php对接百度referer api接口，获取百度搜索关键词

<?php
// 根据RFC 3986，除了：
//   1.大小写英文字符
//   2.阿拉伯数字
//   3.点'.'、波浪线'~'、减号'-'以及下划线'_'
// 以外都要编码
global $PERCENT_ENCODED_STRINGS ;
 __init();
//填充编码数组
function __init()
{
    global $PERCENT_ENCODED_STRINGS ;
    for ($i = 0; $i < 256; ++$i) {
        $PERCENT_ENCODED_STRINGS[$i] = sprintf("%%%02X", $i);
    }
    //a-z不编码
    foreach (range('a', 'z') as $ch) {
        $PERCENT_ENCODED_STRINGS[ord($ch)] = $ch;
    }
    //A-Z不编码
    foreach (range('A', 'Z') as $ch) {
        $PERCENT_ENCODED_STRINGS[ord($ch)] = $ch;
    }
    //0-9不编码
    foreach (range('0', '9') as $ch) {
        $PERCENT_ENCODED_STRINGS[ord($ch)] = $ch;
    }
    //以下4个字符不编码
    $PERCENT_ENCODED_STRINGS[ord('-')] = '-';
    $PERCENT_ENCODED_STRINGS[ord('.')] = '.';
    $PERCENT_ENCODED_STRINGS[ord('_')] = '_';
    $PERCENT_ENCODED_STRINGS[ord('~')] = '~';
}
 
 
//使用编码数组编码
function doUrlEncode($value)
{
    global $PERCENT_ENCODED_STRINGS ;
 
    $result = '';
    for ($i = 0; $i < strlen($value); ++$i) {
        $result .= $PERCENT_ENCODED_STRINGS[ord($value[$i])];
    }
    return $result;
}
 
function urlEncodeExceptSlash($path)
{
    return str_replace("%2F", "/", doUrlEncode($path));
}
 
//生成标准化uri
function getCanonicalURIPath($path)
{
    //空路径设置为'/'
    if (empty($path)) {
        return '/';
    } else {
        //所有的uri必须以'/'开头
        if ($path[0] == '/') {
            return urlEncodeExceptSlash($path);
        } else {
            return '/' . urlEncodeExceptSlash($path);
        }
    }
}
 
 
/**
 * 获取认证字符串
 *
 *  任务一：创建前缀字符串(authStringPrefix)
 *  任务二：创建规范请求(canonicalRequest)，确定签名头域(signedHeaders)
 *  任务三：生成派生签名密钥(signingKey)
 *  任务四：生成签名摘要(signature)，并拼接最终的认证字符串(authorization)
 *
 * @param $accessKey
 * @param $secretKey
 * @param $utcTimeStr
 * @param $url
 * @param $httpMethod
 */
function getAuth($accessKey, $secretKey, $utcTimeStr, $url, $httpMethod)
{
    $urlParseRet = parse_url($url);
 
    if (null === $urlParseRet) {
        throw new \Exception('url error');
    }
 
    $host = isset($urlParseRet['host']) ? $urlParseRet['host'] : '';
    $path = isset($urlParseRet['path']) ? $urlParseRet['path'] : '';
 
    $version = "1";
    $expirationSeconds = "1800";
    $signatureHeaders = "host";
 
    //生成authString
    $authString = sprintf("bce-auth-v%s/%s/%s/%s", $version, $accessKey, $utcTimeStr, $expirationSeconds);
 
    //使用sk和authString生成signKey
    $signingKey = hash_hmac('sha256', $authString, $secretKey);
 
 
    //生成标准化uri
    $canonicalURI = getCanonicalURIPath($path);
 
    //生成标准化QueryString
    $canonicalQueryString = '';
 
    //CanonicalHeaders
    $canonicalHeader = $signatureHeaders . ':' . $host;
 
 
    //组成标准请求串
    $canonicalRequest = "$httpMethod\n$canonicalURI\n" . "$canonicalQueryString\n$canonicalHeader";
 
    //使用signKey和标准请求串完成签名
    $signature = hash_hmac('sha256', $canonicalRequest, $signingKey);
 
    //组成最终签名串
    return "$authString/$signatureHeaders/$signature";
 
}
 
$accessKey = 'XXXXX';//(ak)
$secretKey = 'XXXXX';//(sk)
$eqid = "8dc269c900038be6000000055fa9eb6f";//document.referrer获取
$url = "http://referer.bj.baidubce.com/v1/eqid/{$eqid}";
$httpMethod = 'GET';
 
//设定时间戳，注意：如果自行指定时间戳需要为UTC时间
$timestamp = new \DateTime();
$timestamp->setTimezone(new \DateTimeZone("UTC"));
$utcTimeStr = $timestamp->format("Y-m-d\TH:i:s\Z");
 
//第一步：生成认证字符串
$auth = getAuth($accessKey, $secretKey, $utcTimeStr, $url, $httpMethod);
 
 
// 第二步：构造HTTP请求的header、body等信息
//注意head的格式不是key=>value
$head = array(
    "accept-encoding: gzip, deflate",//非必填
    "host: referer.bj.baidubce.com",//非必填
    "content-type: application/json",
    "authorization:{$auth}",
    "x-bce-date:{$utcTimeStr}",
    "accept: */*"//非必填
);
 
// 第三步：发送HTTP请求，并输出响应信息。
$curl = curl_init();
curl_setopt($curl, CURLOPT_URL, $url);
curl_setopt($curl, CURLOPT_HTTPHEADER, $head);
curl_setopt($curl, CURLOPT_CUSTOMREQUEST, "GET");
curl_setopt($curl, CURLINFO_HEADER_OUT, 1);
curl_setopt($curl, CURLOPT_RETURNTRANSFER, 1);
$response = curl_exec($curl);
$request = curl_getinfo($curl, CURLINFO_HEADER_OUT);
$status = curl_getinfo($curl, CURLINFO_HTTP_CODE);
curl_close($curl);
// print("request: {$request}\n");
// print("status: {$status}\n");
// print("response: {$response}\n");
$keywords = '';
if($status == '200'){
    $arr = json_decode($response, true);
    $keywords = urldecode($arr['wd']);
}
echo $keywords;
exit;
 
 
?>