1085 wiersze
37 KiB
PHP
1085 wiersze
37 KiB
PHP
<?php
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/*
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* "This code is not a code of honour... no highly esteemed code is commemorated here... nothing valued is here."
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* "What is here is dangerous and repulsive to us. This message is a warning about danger."
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* This is a rudimentary, single-file, low complexity, minimum functionality, ActivityPub server.
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* For educational purposes only.
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* The Server produces an Actor who can be followed.
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* The Actor can send messages to followers.
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* The message can have linkable URls, hashtags, and mentions.
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* An image and alt text can be attached to the message.
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* The Server saves logs about requests it receives and sends.
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* This code is NOT suitable for production use.
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* SPDX-License-Identifier: AGPL-3.0-or-later
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* This code is also "licenced" under CRAPL v0 - https://matt.might.net/articles/crapl/
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* "Any appearance of design in the Program is purely coincidental and should not in any way be mistaken for evidence of thoughtful software construction."
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* For more information, please re-read.
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*/
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// Preamble: Set your details here
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// This is where you set up your account's name and bio.
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// You also need to provide a public/private keypair.
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// The posting page is protected with a password that also needs to be set here.
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// Set up the Actor's information
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// Edit these:
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$username = rawurlencode("example"); // Type the @ username that you want. Do not include an "@".
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$realName = "E. Xample. Jr."; // This is the user's "real" name.
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$summary = "Some text about the user."; // This is the bio of your user.
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// Generate locally or from https://cryptotools.net/rsagen
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// Newlines must be replaced with "\n"
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$key_private = "-----BEGIN RSA PRIVATE KEY-----\n...\n-----END RSA PRIVATE KEY-----";
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$key_public = "-----BEGIN PUBLIC KEY-----\n...\n-----END PUBLIC KEY-----";
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// Password for sending messages
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$password = "P4ssW0rd";
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/** No need to edit anything below here. **/
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// Internal data
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$server = $_SERVER["SERVER_NAME"]; // Do not change this!
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// Set up where logs and messages go
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$data = "data";
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$directories = array(
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"inbox" => "{$data}/inbox",
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"followers" => "{$data}/followers",
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"following" => "{$data}/following",
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"logs" => "{$data}/logs",
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"posts" => "posts",
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);
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foreach ( $directories as $directory ) {
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if( !is_dir( $directory ) ) { mkdir( $data ); mkdir( $directory ); }
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}
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// Logging:
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// ActivityPub is a "chatty" protocol. This takes all the requests your server receives and saves them as a datestamped text file.
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// Get all headers and requests sent to this server
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$headers = print_r( getallheaders(), true );
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$postData = print_r( $_POST, true );
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$getData = print_r( $_GET, true );
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$filesData = print_r( $_FILES, true );
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$input = file_get_contents( "php://input" );
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$body = json_decode( $input,true );
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$bodyData = print_r( $body, true );
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$requestData = print_r( $_REQUEST, true );
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$serverData = print_r( $_SERVER, true );
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!empty( $_GET["path"] ) ? $path = $_GET["path"] : $path = "/";
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// Get the type of request - used in the log filename
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if ( isset( $body["type"] ) ) {
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// Sanitise before using it in a filename
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$type = "." . urlencode( $body["type"] );
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} else {
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// Sanitise the path requested
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$type = "." . urlencode( $path );
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}
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// Create a timestamp for the filename
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// This format has milliseconds, so should avoid logs being overwritten.
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// If you have > 1000 requests per second, please use a different server.
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$timestamp = ( new DateTime() )->format( DATE_RFC3339_EXTENDED );
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// Filename for the log
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$filename = "{$timestamp}{$type}.txt";
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// Save headers and request data to the timestamped file in the logs directory
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file_put_contents( $directories["logs"] . "/{$filename}",
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"Headers: \n$headers \n\n" .
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"Body Data: \n$bodyData \n\n" .
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"POST Data: \n$postData \n\n" .
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"GET Data: \n$getData \n\n" .
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"Files Data: \n$filesData \n\n" .
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"Request Data:\n$requestData\n\n" .
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"Server Data: \n$serverData \n\n"
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);
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// Routing:
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// The .htaccess changes /whatever to /?path=whatever
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// This runs the function of the path requested.
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switch ($path) {
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case ".well-known/webfinger":
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webfinger(); // Mandatory. Static.
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case rawurldecode( $username ):
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username(); // Mandatory. Static
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case "following":
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following(); // Mandatory. Static
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case "followers":
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followers(); // Mandatory. Can be dynamic
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case "inbox":
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inbox(); // Mandatory. Only accepts follow requests.
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case "write":
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write(); // User interface for writing posts
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case "send":
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send(); // API for posting content to the Fediverse
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case "outbox":
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outbox(); // Optional. Dynamic.
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case "follow":
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follow(); // User interface for following an external user
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case "follow_user":
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follow_user(); // API for following a user
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case "/":
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home(); // Optional. Can be dynamic
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default:
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die();
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}
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// The WebFinger Protocol is used to identify accounts.
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// It is requested with `example.com/.well-known/webfinger?resource=acct:username@example.com`
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// This server only has one user, so it ignores the query string and always returns the same details.
