File: includes/OAuthSimple.php

<?php
/**
 * This file is being used for the encoding of the tokens
 *
 * Use of this file is an agreement with the copyright notice below
 *
 */ 
 
 
/* OAuthSimple
* A simpler version of OAuth
*
* author: jr conlin
* mail: src@jrconlin.com
* copyright: unitedHeroes.net
* version: 1.2
* url: http://unitedHeroes.net/OAuthSimple
*
* Copyright (c) 2010, unitedHeroes.net
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* * Neither the name of the unitedHeroes.net nor the
* names of its contributors may be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY UNITEDHEROES.NET ''AS IS'' AND ANY
* EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL UNITEDHEROES.NET BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/


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

    /* Simple OAuth
	*
	* This class only builds the OAuth elements, it does not do the actual
	* transmission or reception of the tokens. It does not validate elements
	* of the token. It is for client use only.
	*
	* api_key is the API key, also known as the OAuth consumer key
	* shared_secret is the shared secret (duh).
	*
	* Both the api_key and shared_secret are generally provided by the site
	* offering OAuth services. You need to specify them at object creation
	* because nobody <explative>ing uses OAuth without that minimal set of
	* signatures.
	*
	* If you want to use the higher order security that comes from the
	* OAuth token (sorry, I don't provide the functions to fetch that because
	* sites aren't horribly consistent about how they offer that), you need to
	* pass those in either with .signatures() or as an argument to the
	* .sign() or .getHeaderString() functions.
	*
	* Example:
	<code>
	<?php
	$oauthObject = new OAuthSimple();
	$result = $oauthObject->sign(Array('path'=>'http://example.com/rest/',
	'parameters'=> 'foo=bar&gorp=banana',
	'signatures'=> Array(
	'api_key'=>'12345abcd',
	'shared_secret'=>'xyz-5309'
	)));
	?>
	<a href="<?php print $result['signed_url']; ?>">Some Link</a>;
	</code>
	*
	* that will sign as a "GET" using "SHA1-MAC" the url. If you need more than
	* that, read on, McDuff.
	*/
	
	/** OAuthSimple creator
	*
	* Create an instance of OAuthSimple
	*
	* @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.
	*/
    public 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
	*
	*/
    public function reset() {
        $this->_parameters=null;
        $this->path=null;
        $this->sbs=null;
        return $this;
    }

    /** set the parameters either from a hash or a string
	*
	* @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)
	*/
    public function setParameters ($parameters=Array()) {
        
        if (is_string($parameters))
            $parameters = $this->_parseParameterString($parameters);
        if (empty($this->_parameters))
            $this->_parameters = $parameters;
        elseif (!empty($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;
    }

    // convienence method for 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")
	*/
    public function setURL ($path) {
        $this->_path=$path;
        return $this;
    }

    /** convienence 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.
	*/
    public function setAction ($action) {
        if (empty($action))
            $action = 'GET';
        $action = strtoupper($action);
        $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:}
	*/
    public function signatures ($signatures) {
        if (!empty($signatures)){
            if (empty($this->_secrets)) {
                $this->_secrets=Array();
            }
            $this->_secrets=array_merge($this->_secrets,$signatures);
        }
        // Aliases
        if (isset($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['oauth_secret'] = $this->_secrets['access_secret'];
        if (isset($this->_secrets['access_token_secret']))
            $this->_secrets['oauth_secret'] = $this->_secrets['access_token_secret'];
        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)
	*/
    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;
        }
        return $this;
    }

    /** sign the request
	*
	* note: all arguments are optional, provided you've set them using the
	* other helper functions.
	*
	* @param args {object} hash of arguments for the call
	* {action, path, parameters (array), method, signatures (array)}
	* all arguments are optional.
	*/
    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(); // squelch the warning.
        $this->setParameters($args['parameters']);
        $normParams = $this->_normalizedParameters();
        $this->_parameters['oauth_signature'] = $this->_generateSignature($normParams);
        return Array(
            'parameters' => $this->_parameters,
            'signature' => $this->_oauthEscape($this->_parameters['oauth_signature']),
            'signed_url' => $this->_path . '?' . $this->_normalizedParameters(),
            'header' => $this->getHeaderString(),
            'sbs'=> $this->sbs
            );
    }

    /** Return a formatted "header" string
	*
	* NOTE: This doesn't set the "Authorization: " prefix, which is required.
	* I don't set it because various set header functions prefer different
	* ways to do that.
	*
	* @param args {object} see .sign
	*/
    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 .'="' . $this->_oauthEscape($val) . '", ';
                }
            }
            else
            {
                $result .= $pName . '="' . $this->_oauthEscape($pValue) . '", ';
            }
        }
        return preg_replace('/, $/','',$result);
    }

    // Start private methods. Here be Dragons.
    // No promises are kept that any of these functions will continue to exist
    // in future versions.
    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]=$token;
        }
        //error_log('Parse parameters : '.print_r($result,1));
        return $result;
    }

    private function _oauthEscape($string) {
        if ($string === 0)
            return 0;
        if (empty($string))
            return '';

        $string = urlencode($string);
        $string = str_replace('+','%20',$string);
        $string = str_replace('!','%21',$string);
        $string = str_replace('*','%2A',$string);
        $string = str_replace('\'','%27',$string);
        $string = str_replace('(','%28',$string);
        $string = str_replace(')','%29',$string);
        return $string;
    }

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

    private function _getApiKey() {
        $this->_parameters['oauth_consumer_key']=$this->_secrets['consumer_key'];
        return $this->_parameters['oauth_consumer_key'];
    }

    private function _getAccessToken() {
        if (!isset($this->_secrets['oauth_secret']))
            return '';
        $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() {
        $elements = array();
        $ra = 0;
        ksort($this->_parameters);
        foreach ( $this->_parameters as $paramName=>$paramValue) {
            if (preg_match('/\w+_secret/',$paramName))
                continue;
            if (is_array($paramValue))
            {
                sort($paramValue);
                foreach($paramValue as $element)
                    array_push($elements,$this->_oauthEscape($paramName).'='.$this->_oauthEscape($element));
                continue;
            }
            array_push($elements,$this->_oauthEscape($paramName).'='.$this->_oauthEscape($paramValue));
        }
        return join('&',$elements);
    }

    private function _generateSignature () {
        $secretKey = '';
		if(isset($this->_secrets['shared_secret'])) {
			$secretKey = $this->_oauthEscape($this->_secrets['shared_secret']);		
			$secretKey .= '&';
		}
		if(isset($this->_secrets['oauth_secret'])) {
            $secretKey .= $this->_oauthEscape($this->_secrets['oauth_secret']);
		}

        switch($this->_parameters['oauth_signature_method'])
        {
            case 'PLAINTEXT':
                return $secretKey;

            case 'HMAC-SHA1':
                $this->sbs = $this->_oauthEscape($this->_action).'&'.$this->_oauthEscape($this->_path).'&'.$this->_oauthEscape($this->_normalizedParameters());
                return base64_encode(hash_hmac('sha1',$this->sbs,$secretKey,true));
        }
    }
}