aboutsummaryrefslogtreecommitdiffstats
path: root/Bugzilla/Token.pm
blob: f7caa0e31608aa03b88a043ed1ae94cb51f9749f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this
# file, You can obtain one at http://mozilla.org/MPL/2.0/.
#
# This Source Code Form is "Incompatible With Secondary Licenses", as
# defined by the Mozilla Public License, v. 2.0.

package Bugzilla::Token;

use 5.10.1;
use strict;

use Bugzilla::Constants;
use Bugzilla::Error;
use Bugzilla::Mailer;
use Bugzilla::Util;
use Bugzilla::User;

use Date::Format;
use Date::Parse;
use File::Basename;
use Digest::SHA qw(hmac_sha256_base64);

use base qw(Exporter);

@Bugzilla::Token::EXPORT = qw(issue_session_token check_token_data delete_token
                              issue_hash_token check_hash_token);

################################################################################
# Public Functions
################################################################################

# Creates and sends a token to create a new user account.
# It assumes that the login has the correct format and is not already in use.
sub issue_new_user_account_token {
    my $login_name = shift;
    my $dbh = Bugzilla->dbh;
    my $template = Bugzilla->template;
    my $vars = {};

    # Is there already a pending request for this login name? If yes, do not throw
    # an error because the user may have lost his email with the token inside.
    # But to prevent using this way to mailbomb an email address, make sure
    # the last request is old enough before sending a new email (default: 10 minutes).

    my $pending_requests = $dbh->selectrow_array(
        'SELECT COUNT(*)
           FROM tokens
          WHERE tokentype = ?
                AND ' . $dbh->sql_istrcmp('eventdata', '?') . '
                AND issuedate > '
                    . $dbh->sql_date_math('NOW()', '-', ACCOUNT_CHANGE_INTERVAL, 'MINUTE'),
        undef, ('account', $login_name));

    ThrowUserError('too_soon_for_new_token', {'type' => 'account'}) if $pending_requests;

    my ($token, $token_ts) = _create_token(undef, 'account', $login_name);

    $vars->{'email'} = $login_name . Bugzilla->params->{'emailsuffix'};
    $vars->{'expiration_ts'} = ctime($token_ts + MAX_TOKEN_AGE * 86400);
    $vars->{'token'} = $token;

    my $message;
    $template->process('account/email/request-new.txt.tmpl', $vars, \$message)
      || ThrowTemplateError($template->error());

    # In 99% of cases, the user getting the confirmation email is the same one
    # who made the request, and so it is reasonable to send the email in the same
    # language used to view the "Create a New Account" page (we cannot use his
    # user prefs as the user has no account yet!).
    MessageToMTA($message);
}

sub IssueEmailChangeToken {
    my ($user, $new_email) = @_;
    my $email_suffix = Bugzilla->params->{'emailsuffix'};
    my $old_email = $user->login;

    my ($token, $token_ts) = _create_token($user->id, 'emailold', $old_email . ":" . $new_email);

    my $newtoken = _create_token($user->id, 'emailnew', $old_email . ":" . $new_email);

    # Mail the user the token along with instructions for using it.

    my $template = Bugzilla->template_inner($user->setting('lang'));
    my $vars = {};

    $vars->{'oldemailaddress'} = $old_email . $email_suffix;
    $vars->{'newemailaddress'} = $new_email . $email_suffix;
    $vars->{'expiration_ts'} = ctime($token_ts + MAX_TOKEN_AGE * 86400);
    $vars->{'token'} = $token;
    $vars->{'emailaddress'} = $old_email . $email_suffix;

    my $message;
    $template->process("account/email/change-old.txt.tmpl", $vars, \$message)
      || ThrowTemplateError($template->error());

    MessageToMTA($message);

    $vars->{'token'} = $newtoken;
    $vars->{'emailaddress'} = $new_email . $email_suffix;

    $message = "";
    $template->process("account/email/change-new.txt.tmpl", $vars, \$message)
      || ThrowTemplateError($template->error());

    MessageToMTA($message);
}

# Generates a random token, adds it to the tokens table, and sends it
# to the user with instructions for using it to change their password.
sub IssuePasswordToken {
    my $user = shift;
    my $dbh = Bugzilla->dbh;

    my $too_soon = $dbh->selectrow_array(
        'SELECT 1 FROM tokens
          WHERE userid = ? AND tokentype = ?
                AND issuedate > ' 
                    . $dbh->sql_date_math('NOW()', '-', ACCOUNT_CHANGE_INTERVAL, 'MINUTE'),
        undef, ($user->id, 'password'));

    ThrowUserError('too_soon_for_new_token', {'type' => 'password'}) if $too_soon;

    my ($token, $token_ts) = _create_token($user->id, 'password', remote_ip());