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function webfinger() {
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global $username, $server;
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$webfinger = array(
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"subject" => "acct:{$username}@{$server}",
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"links" => array(
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array(
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"rel" => "self",
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"type" => "application/activity+json",
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"href" => "https://{$server}/{$username}"
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)
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)
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);
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header( "Content-Type: application/json" );
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echo json_encode( $webfinger );
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die();
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}
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// User:
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// Requesting `example.com/username` returns a JSON document with the user's information.
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function username() {
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global $username, $realName, $summary, $server, $key_public;
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$user = array(
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"@context" => [
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"https://www.w3.org/ns/activitystreams",
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"https://w3id.org/security/v1"
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],
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"id" => "https://{$server}/{$username}",
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"type" => "Person",
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"following" => "https://{$server}/following",
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"followers" => "https://{$server}/followers",
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"inbox" => "https://{$server}/inbox",
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"outbox" => "https://{$server}/outbox",
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"preferredUsername" => rawurldecode($username),
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"name" => "{$realName}",
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"summary" => "{$summary}",
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"url" => "https://{$server}/{$username}",
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"manuallyApprovesFollowers" => true,
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"discoverable" => true,
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"published" => "2024-02-29T12:34:00Z",
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"icon" => [
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"type" => "Image",
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"mediaType" => "image/png",
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"url" => "https://{$server}/icon.png"
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],
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"publicKey" => [
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"id" => "https://{$server}/{$username}#main-key",
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"owner" => "https://{$server}/{$username}",
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"publicKeyPem" => $key_public
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]
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);
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header( "Content-Type: application/activity+json" );
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echo json_encode( $user );
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die();
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}
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// Follower / Following:
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// These JSON documents show how many users are following / followers-of this account.
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// The information here is self-attested. So you can lie and use any number you want.
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function following() {
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global $server, $directories;
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// Get all the files
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$following_files = glob( $directories["following"] . "/*.json");
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// Number of posts
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$totalItems = count( $following_files );
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$items = array();
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foreach ( $following_files as $following_file ) {
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$following = json_decode( file_get_contents( $following_file ),true );
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$items[] = $following["id"];
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}
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$following = array(
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"@context" => "https://www.w3.org/ns/activitystreams",
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"id" => "https://{$server}/following",
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"type" => "Collection",
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"totalItems" => $totalItems,
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"items" => $items
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);
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header( "Content-Type: application/activity+json" );
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echo json_encode( $following );
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die();
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}
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function followers() {
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global $server, $directories;
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// The number of followers is self-reported
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// You can set this to any number you like
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// Get all the files
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$follower_files = glob( $directories["followers"] . "/*.json");
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// Number of posts
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$totalItems = count( $follower_files );
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$items = array();
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foreach ( $follower_files as $follower_file ) {
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$following = json_decode( file_get_contents( $follower_file ),true );
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$items[] = $following["id"];
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}
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$followers = array(
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"@context" => "https://www.w3.org/ns/activitystreams",
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"id" => "https://{$server}/followers",
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"type" => "Collection",
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"totalItems" => $totalItems,
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"items" => $items
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);
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header( "Content-Type: application/activity+json" );
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echo json_encode( $followers );
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die();
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}
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// Inbox:
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// The `/inbox` is the main server. It receives all requests.
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// This server only responds to "Follow" requests.
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// A remote server sends a follow request which is a JSON file saying who they are.
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// The details of the remote user's server is saved to a file so that future messages can be delivered to the follower.
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// An accept request is cryptographically signed and POST'd back to the remote server.
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function inbox() {
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global $body, $server, $username, $key_private, $directories;
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// Validate HTTP Message Signature
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// This logs whether the signature was validated or not
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if ( !verifyHTTPSignature() ) { die(); }
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// Get the message and type
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$inbox_message = $body;
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$inbox_type = $inbox_message["type"];
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// Save any Follow, Create, Announce, Like messages
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// This ignores Delete, Undo, and anything else
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if ( match( $inbox_type ) {
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"Follow", "Create", "Announce", "Like" => true,
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default => false,
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} ) {
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// Save the message in `/data/inbox/`
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$timestamp = ( new DateTime() )->format( DATE_RFC3339_EXTENDED );
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$inbox_filename = $timestamp . "." . urlencode( $inbox_type ) . ".json";
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file_put_contents( $directories["inbox"] . "/{$inbox_filename}", json_encode( $inbox_message ) );
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}
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// This inbox only responds to follow requests
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if ( "Follow" != $inbox_type ) { die(); }
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// Get the parameters
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$follower_id = $inbox_message["id"]; // E.g. https://mastodon.social/(unique id)
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$follower_actor = $inbox_message["actor"]; // E.g. https://mastodon.social/users/Edent
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$follower_host = parse_url( $follower_actor, PHP_URL_HOST );
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$follower_path = parse_url( $follower_actor, PHP_URL_PATH );
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// Get the actor's profile as JSON
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// Is the actor an https URl?
