chamilo-lms2/plugin/ims_lti/OAuthSimple.php

<?php
/**
 * OAuthSimple - A simpler version of OAuth
 *
 * https://github.com/jrconlin/oauthsimple
 *
 * @author     jr conlin <src@jrconlin.com>
 * @copyright  unitedHeroes.net 2011
 * @version    1.3
 * @license    See license.txt
 *
 */

class OAuthSimple {
    private $_secrets;
    private $_default_signature_method;
    private $_action;
    private $_nonce_chars;

    /**
	 * Constructor
     *
	 * @access public
     * @param api_key (String) The API Key (sometimes referred to as the consumer key) This value is usually supplied by the site you wish to use.
     * @param shared_secret (String) The shared secret. This value is also usually provided by the site you wish to use.
	 * @return OAuthSimple (Object)
     */
    function __construct ($APIKey = "", $sharedSecret=""){

        if (!empty($APIKey))
		{
			$this->_secrets['consumer_key'] = $APIKey;
		}

        if (!empty($sharedSecret))
		{
			$this->_secrets['shared_secret'] = $sharedSecret;
		}

        $this->_default_signature_method = "HMAC-SHA1";
        $this->_action = "GET";
        $this->_nonce_chars = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";

        return $this;
    }

    /**
	 * Reset the parameters and URL
	 *
	 * @access public
	 * @return OAuthSimple (Object)
	 */
    public function reset() {
        $this->_parameters = Array();
        $this->path = NULL;
        $this->sbs = NULL;

        return $this;
    }

    /**
	 * Set the parameters either from a hash or a string
	 *
	 * @access public
	 * @param(string, object) List of parameters for the call, this can either be a URI string (e.g. "foo=bar&gorp=banana" or an object/hash)
	 * @return OAuthSimple (Object)
	 */
    public function setParameters ($parameters=Array()) {

        if (is_string($parameters))
		{
			$parameters = $this->_parseParameterString($parameters);
		}
        if (empty($this->_parameters))
		{
			$this->_parameters = $parameters;
		}
        else if (!empty($parameters))
		{
			$this->_parameters = array_merge($this->_parameters,$parameters);
		}
        if (empty($this->_parameters['oauth_nonce']))
		{
			$this->_getNonce();
		}
        if (empty($this->_parameters['oauth_timestamp']))
		{
			 $this->_getTimeStamp();
		}
        if (empty($this->_parameters['oauth_consumer_key']))
		{
			$this->_getApiKey();
		}
        if (empty($this->_parameters['oauth_token']))
		{
			  $this->_getAccessToken();
		}
        if (empty($this->_parameters['oauth_signature_method']))
		{
            $this->setSignatureMethod();
		}
        if (empty($this->_parameters['oauth_version']))
		{
            $this->_parameters['oauth_version']="1.0";
		}

        return $this;
    }

    /**
	 * Convenience method for setParameters
	 *
	 * @access public
	 * @see setParameters
	 */
    public function setQueryString ($parameters)
    {
        return $this->setParameters($parameters);
    }

    /**
	 * Set the target URL (does not include the parameters)
	 *
     * @param path (String) the fully qualified URI (excluding query arguments) (e.g "http://example.org/foo")
	 * @return OAuthSimple (Object)
     */
    public function setURL ($path)
	{
        if (empty($path))
		{
            throw new OAuthSimpleException('No path specified for OAuthSimple.setURL');
		}
        $this->_path=$path;

        return $this;
    }

    /**
	 * Convenience method for setURL
     *
     * @param path (String)
	 * @see setURL
     */
    public function setPath ($path)
    {
        return $this->_path=$path;
    }

    /**
	 * Set the "action" for the url, (e.g. GET,POST, DELETE, etc.)
     *
     * @param action (String) HTTP Action word.
	 * @return OAuthSimple (Object)
     */
    public function setAction ($action)
    {
        if (empty($action))
		{
			$action = 'GET';
		}
        $action = strtoupper($action);
        if (preg_match('/[^A-Z]/',$action))
		{
            throw new OAuthSimpleException('Invalid action specified for OAuthSimple.setAction');
		}
        $this->_action = $action;

