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Posts Tagged ‘Temporary Keys’

Tools Plugin – Part1: CodeKey

25 Jun

In this first part of the presentation of my tools plugin I will show you how you can easily manage (store, retrieve, validate) “code keys”.
They are useful in the registration process of users, or if you want to send some double opt in confirmation emails, etc.

function newKey($type, $key = null, $uid = null, $content = null) {}

If you submit an uid (user_id) it can increase security by validation only if the pair “uid + key” are both valid.
As 4th parameter any string content can be stored. This comes in handy if you use it for changing email addresses. The new one will be stored in content until validation is complete and will then replace the old one.

function useKey($type, $key, $uid = null) {}

Usage

register_account(){}

# get new code with key "activate" and specific user id bound to it
$this->CodeKey = ClassRegistry::init('Tools.CodeKey');
$cCode = $this->CodeKey->newKey('activate', null, $uid);

This code can be used to send an activation email with a link to click on.

activate_account($keyToCheck){}

...
$this->CodeKey = ClassRegistry::init('Tools.CodeKey');
$key = $this->CodeKey->useKey('activate', $keyToCheck);
 
if (!empty($key) && $key['CodeKey']['used'] == 1) {
	# warning flash message: already activated
} elseif (!empty($key)) {
	# continue with activation
} else {
	# error flash message: invalid key
}
...

Plugin Model Code

<?php
 
class CodeKey extends ToolsAppModel {
 
	var $name = 'CodeKey';
 
	var $displayField = 'key';
	var $order = array('CodeKey.created' => 'ASC');
 
	private $defaultLength = 22;
 
	var $validate = array(
		'type' => array(
			'notEmpty' => array(
				'rule' => array('notEmpty'),
				'message' => 'valErrMandatoryField',
			),
		),
		'key' => array(
			'isUnique' => array(
				'rule' => array('isUnique'),
				'message' => 'key already exists',
			),
			'notEmpty' => array(
				'rule' => array('notEmpty'),
				'message' => 'valErrMandatoryField',
			),
		),
		'content' => array(
			'maxLength' => array(
				'rule' => array('maxLength', 255),
				'message' => array('valErrMaxCharacters %s', 255),
				'allowEmpty' => true
			),
		),
		'used' => array('numeric')
	);
 
	//var $types = array('activate');
 
	/**
	 * stores new key in DB
	 * @param string type: neccessary
	 * @param string key: optional key, otherwise a key will be generated
	 * @param mixed user_id: optional (if used, only this user can use this key)
	 * @param string content: up to 255 characters of content may be added (optional)
	 * NOW: checks if this key is already used (should be unique in table)
	 * @return string key on SUCCESS, boolean false otherwise
	 * 2009-05-13 ms
	 */
	function newKey($type, $key = null, $uid = null, $content = null) {
		if (empty($type)) {		//  || !in_array($type,$this->types)
			return false;
		}
 
		if (empty($key)) {
			$key = $this->generateKey($this->defaultLength);
			$keyLength = $this->defaultLength;
		} else {
			$keyLength = mb_strlen($key);
		}
 
		$data = array(
			'type' => $type,
			'user_id' => (string)$uid,
			'content' => (string)$content,
			'key' => $key,
		);
 
		$this->set($data);
		$max = 99;
		while (!$this->validates()) {
			$data['key'] = $this->generateKey($keyLength);
			$this->set($data);
			$max--;
			if ($max == 0) { //die('Exeption in CodeKey');
			 	return false;
			}
		}
 
		$this->create();
		if ($this->save($data)) {
			return $key;
		}
		return false;
	}
 
	/**
	 * usesKey (only once!) - by KEY
	 * @param string type: neccessary
	 * @param string key: neccessary
	 * @param mixed user_id: needs to be provided if this key has a user_id stored
	 * @return ARRAY(content) if successfully used or if already used (used=1), FALSE else
	 * 2009-05-13 ms
	 */
	function useKey($type, $key, $uid = null) {
		if (empty($type) || empty($key)) {
			return false;
		}
		$conditions = array('conditions'=>array($this->alias.'.key'=>$key,$this->alias.'.type'=>$type));
		if (!empty($uid)) {
			$conditions['conditions'][$this->alias.'.user_id'] = $uid;
		}
		$res = $this->find('first', $conditions);
		if (empty($res)) {
			return false;
		} elseif(!empty($uid) && !empty($res[$this->alias]['user_id']) && $res[$this->alias]['user_id'] != $uid) {
			// return $res; # more secure to fail here if user_id is not provided, but was submitted prev.
			return false;
		} elseif ($res[$this->alias]['used'] == 1) {
			return $res;
		}
 
		# actually use key
		if ($this->spendKey($res[$this->alias]['id'])) {
			return $res;
		}
		$this->log('VIOLATION in CodeKey Model (method useKey)');
		return false;
	}
 
	/**
	 * sets Key to "used" (only once!) - directly by ID
	 * @param id of key to spend: neccessary
	 * @return boolean true on success, false otherwise
	 * 2009-05-13 ms
	 */
	function spendKey($id = null) {
		if (empty($id)) {
			return false;
		}
		$this->id = $id;
		if ($this->saveField('used', 1)) {
			return true;
		}
		return false;
	}
 
	/**
	 * remove old/invalid keys
	 * does not remove recently used ones (for proper feedback)!
	 * @return boolean success
	 * 2010-06-17 ms
	 */
	function garbigeCollector() {
		$conditions = array(
			$this->alias.'.created <'=>date(FORMAT_DB_DATETIME, time()-MONTH),
		);
		return $this->deleteAll($conditions, false);
	}
 
 
	/**
	 * @param length (defaults to defaultLength)
	 * @return string codekey
	 * 2009-05-13 ms
	 */
	function generateKey($length = null) {
		if (empty($length)) {
			$length = $defaultLength;
		} else {
			if ((class_exists('CommonComponent') || App::import('Component', 'Common')) && method_exists('CommonComponent', 'generatePassword')) {
				return CommonComponent::generatePassword($length);
			} else {
				return $this->_generateKey($length);
			}
		}
	}
 
	/**
	 * backup method - only used if no custom function exists
	 * 2010-06-17 ms
	 */
	function _generateKey($length = null) {
		$chars = "234567890abcdefghijkmnopqrstuvwxyz"; // ABCDEFGHIJKLMNOPQRSTUVWXYZ
		$i = 0;
		$password = "";
		$max = strlen($chars) - 1;
 
		while ($i < $length) {
			$password .= $chars[mt_rand(0, $max)];
			$i++;
		}
		return $password;
	}
 
}
?>
 
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