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if(
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( filter_var( $follower_actor, FILTER_VALIDATE_URL) == true) &&
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( parse_url( $follower_actor, PHP_URL_SCHEME ) == "https" )
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) {
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// Request the JSON representation of the the user
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$ch = curl_init( $follower_actor );
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// Generate signed headers for this request
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$headers = generate_signed_headers( null, $follower_host, $follower_path, "GET" );
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// Set cURL options
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curl_setopt( $ch, CURLOPT_RETURNTRANSFER, true);
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curl_setopt( $ch, CURLOPT_HTTPHEADER, $headers );
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// Execute the cURL session
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$inbox_actor_json = curl_exec( $ch );
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// Check for errors
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if (curl_errno($ch)) {
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// Handle cURL error
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die();
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}
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// Close cURL session
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curl_close($ch);
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// Save the actor's data in `/data/followers/`
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$follower_filename = urlencode( $follower_actor );
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file_put_contents( $directories["followers"] . "/{$follower_filename}.json", $inbox_actor_json );
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} else {
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die();
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}
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// Get the new follower's Inbox
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$follower_actor_details = json_decode( $inbox_actor_json, true );
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$follower_inbox = $follower_actor_details["inbox"];
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// Response Message ID
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// This isn't used for anything important so could just be a random number
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$guid = uuid();
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// Create the Accept message to the new follower
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$message = [
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"@context" => "https://www.w3.org/ns/activitystreams",
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"id" => "https://{$server}/{$guid}",
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"type" => "Accept",
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"actor" => "https://{$server}/{$username}",
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"object" => [
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"@context" => "https://www.w3.org/ns/activitystreams",
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"id" => $follower_id,
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"type" => $inbox_type,
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"actor" => $follower_actor,
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"object" => "https://{$server}/{$username}",
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]
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];
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// The Accept is POSTed to the inbox on the server of the user who requested the follow
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$follower_inbox_path = parse_url( $follower_inbox, PHP_URL_PATH );
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// Get the signed headers
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$headers = generate_signed_headers( $message, $follower_host, $follower_inbox_path, "POST" );
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// POST the message and header to the requester's inbox
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$ch = curl_init( $follower_inbox );
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curl_setopt( $ch, CURLOPT_RETURNTRANSFER, true );
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curl_setopt( $ch, CURLOPT_CUSTOMREQUEST, "POST" );
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curl_setopt( $ch, CURLOPT_POSTFIELDS, json_encode( $message ) );
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curl_setopt( $ch, CURLOPT_HTTPHEADER, $headers );
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curl_exec( $ch );
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// Check for errors
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if( curl_errno( $ch ) ) {
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$timestamp = ( new DateTime() )->format( DATE_RFC3339_EXTENDED );
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file_put_contents( $directories["logs"] . "/{$timestamp}.Error.txt", curl_error( $ch ) );
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}
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curl_close( $ch );
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die();
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}
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// Unique ID:
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// Every message sent should have a unique ID.
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// This can be anything you like. Some servers use a random number.
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// I prefer a date-sortable string.
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function uuid() {
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return sprintf( "%08x-%04x-%04x-%04x-%012x",
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time(),
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mt_rand(0, 0xffff),
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mt_rand(0, 0xffff),
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mt_rand(0, 0x3fff) | 0x8000,
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mt_rand(0, 0xffffffffffff)
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);
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}
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// Headers:
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// Every message that your server sends needs to be cryptographically signed with your Private Key.
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// This is a complicated process.
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// Please read https://blog.joinmastodon.org/2018/07/how-to-make-friends-and-verify-requests/ for more information.
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function generate_signed_headers( $message, $host, $path, $method ) {
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global $server, $username, $key_private;
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// Location of the Public Key
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$keyId = "https://{$server}/{$username}#main-key";
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// Get the Private Key
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$signer = openssl_get_privatekey( $key_private );
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// Timestamp this message was sent
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$date = date( "D, d M Y H:i:s \G\M\T" );
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// There are subtly different signing requirements for POST and GET
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if ( "POST" == $method ) {
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// Encode the message object to JSON
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$message_json = json_encode( $message );
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// Generate signing variables
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$hash = hash( "sha256", $message_json, true );
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$digest = base64_encode( $hash );
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// Sign the path, host, date, and digest
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$stringToSign = "(request-target): post $path\nhost: $host\ndate: $date\ndigest: SHA-256=$digest";
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// The signing function returns the variable $signature
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// https://www.php.net/manual/en/function.openssl-sign.php
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openssl_sign(
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$stringToSign,
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$signature,
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$signer,
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OPENSSL_ALGO_SHA256
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);
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// Encode the signature
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$signature_b64 = base64_encode( $signature );
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// Full signature header
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$signature_header = 'keyId="' . $keyId . '",algorithm="rsa-sha256",headers="(request-target) host date digest",signature="' . $signature_b64 . '"';
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// Header for POST request
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$headers = array(
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"Host: {$host}",
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"Date: {$date}",
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"Digest: SHA-256={$digest}",
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"Signature: {$signature_header}",
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"Content-Type: application/activity+json",
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"Accept: application/activity+json",
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);
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} else if ( "GET" == $method ) {
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// Sign the path, host, date - NO DIGEST
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$stringToSign = "(request-target): get $path\nhost: $host\ndate: $date";
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// The signing function returns the variable $signature
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// https://www.php.net/manual/en/function.openssl-sign.php
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openssl_sign(
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$stringToSign,
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$signature,
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$signer,
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OPENSSL_ALGO_SHA256
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);
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// Encode the signature
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$signature_b64 = base64_encode( $signature );
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// Full signature header
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$signature_header = 'keyId="' . $keyId . '",algorithm="rsa-sha256",headers="(request-target) host date",signature="' . $signature_b64 . '"';
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// Header for GET request
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$headers = array(
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"Host: {$host}",
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"Date: {$date}",
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"Signature: {$signature_header}",
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"Accept: application/activity+json",
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);
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}
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return $headers;
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}
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// User Interface for Homepage:
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// This creates a basic HTML page. This content appears when someone visits the root of your site.
