app/src/main/java/com/stoutner/privacybrowser/dialogs/ViewSslCertificateDialog.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.dialogs;
  21
  22 import android.annotation.SuppressLint;
  23 import android.app.Activity;
  24 import android.app.AlertDialog;
  25 import android.app.Dialog;
  26 import android.app.DialogFragment;
  27 import android.graphics.drawable.BitmapDrawable;
  28 import android.graphics.drawable.Drawable;
  29 import android.net.Uri;
  30 import android.net.http.SslCertificate;
  31 import android.os.AsyncTask;
  32 import android.os.Bundle;
  33 import android.text.SpannableStringBuilder;
  34 import android.text.Spanned;
  35 import android.text.style.ForegroundColorSpan;
  36 import android.view.LayoutInflater;
  37 import android.view.WindowManager;
  38 import android.widget.TextView;
  39
  40 import com.stoutner.privacybrowser.activities.MainWebViewActivity;
  41 import com.stoutner.privacybrowser.R;
  42
  43 import java.lang.ref.WeakReference;
  44 import java.net.InetAddress;
  45 import java.net.UnknownHostException;
  46 import java.text.DateFormat;
  47 import java.util.Calendar;
  48 import java.util.Date;
  49
  50 // `@SuppressLing("InflateParams")` removes the warning about using `null` as the parent view group when inflating the `AlertDialog`.
  51 @SuppressLint("InflateParams")
  52 public class ViewSslCertificateDialog extends DialogFragment {
  53     public Dialog onCreateDialog(Bundle savedInstanceState) {
  54         // Get the activity's layout inflater.
  55         LayoutInflater layoutInflater   = getActivity().getLayoutInflater();
  56
  57         // Create a drawable version of the favorite icon.
  58         Drawable favoriteIconDrawable = new BitmapDrawable(getResources(), MainWebViewActivity.favoriteIconBitmap);
  59
  60         // Use a builder to create the alert dialog.
  61         AlertDialog.Builder dialogBuilder;
  62
  63         // Set the style according to the theme.
  64         if (MainWebViewActivity.darkTheme) {
  65             dialogBuilder = new AlertDialog.Builder(getActivity(), R.style.PrivacyBrowserAlertDialogDark);
  66         } else {
  67             dialogBuilder = new AlertDialog.Builder(getActivity(), R.style.PrivacyBrowserAlertDialogLight);
  68         }
  69
  70         // Set the icon.
  71         dialogBuilder.setIcon(favoriteIconDrawable);
  72
  73         // Set a listener on the negative button.  Using `null` as the listener closes the dialog without doing anything else.
  74         dialogBuilder.setNegativeButton(R.string.close, null);
  75
  76         // Check to see if the website is encrypted.
  77         if (MainWebViewActivity.sslCertificate == null) {  // The website is not encrypted.
  78             // Set the title.
  79             dialogBuilder.setTitle(R.string.unencrypted_website);
  80
  81             // Set the Layout.  The parent view is `null` because it will be assigned by `AlertDialog`.
  82             dialogBuilder.setView(layoutInflater.inflate(R.layout.unencrypted_website, null));
  83
  84             // Create an alert dialog from the alert dialog builder.
  85             final AlertDialog alertDialog = dialogBuilder.create();
  86
  87             // Disable screenshots if not allowed.
  88             if (!MainWebViewActivity.allowScreenshots) {
  89                 // Remove the warning below that `getWindow()` might be null.
  90                 assert alertDialog.getWindow() != null;
  91
  92                 // Disable screenshots.
  93                 alertDialog.getWindow().addFlags(WindowManager.LayoutParams.FLAG_SECURE);
  94             }
  95
  96             // `onCreateDialog` requires the return of an `AlertDialog`.
  97             return alertDialog;
  98
  99         } else {  // Display the SSL certificate information
 100             // Set the title.
 101             dialogBuilder.setTitle(R.string.ssl_certificate);
 102
 103             // Set the layout.  The parent view is `null` because it will be assigned by `AlertDialog`.
