app/src/main/java/com/stoutner/privacybrowser/dialogs/SslCertificateErrorDialog.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.content.Context;
  27 import android.content.DialogInterface;
  28 import android.content.SharedPreferences;
  29 import android.net.Uri;
  30 import android.net.http.SslCertificate;
  31 import android.net.http.SslError;
  32 import android.os.AsyncTask;
  33 import android.os.Bundle;
  34 import android.preference.PreferenceManager;
  35 import android.text.SpannableStringBuilder;
  36 import android.text.Spanned;
  37 import android.text.style.ForegroundColorSpan;
  38 import android.view.LayoutInflater;
  39 import android.view.WindowManager;
  40 import android.widget.TextView;
  41
  42 import androidx.annotation.NonNull;
  43 import androidx.fragment.app.DialogFragment;  // The AndroidX dialog fragment must be used or an error is produced on API <=22.
  44
  45 import com.stoutner.privacybrowser.R;
  46
  47 import java.lang.ref.WeakReference;
  48 import java.net.InetAddress;
  49 import java.net.UnknownHostException;
  50 import java.text.DateFormat;
  51 import java.util.Date;
  52
  53 public class SslCertificateErrorDialog extends DialogFragment {
  54     // `sslCertificateErrorListener` is used in `onAttach` and `onCreateDialog`.
  55     private SslCertificateErrorListener sslCertificateErrorListener;
  56
  57     // The public interface is used to send information back to the parent activity.
  58     public interface SslCertificateErrorListener {
  59         void onSslErrorCancel();
  60
  61         void onSslErrorProceed();
  62     }
  63
  64     public void onAttach(Context context) {
  65         // Run the default commands.
  66         super.onAttach(context);
  67
  68         // Get a handle for `SslCertificateErrorListener` from the launching context.
  69         sslCertificateErrorListener = (SslCertificateErrorListener) context;
  70     }
  71
  72     public static SslCertificateErrorDialog displayDialog(SslError error) {
  73         // Get the various components of the SSL error message.
  74         int primaryErrorIntForBundle = error.getPrimaryError();
  75         String urlWithErrorForBundle = error.getUrl();
  76         SslCertificate sslCertificate = error.getCertificate();
  77         String issuedToCNameForBundle = sslCertificate.getIssuedTo().getCName();
  78         String issuedToONameForBundle = sslCertificate.getIssuedTo().getOName();
  79         String issuedToUNameForBundle = sslCertificate.getIssuedTo().getUName();
  80         String issuedByCNameForBundle = sslCertificate.getIssuedBy().getCName();
  81         String issuedByONameForBundle = sslCertificate.getIssuedBy().getOName();
  82         String issuedByUNameForBundle = sslCertificate.getIssuedBy().getUName();
  83         Date startDateForBundle = sslCertificate.getValidNotBeforeDate();
  84         Date endDateForBundle = sslCertificate.getValidNotAfterDate();
  85
  86         // Store the SSL error message components in a `Bundle`.
  87         Bundle argumentsBundle = new Bundle();
  88         argumentsBundle.putInt("PrimaryErrorInt", primaryErrorIntForBundle);
  89         argumentsBundle.putString("UrlWithError", urlWithErrorForBundle);
  90         argumentsBundle.putString("IssuedToCName", issuedToCNameForBundle);
  91         argumentsBundle.putString("IssuedToOName", issuedToONameForBundle);
  92         argumentsBundle.putString("IssuedToUName", issuedToUNameForBundle);
  93         argumentsBundle.putString("IssuedByCName", issuedByCNameForBundle);
  94         argumentsBundle.putString("IssuedByOName", issuedByONameForBundle);
  95         argumentsBundle.putString("IssuedByUName", issuedByUNameForBundle);
  96         argumentsBundle.putString("StartDate", DateFormat.getDateTimeInstance(DateFormat.MEDIUM, DateFormat.LONG).format(startDateForBundle));
  97         argumentsBundle.putString("EndDate", DateFormat.getDateTimeInstance(DateFormat.MEDIUM, DateFormat.LONG).format(endDateForBundle));
  98
  99         // Add `argumentsBundle` to this instance of `SslCertificateErrorDialog`.
 100         SslCertificateErrorDialog thisSslCertificateErrorDialog = new SslCertificateErrorDialog();
 101         thisSslCertificateErrorDialog.setArguments(argumentsBundle);
 102         return thisSslCertificateErrorDialog;
 103     }
 104
 105     // `@SuppressLing("InflateParams")` removes the warning about using `null` as the parent view group when inflating the `AlertDialog`.