    # Mail the user the token along with instructions for using it.
    my $template = Bugzilla->template_inner($user->setting('lang'));
    my $vars = {};

    $vars->{'token'} = $token;
    $vars->{'emailaddress'} = $user->email;
    $vars->{'expiration_ts'} = ctime($token_ts + MAX_TOKEN_AGE * 86400);
    # The user is not logged in (else he wouldn't request a new password).
    # So we have to pass this information to the template.
    $vars->{'timezone'} = $user->timezone;

    my $message = "";
    $template->process("account/password/forgotten-password.txt.tmpl", 
                                                               $vars, \$message)
      || ThrowTemplateError($template->error());

    MessageToMTA($message);
}

sub issue_session_token {
    # Generates a random token, adds it to the tokens table, and returns
    # the token to the caller.

    my $data = shift;
    return _create_token(Bugzilla->user->id, 'session', $data);
}

sub issue_hash_token {
    my ($data, $time) = @_;
    $data ||= [];
    $time ||= time();

    # For the user ID, use the actual ID if the user is logged in.
    # Otherwise, use the remote IP, in case this is for something
    # such as creating an account or logging in.
    my $user_id = Bugzilla->user->id || remote_ip();

    # The concatenated string is of the form
    # token creation time + user ID (either ID or remote IP) + data
    my @args = ($time, $user_id, @$data);

    my $token = join('*', @args);
    $token = hmac_sha256_base64($token, Bugzilla->localconfig->{'site_wide_secret'});
    $token =~ s/\+/-/g;
    $token =~ s/\//_/g;

    # Prepend the token creation time, unencrypted, so that the token
    # lifetime can be validated.
    return $time . '-' . $token;
}

sub check_hash_token {
    my ($token, $data) = @_;
    $data ||= [];
    my ($time, $expected_token);

    if ($token) {
        ($time, undef) = split(/-/, $token);
        # Regenerate the token based on the information we have.
        $expected_token = issue_hash_token($data, $time);
    }

    if (!$token
        || $expected_token ne $token
        || time() - $time > MAX_TOKEN_AGE * 86400)
    {
        my $template = Bugzilla->template;
        my $vars = {};
        $vars->{'script_name'} = basename($0);
        $vars->{'token'} = issue_hash_token($data);
        $vars->{'reason'} = (!$token) ?                   'missing_token' :
                            ($expected_token ne $token) ? 'invalid_token' :
                                                          'expired_token';
        print Bugzilla->cgi->header();
        $template->process('global/confirm-action.html.tmpl', $vars)
          || ThrowTemplateError($template->error());
        exit;
    }

    # If we come here, then the token is valid and not too old.
    return 1;
}

sub CleanTokenTable {
    my $dbh = Bugzilla->dbh;
    $dbh->do('DELETE FROM tokens
              WHERE ' . $dbh->sql_to_days('NOW()') . ' - ' .
                        $dbh->sql_to_days('issuedate') . ' >= ?',
              undef, MAX_TOKEN_AGE);
}

sub GenerateUniqueToken {
    # Generates a unique random token.  Uses generate_random_password 
    # for the tokens themselves and checks uniqueness by searching for
    # the token in the "tokens" table.  Gives up if it can't come up
    # with a token after about one hundred tries.
    my ($table, $column) = @_;

    my $token;
    my $duplicate = 1;
    my $tries = 0;
    $table ||= "tokens";
    $column ||= "token";

    my $dbh = Bugzilla->dbh;
    my $sth = $dbh->prepare("SELECT 1 FROM $table WHERE $column = ?");

    while ($duplicate) {
        ++$tries;
        if ($tries > 100) {
            ThrowCodeError("token_generation_error");
        }
        $token = generate_random_password();
        $sth->execute($token);
        $duplicate = $sth->fetchrow_array;
    }
    return $token;
}

# Cancels a previously issued token and notifies the user.
# This should only happen when the user accidentally makes a token request
# or when a malicious hacker makes a token request on behalf of a user.
sub Cancel {
    my ($token, $cancelaction, $vars) = @_;
    my $dbh = Bugzilla->dbh;
    $vars ||= {};

    # Get information about the token being canceled.
    trick_taint($token);
    my ($issuedate, $tokentype, $eventdata, $userid) =
        $dbh->selectrow_array('SELECT ' . $dbh->sql_date_format('issuedate') . ',
                                      tokentype, eventdata, userid
                                 FROM tokens
                                WHERE token = ?',
                                undef, $token);

    # If we are canceling the creation of a new user account, then there
    # is no entry in the 'profiles' table.
    my $user = new Bugzilla::User($userid);