 104             dialogBuilder.setView(layoutInflater.inflate(R.layout.view_ssl_certificate, null));
 105
 106             // Create an alert dialog from the builder.
 107             final AlertDialog alertDialog = dialogBuilder.create();
 108
 109             // Disable screenshots if not allowed.
 110             if (!MainWebViewActivity.allowScreenshots) {
 111                 // Remove the warning below that `getWindow()` might be null.
 112                 assert alertDialog.getWindow() != null;
 113
 114                 // Disable screenshots.
 115                 alertDialog.getWindow().addFlags(WindowManager.LayoutParams.FLAG_SECURE);
 116             }
 117
 118             // The alert dialog must be shown before items in the layout can be modified.
 119             alertDialog.show();
 120
 121             // Get handles for the text views.
 122             TextView domainTextView = alertDialog.findViewById(R.id.domain);
 123             TextView ipAddressesTextView = alertDialog.findViewById(R.id.ip_addresses);
 124             TextView issuedToCNameTextView = alertDialog.findViewById(R.id.issued_to_cname);
 125             TextView issuedToONameTextView = alertDialog.findViewById(R.id.issued_to_oname);
 126             TextView issuedToUNameTextView = alertDialog.findViewById(R.id.issued_to_uname);
 127             TextView issuedByCNameTextView = alertDialog.findViewById(R.id.issued_by_cname);
 128             TextView issuedByONameTextView = alertDialog.findViewById(R.id.issued_by_oname);
 129             TextView issuedByUNameTextView = alertDialog.findViewById(R.id.issued_by_uname);
 130             TextView startDateTextView = alertDialog.findViewById(R.id.start_date);
 131             TextView endDateTextView = alertDialog.findViewById(R.id.end_date);
 132
 133             // Setup the labels.
 134             String domainLabel = getString(R.string.domain_label) + "  ";
 135             String cNameLabel = getString(R.string.common_name) + "  ";
 136             String oNameLabel = getString(R.string.organization) + "  ";
 137             String uNameLabel = getString(R.string.organizational_unit) + "  ";
 138             String startDateLabel = getString(R.string.start_date) + "  ";
 139             String endDateLabel = getString(R.string.end_date) + "  ";
 140
 141             // Convert the formatted URL string to a URI.
 142             Uri uri = Uri.parse(MainWebViewActivity.formattedUrlString);
 143
 144             // Extract the domain name from the URI.
 145             String domainString = uri.getHost();
 146
 147             // Get the IP addresses.
 148             new GetIpAddresses(getActivity(), alertDialog).execute(domainString);
 149
 150             // Get the SSL certificate.
 151             SslCertificate sslCertificate = MainWebViewActivity.sslCertificate;
 152
 153             // Get the strings from the SSL certificate.
 154             String issuedToCName = sslCertificate.getIssuedTo().getCName();
 155             String issuedToOName = sslCertificate.getIssuedTo().getOName();
 156             String issuedToUName = sslCertificate.getIssuedTo().getUName();
 157             String issuedByCName = sslCertificate.getIssuedBy().getCName();
 158             String issuedByOName = sslCertificate.getIssuedBy().getOName();
 159             String issuedByUName = sslCertificate.getIssuedBy().getUName();
 160             Date startDate = sslCertificate.getValidNotBeforeDate();
 161             Date endDate = sslCertificate.getValidNotAfterDate();
 162
 163             // Create spannable string builders for each text view that needs multiple colors of text.
