStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 284                 securityPatchTextView.setText(securityPatchStringBuilder);
 285             } else {  // The API < 23.
 286                 // Hide the security patch text view.
 287                 securityPatchTextView.setVisibility(View.GONE);
 288             }
 289
 290             // Only populate the WebView provider if the SDK >= 21.
 291             if (Build.VERSION.SDK_INT >= 21) {
 292                 // Create the WebView provider label.
 293                 String webViewProviderLabel = getString(R.string.webview_provider) + "  ";
 294
 295                 // Get the current WebView package info.
 296                 PackageInfo webViewPackageInfo = WebViewCompat.getCurrentWebViewPackage(context);
 297
 298                 // Remove the warning below that the package info might be null.
 299                 assert webViewPackageInfo != null;
 300
 301                 // Get the WebView provider name.
 302                 String webViewPackageName = webViewPackageInfo.packageName;
 303
 304                 // Create the spannable string builder.
 305                 SpannableStringBuilder webViewProviderStringBuilder = new SpannableStringBuilder(webViewProviderLabel + webViewPackageName);
 306
 307                 // Apply the coloration.
 308                 webViewProviderStringBuilder.setSpan(blueColorSpan, webViewProviderLabel.length(), webViewProviderStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 309
 310                 // Display the WebView provider.
 311                 webViewProviderTextView.setText(webViewProviderStringBuilder);
 312             } else {  // The API < 21.
 313                 // Hide the WebView provider text view.
 314                 webViewProviderTextView.setVisibility(View.GONE);
 315             }
 316
 317             // Only populate the Orbot text view if it is installed.
 318             if (!orbot.isEmpty()) {
 319                 String orbotLabel = getString(R.string.orbot) + "  ";
 320                 SpannableStringBuilder orbotStringBuilder = new SpannableStringBuilder(orbotLabel + orbot);
 321                 orbotStringBuilder.setSpan(blueColorSpan, orbotLabel.length(), orbotStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 322                 orbotTextView.setText(orbotStringBuilder);
 323             } else {  // Orbot is not installed.
 324                 orbotTextView.setVisibility(View.GONE);
 325             }
 326
 327             // Only populate the I2P text view if it is installed.
 328             if (!i2p.isEmpty()) {
 329                 String i2pLabel = getString(R.string.i2p)  + "  ";
 330                 SpannableStringBuilder i2pStringBuilder = new SpannableStringBuilder(i2pLabel + i2p);
 331                 i2pStringBuilder.setSpan(blueColorSpan, i2pLabel.length(), i2pStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 332                 i2pTextView.setText(i2pStringBuilder);
 333             } else {  // I2P is not installed.
 334                 i2pTextView.setVisibility(View.GONE);
 335             }
 336
 337             // Only populate the OpenKeychain text view if it is installed.
 338             if (!openKeychain.isEmpty()) {
 339                 String openKeychainLabel = getString(R.string.openkeychain) + "  ";
 340                 SpannableStringBuilder openKeychainStringBuilder = new SpannableStringBuilder(openKeychainLabel + openKeychain);
 341                 openKeychainStringBuilder.setSpan(blueColorSpan, openKeychainLabel.length(), openKeychainStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 342                 openKeychainTextView.setText(openKeychainStringBuilder);
 343             } else {  //OpenKeychain is not installed.
 344                 openKeychainTextView.setVisibility(View.GONE);
 345             }
 346
 347             // Display the package signature.
 348             try {
 349                 // Get the first package signature.  Suppress the lint warning about the need to be careful in implementing comparison of certificates for security purposes.
 350                 @SuppressLint("PackageManagerGetSignatures") Signature packageSignature = getContext().getPackageManager().getPackageInfo(getContext().getPackageName(),
 351                         PackageManager.GET_SIGNATURES).signatures[0];
 352
 353                 // Convert the signature to a byte array input stream.
 354                 InputStream certificateByteArrayInputStream = new ByteArrayInputStream(packageSignature.toByteArray());
 355
 356                 // Display the certificate information on the screen.
 357                 try {
 358                     // Instantiate a `CertificateFactory`.
