version 1.6, 2004/11/14 07:54:41
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version 1.21, 2007/07/20 19:07:25
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Line 29
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Line 29
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package Apache::lonenc; |
package Apache::lonenc; |
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use strict; |
use strict; |
use Apache::Constants qw(:common :remotehost); |
use Apache::lonnet; |
use Apache::lonnet(); |
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use Apache::File(); |
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use Apache::loncommon; |
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use Crypt::IDEA; |
use Crypt::IDEA; |
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use Time::HiRes qw(gettimeofday); |
sub handler { |
use LONCAPA; |
my $r = shift; |
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my %cookies=CGI::Cookie->parse($r->header_in('Cookie')); |
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my $lonid=$cookies{'lonID'}; |
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my $cookie; |
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if ($lonid) { |
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my $handle=$lonid->value; |
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$handle=~s/\W//g; |
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my $lonidsdir=$r->dir_config('lonIDsDir'); |
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$ENV{'request.enc'}=1; |
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if ((-e "$lonidsdir/$handle.id") && ($handle ne '')) { |
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# Initialize Environment |
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&Apache::lonnet::transfer_profile_to_env($lonidsdir,$handle); |
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# Decrypt URL and redirect |
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&Apache::lonnet::logthis("args ".$r->args); |
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&Apache::lonnet::logthis("uri ".$r->uri); |
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$r->internal_redirect(&unencrypted($r->uri).'?'.$r->args); |
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return OK; |
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} |
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} |
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return FORBIDDEN; |
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} |
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sub encryptseed { |
sub encryptseed { |
my $seed=$ENV{'course.'.$ENV{'request.course.id'}.'.internal.encseed'}; |
my ($cid) = @_; |
$seed=~s/[^0-9a-f]/0/g; |
if (!defined($cid)) { |
$seed.='0123456789abcdef'; |
$cid = $env{'request.course.id'}; |
$seed=substr($seed.$seed,0,32); |
} |
return pack("H32",$seed); |
my $seed; |
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if (defined($cid)) { |
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if (defined$env{'course.'.$cid.'.internal.encseed'}) { |
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$seed = $env{'course.'.$cid.'.internal.encseed'}; |
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} else { |
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my %descargs = ( 'one_time' => 1); |
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my %course = |
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&Apache::lonnet::coursedescription($cid,\%descargs); |
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$seed = $course{'internal.encseed'}; |
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} |
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} |
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if (defined($seed)) { |
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$seed=~s/[^0-9a-f]/0/g; |
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$seed.='0123456789abcdef'; |
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$seed=substr($seed.$seed,0,32); |
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return pack("H32",$seed); |
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} else { |
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return pack("H32",1); |
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} |
} |
} |
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sub unencrypted { |
sub unencrypted { |
my $uri=shift; |
my ($uri,$cid) = @_; |
$uri=~s/^\/enc\/(\d+)\///; |
$uri=~s/^\/enc\/(\d+)\///; |
my $cmdlength=$1; |
my $cmdlength=$1; |
my $seed=&encryptseed(); |
# strip any added extension |
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$uri=~s/\.[^.]*//; |
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my $seed=&encryptseed($cid); |
unless ($seed) { |
unless ($seed) { |
return '/'.$uri; |
return '/'.$uri; |
} |
} |
$uri=&Apache::lonnet::unescape($uri); |
$uri=&unescape($uri); |
my $cipher=new IDEA $seed; |
my $cipher=new IDEA $seed; |
my $decuri=''; |
my $decuri=''; |
for (my $encidx=0;$encidx<length($uri);$encidx+=16) { |
for (my $encidx=0;$encidx<length($uri);$encidx+=16) { |
Line 82 sub unencrypted {
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Line 78 sub unencrypted {
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pack("H16",substr($uri,$encidx,16)) |
pack("H16",substr($uri,$encidx,16)) |
); |
); |
} |
} |
$ENV{'request.enc'}=1; |
$env{'request.enc'}=1; |
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$decuri=&remove_noise($decuri); |
return substr($decuri,0,$cmdlength); |
return substr($decuri,0,$cmdlength); |
} |
} |
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# add a randomish character after every 4th caharacter |