 164             SpannableStringBuilder domainStringBuilder = new SpannableStringBuilder(domainLabel + domainString);
 165             SpannableStringBuilder issuedToCNameStringBuilder = new SpannableStringBuilder(cNameLabel + issuedToCName);
 166             SpannableStringBuilder issuedToONameStringBuilder = new SpannableStringBuilder(oNameLabel + issuedToOName);
 167             SpannableStringBuilder issuedToUNameStringBuilder = new SpannableStringBuilder(uNameLabel + issuedToUName);
 168             SpannableStringBuilder issuedByCNameStringBuilder = new SpannableStringBuilder(cNameLabel + issuedByCName);
 169             SpannableStringBuilder issuedByONameStringBuilder = new SpannableStringBuilder(oNameLabel + issuedByOName);
 170             SpannableStringBuilder issuedByUNameStringBuilder = new SpannableStringBuilder(uNameLabel + issuedByUName);
 171             SpannableStringBuilder startDateStringBuilder = new SpannableStringBuilder(startDateLabel + DateFormat.getDateTimeInstance(DateFormat.MEDIUM, DateFormat.LONG).format(startDate));
 172             SpannableStringBuilder endDateStringBuilder = new SpannableStringBuilder(endDateLabel + DateFormat.getDateTimeInstance(DateFormat.MEDIUM, DateFormat.LONG).format(endDate));
 173
 174             // Create a red foreground color span.  The deprecated `getColor` must be used until the minimum API >= 23.
 175             @SuppressWarnings("deprecation") ForegroundColorSpan redColorSpan = new ForegroundColorSpan(getResources().getColor(R.color.red_a700));
 176
 177             // Create a blue foreground color span.
 178             ForegroundColorSpan blueColorSpan;
 179
 180             // Set the blue color span according to the theme.  The deprecated `getColor()` must be used until the minimum API >= 23.
 181             if (MainWebViewActivity.darkTheme) {
 182                 //noinspection deprecation
 183                 blueColorSpan = new ForegroundColorSpan(getResources().getColor(R.color.blue_400));
 184             } else {
 185                 //noinspection deprecation
 186                 blueColorSpan = new ForegroundColorSpan(getResources().getColor(R.color.blue_700));
 187             }
 188
 189             // Remove the incorrect lint error that `.equals` might produce a NullPointerException.
 190             assert domainString != null;
 191
 192             // Formet the `domainString` and `issuedToCName` colors.
 193             if (domainString.equals(issuedToCName)) {  // `domainString` and `issuedToCName` match.
 194                 // Set the strings to be blue.
 195                 domainStringBuilder.setSpan(blueColorSpan, domainLabel.length(), domainStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 196                 issuedToCNameStringBuilder.setSpan(blueColorSpan, cNameLabel.length(), issuedToCNameStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 197             } else if(issuedToCName.startsWith("*.")){  // `issuedToCName` begins with a wildcard.
 198                 // Remove the initial `*.`.
 199                 String baseCertificateDomain = issuedToCName.substring(2);
 200
 201                 // Setup a copy of `domainString` to test subdomains.
 202                 String domainStringSubdomain = domainString;
 203
 204                 // Initialize `domainNamesMatch`.
 205                 boolean domainNamesMatch = false;
 206
 207                 // Check all the subdomains in `domainStringSubdomain` against `baseCertificateDomain`.
 208                 while (!domainNamesMatch && domainStringSubdomain.contains(".")) {  // Stop checking if we know that `domainNamesMatch` is `true` or if we run out of  `.`.
 209                     // Test the `domainStringSubdomain` against `baseCertificateDomain`.
 210                     if (domainStringSubdomain.equals(baseCertificateDomain)) {
 211                         domainNamesMatch = true;
 212                     }
 213
 214                     // Strip out the lowest subdomain of `certificateCommonNameSubdomain`.
 215                     domainStringSubdomain = domainStringSubdomain.substring(domainStringSubdomain.indexOf(".") + 1);
 216                 }
 217
 218                 // Format the domain and issued to Common Name according to `domainNamesMatch`.
 219                 if (domainNamesMatch) {  // `domainString` is a subdomain of the wildcard `issuedToCNameString`.
 220                     // Set the strings to be blue.
 221                     domainStringBuilder.setSpan(blueColorSpan, domainLabel.length(), domainStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 222                     issuedToCNameStringBuilder.setSpan(blueColorSpan, cNameLabel.length(), issuedToCNameStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 223                 } else {  // `domainString` is not a subdomain of the wildcard `issuedToCNameString`.
