# -*- Mode: perl; indent-tabs-mode: nil -*-
#
# The contents of this file are subject to the Mozilla Public
# License Version 1.1 (the "License"); you may not use this file
# except in compliance with the License. You may obtain a copy of
# the License at http://www.mozilla.org/MPL/
#
# Software distributed under the License is distributed on an "AS
# IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
# implied. See the License for the specific language governing
# rights and limitations under the License.
#
# The Original Code is the Bugzilla Bug Tracking System.
#
# The Initial Developer of the Original Code is Netscape Communications
# Corporation. Portions created by Netscape are
# Copyright (C) 1998 Netscape Communications Corporation. All
# Rights Reserved.
#
# Contributor(s):    Myk Melez <myk@mozilla.org>
#                    Frédéric Buclin <LpSolit@gmail.com>

################################################################################
# Module Initialization
################################################################################

# Make it harder for us to do dangerous things in Perl.
use strict;

# Bundle the functions in this file together into the "Bugzilla::Token" package.
package Bugzilla::Token;

use Bugzilla::Config;
use Bugzilla::Error;
use Bugzilla::BugMail;
use Bugzilla::Util;

use Date::Format;
use Date::Parse;
use File::Basename;

use base qw(Exporter);

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

# This module requires that its caller have said "require globals.pl" to import
# relevant functions from that script.

################################################################################
# Constants
################################################################################

# The maximum number of days a token will remain valid.
my $maxtokenage = 3;

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

sub IssueEmailChangeToken {
    my ($userid, $old_email, $new_email) = @_;

    my ($token, $token_ts) = _create_token($userid, 'emailold', $old_email . ":" . $new_email);

    my $newtoken = _create_token($userid, 'emailnew', $old_email . ":" . $new_email);

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

    my $template = Bugzilla->template;
    my $vars = {};

    $vars->{'oldemailaddress'} = $old_email . Param('emailsuffix');
    $vars->{'newemailaddress'} = $new_email . Param('emailsuffix');
    
    $vars->{'max_token_age'} = $maxtokenage;
    $vars->{'token_ts'} = $token_ts;

    $vars->{'token'} = $token;
    $vars->{'emailaddress'} = $old_email . Param('emailsuffix');

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

    Bugzilla::BugMail::MessageToMTA($message);

    $vars->{'token'} = $newtoken;
    $vars->{'emailaddress'} = $new_email . Param('emailsuffix');

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

    Bugzilla::BugMail::MessageToMTA($message);
}

sub IssuePasswordToken {
    # 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.

    my ($loginname) = @_;

    my $dbh = Bugzilla->dbh;

    # Retrieve the user's ID from the database.
    my $quotedloginname = &::SqlQuote($loginname);
    &::SendSQL("SELECT profiles.userid, tokens.issuedate FROM profiles 
                    LEFT JOIN tokens
                    ON tokens.userid = profiles.userid
                    AND tokens.tokentype = 'password'
                    AND tokens.issuedate > NOW() - " .
                    $dbh->sql_interval(10, 'MINUTE') . "
                 WHERE " . $dbh->sql_istrcmp('login_name', $quotedloginname));
    my ($userid, $toosoon) = &::FetchSQLData();

    if ($toosoon) {
        ThrowUserError('too_soon_for_new_token');
    };

    my ($token, $token_ts) = _create_token($userid, 'password', $::ENV{'REMOTE_ADDR'});

    # Mail the user the token along with instructions for using it.
    
    my $template = Bugzilla->template;
    my $vars = {};

    $vars->{'token'} = $token;
    $vars->{'emailaddress'} = $loginname . Param('emailsuffix');

    $vars->{'max_token_age'} = $maxtokenage;
    $vars->{'token_ts'} = $token_ts;

