path: root/LedgerSMB/Session/DB.pm

#=====================================================================
# LedgerSMB 
# Small Medium Business Accounting software
# http://www.ledgersmb.org/
# 
#
# Copyright (C) 2006
# This work contains copyrighted information from a number of sources all used
# with permission.  It is released under the GNU General Public License 
# Version 2 or, at your option, any later version.  See COPYRIGHT file for 
# details.
#
#
#======================================================================
#
# This file has undergone whitespace cleanup.
#
#======================================================================
# This package contains session related functions:
#
# check - checks validity of session based on the user's cookie and login
#
# create - creates a new session, writes cookie upon success
#
# destroy - destroys session
#
# password_check - compares the password with the stored cryted password 
#                  (ver. < 1.2) and the md5 one (ver. >= 1.2)
#====================================================================
package Session;

sub session_check {

    use Time::HiRes qw(gettimeofday);

    my ($cookie, $form) = @_;
    my ($sessionID, $transactionID, $token) = split /:/, $cookie;

    # use the central database handle
    my $dbh = ${LedgerSMB::Sysconfig::GLOBALDBH}; 

    my $checkQuery = $dbh->prepare("SELECT u.username, s.transaction_id 
                                      FROM session as s, users as u 
                                     WHERE s.session_id = ? 
                                       AND s.token = ?
                                       AND s.users_id = u.id
                                       AND s.last_used > now() - ?::interval");

    my $updateAge = $dbh->prepare("UPDATE session 
                                      SET last_used = now(),
                                          transaction_id = ?
                                    WHERE session_id = ?;");

    #must be an integer
    $sessionID =~ s/[^0-9]//g;
    $sessionID = int $sessionID;

    $transactionID =~ s/[^0-9]//g;
    $transactionID = int $transactionID;

    #must be 32 chars long and contain hex chars
    $token =~ s/[^0-9a-f]//g;
    $token = substr($token, 0, 32);

    if (!$myconfig{timeout}){
        $timeout = "1 day";
    } else {
        $timeout = "$myconfig{timeout} seconds";
    }

    $checkQuery->execute($sessionID, $token, $timeout) 
        || $form->dberror(__FILE__.':'.__LINE__.': Looking for session: ');
    my $sessionValid = $checkQuery->rows;

    if($sessionValid){

        #user has a valid session cookie, now check the user
        my ($sessionLogin, $sessionTransaction) = $checkQuery->fetchrow_array;

        my $login = $form->{login};
        $login =~ s/[^a-zA-Z0-9._+@'-]//g;

        if(($sessionLogin eq $login) and ($sessionTransaction eq $transactionID)){

            #microseconds are more than random enough for transaction_id
            my ($ignore, $newTransactionID) = gettimeofday();

            $newTransactionID = int $newTransactionID;
    
            $updateAge->execute($newTransactionID, $sessionID) 
                || $form->dberror(__FILE__.':'.__LINE__.': Updating session age: ');

            $newCookieValue = $sessionID . ':'.$newTransactionID.':' . $token;

            #now update the cookie in the browser
            print qq|Set-Cookie: LedgerSMB=$newCookieValue; path=/;\n|;
            return 1;

        } else {
            #something's wrong, they have the cookie, but wrong user or the wrong transaction id. Hijack attempt?
            #destroy the session
            my $sessionDestroy = $dbh->prepare("");

            #delete the cookie in the browser
            print qq|Set-Cookie: LedgerSMB=; path=/;\n|;
            return 0;
        }
    
    } else {
        #cookie is not valid
        #delete the cookie in the browser
        print qq|Set-Cookie: LedgerSMB=; path=/;\n|;
        return 0;
    }
}

sub session_create {

    use Time::HiRes qw(gettimeofday);

    #microseconds are more than random enough for transaction_id
    my ($ignore, $newTransactionID) = gettimeofday();
    $newTransactionID = int $newTransactionID;

    my ($form) = @_;

    if (! $ENV{HTTP_HOST}){
        #don't create cookies or sessions for CLI use
        return 1;
    }

    # use the central database handle
    my $dbh = ${LedgerSMB::Sysconfig::GLOBALDBH}; 

    # TODO Change this to use %myconfig
    my $deleteExisting = $dbh->prepare("DELETE FROM session
                                              USING users
                                              WHERE users.username = ?
                                                AND users.id = session.users_id
                                                AND age(last_used) > ?::interval");  

    my $seedRandom = $dbh->prepare("SELECT setseed(?);");

    my $fetchSequence = $dbh->prepare("SELECT nextval('session_session_id_seq'), md5(random());");
    
    my $createNew = $dbh->prepare("INSERT INTO session (session_id, users_id, token, transaction_id) 
                                        VALUES(?, (SELECT id
                                                     FROM users
                                                    WHERE username = ?), ?, ?);");