 224                     // Set the string to be red.
 225                     domainStringBuilder.setSpan(redColorSpan, domainLabel.length(), domainStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 226                     issuedToCNameStringBuilder.setSpan(redColorSpan, cNameLabel.length(), issuedToCNameStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 227                 }
 228             } else {  // The strings do not match and `issuedToCNameString` does not begin with a wildcard.
 229                 // Set the strings to be red.
 230                 domainStringBuilder.setSpan(redColorSpan, domainLabel.length(), domainStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 231                 issuedToCNameStringBuilder.setSpan(redColorSpan, cNameLabel.length(), issuedToCNameStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 232             }
 233
 234             // Set the issued to and issued by spans to display the certificate information in blue.  `SPAN_INCLUSIVE_INCLUSIVE` allows the span to grow in either direction.
 235             issuedToONameStringBuilder.setSpan(blueColorSpan, oNameLabel.length(), issuedToONameStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 236             issuedToUNameStringBuilder.setSpan(blueColorSpan, uNameLabel.length(), issuedToUNameStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 237             issuedByCNameStringBuilder.setSpan(blueColorSpan, cNameLabel.length(), issuedByCNameStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 238             issuedByONameStringBuilder.setSpan(blueColorSpan, oNameLabel.length(), issuedByONameStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 239             issuedByUNameStringBuilder.setSpan(blueColorSpan, uNameLabel.length(), issuedByUNameStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 240
 241             Date currentDate = Calendar.getInstance().getTime();
 242
 243             //  Format the start date color.  `SPAN_INCLUSIVE_INCLUSIVE` allows the span to grow in either direction.
 244             if (startDate.after(currentDate)) {  // The certificate start date is in the future.
 245                 startDateStringBuilder.setSpan(redColorSpan, startDateLabel.length(), startDateStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 246             } else {  // The certificate start date is in the past.
 247                 startDateStringBuilder.setSpan(blueColorSpan, startDateLabel.length(), startDateStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 248             }
 249
 250             // Format the end date color.  `SPAN_INCLUSIVE_INCLUSIVE` allows the span to grow in either direction.
 251             if (endDate.before(currentDate)) {  // The certificate end date is in the past.
 252                 endDateStringBuilder.setSpan(redColorSpan, endDateLabel.length(), endDateStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 253             } else {  // The certificate end date is in the future.
 254                 endDateStringBuilder.setSpan(blueColorSpan, endDateLabel.length(), endDateStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 255             }
 256
 257             // Display the strings.
 258             domainTextView.setText(domainStringBuilder);
 259             ipAddressesTextView.setText(getString(R.string.ip_addresses));
 260             issuedToCNameTextView.setText(issuedToCNameStringBuilder);
 261             issuedToONameTextView.setText(issuedToONameStringBuilder);
 262             issuedToUNameTextView.setText(issuedToUNameStringBuilder);
 263             issuedByCNameTextView.setText(issuedByCNameStringBuilder);
 264             issuedByONameTextView.setText(issuedByONameStringBuilder);
 265             issuedByUNameTextView.setText(issuedByUNameStringBuilder);
 266             startDateTextView.setText(startDateStringBuilder);
 267             endDateTextView.setText(endDateStringBuilder);
 268
 269             // `onCreateDialog` requires the return of an `AlertDialog`.
 270             return alertDialog;
 271         }
 272     }
 273
 274     // This must run asynchronously because it involves a network request.  `String` declares the parameters.  `Void` does not declare progress units.  `String` contains the results.
 275     private static class GetIpAddresses extends AsyncTask<String, Void, SpannableStringBuilder> {
 276         // The weak references are used to determine if the activity or the alert dialog have disappeared while the AsyncTask is running.