        return $this;
    }

    /**
	 * Set the signatures (as well as validate the ones you have)
     *
     * @param signatures (object) object/hash of the token/signature pairs {api_key:, shared_secret:, oauth_token: oauth_secret:}
	 * @return OAuthSimple (Object)
     */
    public function signatures ($signatures)
    {
        if (!empty($signatures) && !is_array($signatures))
		{
            throw new OAuthSimpleException('Must pass dictionary array to OAuthSimple.signatures');
		}
        if (!empty($signatures))
        {
            if (empty($this->_secrets))
            {
                $this->_secrets=Array();
            }
            $this->_secrets=array_merge($this->_secrets,$signatures);
        }
        if (isset($this->_secrets['api_key']))
		{
            $this->_secrets['consumer_key'] = $this->_secrets['api_key'];
		}
        if (isset($this->_secrets['access_token']))
		{
            $this->_secrets['oauth_token'] = $this->_secrets['access_token'];
		}
        if (isset($this->_secrets['access_secret']))
		{
            $this->_secrets['shared_secret'] = $this->_secrets['access_secret'];
        }
        if (isset($this->_secrets['oauth_token_secret']))
		{
            $this->_secrets['oauth_secret'] = $this->_secrets['oauth_token_secret'];
		}
        if (empty($this->_secrets['consumer_key']))
		{
            throw new OAuthSimpleException('Missing required consumer_key in OAuthSimple.signatures');
        }
        if (empty($this->_secrets['shared_secret']))
		{
            throw new OAuthSimpleException('Missing requires shared_secret in OAuthSimple.signatures');
		}
        if (!empty($this->_secrets['oauth_token']) && empty($this->_secrets['oauth_secret']))
		{
            throw new OAuthSimpleException('Missing oauth_secret for supplied oauth_token in OAuthSimple.signatures');
		}

        return $this;
    }

    public function setTokensAndSecrets($signatures)
    {
        return $this->signatures($signatures);
    }

    /**
	 * Set the signature method (currently only Plaintext or SHA-MAC1)
     *
     * @param method (String) Method of signing the transaction (only PLAINTEXT and SHA-MAC1 allowed for now)
	 * @return OAuthSimple (Object)
    */
    public function setSignatureMethod ($method="")
	{
        if (empty($method))
		{
            $method = $this->_default_signature_method;
		}
        $method = strtoupper($method);
        switch($method)
        {
            case 'PLAINTEXT':
            case 'HMAC-SHA1':
                $this->_parameters['oauth_signature_method']=$method;
				break;
            default:
                throw new OAuthSimpleException ("Unknown signing method $method specified for OAuthSimple.setSignatureMethod");
				break;
        }

		return $this;
    }

    /** sign the request
     *
     * note: all arguments are optional, provided you've set them using the
     * other helper functions.
     *
     * @param args (Array) hash of arguments for the call {action, path, parameters (array), method, signatures (array)} all arguments are optional.
	 * @return (Array) signed values
     */
    public function sign($args=array())
    {
        if (!empty($args['action']))
		{
            $this->setAction($args['action']);
		}
        if (!empty($args['path']))
		{
            $this->setPath($args['path']);
        }
        if (!empty($args['method']))
		{
            $this->setSignatureMethod($args['method']);
		}
        if (!empty($args['signatures']))
		{
            $this->signatures($args['signatures']);
		}
        if (empty($args['parameters']))
		{
            $args['parameters']=array();
		}
        $this->setParameters($args['parameters']);
        $normParams = $this->_normalizedParameters();

        return Array (
            'parameters' => $this->_parameters,
            'signature' => self::_oauthEscape($this->_parameters['oauth_signature']),
            'signed_url' => $this->_path . '?' . $normParams,
            'header' => $this->getHeaderString(),
            'sbs'=> $this->sbs
            );
    }

    /**
	 * Return a formatted "header" string
     *
     * NOTE: This doesn't set the "Authorization: " prefix, which is required.
     * It's not set because various set header functions prefer different
     * ways to do that.
     *
     * @param args (Array)
	 * @return $result (String)
    */
    public function getHeaderString ($args=array())
    {
        if (empty($this->_parameters['oauth_signature']))
		{
            $this->sign($args);
		}
        $result = 'OAuth ';

        foreach ($this->_parameters as $pName => $pValue)
        {
            if (strpos($pName,'oauth_') !== 0)
			{
                continue;
			}
            if (is_array($pValue))
            {
                foreach ($pValue as $val)
                {
                    $result .= $pName .'="' . self::_oauthEscape($val) . '", ';
                }
            }
            else
            {
                $result .= $pName . '="' . self::_oauthEscape($pValue) . '", ';
            }
        }

        return preg_replace('/, $/','',$result);
    }

    private function _parseParameterString ($paramString)
    {
        $elements = explode('&',$paramString);
        $result = array();
        foreach ($elements as $element)
        {
            list ($key,$token) = explode('=',$element);
            if ($token)
			{
                $token = urldecode($token);
			}
            if (!empty($result[$key]))
            {
                if (!is_array($result[$key]))
				{
                    $result[$key] = array($result[$key],$token);
				}
                else
				{
                    array_push($result[$key],$token);
				}
            }
            else
                $result[$key]=$token;
        }
        return $result;
    }


    private static function _oauthEscape($string)
    {
        if ($string === 0) { return 0; }
		if ($string == '0') { return '0'; }
        if (strlen($string) == 0) { return ''; }
        if (is_array($string)) {
            throw new OAuthSimpleException('Array passed to _oauthEscape');
		}
        $string = urlencode($string);