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function home() {
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global $username, $server, $realName, $summary;
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echo <<< HTML
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<!DOCTYPE html>
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<html lang="en-GB">
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<head>
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<meta charset="UTF-8">
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<title>{$realName}</title>
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<style>
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body { text-align: center; font-family:sans-serif; font-size:1.1em; }
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ul { text-align: left; }
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img { max-width: 50%; }
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</style>
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</head>
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<body>
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<span class="h-card">
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<img src="icon.png" alt="icon" class="u-photo " width="140px" />
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<h1><span class="p-name">{$realName}</span></h1>
|
|
<h2><a class="p-nickname u-url" href="https://{$server}/{$username}">@{$username}@{$server}</a></h2>
|
|
<p class="note">{$summary}</p>
|
|
</span>
|
|
<p><a href="https://gitlab.com/edent/activitypub-single-php-file/">This software is licenced under AGPL 3.0</a>.</p>
|
|
<p>This site is a basic <a href="https://www.w3.org/TR/activitypub/">ActivityPub</a> server designed to be <a href="https://shkspr.mobi/blog/2024/02/activitypub-server-in-a-single-file/">a lightweight educational tool</a>.</p>
|
|
<ul>
|
|
HTML;
|
|
// Get all posts, most recent first
|
|
$posts = array_reverse( glob("posts/*.json") );
|
|
|
|
// Loop through the posts
|
|
foreach ($posts as $post) {
|
|
$postJSON = file_get_contents($post);
|
|
$postData = json_decode($postJSON, true);
|
|
$postTime = $postData["published"];
|
|
$postHTML = $postData["content"];
|
|
if ( isset($postData["attachment"]) ) {
|
|
$postImgUrl = $postData["attachment"]["url"];
|
|
$postImgAlt = $postData["attachment"]["name"];
|
|
$postImg = "<img src='{$postImgUrl}' alt='$postImgAlt'>";
|
|
} else {
|
|
$postImg = "";
|
|
}
|
|
// Display the post
|
|
echo "<li><a href='/{$post}'><time datetime='{$postTime}'>$postTime</time></a><br>{$postHTML}<br>{$postImg}</li>";
|
|
}
|
|
echo <<< HTML
|
|
</ul>
|
|
</body>
|
|
</html>
|
|
HTML;
|
|
die();
|
|
}
|
|
|
|
// User Interface for Writing:
|
|
// This creates a basic HTML form. Type in your message and your password. It then POSTs the data to the `/send` endpoint.
|
|
function write() {
|
|
echo <<< HTML
|
|
<!DOCTYPE html>
|
|
<html lang="en-GB">
|
|
<head>
|
|
<meta charset="UTF-8">
|
|
<title>Send Message</title>
|
|
<style>
|
|
*{font-family:sans-serif;font-size:1.1em;}
|
|
</style>
|
|
</head>
|
|
<body>
|
|
<form action="/send" method="post" enctype="multipart/form-data">
|
|
<label for="content">Your message:</label><br>
|
|
<textarea id="content" name="content" rows="5" cols="32"></textarea><br>
|
|
<label for="image">Attach an image</label><br>
|
|
<input type="file" name="image" id="image" accept="image/*"><br>
|
|
<label for="alt">Alt Text</label>
|
|
<input type="text" name="alt" id="alt" size="32" /><br>
|
|
<label for="password">Password</label><br>
|
|
<input type="password" name="password" id="password" size="32"><br>
|
|
<input type="submit" value="Post Message">
|
|
</form>
|
|
</body>
|
|
</html>
|
|
HTML;
|
|
die();
|
|
}
|
|
|
|
// Send Endpoint:
|
|
// This takes the submitted message and checks the password is correct.
|
|
// It reads all the followers' data in `data/followers`
|
|
// It constructs a list of shared inboxes and unique inboxes
|
|
// It sends the message to every server that is following this account.
|
|
function send() {
|
|
global $password, $server, $username, $key_private, $directories;
|
|
|
|
// Does the posted password match the stored password?
|
|
if( $password != $_POST["password"] ) { die(); }
|
|
|
|
// Get the posted content
|
|
$content = $_POST["content"];
|
|
|
|
// Process the content into HTML to get hashtags etc
|
|
list( "HTML" => $content, "TagArray" => $tags ) = process_content( $content );
|
|
|
|
// Is there an image attached?
