--- loncom/lond 2002/07/17 19:06:30 1.83 +++ loncom/lond 2002/10/07 13:50:36 1.102 @@ -2,7 +2,7 @@ # The LearningOnline Network # lond "LON Daemon" Server (port "LOND" 5663) # -# $Id: lond,v 1.83 2002/07/17 19:06:30 stredwic Exp $ +# $Id: lond,v 1.102 2002/10/07 13:50:36 www Exp $ # # Copyright Michigan State University Board of Trustees # @@ -74,6 +74,7 @@ use Crypt::IDEA; use LWP::UserAgent(); use GDBM_File; use Authen::Krb4; +use Authen::Krb5; use lib '/home/httpd/lib/perl/'; use localauth; @@ -82,6 +83,68 @@ my $DEBUG = 0; # Non zero to ena my $status=''; my $lastlog=''; +# +# The array below are password error strings." +# +my $lastpwderror = 13; # Largest error number from lcpasswd. +my @passwderrors = ("ok", + "lcpasswd must be run as user 'www'", + "lcpasswd got incorrect number of arguments", + "lcpasswd did not get the right nubmer of input text lines", + "lcpasswd too many simultaneous pwd changes in progress", + "lcpasswd User does not exist.", + "lcpasswd Incorrect current passwd", + "lcpasswd Unable to su to root.", + "lcpasswd Cannot set new passwd.", + "lcpasswd Username has invalid characters", + "lcpasswd Invalid characters in password", + "11", "12", + "lcpasswd Password mismatch"); + + +# The array below are lcuseradd error strings.: + +my $lastadderror = 13; +my @adderrors = ("ok", + "User ID mismatch, lcuseradd must run as user www", + "lcuseradd Incorrect number of command line parameters must be 3", + "lcuseradd Incorrect number of stdinput lines, must be 3", + "lcuseradd Too many other simultaneous pwd changes in progress", + "lcuseradd User does not exist", + "lcuseradd Unabel to mak ewww member of users's group", + "lcuseradd Unable to su to root", + "lcuseradd Unable to set password", + "lcuseradd Usrname has invbalid charcters", + "lcuseradd Password has an invalid character", + "lcuseradd User already exists", + "lcuseradd Could not add user.", + "lcuseradd Password mismatch"); + + +# +# Convert an error return code from lcpasswd to a string value. +# +sub lcpasswdstrerror { + my $ErrorCode = shift; + if(($ErrorCode < 0) || ($ErrorCode > $lastpwderror)) { + return "lcpasswd Unrecognized error return value ".$ErrorCode; + } else { + return $passwderrors[$ErrorCode]; + } +} + +# +# Convert an error return code from lcuseradd to a string value: +# +sub lcuseraddstrerror { + my $ErrorCode = shift; + if(($ErrorCode < 0) || ($ErrorCode > $lastadderror)) { + return "lcuseradd - Unrecognized error code: ".$ErrorCode; + } else { + return $adderrors[$ErrorCode]; + } +} + # grabs exception and records it to log before exiting sub catchexception { my ($error)=@_; @@ -106,9 +169,8 @@ $SIG{'QUIT'}=\&catchexception; $SIG{__DIE__}=\&catchexception; # ---------------------------------- Read loncapa_apache.conf and loncapa.conf -&status("Read loncapa_apache.conf and loncapa.conf"); -my $perlvarref=LONCAPA::Configuration::read_conf('loncapa_apache.conf', - 'loncapa.conf'); +&status("Read loncapa.conf and loncapa_apache.conf"); +my $perlvarref=LONCAPA::Configuration::read_conf('loncapa.conf'); my %perlvar=%{$perlvarref}; undef $perlvarref; @@ -488,7 +550,10 @@ sub make_new_child { or die "Can't unblock SIGINT for fork: $!