	    //FIX: urlencode of ~ and '+'
        $string = str_replace(
            Array('%7E','+'  ), // Replace these
            Array('~',  '%20'), // with these
            $string);

        return $string;
    }

    private function _getNonce($length=5)
    {
        $result = '';
        $cLength = strlen($this->_nonce_chars);
        for ($i=0; $i < $length; $i++)
        {
            $rnum = rand(0,$cLength - 1);
            $result .= substr($this->_nonce_chars,$rnum,1);
        }
        $this->_parameters['oauth_nonce'] = $result;

        return $result;
    }

    private function _getApiKey()
    {
        if (empty($this->_secrets['consumer_key']))
        {
            throw new OAuthSimpleException('No consumer_key set for OAuthSimple');
        }
        $this->_parameters['oauth_consumer_key']=$this->_secrets['consumer_key'];

        return $this->_parameters['oauth_consumer_key'];
    }

    private function _getAccessToken()
    {
        if (!isset($this->_secrets['oauth_secret']))
		{
            return '';
		}
        if (!isset($this->_secrets['oauth_token']))
		{
            throw new OAuthSimpleException('No access token (oauth_token) set for OAuthSimple.');
		}
        $this->_parameters['oauth_token'] = $this->_secrets['oauth_token'];

        return $this->_parameters['oauth_token'];
    }

    private function _getTimeStamp()
    {
        return $this->_parameters['oauth_timestamp'] = time();
    }

    private function _normalizedParameters()
    {
		$normalized_keys = array();
		$return_array = array();

        foreach ( $this->_parameters as $paramName=>$paramValue) {
            if (preg_match('/w+_secret/', $paramName) OR
                $paramName == "oauth_signature") {
                    continue;
                }
            // Read parameters from a file. Hope you're practicing safe PHP.
            //if (strpos($paramValue, '@') !== 0 && !file_exists(substr($paramValue, 1)))
			//{
				if (is_array($paramValue))
				{
					$normalized_keys[self::_oauthEscape($paramName)] = array();
					foreach($paramValue as $item)
					{
						array_push($normalized_keys[self::_oauthEscape($paramName)],  self::_oauthEscape($item));
					}
				}
				else
				{
					$normalized_keys[self::_oauthEscape($paramName)] = self::_oauthEscape($paramValue);
				}
			//}
        }

		ksort($normalized_keys);

		foreach($normalized_keys as $key=>$val)
		{
			if (is_array($val))
			{
				sort($val);
				foreach($val as $element)
				{
					array_push($return_array, $key . "=" . $element);
				}
			}
			else
			{
				array_push($return_array, $key .'='. $val);
			}

        }
        $presig = join("&", $return_array);
        $sig = $this->_generateSignature($presig);
        $this->_parameters['oauth_signature']=$sig;
        array_push($return_array, "oauth_signature=$sig");
		return join("&", $return_array);
    }


    private function _generateSignature ($parameters="")
    {
        $secretKey = '';
		if(isset($this->_secrets['shared_secret']))
		{
			$secretKey = self::_oauthEscape($this->_secrets['shared_secret']);
		}

		$secretKey .= '&';
		if(isset($this->_secrets['oauth_secret']))
		{
            $secretKey .= self::_oauthEscape($this->_secrets['oauth_secret']);
        }
        if(!empty($parameters)){
            $parameters = urlencode($parameters);
        }
        switch($this->_parameters['oauth_signature_method'])
        {
            case 'PLAINTEXT':
                return urlencode($secretKey);;
            case 'HMAC-SHA1':
                $this->sbs = self::_oauthEscape($this->_action).'&'.self::_oauthEscape($this->_path).'&'.$parameters;

                return base64_encode(hash_hmac('sha1',$this->sbs,$secretKey,TRUE));
            default:
                throw new OAuthSimpleException('Unknown signature method for OAuthSimple');
				break;
        }
    }
}

class OAuthSimpleException extends Exception {

	public function __construct($err, $isDebug = FALSE)
	{
		self::log_error($err);
		if ($isDebug)
		{
			self::display_error($err, TRUE);
		}
	}

	public static function log_error($err)
	{
		error_log($err, 0);
	}

	public static function display_error($err, $kill = FALSE)
	{
		print_r($err);
		if ($kill === FALSE)
		{
			die();
		}
	}
}