POP3 class with secure APOP authentication

# A class to allow you to connect to POP3 servers 

# Written by someone on some newsgroup, but modified by me, 
# Kevin McDermott [email protected]

class Pop3 {
	var $user;
	var $pass;
	var $Socket;				// the current socket
	var $Line;
	var $Status;
	var $Banner;

	function Pop3($Server = "localhost",$Port = 110)
	{    
		return $this->pop3_open($Server, $Port);
	}

	# This will handle the connection process for you, just feed it the
	# information it needs. It will default to APOP secure connection but
	# fall back to plain text if that doesn't work.  WARNING: some servers
	# will kick you out after one failed attempt so after the failed APOP
	# authentication, you'll be kicked out, and this will fail, disable
	# APOP authentication if this is the case, and APOP doesn't work.
	function Pop3($Server = "localhost", $Port = 110, $user = "", $pass = "") {
		if ( !$this->pop3_open($Server, $Port) ) {
			$this->Status["Connection"] = 
			    "Could not contact server '$Server' on port $Port";
			return;
		}

		if (false && $this->Banner) { # disable this pending further APOP tests
			 if (!$this->pop3_apop($user, $pass)) {
				if ( !$this->pop3_user($user) ) {
					$this->Status["Connection"] = "Username '$user' is invalid";
					return;
				}
				if ( !$this->pop3_pass($pass) ) {
					$this->Status["Connection"] = 
					    "Username '$user' or Password is invalid";
					return;
				}
			}
		} else {
			if ( !$this->pop3_user($user) ) {
				$this->Status["Connection"] = "Username '$user' is invalid";
				return;
			}
			if ( !$this->pop3_pass($pass) ) {
				$this->Status["Connection"] = 
				    "Username '$user' or Password is invalid";
				return;
			}	
		}
		return true;
	}

	function pop3_open($server, $port)  
	{

		$this->Socket = fsockopen($server, $port);
		if ($this->Socket <= 0){
			return false;
		}
		$this->Line = fgets($this->Socket, 1024);
		$this->Status["LASTRESULT"] = substr($this->Line, 0, 1);
		$this->Status["LASTRESULTTXT"] = substr($this->Line, 0, 1024);
		if (preg_match("/<[wd-.]+@[wd-.]+>/",
			$this->Status["LASTRESULTTXT"], $matched)) {
			$this->Banner = $matched[0];
		} else {
			$this->Banner = "";
		}
	
		if ($this->Status["LASTRESULT"] <> "+") return false;
		return true;
	}

	function pop3_user($user)
	{
		$this->user = $user;
		if ($this->Socket < 0){
		  return false;
		}
		fputs($this->Socket, "USER $this->userrn");
		$this->Line = fgets($this->Socket, 1024);
		$this->Status["LASTRESULT"] = substr($this->Line, 0, 1);
		$this->Status["LASTRESULTTXT"] = substr($this->Line, 0, 1024);

		if ($this->Status["LASTRESULT"] <> "+") return false;

		return true;
	}

	function pop3_pass($pass)
	{
		$this->pass = $pass;
		fputs($this->Socket, "PASS $this->passrn");
		$this->Line = fgets($this->Socket, 1024);
		$this->Status["LASTRESULT"] = substr($this->Line, 0, 1);
		$this->Status["LASTRESULTTXT"] = substr($this->Line, 0, 1024);

		if ($this->Status["LASTRESULT"] <> "+") return false;

		return true;
	}
	function pop3_apop($user, $pass)
	{
		fputs($this->Socket, "APOP $user ".md5($this->Banner.$pass)."rn");
		$this->Line = fgets($this->Socket, 1024);
		$this->Status["LASTRESULT"] = substr($this->Line, 0, 1);
		$this->Status["LASTRESULTTXT"] = substr($this->Line, 0, 1024);

		if ($this->Status["LASTRESULT"] <> "+") return false;

		return true;
	}
	function pop3_stat()
	{

		fputs($this->Socket, "STATrn");
		$this->Line = fgets($this->Socket, 1024);
		$this->Status["LASTRESULT"] = substr($this->Line, 0, 1);
		$this->Status["LASTRESULTTXT"] = substr($this->Line, 0, 1024);

		if ($this->Status["LASTRESULT"] <> "+") return false;

		if (!eregi("+OK (.*) (.*)", $this->Line, $regs)) 
			return false;

		return $regs[1];
	}

	function pop3_list()
	{
		fputs($this->Socket, "LISTrn");
		$this->Line = fgets($this->Socket, 1024);
		$this->Status["LASTRESULT"] = substr($this->Line, 0, 1);
		$this->Status["LASTRESULTTXT"] = substr($this->Line, 0, 1024);

		if ($this->Status["LASTRESULT"] <> "+") return false;

		$i = 0;
		while (substr($this->Line = fgets($this->Socket, 1024), 0, 1) <> ".") {
			$articles[$i] = $this->Line;
			$i++;
		}

		return $articles;
	}

	# This retreaves the whole message, and sets the Status: field in the 
	# message to read (it adds an 'R' to that field).
	function pop3_retr($nr)
	{
	
		fputs($this->Socket, "RETR $nrrn");
		$this->Line = fgets($this->Socket, 1024);
		$this->Status["LASTRESULT"] = substr($this->Line, 0, 1);
		$this->Status["LASTRESULTTXT"] = substr($this->Line, 0, 1024);

		if ($this->Status["LASTRESULT"] <> "+") return 0;

		while (substr($this->Line = fgets($this->Socket, 1024), 0, 1) <> ".") {
			$data[$i] = $this->Line;
			$i++;
		}

		return $data;
	}

	# This will view the header of a message (and $lines number of lines
	# afterwards WITHOUT setting the Status: field as read (doesn't add an 'R'
	# to that field.
	function pop3_top($nr, $lines)
	{
	
		fputs($this->Socket, "TOP $nr $linesrn");
		$this->Line = fgets($this->Socket, 1024);
		$this->Status["LASTRESULT"] = substr($this->Line, 0, 1);
		$this->Status["LASTRESULTTXT"] = substr($this->Line, 0, 1024);

		if ($this->Status["LASTRESULT"] <> "+") return 0;

		while (substr($this->Line = fgets($this->Socket, 1024), 0, 1) <> ".") {
			$data[$i] = $this->Line;
			$i++;
		}

		return $data;
	}

	function pop3_dele( $nr)
	{

		fputs($this->Socket, "DELE $nrrn");
		$this->Line = fgets($this->Socket, 1024);
		$this->Status["LASTRESULT"] = substr($this->Line, 0, 1);
		$this->Status["LASTRESULTTXT"] = substr($this->Line, 0, 1024);

		if ($this->Status["LASTRESULT"] <> "+") return 0;
		return 1;
	}

	function pop3_quit()
	{

		fputs($this->Socket, "QUITrn");
		$this->Line = fgets($this->Socket, 1024);
		$this->Status["LASTRESULT"] = substr($this->Line, 0, 1);
		$this->Status["LASTRESULTTXT"] = substr($this->Line, 0, 1024);

		if ($this->Status["LASTRESULT"] <> "+") return 0;

		return 1;
	}
}