 277         private WeakReference<Activity> activityWeakReference;
 278         private WeakReference<AlertDialog> alertDialogWeakReference;
 279
 280         GetIpAddresses(Activity activity, AlertDialog alertDialog) {
 281             // Populate the weak references.
 282             activityWeakReference = new WeakReference<>(activity);
 283             alertDialogWeakReference = new WeakReference<>(alertDialog);
 284         }
 285
 286         @Override
 287         protected SpannableStringBuilder doInBackground(String... domainName) {
 288             // Get handles for the activity and the alert dialog.
 289             Activity activity = activityWeakReference.get();
 290             AlertDialog alertDialog = alertDialogWeakReference.get();
 291
 292             // Abort if the activity or the dialog is gone.
 293             if ((activity == null) || (activity.isFinishing()) || (alertDialog == null)) {
 294                 return new SpannableStringBuilder();
 295             }
 296
 297             // Initialize an IP address string builder.
 298             StringBuilder ipAddresses = new StringBuilder();
 299
 300             // Get an array with the IP addresses for the host.
 301             try {
 302                 // Get an array with all the IP addresses for the domain.
 303                 InetAddress[] inetAddressesArray = InetAddress.getAllByName(domainName[0]);
 304
 305                 // Add each IP address to the string builder.
 306                 for (InetAddress inetAddress : inetAddressesArray) {
 307                     if (ipAddresses.length() == 0) {  // This is the first IP address.
 308                         // Add the IP Address to the string builder.
 309                         ipAddresses.append(inetAddress.getHostAddress());
 310                     } else {  // This is not the first IP address.
 311                         // Add a line break to the string builder first.
 312                         ipAddresses.append("\n");
 313
 314                         // Add the IP address to the string builder.
 315                         ipAddresses.append(inetAddress.getHostAddress());
 316                     }
 317                 }
 318             } catch (UnknownHostException exception) {
 319                 // Do nothing.
 320             }
 321
 322             // Set the label.
 323             String ipAddressesLabel = activity.getString(R.string.ip_addresses) + "  ";
 324
 325             // Create a spannable string builder.
 326             SpannableStringBuilder ipAddressesStringBuilder = new SpannableStringBuilder(ipAddressesLabel + ipAddresses);
 327
 328             // Create a blue foreground color span.
 329             ForegroundColorSpan blueColorSpan;
 330
 331             // Set the blue color span according to the theme.  The deprecated `getColor()` must be used until the minimum API >= 23.
 332             if (MainWebViewActivity.darkTheme) {
 333                 //noinspection deprecation
 334                 blueColorSpan = new ForegroundColorSpan(activity.getResources().getColor(R.color.blue_400));
 335             } else {
 336                 //noinspection deprecation
 337                 blueColorSpan = new ForegroundColorSpan(activity.getResources().getColor(R.color.blue_700));
 338             }
 339
 340             // Set the string builder to display the certificate information in blue.  `SPAN_INCLUSIVE_INCLUSIVE` allows the span to grow in either direction.
 341             ipAddressesStringBuilder.setSpan(blueColorSpan, ipAddressesLabel.length(), ipAddressesStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 342
 343             // Return the formatted string.
 344             return ipAddressesStringBuilder;
 345         }
 346
 347         // `onPostExecute()` operates on the UI thread.
 348         @Override
 349         protected void onPostExecute(SpannableStringBuilder ipAddresses) {
 350             // Get handles for the activity and the alert dialog.
 351             Activity activity = activityWeakReference.get();
 352             AlertDialog alertDialog = alertDialogWeakReference.get();
 353
 354             // Abort if the activity or the alert dialog is gone.
 355             if ((activity == null) || (activity.isFinishing()) || (alertDialog == null)) {
 356                 return;
 357             }
 358
 359             // Get a handle for the IP addresses text view.
 360             TextView ipAddressesTextView = alertDialog.findViewById(R.id.ip_addresses);
 361
 362             // Populate the IP addresses text view.
 363             ipAddressesTextView.setText(ipAddresses);
 364         }
 365     }
 366 }