|
|
if ( isset( $_FILES['image']['tmp_name'] ) && ("" != $_FILES['image']['tmp_name'] ) ) {
|
|
// Get information about the image
|
|
$image = $_FILES['image']['tmp_name'];
|
|
$image_info = getimagesize( $image );
|
|
$image_ext = image_type_to_extension( $image_info[2] );
|
|
$image_mime = $image_info["mime"];
|
|
|
|
// Files are stored according to their hash
|
|
// A hash of "abc123" is stored in "/images/abc123.jpg"
|
|
$sha1 = sha1_file( $image );
|
|
$image_path = "images";
|
|
$image_full_path = "{$image_path}/{$sha1}.{$image_ext}";
|
|
|
|
// Move media to the correct location
|
|
// Create a directory if it doesn't exist
|
|
if( ! is_dir( $image_path ) ) { mkdir( $image_path ); }
|
|
move_uploaded_file( $image, $image_full_path );
|
|
|
|
// Get the alt text
|
|
if ( isset( $_POST["alt"] ) ) {
|
|
$alt = $_POST["alt"];
|
|
} else {
|
|
$alt = "";
|
|
}
|
|
|
|
// Construct the attachment value for the post
|
|
$attachment = [
|
|
"type" => "Image",
|
|
"mediaType" => "{$image_mime}",
|
|
"url" => "https://{$server}/{$image_full_path}",
|
|
"name" => $alt
|
|
];
|
|
|
|
} else {
|
|
$attachment = [];
|
|
}
|
|
|
|
// Current time - ISO8601
|
|
$timestamp = date( "c" );
|
|
|
|
// Outgoing Message ID
|
|
$guid = uuid();
|
|
|
|
// Construct the Note
|
|
// contentMap is used to prevent unnecessary "translate this post" pop ups
|
|
// hardcoded to English
|
|
$note = [
|
|
"@context" => array(
|
|
"https://www.w3.org/ns/activitystreams"
|
|
),
|
|
"id" => "https://{$server}/posts/{$guid}.json",
|
|
"type" => "Note",
|
|
"published" => $timestamp,
|
|
"attributedTo" => "https://{$server}/{$username}",
|
|
"content" => $content,
|
|
"contentMap" => ["en" => $content],
|
|
"to" => ["https://www.w3.org/ns/activitystreams#Public"],
|
|
"tag" => $tags,
|
|
"attachment" => $attachment
|
|
];
|
|
|
|
// Construct the Message
|
|
// The audience is public and it is sent to all followers
|
|
$message = [
|
|
"@context" => "https://www.w3.org/ns/activitystreams",
|
|
"id" => "https://{$server}/posts/{$guid}.json",
|
|
"type" => "Create",
|
|
"actor" => "https://{$server}/{$username}",
|
|
"to" => [
|
|
"https://www.w3.org/ns/activitystreams#Public"
|
|
],
|
|
"cc" => [
|
|
"https://{$server}/followers"
|
|
],
|
|
"object" => $note
|
|
];
|
|
|
|
// Save the permalink
|
|
$note_json = json_encode( $note );
|
|
// Check for posts/ directory and create it
|
|
file_put_contents( $directories["posts"] . "/{$guid}.json", print_r( $note_json, true ) );
|
|
|
|
// Read existing followers
|
|
$followers = glob( "data/followers/*.json" );
|
|
|
|
// Get all the inboxes
|
|
$inboxes = [];
|
|
foreach ( $followers as $follower ) {
|
|
$follower_info = json_decode( file_get_contents( $follower ), true );
|
|
|
|
// Some servers have "Shared inboxes"
|
|
// If you have lots of followers on a single server, you only need to send the message once
|
|
if( isset( $follower_info["endpoints"]["sharedInbox"] ) ) {
|
|
$sharedInbox = $follower_info["endpoints"]["sharedInbox"];
|
|
if ( !in_array( $sharedInbox, $inboxes ) ) {
|
|
$inboxes[] = $sharedInbox;
|
|
}
|
|
} else {
|
|
// If not, use the individual inbox
|
|
$inbox = $follower_info["inbox"];
|
|
if ( !in_array( $inbox, $inboxes ) ) {
|
|
$inboxes[] = $inbox;
|
|
}
|
|
}
|
|
}
|
|
|
|
// Prepare to use the multiple cURL handle
|
|
// This makes it more efficient to send many simultaneous messages
|
|
$mh = curl_multi_init();
|
|
|
|
// Loop through all the inboxes of the followers
|
|
// Each server needs its own cURL handle
|
|
// Each POST to an inbox needs to be signed separately
|
|
foreach ( $inboxes as $inbox ) {
|
|
|
|
$inbox_host = parse_url( $inbox, PHP_URL_HOST );
|
|
$inbox_path = parse_url( $inbox, PHP_URL_PATH );
|
|
|
|
// Get the signed headers
|
|
$headers = generate_signed_headers( $message, $inbox_host, $inbox_path, "POST" );
|
|
|
|
// POST the message and header to the requester's inbox
|
|
$ch = curl_init( $inbox );
|
|
curl_setopt( $ch, CURLOPT_RETURNTRANSFER, true );
|
|
curl_setopt( $ch, CURLOPT_CUSTOMREQUEST, "POST" );
|
|
curl_setopt( $ch, CURLOPT_POSTFIELDS, json_encode($message) );
|
|
curl_setopt( $ch, CURLOPT_HTTPHEADER, $headers );
|
|
|
|
// Add the handle to the multi-handle
|
|
curl_multi_add_handle( $mh, $ch );
|
|
}
|
|
|
|
// Execute the multi-handle
|
|
do {
|
|
$status = curl_multi_exec( $mh, $active );
|
|
if ( $active ) {
|
|
curl_multi_select( $mh );
|
|
}
|
|
} while ( $active && $status == CURLM_OK );
|
|
|
|
// Close the multi-handle
|
|
curl_multi_close( $mh );
|
|
|
|
// Render the JSON so the user can see the POST has worked
|
|
header( "Location: https://{$server}/posts/{$guid}.json" );
|
|
die();
|
|
}
|
|
|
|
// Content can be plain text. But to add clickable links and hashtags, it needs to be turned into HTML.