\n"; $tmpsnum=0; - +#---------------------------------------------------- kerberos 5 initialization + &Authen::Krb5::init_context(); + &Authen::Krb5::init_ets(); + # handle connections until we've reached $MAX_CLIENTS_PER_CHILD for ($i=0; $i < $MAX_CLIENTS_PER_CHILD; $i++) { &status('Idle, waiting for connection'); @@ -497,6 +562,8 @@ sub make_new_child { # ============================================================================= # do something with the connection # ----------------------------------------------------------------------------- + $client->sockopt(SO_KEEPALIVE, 1);# Enable monitoring of + # connection liveness. # see if we know client and check for spoof IP by challenge my $caller=getpeername($client); my ($port,$iaddr)=unpack_sockaddr_in($caller); @@ -628,15 +695,22 @@ sub make_new_child { my ($howpwd,$contentpwd)=split(/:/,$realpasswd); my $pwdcorrect=0; if ($howpwd eq 'internal') { + &Debug("Internal auth"); $pwdcorrect= (crypt($upass,$contentpwd) eq $contentpwd); } elsif ($howpwd eq 'unix') { - $contentpwd=(getpwnam($uname))[1]; - my $pwauth_path="/usr/local/sbin/pwauth"; - unless ($contentpwd eq 'x') { - $pwdcorrect= - (crypt($upass,$contentpwd) eq $contentpwd); - } + &Debug("Unix auth"); + if((getpwnam($uname))[1] eq "") { #no such user! + $pwdcorrect = 0; + } else { + $contentpwd=(getpwnam($uname))[1]; + my $pwauth_path="/usr/local/sbin/pwauth"; + unless ($contentpwd eq 'x') { + $pwdcorrect= + (crypt($upass,$contentpwd) eq + $contentpwd); + } + elsif (-e $pwauth_path) { open PWAUTH, "|$pwauth_path" or die "Cannot invoke authentication"; @@ -644,6 +718,7 @@ sub make_new_child { close PWAUTH; $pwdcorrect=!$?; } + } } elsif ($howpwd eq 'krb4') { $null=pack("C",0); unless ($upass=~/$null/) { @@ -652,6 +727,23 @@ sub make_new_child { $contentpwd,'krbtgt',$contentpwd,1, $upass) == 0); } else { $pwdcorrect=0; } + } elsif ($howpwd eq 'krb5') { + $null=pack("C",0); + unless ($upass=~/$null/) { + my $krbclient=&Authen::Krb5::parse_name($uname.'@'.$contentpwd); + my $krbservice="krbtgt/".$contentpwd."\@".$contentpwd; + my $krbserver=&Authen::Krb5::parse_name($krbservice); + my $credentials=&Authen::Krb5::cc_default(); + $credentials->initialize($krbclient); + my $krbreturn = + &Authen::Krb5::get_in_tkt_with_password( + $krbclient,$krbserver,$upass,$credentials); +# unless ($krbreturn) { +# &logthis("Krb5 Error: ". +# &Authen::Krb5::error()); +# } + $pwdcorrect = ($krbreturn == 1); + } else { $pwdcorrect=0; } } elsif ($howpwd eq 'localauth') { $pwdcorrect=&localauth::localauth($uname,$upass, $contentpwd); @@ -675,7 +767,7 @@ sub make_new_child { chomp($npass); $upass=&unescape($upass); $npass=&unescape($npass); - &logthis("Trying to change password for $uname"); + &Debug("Trying to change password for $uname"); my $proname=propath($udom,$uname); my $passfilename="$proname/passwd"; if (-e $passfilename) { @@ -685,6 +777,7 @@ sub make_new_child { chomp($realpasswd); my ($howpwd,$contentpwd)=split(/:/,$realpasswd); if ($howpwd eq 'internal') { + &Debug("internal auth"); if (crypt($upass,$contentpwd) eq $contentpwd) { my $salt=time; $salt=substr($salt,6,2); @@ -701,6 +794,7 @@ sub make_new_child { # one way or another. # First: Make sure the current password is # correct + &Debug("auth is unix"); $contentpwd=(getpwnam($uname))[1]; my $pwdcorrect = "0"; my $pwauth_path="/usr/local/sbin/pwauth"; @@ -712,16 +806,20 @@ sub make_new_child { die "Cannot invoke authentication"; print PWAUTH "$uname\n$upass\n"; close PWAUTH; - $pwdcorrect=!$?; + &Debug("exited pwauth with $? ($uname,$upass) "); + $pwdcorrect=($? == 0); } if ($pwdcorrect) { my $execdir=$perlvar{'lonDaemons'}; - my $pf = IO::File->new("|$execdir/lcpasswd"); + &Debug("Opening lcpasswd pipeline"); + my $pf = IO::File->new("|$execdir/lcpasswd > /home/www/lcpasswd.log"); print $pf "$uname\n$npass\n$npass\n"; close $pf; - my $result = ($?