php - cURL 可在终端中使用，但不能在 PHP 中使用

Question

我遇到了一个相当奇怪的问题。

我正在尝试使用 PHP 中的curl 登录远程moodle 安装。

我有一个curl命令，它在终端中完美运行。

当我将同样的内容翻译成 PHP 时，它可以工作，但就是无法登录。通过终端成功登录的完全相同的值，不知何故通过 PHP 使登录系统出错并且无法登录。相反，它会再次返回登录页面。

我的 cURL 命令(数据部分被省略，因为它有我的用户名和密码):

curl 'http://moodle.tsrs.org/login/index.php'
-H 'Pragma: no-cache'
-H 'Origin: http://moodle.tsrs.org'
-H 'Accept-Encoding: gzip, deflate'
-H 'Accept-Language: en-US,en;q=0.8'
-H 'User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/39.0.2171.65 Safari/537.36'
-H 'Content-Type: application/x-www-form-urlencoded'
-H 'Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8'
-H 'Cache-Control: no-cache'
-H 'Referer: http://moodle.tsrs.org/login/index.php'
-H 'Cookie: MoodleSession=ngcidh028m37gm8gbdfe07mvs7; MOODLEID_=%25F1%25CD%2519D%25B2k%25FE%251D%25EFH%25E5t%25B1%2503%258E; MoodleSessionTest=NhzaTNij6j; _ga=GA1.2.925953522.1416155774; _gat=1; __utmt=1; __utma=147409963.925953522.1416155774.1416642544.1416692798.3; __utmb=147409963.1.10.1416692798; __utmc=147409963; __utmz=147409963.1416155774.1.1.utmcsr=(direct)|utmccn=(direct)|utmcmd=(none)'
-H 'Connection: keep-alive'

对应的PHP代码:

function login() {
    $username = $_POST['username'];
    $password = $_POST['password'];

    if(!isset($_POST['username']) || !isset($_POST['password'])) {
        echo "No login data received";
        return;
    }

    $creq = curl_init();

    $data = array('username' => $username, 'password' => $password, 'testcookies'=> '1');

    $headers = array('Pragma: no-cache', 'Origin: http://moodle.tsrs.org', 'Accept-Encoding: ', 'Accept-Language: en-US,en;q=0.8', 'User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/39.0.2171.65 Safari/537.36', 'Content-Type: application/x-www-form-urlencoded', 'Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8', 'Cache-Control: no-cache', 'Cookie: MoodleSession=ngcidh028m37gm8gbdfe07mvs7; MOODLEID_=%25F1%25CD%2519D%25B2k%25FE%251D%25EFH%25E5t%25B1%2503%258E; MoodleSessionTest=NhzaTNij6j; _ga=GA1.2.925953522.1416155774; _gat=1; __utmt=1; __utma=147409963.925953522.1416155774.1416642544.1416692798.3; __utmb=147409963.1.10.1416692798; __utmc=147409963; __utmz=147409963.1416155774.1.1.utmcsr=(direct)|utmccn=(direct)|utmcmd=(none)', 'Connection: keep-alive' );
        curl_setopt_array($creq, array(
        CURLOPT_URL => 'http://moodle.tsrs.org/login/index.php',
        CURLOPT_RETURNTRANSFER => true,
        CURLOPT_POST => true,
        CURLOPT_ENCODING => '',
        CURLINFO_HEADER_OUT => true,
        CURLOPT_POSTFIELDS => $data,
        CURLOPT_HTTPHEADER => $headers,
        CURLOPT_FOLLOWLOCATION => false
    ));

    $output = curl_exec($creq);

    echo print_r(curl_getinfo($creq));

    echo "\n" . $output . "\n";
}

以及curlinfo的输出:

Array
(
    [url] => http://moodle.tsrs.org/login/index.php
    [content_type] => text/html; charset=utf-8
    [http_code] => 200
    [header_size] => 541
    [request_size] => 945
    [filetime] => -1
    [ssl_verify_result] => 0
    [redirect_count] => 0
    [total_time] => 1.462409
    [namelookup_time] => 0.002776
    [connect_time] => 0.330766
    [pretransfer_time] => 0.330779
    [size_upload] => 365
    [size_download] => 8758
    [speed_download] => 5988
    [speed_upload] => 249
    [download_content_length] => -1
    [upload_content_length] => 365
    [starttransfer_time] => 0.694866
    [redirect_time] => 0
    [certinfo] => Array
        (
        )