    $vars->{'emailaddress'} = $userid ? $user->email : $eventdata;
    $vars->{'remoteaddress'} = remote_ip();
    $vars->{'token'} = $token;
    $vars->{'tokentype'} = $tokentype;
    $vars->{'issuedate'} = $issuedate;
    # The user is probably not logged in.
    # So we have to pass this information to the template.
    $vars->{'timezone'} = $user->timezone;
    $vars->{'eventdata'} = $eventdata;
    $vars->{'cancelaction'} = $cancelaction;

    # Notify the user via email about the cancellation.
    my $template = Bugzilla->template_inner($user->setting('lang'));

    my $message;
    $template->process("account/cancel-token.txt.tmpl", $vars, \$message)
      || ThrowTemplateError($template->error());

    MessageToMTA($message);

    # Delete the token from the database.
    delete_token($token);
}

sub DeletePasswordTokens {
    my ($userid, $reason) = @_;
    my $dbh = Bugzilla->dbh;

    detaint_natural($userid);
    my $tokens = $dbh->selectcol_arrayref('SELECT token FROM tokens
                                           WHERE userid = ? AND tokentype = ?',
                                           undef, ($userid, 'password'));

    foreach my $token (@$tokens) {
        Bugzilla::Token::Cancel($token, $reason);
    }
}

# Returns an email change token if the user has one. 
sub HasEmailChangeToken {
    my $userid = shift;
    my $dbh = Bugzilla->dbh;

    my $token = $dbh->selectrow_array('SELECT token FROM tokens
                                       WHERE userid = ?
                                       AND (tokentype = ? OR tokentype = ?) ' .
                                       $dbh->sql_limit(1),
                                       undef, ($userid, 'emailnew', 'emailold'));
    return $token;
}

# Returns the userid, issuedate and eventdata for the specified token
sub GetTokenData {
    my ($token) = @_;
    my $dbh = Bugzilla->dbh;

    return unless defined $token;
    $token = clean_text($token);
    trick_taint($token);

    return $dbh->selectrow_array(
        "SELECT userid, " . $dbh->sql_date_format('issuedate') . ", eventdata, tokentype
         FROM   tokens 
         WHERE  token = ?", undef, $token);
}

# Deletes specified token
sub delete_token {
    my ($token) = @_;
    my $dbh = Bugzilla->dbh;

    return unless defined $token;
    trick_taint($token);

    $dbh->do("DELETE FROM tokens WHERE token = ?", undef, $token);
}

# Given a token, makes sure it comes from the currently logged in user
# and match the expected event. Returns 1 on success, else displays a warning.
sub check_token_data {
    my ($token, $expected_action, $alternate_script) = @_;
    my $user = Bugzilla->user;
    my $template = Bugzilla->template;
    my $cgi = Bugzilla->cgi;

    my ($creator_id, $date, $token_action) = GetTokenData($token);
    unless ($creator_id
            && $creator_id == $user->id
            && $token_action eq $expected_action)
    {
        # Something is going wrong. Ask confirmation before processing.
        # It is possible that someone tried to trick an administrator.
        # In this case, we want to know his name!
        require Bugzilla::User;

        my $vars = {};
        $vars->{'abuser'} = Bugzilla::User->new($creator_id)->identity;
        $vars->{'token_action'} = $token_action;
        $vars->{'expected_action'} = $expected_action;
        $vars->{'script_name'} = basename($0);
        $vars->{'alternate_script'} = $alternate_script || basename($0);

        # Now is a good time to remove old tokens from the DB.
        CleanTokenTable();

        # If no token was found, create a valid token for the given action.
        unless ($creator_id) {
            $token = issue_session_token($expected_action);
            $cgi->param('token', $token);
        }

        print $cgi->header();

        $template->process('admin/confirm-action.html.tmpl', $vars)
          || ThrowTemplateError($template->error());
        exit;
    }
    return 1;
}

################################################################################
# Internal Functions
################################################################################

# Generates a unique token and inserts it into the database
# Returns the token and the token timestamp
sub _create_token {
    my ($userid, $tokentype, $eventdata) = @_;
    my $dbh = Bugzilla->dbh;

    detaint_natural($userid) if defined $userid;
    trick_taint($tokentype);
    trick_taint($eventdata);

    $dbh->bz_start_transaction();

    my $token = GenerateUniqueToken();

    $dbh->do("INSERT INTO tokens (userid, issuedate, token, tokentype, eventdata)
        VALUES (?, NOW(), ?, ?, ?)", undef, ($userid, $token, $tokentype, $eventdata));

    $dbh->bz_commit_transaction();

    if (wantarray) {
        my (undef, $token_ts, undef) = GetTokenData($token);
        $token_ts = str2time($token_ts);
        return ($token, $token_ts);
    } else {
        return $token;
    }
}

1;

__END__

=head1 NAME

Bugzilla::Token - Provides different routines to manage tokens.