>0 ? 'pwchange_failure' + my $err = $?; + my $result = ($err>0 ? 'pwchange_failure' : 'ok'); - &logthis("Result of password change for $uname: $result"); + &logthis("Result of password change for $uname: ". + &lcpasswdstrerror($?)); print $client "$result\n"; } else { print $client "non_authorized\n"; @@ -737,7 +835,7 @@ sub make_new_child { } # -------------------------------------------------------------------- makeuser } elsif ($userinput =~ /^makeuser/) { - Debug("Make user received"); + &Debug("Make user received"); my $oldumask=umask(0077); if ($wasenc==1) { my @@ -767,53 +865,9 @@ sub make_new_child { } } unless ($fperror) { - if ($umode eq 'krb4') { - { - my $pf = IO::File->new(">$passfilename"); - print $pf "krb4:$npass\n"; - } - print $client "ok\n"; - } elsif ($umode eq 'internal') { - my $salt=time; - $salt=substr($salt,6,2); - my $ncpass=crypt($npass,$salt); - { - &Debug("Creating internal auth"); - my $pf = IO::File->new(">$passfilename"); - print $pf "internal:$ncpass\n"; - } - print $client "ok\n"; - } elsif ($umode eq 'localauth') { - { - my $pf = IO::File->new(">$passfilename"); - print $pf "localauth:$npass\n"; - } - print $client "ok\n"; - } elsif ($umode eq 'unix') { - { - my $execpath="$perlvar{'lonDaemons'}/". - "lcuseradd"; - { - &Debug("Executing external: ". - $execpath); - my $se = IO::File->new("|$execpath"); - print $se "$uname\n"; - print $se "$npass\n"; - print $se "$npass\n"; - } - my $pf = IO::File->new(">$passfilename"); - print $pf "unix:\n"; - } - print $client "ok\n"; - } elsif ($umode eq 'none') { - { - my $pf = IO::File->new(">$passfilename"); - print $pf "none:\n"; - } - print $client "ok\n"; - } else { - print $client "auth_mode_error\n"; - } + my $result=&make_passwd_file($uname, $umode,$npass, + $passfilename); + print $client $result; } else { print $client "$fperror\n"; } @@ -827,60 +881,19 @@ sub make_new_child { &Debug("Changing authorization"); if ($wasenc==1) { my - ($cmd,$udom,$uname,$umode,$npass)=split(/:/,$userinput); + ($cmd,$udom,$uname,$umode,$npass)=split(/:/,$userinput); chomp($npass); &Debug("cmd = ".$cmd." domain= ".$udom. "uname =".$uname." umode= ".$umode); $npass=&unescape($npass); - my $proname=propath($udom,$uname); + my $proname=&propath($udom,$uname); my $passfilename="$proname/passwd"; if ($udom ne $perlvar{'lonDefDomain'}) { print $client "not_right_domain\n"; } else { - if ($umode eq 'krb4') { - { - my $pf = IO::File->new(">$passfilename"); - print $pf "krb4:$npass\n"; - } - print $client "ok\n"; - } elsif ($umode eq 'internal') { - my $salt=time; - $salt=substr($salt,6,2); - my $ncpass=crypt($npass,$salt); - { - my $pf = IO::File->new(">$passfilename"); - print $pf "internal:$ncpass\n"; - } - print $client "ok\n"; - } elsif ($umode eq 'localauth') { - { - my $pf = IO::File->new(">$passfilename"); - print $pf "localauth:$npass\n"; - } - print $client "ok\n"; - } elsif ($umode eq 'unix') { - { - my $execpath="$perlvar{'lonDaemons'}/". - "lcuseradd"; - { - my $se = IO::File->new("|$execpath"); - print $se "$uname\n"; - print $se "$npass\n"; - print $se "$npass\n"; - } - my $pf = IO::File->new(">$passfilename"); - print $pf "unix:\n"; - } - print $client "ok\n"; - } elsif ($umode eq 'none') { - { - my $pf = IO::File->new(">$passfilename"); - print $pf "none:\n"; - } - print $client "ok\n"; - } else { - print $client "auth_mode_error\n"; - } + my $result=&make_passwd_file($uname, $umode,$npass, + $passfilename); + print $client $result; } } else { print $client "refused\n"; @@ -947,48 +960,65 @@ sub make_new_child { } else { print $client "rejected\n"; } +# -------------------------------------- fetch a user file from a remote server + } elsif ($userinput =~ /^fetchuserfile/) { + my ($cmd,$fname)=split(/:/,$userinput); + my ($udom,$uname,$ufile)=split(/\//,$fname); + my $udir=propath($udom,$uname).'