 359                     CertificateFactory certificateFactory = CertificateFactory.getInstance("X509");
 360
 361                     // Generate an `X509Certificate`.
 362                     X509Certificate x509Certificate = (X509Certificate) certificateFactory.generateCertificate(certificateByteArrayInputStream);
 363
 364                     // Store the individual sections of the certificate that we are interested in.
 365                     Principal issuerDNPrincipal = x509Certificate.getIssuerDN();
 366                     Principal subjectDNPrincipal = x509Certificate.getSubjectDN();
 367                     Date startDate = x509Certificate.getNotBefore();
 368                     Date endDate = x509Certificate.getNotAfter();
 369                     int certificateVersion = x509Certificate.getVersion();
 370                     BigInteger serialNumberBigInteger = x509Certificate.getSerialNumber();
 371                     String signatureAlgorithmNameString = x509Certificate.getSigAlgName();
 372
 373                     // Create a `SpannableStringBuilder` for each `TextView` that needs multiple colors of text.
 374                     SpannableStringBuilder issuerDNStringBuilder = new SpannableStringBuilder(issuerDNLabel + issuerDNPrincipal.toString());
 375                     SpannableStringBuilder subjectDNStringBuilder = new SpannableStringBuilder(subjectDNLabel + subjectDNPrincipal.toString());
 376                     SpannableStringBuilder startDateStringBuilder = new SpannableStringBuilder(startDateLabel + DateFormat.getDateTimeInstance(DateFormat.MEDIUM, DateFormat.LONG).format(startDate));
 377                     SpannableStringBuilder endDataStringBuilder = new SpannableStringBuilder(endDateLabel + DateFormat.getDateTimeInstance(DateFormat.MEDIUM, DateFormat.LONG).format(endDate));
 378                     SpannableStringBuilder certificateVersionStringBuilder = new SpannableStringBuilder(certificateVersionLabel + certificateVersion);
 379                     SpannableStringBuilder serialNumberStringBuilder = new SpannableStringBuilder(serialNumberLabel + serialNumberBigInteger);
 380                     SpannableStringBuilder signatureAlgorithmStringBuilder = new SpannableStringBuilder(signatureAlgorithmLabel + signatureAlgorithmNameString);
 381
 382                     // Setup the spans to display the device information in blue.  `SPAN_INCLUSIVE_INCLUSIVE` allows the span to grow in either direction.
 383                     issuerDNStringBuilder.setSpan(blueColorSpan, issuerDNLabel.length(), issuerDNStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 384                     subjectDNStringBuilder.setSpan(blueColorSpan, subjectDNLabel.length(), subjectDNStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 385                     startDateStringBuilder.setSpan(blueColorSpan, startDateLabel.length(), startDateStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 386                     endDataStringBuilder.setSpan(blueColorSpan, endDateLabel.length(), endDataStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 387                     certificateVersionStringBuilder.setSpan(blueColorSpan, certificateVersionLabel.length(), certificateVersionStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 388                     serialNumberStringBuilder.setSpan(blueColorSpan, serialNumberLabel.length(), serialNumberStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 389                     signatureAlgorithmStringBuilder.setSpan(blueColorSpan, signatureAlgorithmLabel.length(), signatureAlgorithmStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 390
 391                     // Display the strings in the text boxes.
 392                     certificateIssuerDNTextView.setText(issuerDNStringBuilder);
 393                     certificateSubjectDNTextView.setText(subjectDNStringBuilder);
 394                     certificateStartDateTextView.setText(startDateStringBuilder);
 395                     certificateEndDateTextView.setText(endDataStringBuilder);
 396                     certificateVersionTextView.setText(certificateVersionStringBuilder);
 397                     certificateSerialNumberTextView.setText(serialNumberStringBuilder);
 398                     certificateSignatureAlgorithmTextView.setText(signatureAlgorithmStringBuilder);
 399                 } catch (CertificateException e) {
 400                     // Do nothing if there is a certificate error.
 401                 }
 402             } catch (PackageManager.NameNotFoundException e) {
 403                 // Do nothing if `PackageManager` says Privacy Browser isn't installed.
