https://oauth2.googleapis.com/token curl: (28) Failed to connect to oauth2.googleapis.com port 443 after 227030 ms: Couldn't connect to server

[wenshan]

https://oauth2.googleapis.com/token curl: (28) Failed to connect to oauth2.googleapis.com port 443 after 227030 ms: Couldn't connect to server

[yash30201]

Hi @wenshan, thanks for raising this issue. The "Failed to connect" error (code 28) usually indicates a network-level problem rather than an issue with the code (and thus this library) itself. I've tried reproducing it with curl as well as using PHP curl and didn't face any issue.

Code

<?php

use Firebase\JWT\JWT;

require_once __DIR__ . '/../vendor/autoload.php';

$key = getSignedJwtClaim();
sendCurlRequest($key);

function getSignedJwtClaim()
{
    $jwtClaims = [
        "iss" => getenv('SERVICE_ACCOUNT_EMAIL'),
        "scope" => "https://www.googleapis.com/auth/devstorage.read_only",
        "aud" => "https://oauth2.googleapis.com/token",
        "exp" => time() + 3600,
        "iat" => time()
    ];

    $key = json_decode(file_get_contents(getenv('GOOGLE_APPLICATION_CREDENTIALS')), true);
    return JWT::encode(
        $jwtClaims,
        $key['private_key'],
        'RS256'
    );
}

function sendCurlRequest($key) {
    $ch = curl_init();
    curl_setopt($ch, CURLOPT_URL, 'https://oauth2.googleapis.com/token');
    curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
    curl_setopt($ch, CURLOPT_CUSTOMREQUEST, 'POST');
    curl_setopt($ch, CURLOPT_HTTPHEADER, [
        'Content-Type: application/x-www-form-urlencoded',
    ]);
    curl_setopt(
        $ch,
        CURLOPT_POSTFIELDS,
        'grant_type=urn%3Aietf%3Aparams%3Aoauth%3Agrant-type%3Ajwt-bearer&assertion=' . $key
    );

    $response = curl_exec($ch);
    $response = json_decode($response, true);
    echo "Access token => " . $response['access_token'] . PHP_EOL;
    curl_close($ch);
}

You can try adding -v flag to you curl command to get more verbose output and get some clue as to why it's happening on your system. It's very helpful that you've confirmed it works with Postman. This reinforces the idea that the issue likely lies in the network configuration on the machine where cURL is running.

As there isn't anything actionable in this library, hence closing this issue.