php-微信分享签名

//测试
$appid='*************************';
$secret='***********************';

$url = trim($_request['url']);

$root['url'] = $url;

$memcache = getredis();
$mem_valid_time = 7100;

//获取access_token，并缓存
$memcache_key = 'wx_share_sign_access_token';
$mem_list = $memcache->get($memcache_key);

//缓存中没有数据
if (empty($mem_list)) {

    $token = null;

    if (!$token || strlen($token) < 6) {
        $res = file_get_contents("https://api.weixin.qq.com/cgi-bin/token?grant_type=client_credential&appid=".$appid."&secret=".$secret."");
        $res = json_decode($res, true);
        $token = $res['access_token'];
    }

    $new_list = $token;
    //更新缓存
    $memcache->set($memcache_key,$new_list,$mem_valid_time);

} else {

    $token = $mem_list;//缓存中的数据
}
$root['access_token'] = $token;
//获取jsapi_ticket，并缓存
$memcache_key = 'sign_jsapi_ticket';
$mem_list = $memcache->get($memcache_key);
//缓存中没有取数据库
if (empty($mem_list)) {

    $jsapi_ticket = null;

    if (!$jsapi_ticket || strlen($jsapi_ticket) < 6) {
        $ur = "https://api.weixin.qq.com/cgi-bin/ticket/getticket?access_token={$token}&type=jsapi";
        $res = file_get_contents($ur);
        $res = json_decode($res, true);
        $jsapi_ticket = $res['ticket'];
    }

    $new_list = $jsapi_ticket;
    //更新缓存
    $memcache->set($memcache_key,$new_list,$mem_valid_time);

} else {
    $jsapi_ticket = $mem_list;//缓存中的数据
}

$root['jsapi_ticket'] = $jsapi_ticket;

$timestamp = time();//生成签名的时间戳
$metas = range(0, 9);
$metas = array_merge($metas, range('a', 'z'));
$metas = array_merge($metas, range('a', 'z'));
$noncestr = '';
for ($i=0; $i < 16; $i++) {
    $noncestr .= $metas[rand(0, count($metas)-1)];//生成签名的随机串
}

$string1="jsapi_ticket=".$jsapi_ticket."&noncestr=".$noncestr."&timestamp=".$timestamp."&url=".$url."";
$signature=sha1($string1);
$root['appid'] = $appid;
$root['noncestr'] = $noncestr;
$root['timestamp'] = $timestamp;
$root['signature'] = $signature;

return $tag;