 106     @SuppressLint("InflateParams")
 107     @SuppressWarnings("deprecation")
 108     @Override
 109     @NonNull
 110     public Dialog onCreateDialog(Bundle savedInstanceState) {
 111         // Remove the incorrect lint warning that `getArguments()` might be null.
 112         assert getArguments() != null;
 113
 114         // Get the components of the SSL error message from the bundle.
 115         int primaryErrorInt = getArguments().getInt("PrimaryErrorInt");
 116         String urlWithErrors = getArguments().getString("UrlWithError");
 117         String issuedToCName = getArguments().getString("IssuedToCName");
 118         String issuedToOName = getArguments().getString("IssuedToOName");
 119         String issuedToUName = getArguments().getString("IssuedToUName");
 120         String issuedByCName = getArguments().getString("IssuedByCName");
 121         String issuedByOName = getArguments().getString("IssuedByOName");
 122         String issuedByUName = getArguments().getString("IssuedByUName");
 123         String startDate = getArguments().getString("StartDate");
 124         String endDate = getArguments().getString("EndDate");
 125
 126         // Remove the incorrect lint warning that `getActivity()` might be null.
 127         assert getActivity() != null;
 128
 129         // Get the activity's layout inflater.
 130         LayoutInflater layoutInflater = getActivity().getLayoutInflater();
 131
 132         // Use an alert dialog builder to create the alert dialog.
 133         AlertDialog.Builder dialogBuilder;
 134
 135         // Get a handle for the shared preferences.
 136         SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(getContext());
 137
 138         // Get the screenshot and theme preferences.
 139         boolean darkTheme = sharedPreferences.getBoolean("dark_theme", false);
 140         boolean allowScreenshots = sharedPreferences.getBoolean("allow_screenshots", false);
 141
 142         // Set the style and icon according to the theme.
 143         if (darkTheme) {
 144             // Set the style.
 145             dialogBuilder = new AlertDialog.Builder(getActivity(), R.style.PrivacyBrowserAlertDialogDark);
 146
 147             // Set the icon.
 148             dialogBuilder.setIcon(R.drawable.ssl_certificate_enabled_dark);
 149         } else {
 150             // Set the style.
 151             dialogBuilder = new AlertDialog.Builder(getActivity(), R.style.PrivacyBrowserAlertDialogLight);
 152
 153             // Set the icon.
 154             dialogBuilder.setIcon(R.drawable.ssl_certificate_enabled_light);
 155         }
 156
 157         // Set the title.
 158         dialogBuilder.setTitle(R.string.ssl_certificate_error);
 159
 160         // Set the view.  The parent view is `null` because it will be assigned by `AlertDialog`.
 161         dialogBuilder.setView(layoutInflater.inflate(R.layout.ssl_certificate_error, null));
 162
 163         // Set a listener on the negative button.
 164         dialogBuilder.setNegativeButton(R.string.cancel, (DialogInterface dialog, int which) -> sslCertificateErrorListener.onSslErrorCancel());
 165
 166         // Set a listener on the positive button.
 167         dialogBuilder.setPositiveButton(R.string.proceed, (DialogInterface dialog, int which) -> sslCertificateErrorListener.onSslErrorProceed());
 168
 169
 170         // Create an alert dialog from the alert dialog builder.
 171         AlertDialog alertDialog = dialogBuilder.create();
 172
 173         // Disable screenshots if not allowed.
 174         if (!allowScreenshots) {
 175             // Remove the warning below that `getWindow()` might be null.
 176             assert alertDialog.getWindow() != null;
 177
 178             // Disable screenshots.
 179             alertDialog.getWindow().addFlags(WindowManager.LayoutParams.FLAG_SECURE);
 180         }
 181
 182         // Get a URI for the URL with errors.
 183         Uri uriWithErrors = Uri.parse(urlWithErrors);
 184
 185         // Get the IP addresses for the URI.
 186         new GetIpAddresses(getActivity(), alertDialog).execute(uriWithErrors.getHost());
 187
 188         // The alert dialog must be shown before the contents can be modified.
