I have been using some great email obfuscation code created by Ross Killen ,Tim Williams and Andrew Moulden. And like Andrew’s generator that allows for “link text”, I needed a PHP solution for sites I’m developing. So here’s my twist:

function munge($address,$link_text) {
	$address = strtolower($address);
	$coded = "";
	$unmixedkey = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789.@-_";
	$inprogresskey = $unmixedkey;
	$mixedkey="";
	$unshuffled = strlen($unmixedkey);
	for ($i = 1; $i <= strlen($unmixedkey); $i++) {
        // set i = 1 because i = 0 was throwing an offset error in PHP 
		$ranpos = rand(0,$unshuffled-1);
		$nextchar = $inprogresskey{$ranpos};
		$mixedkey .= $nextchar;
		$before = substr($inprogresskey,0,$ranpos);
		$after = substr($inprogresskey,$ranpos+1,$unshuffled-($ranpos+1));
		$inprogresskey = $before.''.$after;
		$unshuffled -= 1;
	}
	$cipher = $mixedkey;
	$shift = strlen($address);
	$txt = "<script type=\"text/javascript\" language=\"javascript\">\n" .
           "<!-"."-\n" .
           "// Email obfuscator script 2.1 by Tim Williams, University of Arizona\n".
		   "// Random encryption key feature by Andrew Moulden, Site Engineering Ltd\n".
		   "// PHP version coded by Ross Killen, Celtic Productions Ltd\n".
		   "// This code is freeware provided these six comment lines remain intact\n".
		   "// A wizard to generate this code is at http://www.jottings.com/obfuscator/\n".
		   "// The PHP code may be obtained from http://www.celticproductions.net/\n\n";
		   
	for ($j=0; $j<strlen($address); $j++) {
		if (strpos($cipher,$address{$j}) == -1 ) {
			$chr = $address{$j};
			$coded .= $address{$j};
		} else {
			$chr = (strpos($cipher,$address{$j}) + $shift) %
			strlen($cipher);
			$coded .= $cipher{$chr};
		}
	}
	
	if($link_text):
	
		$link_text_block = "document.write(\"<a href='mailto:\"+link+\"'>" . $link_text . "</a>\")\n";
		
	else:
		
		$link_text_block = "document.write(\"<a href='mailto:\"+link+\"'>\"+link+\"</a>\")\n";
		
	endif;
		
	$txt .= "\ncoded = \"" . $coded . "\"\n" .
			"  key = \"".$cipher."\"\n".
			"  shift=coded.length\n".
			"  link=\"\"\n".
			"  for (i=0; i<coded.length; i++) {\n" .
			"    if (key.indexOf(coded.charAt(i))==-1) {\n" .
			"      ltr = coded.charAt(i)\n" .
			"      link += (ltr)\n" .
			"    }\n" .
			"    else {     \n".
			"      ltr = (key.indexOf(coded.charAt(i))-shift+key.length) % key.length\n".
			"      link += (key.charAt(ltr))\n".
			"    }\n".
			"  }\n".
			// Original link markup
			//"document.write(\"<a href='mailto:\"+link+\"'>\"+link+\"</a>\")\n" .
			// Link markup from above
                        $link_text_block .
			"\n".
			"//-"."->\n" .
			"<" . "/script><noscript>Please turn on javascript to email me." .
			"<"."/noscript>";
	
	return $txt;
}

Published on October 16, 2013