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sub add_noise { |
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my ($uri)=@_; |
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my @noise=split(/(.)/,(&gettimeofday())[1]); |
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my $noisy; |
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my $i; |
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foreach my $chunk (split(/(....)/,$uri)) { |
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$noisy.=$chunk; |
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$noisy.=$noise[($i++)%(scalar@noise)]; |
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} |
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return $noisy; |
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} |
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# remove every fifth character |
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sub remove_noise { |
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my ($uri)=@_; |
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my $clean; |
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foreach my $chunk (split(/(....)./,$uri)) { $clean.=$chunk; } |
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return $clean; |
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} |
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sub encrypted { |
sub encrypted { |
my $uri=shift; |
my ($uri,$force_enc) = @_; |
if ($ENV{'request.role.adv'}) { return($uri); } |
if (!$force_enc && $env{'request.role.adv'}) { return($uri); } |
my $seed=&encryptseed(); |
my $seed=&encryptseed(); |
unless ($seed) { |
unless ($seed) { |
return $uri; |
return $uri; |
} |
} |
my $cmdlength=length($uri); |
my $cmdlength=length($uri); |
$uri.='00000000'; |
# add noise before enc so that that same url's look different |
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$uri=&add_noise($uri); |
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my $noiselength=length($uri); |
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$uri.=time; |
my $encuri=''; |
my $encuri=''; |
my $cipher=new IDEA $seed; |
my $cipher=new IDEA $seed; |
for (my $encidx=0;$encidx<=$cmdlength;$encidx+=8) { |
for (my $encidx=0;$encidx<=$noiselength;$encidx+=8) { |
$encuri.=unpack("H16", |
$encuri.=unpack("H16", |
$cipher->encrypt(substr($uri,$encidx,8))); |
$cipher->encrypt(substr($uri,$encidx,8))); |
} |
} |
return '/enc/'.$cmdlength.'/'.&Apache::lonnet::escape($encuri); |
return '/enc/'.$cmdlength.'/'.&escape($encuri); |
} |
} |
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sub check_encrypt { |
sub check_encrypt { |
my $str=shift; |
my $str=shift; |
if ($ENV{'request.enc'}) { return &Apache::lonenc::encrypted($str); } |
if (ref($str)) { |
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if ($env{'request.enc'}) { $$str = &Apache::lonenc::encrypted($$str); } |
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return; |
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} else { |
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if ($env{'request.enc'}) { return &Apache::lonenc::encrypted($str); } |
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} |
return $str; |
return $str; |
} |
} |
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sub check_decrypt { |
sub check_decrypt { |
my ($str)=@_; |
my ($str)=@_; |
if ($$str=~m|^/enc/|) { $$str=&Apache::lonenc::unencrypted($$str); } |
if (ref($str)) { |
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if ($$str=~m|^/enc/|) { $$str=&Apache::lonenc::unencrypted($$str); } |
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return; |
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} |
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if ($str=~m|^/enc/|) { return &Apache::lonenc::unencrypted($str); } |
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return $str; |
} |
} |
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sub encrypt_ref { |
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my ($token,$elements,$force_enc)=@_; |
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my $html; |
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if ($force_enc || $env{'request.enc'}) { |
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while (my ($name,$value)= each(%{ $elements })) { |
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if (!$value) { next; } |
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my $href=&Apache::lonnet::hreflocation($Apache::lonxml::pwd[-1],$value); |
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if ($href !~ /^http:/) { |
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# IE really wants an extension |
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my ($extension) = ($href =~ m/(\.[^.]*)$/); |
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$href = &Apache::lonenc::encrypted($href,$force_enc); |
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$href .= $extension; |
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} |
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$token->[2]->{$name}=$href; |
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} |
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delete($token->[2]->{'encrypturl'}); |
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$html = &Apache::edit::rebuild_tag($token); |
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} else { |
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$html = $token->[4]; |
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} |
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return $html; |
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} |
1; |
1; |
__END__ |
__END__ |
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