/userfiles'; + unless (-e $udir) { mkdir($udir,0770); } + if (-e $udir) { + $ufile=~s/^[\.\~]+//; + $ufile=~s/\///g; + my $transname=$udir.'/'.$ufile; + my $remoteurl='http://'.$clientip.'/userfiles/'.$fname; + my $response; + { + my $ua=new LWP::UserAgent; + my $request=new HTTP::Request('GET',"$remoteurl"); + $response=$ua->request($request,$transname); + } + if ($response->is_error()) { + unlink($transname); + my $message=$response->status_line; + &logthis( + "LWP GET: $message for $fname ($remoteurl)"); + print $client "failed\n"; + } else { + print $client "ok\n"; + } + } else { + print $client "not_home\n"; + } +# ------------------------------------------ authenticate access to a user file + } elsif ($userinput =~ /^tokenauthuserfile/) { + my ($cmd,$fname,$session)=split(/:/,$userinput); + chomp($session); + $reply='non_auth'; + if (open(ENVIN,$perlvar{'lonIDsDir'}.'/'. + $session.'.id')) { + while ($line=) { + if ($line=~/userfile\.$fname\=/) { $reply='ok'; } + } + close(ENVIN); + print $client $reply."\n"; + } else { + print $client "invalid_token\n"; + } # ----------------------------------------------------------------- unsubscribe } elsif ($userinput =~ /^unsub/) { my ($cmd,$fname)=split(/:/,$userinput); if (-e $fname) { - if (unlink("$fname.$hostid{$clientip}")) { - print $client "ok\n"; - } else { - print $client "not_subscribed\n"; - } + print $client &unsub($client,$fname,$clientip); } else { print $client "not_found\n"; } # ------------------------------------------------------------------- subscribe } elsif ($userinput =~ /^sub/) { + print $client &subscribe($userinput,$clientip); +# ------------------------------------------------------------- current version + } elsif ($userinput =~ /^currentversion/) { my ($cmd,$fname)=split(/:/,$userinput); - my $ownership=ishome($fname); - if ($ownership eq 'owner') { - if (-e $fname) { - if (-d $fname) { - print $client "directory\n"; - } else { - $now=time; - { - my $sh; - if ($sh= - IO::File->new(">$fname.$hostid{$clientip}")) { - print $sh "$clientip:$now\n"; - } - } - unless ($fname=~/\.meta$/) { - unlink("$fname.meta.$hostid{$clientip}"); - } - $fname=~s/\/home\/httpd\/html\/res/raw/; - $fname="http://$thisserver/".$fname; - print $client "$fname\n"; - } - } else { - print $client "not_found\n"; - } - } else { - print $client "rejected\n"; - } + print $client ¤tversion($fname)."\n"; # ------------------------------------------------------------------------- log } elsif ($userinput =~ /^log/) { my ($cmd,$udom,$uname,$what)=split(/:/,$userinput); @@ -1198,19 +1228,25 @@ sub make_new_child { } else { $regexp='.'; } - my $proname=propath($udom,$uname); my $qresult=''; - if (tie(%hash,'GDBM_File',"$proname/$namespace.db",&GDBM_READER,0640)) { - foreach $key (keys %hash) { - if (eval('$key=~/$regexp/')) { - $qresult.="$key=$hash{$key}&"; - } + my $proname=propath($udom,$uname); + if (tie(%hash,'GDBM_File',"$proname/$namespace.db",&GDBM_READER(),0640)) { + study($regexp); + while (($key,$value) = each(%hash)) { + if ($regexp eq '.') { + $qresult.