Tfe

Blog/activity_pub_php/2_sinadura.php

<?php

    function makeRequest($private_key_file, $actorInbox, $user, $message)
    {
        $publicKeyId = "https://".$_SERVER["HTTP_HOST"]."/activityPub/users/$user#main-key";
        $date_gmt = new \DateTime();
        $date = $date_gmt->format(DATE_RFC7231);


        $message_str = json_encode($message);
        $sha256 = hash('sha256', $message_str, true);
        $digest = 'SHA-256=' . base64_encode($sha256);

        $inboxUrl = parse_url($actorInbox);


        $sigparts = [
            '(request-target)' => 'post ' . $inboxUrl['path'],
            'host' => $inboxUrl['host'],
            'date' => $date,
            'digest' => $digest,
        ];
        $dataToSign = join("\n", array_map(
            fn($k, $v) => "{$k}: {$v}",
            array_keys($sigparts),
            array_values($sigparts)
        ));

        $privateKey = openssl_pkey_get_private(file_get_contents($private_key_file));

        $signature = null; // mutated by openssl
        $enodedSignature = null;
        if (!openssl_sign($dataToSign, $signature, $privateKey, OPENSSL_ALGO_SHA256)) {
            throw new Exception('Could not sign activityPub data');
        }
        $signatureHeader = sprintf( 'keyId="%s",algorithm="rsa-sha256",headers="(request-target) host date digest",signature="%s"', $publicKeyId, base64_encode($signature));

        $headers = [
            'accept: application/activity+json, text/json',
            'host: '.$inboxUrl['host'],
            'date: '.$date,
            'digest: '.$digest,
            'signature: '.$signatureHeader,
            'content-type: application/activity+json',
        ];
        $ch=curl_init($actorInbox);
        curl_setopt($ch, CURLOPT_CUSTOMREQUEST, "POST");
        curl_setopt($ch, CURLOPT_RETURNTRANSFER, TRUE);
        curl_setopt($ch, CURLOPT_HEADER, 1);
        curl_setopt($ch, CURLOPT_POST, 1);
        curl_setopt($ch, CURLOPT_POSTFIELDS, $message_str);
        curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);
        $result = curl_exec($ch);
        $header_size = curl_getinfo($ch, CURLINFO_HEADER_SIZE);
        $header = substr($result, 0, $header_size);
        $body = substr($result, $header_size);
        curl_close($ch);
        return json_decode($body,true);
    }