 189         alertDialog.show();
 190
 191         // Get handles for the `TextViews`
 192         TextView primaryErrorTextView = alertDialog.findViewById(R.id.primary_error);
 193         TextView urlTextView = alertDialog.findViewById(R.id.url);
 194         TextView issuedToCNameTextView = alertDialog.findViewById(R.id.issued_to_cname);
 195         TextView issuedToONameTextView = alertDialog.findViewById(R.id.issued_to_oname);
 196         TextView issuedToUNameTextView = alertDialog.findViewById(R.id.issued_to_uname);
 197         TextView issuedByTextView = alertDialog.findViewById(R.id.issued_by_textview);
 198         TextView issuedByCNameTextView = alertDialog.findViewById(R.id.issued_by_cname);
 199         TextView issuedByONameTextView = alertDialog.findViewById(R.id.issued_by_oname);
 200         TextView issuedByUNameTextView = alertDialog.findViewById(R.id.issued_by_uname);
 201         TextView validDatesTextView = alertDialog.findViewById(R.id.valid_dates_textview);
 202         TextView startDateTextView = alertDialog.findViewById(R.id.start_date);
 203         TextView endDateTextView = alertDialog.findViewById(R.id.end_date);
 204
 205         // Setup the common strings.
 206         String urlLabel = getString(R.string.url_label) + "  ";
 207         String cNameLabel = getString(R.string.common_name) + "  ";
 208         String oNameLabel = getString(R.string.organization) + "  ";
 209         String uNameLabel = getString(R.string.organizational_unit) + "  ";
 210         String startDateLabel = getString(R.string.start_date) + "  ";
 211         String endDateLabel = getString(R.string.end_date) + "  ";
 212
 213         // Create a spannable string builder for each text view that needs multiple colors of text.
 214         SpannableStringBuilder urlStringBuilder = new SpannableStringBuilder(urlLabel + urlWithErrors);
 215         SpannableStringBuilder issuedToCNameStringBuilder = new SpannableStringBuilder(cNameLabel + issuedToCName);
 216         SpannableStringBuilder issuedToONameStringBuilder = new SpannableStringBuilder(oNameLabel + issuedToOName);
 217         SpannableStringBuilder issuedToUNameStringBuilder = new SpannableStringBuilder(uNameLabel + issuedToUName);
 218         SpannableStringBuilder issuedByCNameStringBuilder = new SpannableStringBuilder(cNameLabel + issuedByCName);
 219         SpannableStringBuilder issuedByONameStringBuilder = new SpannableStringBuilder(oNameLabel + issuedByOName);
 220         SpannableStringBuilder issuedByUNameStringBuilder = new SpannableStringBuilder(uNameLabel + issuedByUName);
 221         SpannableStringBuilder startDateStringBuilder = new SpannableStringBuilder(startDateLabel + startDate);
 222         SpannableStringBuilder endDateStringBuilder = new SpannableStringBuilder((endDateLabel + endDate));
 223
 224         // Create a red foreground color span.  The deprecated `getResources().getColor` must be used until the minimum API >= 23.
 225         @SuppressWarnings("deprecation") ForegroundColorSpan redColorSpan = new ForegroundColorSpan(getResources().getColor(R.color.red_a700));
 226
 227         // Create a blue `ForegroundColorSpan`.
 228         ForegroundColorSpan blueColorSpan;
 229
 230         // Set a blue color span according to the theme.  The deprecated `getResources().getColor` must be used until the minimum API >= 23.
 231         if (darkTheme) {
 232             //noinspection deprecation
 233             blueColorSpan = new ForegroundColorSpan(getResources().getColor(R.color.blue_400));
 234         } else {
 235             //noinspection deprecation
 236             blueColorSpan = new ForegroundColorSpan(getResources().getColor(R.color.blue_700));
 237         }
 238
 239         // Setup the spans to display the certificate information in blue.  `SPAN_INCLUSIVE_INCLUSIVE` allows the span to grow in either direction.
 240         urlStringBuilder.setSpan(blueColorSpan, urlLabel.length(), urlStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 241         issuedToCNameStringBuilder.setSpan(blueColorSpan, cNameLabel.length(), issuedToCNameStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 242         issuedToONameStringBuilder.setSpan(blueColorSpan, oNameLabel.length(), issuedToONameStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 243         issuedToUNameStringBuilder.setSpan(blueColorSpan, uNameLabel.length(), issuedToUNameStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 244         issuedByCNameStringBuilder.setSpan(blueColorSpan, cNameLabel.length(), issuedByCNameStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 245         issuedByONameStringBuilder.setSpan(blueColorSpan, oNameLabel.length(), issuedByONameStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 246         issuedByUNameStringBuilder.setSpan(blueColorSpan, uNameLabel.length(), issuedByUNameStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 247         startDateStringBuilder.setSpan(blueColorSpan, startDateLabel.length(), startDateStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 248         endDateStringBuilder.setSpan(blueColorSpan, endDateLabel.length(), endDateStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 249
 250         // Initialize `primaryErrorString`.