    [primary_ip] => 125.22.33.149
    [redirect_url] =>
    [request_header] => POST /login/index.php HTTP/1.1
Host: moodle.tsrs.org
Pragma: no-cache
Origin: http://moodle.tsrs.org
Accept-Language: en-US,en;q=0.8
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/39.0.2171.65 Safari/537.36
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8
Cache-Control: no-cache
Cookie: MoodleSession=ngcidh028m37gm8gbdfe07mvs7; MOODLEID_=%25F1%25CD%2519D%25B2k%25FE%251D%25EFH%25E5t%25B1%2503%258E; MoodleSessionTest=NhzaTNij6j; _ga=GA1.2.925953522.1416155774; _gat=1; __utmt=1; __utma=147409963.925953522.1416155774.1416642544.1416692798.3; __utmb=147409963.1.10.1416692798; __utmc=147409963; __utmz=147409963.1416155774.1.1.utmcsr=(direct)|utmccn=(direct)|utmcmd=(none)
Connection: keep-alive
Content-Length: 365
Expect: 100-continue
Content-Type: application/x-www-form-urlencoded; boundary=----------------------------83564ee60d56


)

有谁知道这可能的原因吗？我尝试过用 COOKIEFILE 和 COOKIEJAR 替换硬编码的 cookie，但它没有改变任何东西。

Answer 1

通过查看 cURL 实际完成的所有内容，可以更好地进行调试。这是通过向命令添加详细标志来完成的:-v。

$ curl localhost/login [...] -v

通过添加 CURLOPT_VERBOSE 选项，我们可以从 PHP 的 curl 获得相同输出。请注意，通过添加此行，您将指示 cURL 将相同的信息输出到 STDOUT - 它不会返回，内容也不会发送到浏览器，因此必须在终端中进行调试。

curl_setopt($curl, CURLOPT_VERBOSE, 1);

通过这样做，您可以获得两个 HTTP 请求的一致且可比较的输出，它应该看起来像这样:

POST / HTTP/1.1
Host: localhost:3000
Pragma: no-cache
Origin: http://moodle.tsrs.org
Accept-Language: en-US,en;q=0.8
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/39.0.2171.65 Safari/537.36
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8
Cache-Control: no-cache
Cookie: MoodleSession=ngcidh028m37gm8gbdfe07mvs7; MOODLEID_=%25F1%25CD%2519D%25B2k%25FE%251D%25EFH%25E5t%25B1%2503%258E; MoodleSessionTest=NhzaTNij6j; _ga=GA1.2.925953522.1416155774; _gat=1; __utmt=1; __utma=147409963.925953522.1416155774.1416642544.1416692798.3; __utmb=147409963.1.10.1416692798; __utmc=147409963; __utmz=147409963.1416155774.1.1.utmcsr=(direct)|utmccn=(direct)|utmcmd=(none)
Connection: keep-alive
Content-Length: 250
Expect: 100-continue
Content-Type: application/x-www-form-urlencoded; boundary=------------------------b4d79f17a3887f2d

< HTTP/1.1 100 Continue
< HTTP/1.1 200 OK
< X-Powered-By: Express
< Content-Type: application/json; charset=utf-8
< Content-Length: 2
< ETag: W/"2-mZFLkyvTelC5g8XnyQrpOw"
< Date: Thu, 22 Dec 2016 19:13:40 GMT
< Connection: keep-alive

左:问题中提供的命令行 cURL(带有额外的 -v 标志)

右:问题中发布的 PHP cURL(启用了 CURLOUT_VERBOSE)

正如您所看到的，标题并不相同，这清楚地表明了这一点。 PHP 调用缺少 Accept-Encoding 和 Referer header 。

<小时/>

如果没有出现任何结果，让我们尝试将 PHP 中的更多 cURL 设置更改回原始 cURL 默认值。

Internally, PHP opts to override some defaults in cURL不告诉你。虽然这些设置应该没问题，但让我们通过显式地将它们重置回 cURL 默认值来将它们更改回来:

curl_setopt($curl, CURLOPT_DNS_CACHE_TIMEOUT, 60);
curl_setopt($curl, CURLOPT_DNS_USE_GLOBAL_CACHE, 0);
curl_setopt($curl, CURLOPT_MAXREDIRS, -1);
curl_setopt($curl, CURLOPT_NOSIGNAL, 0);