=$key.'='.$value.'&'; + } else { + my $unescapeKey = &unescape($key); + if (eval('$unescapeKey=~/$regexp/')) { + $qresult.="$key=$value&"; + } + } } - if (untie(%hash)) { - $qresult=~s/\&$//; - print $client "$qresult\n"; + if (untie(%hash)) { + chop($qresult); + print $client "$qresult\n"; } else { - print $client "error:$!\n"; + print $client "error:$!\n"; } } else { print $client "error:$!\n"; @@ -1289,6 +1325,20 @@ sub make_new_child { } else { print $client "error:$!\n"; } +# -------------------------------------------------------------------- chatsend + } elsif ($userinput =~ /^chatsend/) { + my ($cmd,$cdom,$cnum,$newpost)=split(/\:/,$userinput); + &chatadd($cdom,$cnum,$newpost); + print $client "ok\n"; +# -------------------------------------------------------------------- chatretr + } elsif ($userinput =~ /^chatretr/) { + my ($cmd,$cdom,$cnum)=split(/\:/,$userinput); + my $reply=''; + foreach (&getchat($cdom,$cnum)) { + $reply.=&escape($_).':'; + } + $reply=~s/\:$//; + print $client $reply."\n"; # ------------------------------------------------------------------- querysend } elsif ($userinput =~ /^querysend/) { my ($cmd,$query, @@ -1510,7 +1560,7 @@ sub GetAuthType my ($authtype, $contentpwd) = split(/:/, $realpassword); Debug("Authtype = $authtype, content = $contentpwd\n"); my $availinfo = ''; - if($authtype eq 'krb4') { + if($authtype eq 'krb4' or $authtype eq 'krb5') { $availinfo = $contentpwd; } @@ -1520,7 +1570,224 @@ sub GetAuthType Debug("Returning nouser"); return "nouser"; } - +} + +sub addline { + my ($fname,$hostid,$ip,$newline)=@_; + my $contents; + my $found=0; + my $expr='^'.$hostid.':'.$ip.':'; + $expr =~ s/\./\\\./g; + if ($sh=IO::File->new("$fname.subscription")) { + while (my $subline=<$sh>) { + if ($subline !~ /$expr/) {$contents.= $subline;} else {$found=1;} + } + $sh->close(); + } + $sh=IO::File->new(">$fname.subscription"); + if ($contents) { print $sh $contents; } + if ($newline) { print $sh $newline; } + $sh->close(); + return $found; +} + +sub getchat { + my ($cdom,$cname)=@_; + my %hash; + my $proname=&propath($cdom,$cname); + my @entries=(); + if (tie(%hash,'GDBM_File',"$proname/nohist_chatroom.db", + &GDBM_READER(),0640)) { + @entries=map { $_.':'.$hash{$_} } sort keys %hash; + untie %hash; + } + return @entries; +} + +sub chatadd { + my ($cdom,$cname,$newchat)=@_; + my %hash; + my $proname=&propath($cdom,$cname); + my @entries=(); + if (tie(%hash,'GDBM_File',"$proname/nohist_chatroom.db", + &GDBM_WRCREAT(),0640)) { + @entries=map { $_.':'.$hash{$_} } sort keys %hash; + my $time=time; + my ($lastid)=($entries[$#entries]=~/^(\w+)\:/); + my ($thentime,$idnum)=split(/\_/,$lastid); + my $newid=$time.'_000000'; + if ($thentime==$time) { + $idnum=~s/^0+//; + $idnum++; + $idnum=substr('000000'.$idnum,-6,6); + $newid=$time.'_'.$idnum; + } + $hash{$newid}=$newchat; + my $expired=$time-3600; + foreach (keys %hash) { + my ($thistime)=($_=~/(\d+)\_/); + if ($thistime<$expired) { + delete $hash{$_}; + } + } + untie %hash; + } +} + +sub unsub { + my ($fname,$clientip)=@_; + my $result; + if (unlink("$fname.$hostid{$clientip}")) { + $result="ok\n"; + } else { + $result="not_subscribed\n"; + } + if (-e "$fname.subscription") { + my $found=&addline($fname,$hostid{$clientip},$clientip,''); + if ($found) { $result="ok\n"; } + } else { + if ($result != "ok\n") { $result="not_subscribed\n"; } + } + return $result; +} + +sub currentversion { + my $fname=shift; + my $version=-1; + my $ulsdir=''; + if ($fname=~/^(.