 251         String primaryErrorString = "";
 252
 253         // Highlight the primary error in red and store the primary error string in `primaryErrorString`.
 254         switch (primaryErrorInt) {
 255             case SslError.SSL_IDMISMATCH:
 256                 // Change the URL span colors to red.
 257                 urlStringBuilder.setSpan(redColorSpan, urlLabel.length(), urlStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 258                 issuedToCNameStringBuilder.setSpan(redColorSpan, cNameLabel.length(), issuedToCNameStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 259
 260                 // Store the primary error string.
 261                 primaryErrorString = getString(R.string.cn_mismatch);
 262                 break;
 263
 264             case SslError.SSL_UNTRUSTED:
 265                 // Change the issued by text view text to red.  The deprecated `getResources().getColor` must be used until the minimum API >= 23.
 266                 issuedByTextView.setTextColor(getResources().getColor(R.color.red_a700));
 267
 268                 // Change the issued by span color to red.
 269                 issuedByCNameStringBuilder.setSpan(redColorSpan, cNameLabel.length(), issuedByCNameStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 270                 issuedByONameStringBuilder.setSpan(redColorSpan, oNameLabel.length(), issuedByONameStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 271                 issuedByUNameStringBuilder.setSpan(redColorSpan, uNameLabel.length(), issuedByUNameStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 272
 273                 // Store the primary error string.
 274                 primaryErrorString = getString(R.string.untrusted);
 275                 break;
 276
 277             case SslError.SSL_DATE_INVALID:
 278                 // Change the valid dates text view text to red.  The deprecated `getResources().getColor` must be used until the minimum API >= 23.
 279                 validDatesTextView.setTextColor(getResources().getColor(R.color.red_a700));
 280
 281                 // Change the date span colors to red.
 282                 startDateStringBuilder.setSpan(redColorSpan, startDateLabel.length(), startDateStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 283                 endDateStringBuilder.setSpan(redColorSpan, endDateLabel.length(), endDateStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 284
 285                 // Store the primary error string.
 286                 primaryErrorString = getString(R.string.invalid_date);
 287                 break;
 288
 289             case SslError.SSL_NOTYETVALID:
 290                 // Change the start date span color to red.
 291                 startDateStringBuilder.setSpan(redColorSpan, startDateLabel.length(), startDateStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 292
 293                 // Store the primary error string.
 294                 primaryErrorString = getString(R.string.future_certificate);
 295                 break;
 296
 297             case SslError.SSL_EXPIRED:
 298                 // Change the end date span color to red.
 299                 endDateStringBuilder.setSpan(redColorSpan, endDateLabel.length(), endDateStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 300
 301                 // Store the primary error string.
 302                 primaryErrorString = getString(R.string.expired_certificate);
 303                 break;
 304
 305             case SslError.SSL_INVALID:
 306                 // Store the primary error string.
 307                 primaryErrorString = getString(R.string.invalid_certificate);
 308                 break;
 309         }
 310
 311
 312         // Display the strings.
 313         primaryErrorTextView.setText(primaryErrorString);
 314         urlTextView.setText(urlStringBuilder);
 315         issuedToCNameTextView.setText(issuedToCNameStringBuilder);
 316         issuedToONameTextView.setText(issuedToONameStringBuilder);
 317         issuedToUNameTextView.setText(issuedToUNameStringBuilder);
 318         issuedByCNameTextView.setText(issuedByCNameStringBuilder);
 319         issuedByONameTextView.setText(issuedByONameStringBuilder);
 320         issuedByUNameTextView.setText(issuedByUNameStringBuilder);
 321         startDateTextView.setText(startDateStringBuilder);
 322         endDateTextView.setText(endDateStringBuilder);
 323
 324         // `onCreateDialog` requires the return of an alert dialog.
 325         return alertDialog;
 326     }
 327
 328
 329     // This must run asynchronously because it involves a network request.  `String` declares the parameters.  `Void` does not declare progress units.  `SpannableStringBuilder` contains the results.
 330     private static class GetIpAddresses extends AsyncTask<String, Void, SpannableStringBuilder> {
 331         // The weak references are used to determine if the activity or the alert dialog have disappeared while the AsyncTask is running.