|
|
// Tags are also included separately in the note
|
|
function process_content( $content ) {
|
|
global $server;
|
|
|
|
// Convert any URls into hyperlinks
|
|
$link_pattern = '/\bhttps?:\/\/\S+/iu';
|
|
$replacement = function ( $match ) {
|
|
$url = htmlspecialchars( $match[0], ENT_QUOTES, "UTF-8" );
|
|
return "<a href=\"$url\">$url</a>";
|
|
};
|
|
$content = preg_replace_callback( $link_pattern, $replacement, $content );
|
|
|
|
// Get any hashtags
|
|
$hashtags = [];
|
|
$hashtag_pattern = '/(?:^|\s)\#(\w+)/'; // Beginning of string, or whitespace, followed by #
|
|
preg_match_all( $hashtag_pattern, $content, $hashtag_matches );
|
|
foreach ($hashtag_matches[1] as $match) {
|
|
$hashtags[] = $match;
|
|
}
|
|
|
|
// Construct the tag value for the note object
|
|
$tags = [];
|
|
foreach ( $hashtags as $hashtag ) {
|
|
$tags[] = array(
|
|
"type" => "Hashtag",
|
|
"name" => "#{$hashtag}",
|
|
);
|
|
}
|
|
|
|
// Add HTML links for hashtags into the text
|
|
$content = preg_replace(
|
|
$hashtag_pattern,
|
|
" <a href='https://{$server}/tag/$1'>#$1</a>",
|
|
$content
|
|
);
|
|
|
|
// Detect user mentions
|
|
$usernames = [];
|
|
$usernames_pattern = '/@(\S+)@(\S+)/'; // This is a *very* sloppy regex
|
|
preg_match_all( $usernames_pattern, $content, $usernames_matches );
|
|
foreach ( $usernames_matches[0] as $match ) {
|
|
$usernames[] = $match;
|
|
}
|
|
|
|
// Construct the mentions value for the note object
|
|
// This goes in the generic "tag" property
|
|
// TODO: Add this to the CC field
|
|
foreach ( $usernames as $username ) {
|
|
list( , $user, $domain ) = explode( "@", $username );
|
|
$tags[] = array(
|
|
"type" => "Mention",
|
|
"href" => "https://{$domain}/@{$user}",
|
|
"name" => "{$username}"
|
|
);
|
|
|
|
// Add HTML links to usernames
|
|
$username_link = "<a href=\"https://{$domain}/@{$user}\">$username</a>";
|
|
$content = str_replace( $username, $username_link, $content );
|
|
}
|
|
|
|
// Construct HTML breaks from carriage returns and line breaks
|
|
$linebreak_patterns = array("\r\n", "\r", "\n"); // Variations of line breaks found in raw text
|
|
$content = str_replace($linebreak_patterns, "<br/>", $content);
|
|
|
|
// Construct the content
|
|
$content = "<p>{$content}</p>";
|
|
|
|
return [
|
|
"HTML" => $content,
|
|
"TagArray" => $tags
|
|
];
|
|
}
|
|
|
|
// The Outbox contains a date-ordered list (newest first) of all the user's posts
|
|
// This is optional.