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

    Bugzilla::BugMail::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 CleanTokenTable {
    my $dbh = Bugzilla->dbh;
    $dbh->bz_lock_tables('tokens WRITE');
    &::SendSQL("DELETE FROM tokens WHERE " .
               $dbh->sql_to_days('NOW()') . " - " .
               $dbh->sql_to_days('issuedate') . " >= " . $maxtokenage);
    $dbh->bz_unlock_tables();
}

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 userid 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;
}

sub Cancel {
    # Cancels a previously issued token and notifies the system administrator.
    # 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.
    
    my ($token, $cancelaction, $vars) = @_;

    my $dbh = Bugzilla->dbh;
    $vars ||= {};

    # Quote the token for inclusion in SQL statements.
    my $quotedtoken = &::SqlQuote($token);
    
    # Get information about the token being cancelled.
    &::SendSQL("SELECT  " . $dbh->sql_date_format('issuedate') . ",
                        tokentype , eventdata , login_name , realname
                FROM    tokens, profiles 
                WHERE   tokens.userid = profiles.userid
                AND     token = $quotedtoken");
    my ($issuedate, $tokentype, $eventdata, $loginname, $realname) = &::FetchSQLData();

    # Get the email address of the Bugzilla maintainer.
    my $maintainer = Param('maintainer');

    my $template = Bugzilla->template;

    $vars->{'emailaddress'} = $loginname . Param('emailsuffix');
    $vars->{'maintainer'} = $maintainer;
    $vars->{'remoteaddress'} = $::ENV{'REMOTE_ADDR'};
    $vars->{'token'} = $token;
    $vars->{'tokentype'} = $tokentype;
    $vars->{'issuedate'} = $issuedate;
    $vars->{'eventdata'} = $eventdata;
    $vars->{'cancelaction'} = $cancelaction;

    # Notify the user via email about the cancellation.

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

    Bugzilla::BugMail::MessageToMTA($message);

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

sub DeletePasswordTokens {
    my ($userid, $reason) = @_;

    my $dbh = Bugzilla->dbh;
    my $sth = $dbh->prepare("SELECT token " .
                            "FROM tokens " .
                            "WHERE userid=? AND tokentype='password'");
    $sth->execute($userid);
    while (my $token = $sth->fetchrow_array) {
        Bugzilla::Token::Cancel($token, $reason);
    }
}

sub HasEmailChangeToken {
    # Returns an email change token if the user has one. 
    
    my ($userid) = @_;

    my $dbh = Bugzilla->dbh;
    &::SendSQL("SELECT token FROM tokens WHERE userid = $userid " . 
               "AND (tokentype = 'emailnew' OR tokentype = 'emailold') " . 
               $dbh->sql_limit(1));
    my ($token) = &::FetchSQLData();
    
    return $token;
}

sub GetTokenData {
    # Returns the userid, issuedate and eventdata for the specified token

    my ($token) = @_;
    return unless defined $token;
    $token = clean_text($token);
    trick_taint($token);
    
    my $dbh = Bugzilla->dbh;
    return $dbh->selectrow_array(
        "SELECT userid, " . $dbh->sql_date_format('issuedate') . ", eventdata 
         FROM   tokens 
         WHERE  token = ?", undef, $token);
}

sub delete_token {
    # Deletes specified token

    my ($token) = @_;
    return unless defined $token;
    trick_taint($token);

    my $dbh = Bugzilla->dbh;
    $dbh->bz_lock_tables('tokens WRITE');
    $dbh->do("DELETE FROM tokens WHERE token = ?", undef, $token);
    $dbh->bz_unlock_tables();
}

# 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.
# Note: this routine must not be called while tables are locked as it will try
# to lock some tables itself, see CleanTokenTable().
sub check_token_data {
    my ($token, $expected_action) = @_;
    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);

        # 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
################################################################################

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

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

    my $dbh = Bugzilla->dbh;
    $dbh->bz_lock_tables('tokens WRITE');

    my $token = GenerateUniqueToken();

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

    $dbh->bz_unlock_tables();

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

1;