 404             }
 405         } else { // load a WebView for all the other tabs.  Tab numbers start at 0.
 406             // 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.
 407             tabLayout = layoutInflater.inflate(R.layout.bare_webview, container, false);
 408
 409             // Get a handle for `tabWebView`.
 410             WebView tabWebView = (WebView) tabLayout;
 411
 412             // Load the tabs according to the theme.
 413             if (currentThemeStatus == Configuration.UI_MODE_NIGHT_YES) {  // The dark theme is applied.
 414                 // Set the background color.  The deprecated `.getColor()` must be used until the minimum API >= 23.
 415                 tabWebView.setBackgroundColor(getResources().getColor(R.color.gray_850));
 416
 417                 switch (tabNumber) {
 418                     case 1:
 419                         tabWebView.loadUrl("file:///android_asset/" + getString(R.string.android_asset_path) + "/about_permissions_dark.html");
 420                         break;
 421
 422                     case 2:
 423                         tabWebView.loadUrl("file:///android_asset/" + getString(R.string.android_asset_path) + "/about_privacy_policy_dark.html");
 424                         break;
 425
 426                     case 3:
 427                         tabWebView.loadUrl("file:///android_asset/" + getString(R.string.android_asset_path) + "/about_changelog_dark.html");
 428                         break;
 429
 430                     case 4:
 431                         tabWebView.loadUrl("file:///android_asset/" + getString(R.string.android_asset_path) + "/about_licenses_dark.html");
 432                         break;
 433
 434                     case 5:
 435                         tabWebView.loadUrl("file:///android_asset/" + getString(R.string.android_asset_path) + "/about_contributors_dark.html");
 436                         break;
 437
 438                     case 6:
 439                         tabWebView.loadUrl("file:///android_asset/" + getString(R.string.android_asset_path) + "/about_links_dark.html");
 440                         break;
 441                 }
 442             } else {  // The light theme is applied.
 443                 switch (tabNumber) {
 444                     case 1:
 445                         tabWebView.loadUrl("file:///android_asset/" + getString(R.string.android_asset_path) + "/about_permissions_light.html");
 446                         break;
 447
 448                     case 2:
 449                         tabWebView.loadUrl("file:///android_asset/" + getString(R.string.android_asset_path) + "/about_privacy_policy_light.html");
 450                         break;
 451
 452                     case 3:
 453                         tabWebView.loadUrl("file:///android_asset/" + getString(R.string.android_asset_path) + "/about_changelog_light.html");
 454                         break;
 455
 456                     case 4:
 457                         tabWebView.loadUrl("file:///android_asset/" + getString(R.string.android_asset_path) + "/about_licenses_light.html");
 458                         break;
 459
 460                     case 5:
 461                         tabWebView.loadUrl("file:///android_asset/" + getString(R.string.android_asset_path) + "/about_contributors_light.html");
 462                         break;
 463
 464                     case 6:
 465                         tabWebView.loadUrl("file:///android_asset/" + getString(R.string.android_asset_path) + "/about_links_light.html");
 466                         break;
 467                 }
 468             }
 469         }
 470
 471         // Scroll the tab if the saved instance state is not null.
 472         if (savedInstanceState != null) {
 473             tabLayout.post(() -> {
 474                 tabLayout.setScrollX(savedInstanceState.getInt("scroll_x"));
 475                 tabLayout.setScrollY(savedInstanceState.getInt("scroll_y"));
 476             });
 477         }
 478
 479         // Return the formatted `tabLayout`.
 480         return tabLayout;
 481     }
 482
 483     @Override
 484     public void onSaveInstanceState(@NonNull Bundle savedInstanceState) {
 485         // Run the default commands.
 486         super.onSaveInstanceState(savedInstanceState);
 487
 488         // Save the scroll positions if the tab layout is not null, which can happen if a tab is not currently selected.
 489         if (tabLayout != null) {
 490             savedInstanceState.putInt("scroll_x", tabLayout.getScrollX());
 491             savedInstanceState.putInt("scroll_y", tabLayout.getScrollY());
 492         }
 493     }
 494 }