#!/usr/bin/php

<?php

	require_once __DIR__.'/../../include/const';


	function cyclichash_new(){

		/* [1] Fetch necessary data
		=========================================================*/
		/* (1) Fetch secret file */
		$secret = @file_get_contents(SECRET_CONF);
		
		/* (2) Check secret file format */
		if( !is_string($secret) || !preg_match("/^(.{".SECRET_SIZE."}):(\d+):(.{".SECRET_SIZE."})$/", $secret, $match) ){
			slog("Error while reading secret", 'cyclic-hash:new');
			return 127;
		}

		/* (3) Extract data for hashing from @secret */
		$key   = (string) $match[1];
		$depth = (int)    $match[2];
		$next  = (string) $match[3];


		/* (4) Die if not token not changed */
		if( $depth > 1 ){
			slog("No new secret with $depth depth", 'cyclic-hash:new');
			return 0;
		}
		

		/* [2] If hash have just been created (original depth = 1000)
		=========================================================*/
		/* (1) Return new hash (from @next) */
		$newhash = $next;

		/* (2) Hash @depth times = 1000 */
		for( $d = 0 ; $d < 1000 ; $d++ )
			$newhash = hash('sha512', $newhash);

		slog("New secret with $depth depth", 'cyclic-hash:new');
		return $newhash;

	}

	echo cyclichash_new();
?>