    # this is assuming that $form->{login} is safe, which might be a bad assumption
    # so, I'm going to remove some chars, which might make previously valid logins invalid
    my $login = $form->{login};
    $login =~ s/[^a-zA-Z0-9._+@'-]//g;

    #delete any existing stale sessions with this login if they exist
    if (!$myconfig{timeout}){
       $myconfig{timeout} = 86400;
    }

    $deleteExisting->execute($login, "$myconfig{timeout} seconds") 
        || $form->dberror(__FILE__.':'.__LINE__.': Delete from session: ');

    #doing the random stuff in the db so that LedgerSMB won't
    #require a good random generator - maybe this should be reviewed, pgsql's isn't great either
    $fetchSequence->execute() || $form->dberror(__FILE__.':'.__LINE__.': Fetch sequence id: ');
    my ($newSessionID, $newToken) = $fetchSequence->fetchrow_array;

    #create a new session
    $createNew->execute($newSessionID, $login, $newToken, $newTransactionID) 
        || $form->dberror(__FILE__.':'.__LINE__.': Create new session: ');

    #reseed the random number generator
    my $randomSeed = 1.0 * ('0.'. (time() ^ ($$ + ($$ <<15))));

    $seedRandom->execute($randomSeed) 
        || $form->dberror(__FILE__.':'.__LINE__.': Reseed random generator: ');

    $newCookieValue = $newSessionID . ':'.$newTransactionID.':' . $newToken;

    #now set the cookie in the browser
    #TODO set domain from ENV, also set path to install path
    print qq|Set-Cookie: LedgerSMB=$newCookieValue; path=/;\n|;
    $form->{LedgerSMB} = $newCookieValue;
}

sub session_destroy {

    my ($form) = @_;

    my $login = $form->{login};
    $login =~ s/[^a-zA-Z0-9._+@'-]//g;

    # use the central database handle
    my $dbh = ${LedgerSMB::Sysconfig::GLOBALDBH};

    my $deleteExisting = $dbh->prepare("DELETE FROM session 
                                              USING users
                                              WHERE users.username = ?
                                                AND users.id = session.users_id;");

    $deleteExisting->execute($login)
        || $form->dberror(__FILE__.':'.__LINE__.': Delete from session: ');

    #delete the cookie in the browser
    print qq|Set-Cookie: LedgerSMB=; path=/;\n|;

}

sub password_check {

    use Digest::MD5;

    my ($form, $username, $password) = @_;

    $username =~ s/[^a-zA-Z0-9._+@'-]//g;

    # use the central database handle
    my $dbh = ${LedgerSMB::Sysconfig::GLOBALDBH};

    my $fetchPassword = $dbh->prepare("SELECT u.username, uc.password, uc.crypted_password
                                         FROM users as u, users_conf as uc
                                        WHERE u.username = ?
                                          AND u.id = uc.id;");

    $fetchPassword->execute($username) || $form->dberror(__FILE__.':'.__LINE__.': Fetching password : ');

    my ($dbusername, $md5Password, $cryptPassword) = $fetchPassword->fetchrow_array;

    if ($dbusername ne $username) {
        # User data retrieved from db not for the requested user
        return 0;
    } elsif ($cryptPassword){
        #First time login from old system, check crypted password

        if ((crypt $password, substr($username, 0, 2)) eq $cryptPassword) { 

            #password was good, convert to md5 password and null crypted
            my $updatePassword = $dbh->prepare("UPDATE users_conf
                                                   SET password = md5(?),
                                                       crypted_password = null
                                                  FROM users
                                                 WHERE users_conf.id = users.id
                                                   AND users.username = ?;");

            $updatePassword->execute($password, $username) 
                || $form->dberror(__FILE__.':'.__LINE__.': Converting password : ');

            return 1;

        } else {
            return 0; #password failed
        }

    } elsif ($md5Password){

        if ($md5Password ne (Digest::MD5::md5_hex $password) ) {
            return 0;
        }
        else {
            return 1;
        }
    
    } else {
        #both the md5Password and cryptPasswords were blank
        return 0;
    }
}

1;