微信公众号获取签名

<?php 
class JSSDK
{
    private $appId;
    private $appSecret;

    public function __construct($appId, $appSecret) 
    {
        $this->appId = $appId;
        $this->appSecret = $appSecret;
    }

    public function getSignPackage() 
    {
        $jsapiTicket = $this->getJsApiTicket();
        $url = "https://$_SERVER[HTTP_HOST]$_SERVER[REQUEST_URI]";
        $timestamp = time();
        $nonceStr = $this->createNonceStr();
        $string = "jsapi_ticket=$jsapiTicket&noncestr=$nonceStr&timestamp=$timestamp&url=$url";
        $signature = sha1($string);
        $signPackage = array(
            "appId"     => $this->appId,
            "nonceStr"  => $nonceStr,
            "timestamp" => $timestamp,
            "url"       => $url,
            "signature" => $signature,
            "rawString" => $string
        );
        return $signPackage;
    }

    private function getJsApiTicket() 
    {
        $accessToken = $this->getAccessToken();
        $url = "https://api.weixin.qq.com/cgi-bin/ticket/getticket?type=jsapi&access_token=$accessToken";
        $res = json_decode($this->httpGet($url),true);
        $ticket = $res['ticket'];

        return $ticket;
    }

    private function getAccessToken() 
    {

        $url = "https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid=$this->appId&secret=$this->appSecret";
        $res = json_decode($this->httpGet($url),true);
        $access_token = $res['access_token'];

        return $access_token;
    }

    private function createNonceStr($length = 16) 
    {
        $chars = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789";
        $str = "";
        for ($i = 0; $i < $length; $i++) {
            $str .= substr($chars, mt_rand(0, strlen($chars) - 1), 1);
        }
        return $str;
    }

    private function httpGet($url) 
    {
        $curl = curl_init();
        curl_setopt($curl, CURLOPT_RETURNTRANSFER, true);
        curl_setopt($curl, CURLOPT_TIMEOUT, 500);
        curl_setopt($curl,CURLOPT_SSL_VERIFYPEER,false);
        curl_setopt($curl,CURLOPT_SSL_VERIFYHOST,false);
        curl_setopt($curl, CURLOPT_URL, $url);

        $res = curl_exec($curl);
        if(curl_error($curl )){
            echo curl_error($curl );
        }
        curl_close($curl);

        return $res;
    }

}

调用

<?php

require_once("JSSDK.php");
$jssdk=new JSSDK('appId','appSecret');
$signPackage = $jssdk->GetSignPackage();

?>