+)\/[^\/]+$/) { + $ulsdir=$1; + } + $fname=~s/\.\d+\.(\w+(?:\.meta)*)$/\.$1/; + $fname=~s/\.(\w+(?:\.meta)*)$/\.\(\\d\+\)\.$1\$/; + + if (-e $fname) { $version=1; } + if (-e $ulsdir) { + if(-d $ulsdir) { + if (opendir(LSDIR,$ulsdir)) { + while ($ulsfn=readdir(LSDIR)) { +# see if this is a regular file (ignore links produced earlier) + my $thisfile=$ulsdir.'/'.$ulsfn; + unless (-l $thisfile) { + if ($thisfile=~/$fname/) { + if ($1>$version) { $version=$1; } + } + } + } + closedir(LSDIR); + $version++; + } + } + } + return $version; +} + +sub thisversion { + my $fname=shift; + my $version=-1; + if ($fname=~/\.(\d+)\.\w+(?:\.meta)*$/) { + $version=$1; + } + return $version; +} + +sub subscribe { + my ($userinput,$clientip)=@_; + my $result; + my ($cmd,$fname)=split(/:/,$userinput); + my $ownership=&ishome($fname); + if ($ownership eq 'owner') { +# explitly asking for the current version? + unless (-e $fname) { + my $currentversion=¤tversion($fname); + if (&thisversion($fname)==$currentversion) { + if ($fname=~/^(.+)\.\d+\.(\w+(?:\.meta)*)$/) { + my $root=$1; + my $extension=$2; + symlink($root.'.'.$extension, + $root.'.'.$currentversion.'.'.$extension); + unless ($extension=~/\.meta$/) { + symlink($root.'.'.$extension.'.meta', + $root.'.'.$currentversion.'.'.$extension.'.meta'); + } + } + } + } + if (-e $fname) { + if (-d $fname) { + $result="directory\n"; + } else { + if (-e "$fname.$hostid{$clientip}") {&unsub($fname,$clientip);} + $now=time; + my $found=&addline($fname,$hostid{$clientip},$clientip, + "$hostid{$clientip}:$clientip:$now\n"); + if ($found) { $result="$fname\n"; } + # if they were subscribed to only meta data, delete that + # subscription, when you subscribe to a file you also get + # the metadata + unless ($fname=~/\.meta$/) { &unsub("$fname.meta",$clientip); } + $fname=~s/\/home\/httpd\/html\/res/raw/; + $fname="http://$thisserver/".$fname; + $result="$fname\n"; + } + } else { + $result="not_found\n"; + } + } else { + $result="rejected\n"; + } + return $result; +} + +sub make_passwd_file { + my ($uname, $umode,$npass,$passfilename)=@_; + my $result="ok\n"; + if ($umode eq 'krb4' or $umode eq 'krb5') { + { + my $pf = IO::File->new(">$passfilename"); + print $pf "$umode:$npass\n"; + } + } elsif ($umode eq 'internal') { + my $salt=time; + $salt=substr($salt,6,2); + my $ncpass=crypt($npass,$salt); + { + &Debug("Creating internal auth"); + my $pf = IO::File->new(">$passfilename"); + print $pf "internal:$ncpass\n"; + } + } elsif ($umode eq 'localauth') { + { + my $pf = IO::File->new(">$passfilename"); + print $pf "localauth:$npass\n"; + } + } elsif ($umode eq 'unix') { + { + my $execpath="$perlvar{'lonDaemons'}/"."lcuseradd"; + { + &Debug("Executing external: ".$execpath); + &Debug("user = ".$uname.", Password =". $npass); + my $se = IO::File->new("|$execpath > /home/www/lcuseradd.log"); + print $se "$uname\n"; + print $se "$npass\n"; + print $se "$npass\n"; + } + my $useraddok = $?; + if($useraddok > 0) { + &logthis("Failed lcuseradd: ".&lcuseraddstrerror($useraddok)); + } + my $pf = IO::File->new(">$passfilename"); + print $pf "unix:\n"; + } + } elsif ($umode eq 'none') { + { + my $pf = IO::File->new(">$passfilename"); + print $pf "none:\n"; + } + } else { + $result="auth_mode_error\n"; + } + return $result; } # ----------------------------------- POD (plain old documentation, CPAN style) @@ -1821,6 +2088,7 @@ Crypt::IDEA LWP::UserAgent() GDBM_File Authen::Krb4 +Authen::Krb5 =head1 COREQUISITES