=head1 SYNOPSIS

    use Bugzilla::Token;

    Bugzilla::Token::issue_new_user_account_token($login_name);
    Bugzilla::Token::IssueEmailChangeToken($user, $new_email);
    Bugzilla::Token::IssuePasswordToken($user);
    Bugzilla::Token::DeletePasswordTokens($user_id, $reason);
    Bugzilla::Token::Cancel($token, $cancelaction, $vars);

    Bugzilla::Token::CleanTokenTable();

    my $token = issue_session_token($event);
    check_token_data($token, $event)
    delete_token($token);

    my $token = Bugzilla::Token::GenerateUniqueToken($table, $column);
    my $token = Bugzilla::Token::HasEmailChangeToken($user_id);
    my ($token, $date, $data, $type) = Bugzilla::Token::GetTokenData($token);

=head1 SUBROUTINES

=over

=item C<issue_new_user_account_token($login_name)>

 Description: Creates and sends a token per email to the email address
              requesting a new user account. It doesn't check whether
              the user account already exists. The user will have to
              use this token to confirm the creation of his user account.

 Params:      $login_name - The new login name requested by the user.

 Returns:     Nothing. It throws an error if the same user made the same
              request in the last few minutes.

=item C<sub IssueEmailChangeToken($user, $new_email)>

 Description: Sends two distinct tokens per email to the old and new email
              addresses to confirm the email address change for the given
              user. These tokens remain valid for the next MAX_TOKEN_AGE days.

 Params:      $user      - User object of the user requesting a new
                           email address.
              $new_email - The new email address of the user.

 Returns:     Nothing.

=item C<IssuePasswordToken($user)>

 Description: Sends a token per email to the given user. This token
              can be used to change the password (e.g. in case the user
              cannot remember his password and wishes to enter a new one).

 Params:      $user - User object of the user requesting a new password.

 Returns:     Nothing. It throws an error if the same user made the same
              request in the last few minutes.

=item C<CleanTokenTable()>

 Description: Removes all tokens older than MAX_TOKEN_AGE days from the DB.
              This means that these tokens will now be considered as invalid.

 Params:      None.

 Returns:     Nothing.

=item C<GenerateUniqueToken($table, $column)>

 Description: Generates and returns a unique token. This token is unique
              in the $column of the $table. This token is NOT stored in the DB.

 Params:      $table (optional): The table to look at (default: tokens).
              $column (optional): The column to look at for uniqueness (default: token).

 Returns:     A token which is unique in $column.

=item C<Cancel($token, $cancelaction, $vars)>

 Description: Invalidates an existing token, generally when the token is used
              for an action which is not the one expected. An email is sent
              to the user who originally requested this token to inform him
              that this token has been invalidated (e.g. because an hacker
              tried to use this token for some malicious action).

 Params:      $token:        The token to invalidate.
              $cancelaction: The reason why this token is invalidated.
              $vars:         Some additional information about this action.

 Returns:     Nothing.

=item C<DeletePasswordTokens($user_id, $reason)>

 Description: Cancels all password tokens for the given user. Emails are sent
              to the user to inform him about this action.

 Params:      $user_id: The user ID of the user account whose password tokens
                        are canceled.
              $reason:  The reason why these tokens are canceled.

 Returns:     Nothing.

=item C<HasEmailChangeToken($user_id)>

 Description: Returns any existing token currently used for an email change
              for the given user.

 Params:      $user_id - A user ID.

 Returns:     A token if it exists, else undef.

=item C<GetTokenData($token)>

 Description: Returns all stored data for the given token.

 Params:      $token - A valid token.

 Returns:     The user ID, the date and time when the token was created,
              the (event)data stored with that token, and its type.

=back

=head2 Security related routines

The following routines have been written to be used together as described below,
although they can be used separately.

=over

=item C<issue_session_token($event)>

 Description: Creates and returns a token used internally.

 Params:      $event - The event which needs to be stored in the DB for future
                       reference/checks.

 Returns:     A unique token.

=item C<check_token_data($token, $event)>

 Description: Makes sure the $token has been created by the currently logged in
              user and to be used for the given $event. If this token is used for
              an unexpected action (i.e. $event doesn't match the information stored
              with the token), a warning is displayed asking whether the user really
              wants to continue. On success, it returns 1.
              This is the routine to use for security checks, combined with
              issue_session_token() and delete_token() as follows:

              1. First, create a token for some coming action.
              my $token = issue_session_token($action);
              2. Some time later, it's time to make sure that the expected action
                 is going to be executed, and by the expected user.
              check_token_data($token, $action);
              3. The check has been done and we no longer need this token.
              delete_token($token);

 Params:      $token - The token used for security checks.
              $event - The expected event to be run.

 Returns:     1 on success, else a warning is thrown.

=item C<delete_token($token)>

 Description: Deletes the specified token. No notification is sent.

 Params:      $token - The token to delete.

 Returns:     Nothing.

=back

=cut