#!/usr/bin/perl

use strict;
use Pod::Usage;
use Getopt::Long;

=pod

=head1 NAME

 basic_db_auth - Database auth helper for Squid

=head1 SYNOPSIS

 basic_db_auth [options]

=head1 DESCRIPTION

This program verifies username & password to a database

=head1 OPTIONS

=over 12

=item B<--debug>

Write debug info to stderr.

=item B<--dsn>

Database DSN. Default "DBI:mysql:database=squid"

=item B<--user>

Database User

=item B<--password>

Database password

=item B<--table>

Database table. Default "passwd".

=item B<--usercol>

Username column. Default "user".

=item B<--passwdcol>

Password column. Default "password".

=item B<--cond>

Condition, defaults to enabled=1. Specify 1 or "" for no condition
If you use --joomla flag, this condition will be changed to block=0

=item B<--plaintext>

Database contains plain-text passwords

=item B<--md5>

Database contains unsalted MD5 passwords

=item B<--sha1>

Database contains unsalted SHA1 passwords

=item B<--salt>

Selects the correct salt to evaluate passwords

=item B<--persist>

Keep a persistent database connection open between queries.

=item B<--joomla>

Tells helper that user database is Joomla DB.  So their unusual salt
hashing is understood.

=back

=head1 AUTHOR

This program was written by
I<Henrik Nordstrom <henrik@henriknordstrom.net>> and
I<Luis Daniel Lucio Quiroz <dlucio@okay.com.mx>>

This manual was written by I<Henrik Nordstrom <henrik@henriknordstrom.net>>

=head1 COPYRIGHT

 * Copyright (C) 1996-2023 The Squid Software Foundation and contributors
 *
 * Squid software is distributed under GPLv2+ license and includes
 * contributions from numerous individuals and organizations.
 * Please see the COPYING and CONTRIBUTORS files for details.

Copyright (C) 2007 Henrik Nordstrom <henrik@henriknordstrom.net>
Copyright (C) 2010 Luis Daniel Lucio Quiroz <dlucio@okay.com.mx> (Joomla support)
This program is free software. You may redistribute copies of it under the
terms of the GNU General Public License version 2, or (at your opinion) any
later version.

=head1 QUESTIONS

Questions on the usage of this program can be sent to the I<Squid Users mailing list <squid-users@lists.squid-cache.org>>

=head1 REPORTING BUGS

Bug reports need to be made in English.
See https://wiki.squid-cache.org/SquidFaq/BugReporting for details of what you need to include with your bug report.

Report bugs or bug fixes using https://bugs.squid-cache.org/

Report serious security bugs to I<Squid Bugs <squid-bugs@lists.squid-cache.org>>

Report ideas for new improvements to the I<Squid Developers mailing list <squid-dev@lists.squid-cache.org>>

=head1 SEE ALSO

squid (8), GPL (7),

The Squid FAQ wiki https://wiki.squid-cache.org/SquidFaq

The Squid Configuration Manual http://www.squid-cache.org/Doc/config/

=cut

use DBI;
use Digest::MD5 qw(md5 md5_hex md5_base64);
use Digest::SHA qw(sha1 sha1_hex sha1_base64);

my $dsn = "DBI:mysql:database=squid";
my $db_user = undef;
my $db_passwd = undef;
my $db_table = "passwd";
my $db_usercol = "user";
my $db_passwdcol = "password";
my $db_cond = "enabled = 1";
my $plaintext = 0;
my $md5 = 0;
my $sha1 = 0;
my $persist = 0;
my $isjoomla = 0;
my $debug = 0;
my $hashsalt = undef;

GetOptions(
    'dsn=s' => \$dsn,
    'user=s' => \$db_user,
    'password=s' => \$db_passwd,
    'table=s' => \$db_table,
    'usercol=s' => \$db_usercol,
    'passwdcol=s' => \$db_passwdcol,
    'cond=s' => \$db_cond,
    'plaintext' => \$plaintext,
    'md5' => \$md5,
    'sha1' => \$sha1,
    'persist' => \$persist,
    'joomla' => \$isjoomla,
    'debug' => \$debug,
    'salt=s' => \$hashsalt,
    );

my ($_dbh, $_sth);
$db_cond = "block = 0" if $isjoomla;

sub close_db()
{
    return if !defined($_dbh);
    undef $_sth;
    $_dbh->disconnect();
    undef $_dbh;
}

sub open_db()
{
    return $_sth if defined $_sth;
    $_dbh = DBI->connect($dsn, $db_user, $db_passwd);
    if (!defined $_dbh) {
        warn ("Could not connect to $dsn\n");
        my @driver_names = DBI->available_drivers();
        my $msg = "DSN drivers apparently installed, available:\n";
        foreach my $dn (@driver_names) {
            $msg .= "\t$dn";
        }
        warn($msg."\n");
        return undef;
    }
    my $sql_query;
    $sql_query = "SELECT $db_passwdcol FROM $db_table WHERE $db_usercol = ?" . ($db_cond ne "" ? " AND $db_cond" : "");
    $_sth = $_dbh->prepare($sql_query) || die;
    return $_sth;
}

sub check_password($$)
{
    my ($password, $key) = @_;

    if ($isjoomla){
        my $salt;
        my $key2;
        ($key2,$salt) = split (/:/, $key);
        return 1 if md5_hex($password.$salt).':'.$salt eq $key;
    }
    else{
        return 1 if defined $hashsalt && crypt($password, $hashsalt) eq $key;
        return 1 if crypt($password, $key) eq $key;
        return 1 if $md5 && md5_hex($password) eq $key;
        return 1 if $sha1 && sha1_hex($password) eq $key;
        return 1 if $plaintext && $password eq $key;
    }

    return 0;
}

sub query_db($) {
    my ($user) = @_;
    my ($sth) = open_db() || return undef;
    if (!$sth->execute($user)) {
        close_db();
        open_db() || return undef;
        $sth->execute($user) || return undef;;
    }
    return $sth;
}
my $status;

$|=1;
while (<>) {
    my ($user, $password) = split;
    $status = "ERR";
    $user =~ s/%(..)/pack("H*", $1)/ge;
    $password =~ s/%(..)/pack("H*", $1)/ge;

    $status = "ERR database error";
    my $sth = query_db($user) || next;
    $status = "ERR unknown login";
    my $row = $sth->fetchrow_arrayref() || next;
    $status = "ERR login failure";
    next if (!check_password($password, @$row[0]));
    $status = "OK";
} continue {
    close_db() if (!$persist);
    print $status . "\n";
}