|
|
function outbox() {
|
|
global $server, $username;
|
|
|
|
// Get all posts
|
|
$posts = array_reverse( glob("posts/*.json") );
|
|
// Number of posts
|
|
$totalItems = count( $posts );
|
|
// Create an ordered list
|
|
$orderedItems = [];
|
|
foreach ($posts as $post) {
|
|
$orderedItems[] = array(
|
|
"type" => "Create",
|
|
"actor" => "https://{$server}/{$username}",
|
|
"object" => "https://{$server}/{$post}"
|
|
);
|
|
}
|
|
|
|
// Create User's outbox
|
|
$outbox = array(
|
|
"@context" => "https://www.w3.org/ns/activitystreams",
|
|
"id" => "https://{$server}/outbox",
|
|
"type" => "OrderedCollection",
|
|
"totalItems" => $totalItems,
|
|
"summary" => "All the user's posts",
|
|
"orderedItems" => $orderedItems
|
|
);
|
|
|
|
// Render the page
|
|
header( "Content-Type: application/activity+json" );
|
|
echo json_encode( $outbox );
|
|
die();
|
|
}
|
|
|
|
// This creates a UI for the user to follow another user
|
|
function follow() {
|
|
echo <<< HTML
|
|
<!DOCTYPE html>
|
|
<html lang="en-GB">
|
|
<head>
|
|
<meta charset="UTF-8">
|
|
<title>Follow</title>
|
|
<style>
|
|
*{font-family:sans-serif;font-size:1.1em;}
|
|
</style>
|
|
</head>
|
|
<body>
|
|
<form action="/follow_user" method="post" enctype="multipart/form-data">
|
|
<label for="user">User to follow</label>
|
|
<input name="user" id="user" type="text" size="32" placeholder="@user@example.com" /><br>
|
|
<label for="password">Password</label><br>
|
|
<input name="password" id="password" type="password" size="32"><br>
|
|
<input type="submit" value="Send Follow Request">
|
|
</form>
|
|
</body>
|
|
</html>
|
|
HTML;
|
|
die();
|
|
}
|
|
|
|
// This receives a request to follow an external user
|
|
// It looks up the external user's details
|
|
// Then it sends a follow request
|
|
// If the request is accepted, it saves the details in `data/following/` as a JSON file
|
|
function follow_user() {
|
|
global $password, $server, $username, $key_private, $directories;
|
|
|
|
// Does the posted password match the stored password?
|
|
if( $password != $_POST["password"] ) { echo "Wrong Password!"; die(); }
|
|
|
|
// Get the posted content
|
|
$user = $_POST["user"];
|
|
|
|
// Split the user into username and server
|
|
list( , $follow_name, $follow_server ) = explode( "@", $user );
|
|
|
|
// Get the Webfinger
|
|
$webfingerURl = "https://{$follow_server}/.well-known/webfinger?resource=acct:{$follow_name}@{$follow_server}";
|
|
$webfingerJSON = file_get_contents( $webfingerURl );
|
|
$webfinger = json_decode( $webfingerJSON, true );
|
|
|
|
foreach( $webfinger["links"] as $link ) {
|
|
if ( "self" == $link["rel"] ) {
|
|
$profileURl = $link["href"];
|
|
}
|
|
}
|
|
if ( !isset( $profileURl ) ) { echo "No profile"; die(); }
|
|
|
|
// Get the user's details
|
|
// This request does not need to be signed. But it does need to specify that it wants a JSON response
|
|
$context = stream_context_create(
|
|
[ "http" => [ "header" => "Accept: application/activity+json" ] ]
|
|
);
|
|
$profileJSON = file_get_contents( $profileURl, false, $context );
|
|
$profileData = json_decode( $profileJSON, true );
|
|
|
|
// Get the user's inbox
|
|
$profileInbox = $profileData["inbox"];
|
|
$inbox_host = parse_url( $profileInbox, PHP_URL_HOST );
|
|
$inbox_path = parse_url( $profileInbox, PHP_URL_PATH );
|
|
|
|
// Create a follow request
|
|
$guid = uuid();
|
|
$message = [
|
|
"@context" => "https://www.w3.org/ns/activitystreams",
|
|
"id" => "https://{$server}/{$guid}",
|
|
"type" => "Follow",
|
|
"actor" => "https://{$server}/{$username}",
|
|
"object" => $profileURl
|
|
];
|
|
|
|
// Sign a request follow
|
|
// The Accept is POSTed to the inbox on the server of the user who requested the follow
|
|
// Get the signed headers
|
|
$headers = generate_signed_headers( $message, $inbox_host, $inbox_path, "POST" );
|
|
|
|
// POST the message and header to the requester's inbox
|
|
$ch = curl_init( $profileInbox );
|
|
curl_setopt( $ch, CURLOPT_RETURNTRANSFER, true );
|
|
curl_setopt( $ch, CURLOPT_CUSTOMREQUEST, "POST" );
|
|
curl_setopt( $ch, CURLOPT_POSTFIELDS, json_encode( $message ) );
|
|
curl_setopt( $ch, CURLOPT_HTTPHEADER, $headers );
|
|
curl_exec( $ch );
|
|
|
|
// Check for errors
|
|
if( curl_errno( $ch ) ) {
|
|
$timestamp = ( new DateTime() )->format( DATE_RFC3339_EXTENDED );
|
|
file_put_contents( $directories["logs"] . "/{$timestamp}.Error.txt", curl_error( $ch ) );
|
|
}
|
|
curl_close($ch);
|
|
|
|
// Save the user's details
|
|
$following_filename = urlencode( $profileURl );
|
|
file_put_contents( $directories["following"] . "/{$following_filename}.json", $profileJSON );
|
|
|
|
// Render the JSON so the user can see the POST has worked
|
|
header( "Location: https://{$server}/data/following/" . urlencode( $following_filename ) . ".json" );
|
|
die();
|
|
}
|
|
|
|
// Verify the signature sent with the message.