 332         private WeakReference<Activity> activityWeakReference;
 333         private WeakReference<AlertDialog> alertDialogWeakReference;
 334
 335         GetIpAddresses(Activity activity, AlertDialog alertDialog) {
 336             // Populate the weak references.
 337             activityWeakReference = new WeakReference<>(activity);
 338             alertDialogWeakReference = new WeakReference<>(alertDialog);
 339         }
 340
 341         @Override
 342         protected SpannableStringBuilder doInBackground(String... domainName) {
 343             // Get handles for the activity and the alert dialog.
 344             Activity activity = activityWeakReference.get();
 345             AlertDialog alertDialog = alertDialogWeakReference.get();
 346
 347             // Abort if the activity or the dialog is gone.
 348             if ((activity == null) || (activity.isFinishing()) || (alertDialog == null)) {
 349                 return new SpannableStringBuilder();
 350             }
 351
 352             // Initialize an IP address string builder.
 353             StringBuilder ipAddresses = new StringBuilder();
 354
 355             // Get an array with the IP addresses for the host.
 356             try {
 357                 // Get an array with all the IP addresses for the domain.
 358                 InetAddress[] inetAddressesArray = InetAddress.getAllByName(domainName[0]);
 359
 360                 // Add each IP address to the string builder.
 361                 for (InetAddress inetAddress : inetAddressesArray) {
 362                     if (ipAddresses.length() == 0) {  // This is the first IP address.
 363                         // Add the IP Address to the string builder.
 364                         ipAddresses.append(inetAddress.getHostAddress());
 365                     } else {  // This is not the first IP address.
 366                         // Add a line break to the string builder first.
 367                         ipAddresses.append("\n");
 368
 369                         // Add the IP address to the string builder.
 370                         ipAddresses.append(inetAddress.getHostAddress());
 371                     }
 372                 }
 373             } catch (UnknownHostException exception) {
 374                 // Do nothing.
 375             }
 376
 377             // Set the label.
 378             String ipAddressesLabel = activity.getString(R.string.ip_addresses) + "  ";
 379
 380             // Create a spannable string builder.
 381             SpannableStringBuilder ipAddressesStringBuilder = new SpannableStringBuilder(ipAddressesLabel + ipAddresses);
 382
 383             // Get a handle for the shared preferences.
 384             SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(activity.getApplicationContext());
 385
 386             // Get the screenshot and theme preferences.
 387             boolean darkTheme = sharedPreferences.getBoolean("dark_theme", false);
 388
 389             // Create a blue foreground color span.
 390             ForegroundColorSpan blueColorSpan;
 391
 392             // Set the blue color span according to the theme.  The deprecated `getColor()` must be used until the minimum API >= 23.
 393             if (darkTheme) {
 394                 //noinspection deprecation
 395                 blueColorSpan = new ForegroundColorSpan(activity.getResources().getColor(R.color.blue_400));
 396             } else {
 397                 //noinspection deprecation
 398                 blueColorSpan = new ForegroundColorSpan(activity.getResources().getColor(R.color.blue_700));
 399             }
 400
 401             // Set the string builder to display the certificate information in blue.  `SPAN_INCLUSIVE_INCLUSIVE` allows the span to grow in either direction.
 402             ipAddressesStringBuilder.setSpan(blueColorSpan, ipAddressesLabel.length(), ipAddressesStringBuilder.length(), Spanned.SPAN_INCLUSIVE_INCLUSIVE);
 403
 404             // Return the formatted string.
 405             return ipAddressesStringBuilder;
 406         }
 407
 408         // `onPostExecute()` operates on the UI thread.
 409         @Override
 410         protected void onPostExecute(SpannableStringBuilder ipAddresses) {
 411             // Get handles for the activity and the alert dialog.
 412             Activity activity = activityWeakReference.get();
 413             AlertDialog alertDialog = alertDialogWeakReference.get();
 414
 415             // Abort if the activity or the alert dialog is gone.
 416             if ((activity == null) || (activity.isFinishing()) || (alertDialog == null)) {
 417                 return;
 418             }
 419
 420             // Get a handle for the IP addresses text view.
 421             TextView ipAddressesTextView = alertDialog.findViewById(R.id.ip_addresses);
 422
 423             // Populate the IP addresses text view.
 424             ipAddressesTextView.setText(ipAddresses);
 425         }
 426     }
 427 }