|
|
// This is optional
|
|
// It is very confusing
|
|
function verifyHTTPSignature() {
|
|
global $input, $body, $server, $directories;
|
|
|
|
// Get the headers send with the request
|
|
$headers = getallheaders();
|
|
// Ensure the header keys match the format expected by the signature
|
|
$headers = array_change_key_case( $headers, CASE_LOWER );
|
|
|
|
// Validate the timestamp is within ±30 seconds
|
|
if ( !isset( $headers["date"] ) ) { return null; } // No date set
|
|
$dateHeader = $headers["date"];
|
|
$headerDatetime = DateTime::createFromFormat('D, d M Y H:i:s T', $dateHeader);
|
|
$currentDatetime = new DateTime();
|
|
|
|
// Calculate the time difference in seconds
|
|
$timeDifference = abs($currentDatetime->getTimestamp() - $headerDatetime->getTimestamp());
|
|
if ($timeDifference > 30) {
|
|
// Write a log detailing the error
|
|
$timestamp = ( new DateTime() )->format( DATE_RFC3339_EXTENDED );
|
|
// Filename for the log
|
|
$filename = "{$timestamp}.Signature.Time_Failure.txt";
|
|
|
|
// Save headers and request data to the timestamped file in the logs directory
|
|
file_put_contents( $directories["logs"] . "/{$filename}",
|
|
"Original Date:\n" . print_r( $dateHeader, true ) . "\n" .
|
|
"Local Date:\n" . print_r( $currentDatetime->format('D, d M Y H:i:s T'), true ) . "\n"
|
|
);
|
|
return false;
|
|
}
|
|
|
|
// Validate the Digest
|
|
// It is the hash of the raw input string, in binary, encoded as base64
|
|
$digestString = $headers["digest"];
|
|
// Usually in the form `SHA-256=Ofv56Jm9rlowLR9zTkfeMGLUG1JYQZj0up3aRPZgT0c=`
|
|
// The Base64 encoding may have multiple `=` at the end. So split this at the first `=`
|
|
$digestData = explode( "=", $digestString, 2 );
|
|
$digestAlgorithm = $digestData[0];
|
|
$digestHash = $digestData[1];
|
|
|
|
// There might be many different hashing algorithms
|
|
// TODO: Find a way to transform these automatically
|
|
if ( "SHA-256" == $digestAlgorithm ) {
|
|
$digestAlgorithm = "sha256";
|
|
} else if ( "SHA-512" == $digestAlgorithm ) {
|
|
$digestAlgorithm = "sha512";
|
|
}
|
|
|
|
// Manually calculate the digest based on the data sent
|
|
$digestCalculated = base64_encode( hash( $digestAlgorithm, $input, true ) );
|
|
|
|
// Does our calculation match what was sent?
|
|
if ( !( $digestCalculated == $digestHash ) ) {
|
|
// Write a log detailing the error
|
|
$timestamp = ( new DateTime() )->format( DATE_RFC3339_EXTENDED );
|
|
// Filename for the log
|
|
$filename = "{$timestamp}.Signature.Digest_Failure.txt";
|
|
|
|
// Save headers and request data to the timestamped file in the logs directory
|
|
file_put_contents( $directories["logs"] . "/{$filename}",
|
|
"Original Input:\n" . print_r( $input, true ) . "\n" .
|
|
"Original Digest:\n" . print_r( $digestString, true ) . "\n" .
|
|
"Calculated Digest:\n" . print_r( $digestCalculated, true ) . "\n"
|
|
);
|
|
return false;
|
|
}
|
|
|
|
// Examine the signature
|
|
$signatureHeader = $headers["signature"];
|
|
|
|
// Extract key information from the Signature header
|
|
$signatureParts = [];
|
|
// Converts 'a=b,c=d e f' into ["a"=>"b", "c"=>"d e f"]
|
|
// word="text"
|
|
preg_match_all('/(\w+)="([^"]+)"/', $signatureHeader, $matches);
|
|
foreach ($matches[1] as $index => $key) {
|
|
$signatureParts[$key] = $matches[2][$index];
|
|
}
|
|
|
|
// Manually reconstruct the header string
|
|
$signatureHeaders = explode(" ", $signatureParts["headers"] );
|
|
$signatureString = "";
|
|
foreach ($signatureHeaders as $signatureHeader) {
|
|
if ( "(request-target)" == $signatureHeader ) {
|
|
$method = strtolower( $_SERVER["REQUEST_METHOD"] );
|
|
$target = $_SERVER["REQUEST_URI"];
|
|
$signatureString .= "(request-target): {$method} {$target}\n";
|
|
} else if ( "host" == $signatureHeader ) {
|
|
$host = strtolower( $_SERVER["HTTP_HOST"] );
|
|
$signatureString .= "host: {$host}\n";
|
|
} else {
|
|
$signatureString .= "{$signatureHeader}: " . $headers[$signatureHeader] . "\n";
|
|
}
|
|
}
|
|
|
|
// Remove trailing newline
|
|
$signatureString = trim( $signatureString );
|
|
|
|
// Get the Public Key
|
|
// The link to the key might be sent with the body, but is always sent in the Signature header.
|
|
$publicKeyURL = $signatureParts["keyId"];
|
|
|
|
// This is usually in the form `https://example.com/user/username#main-key`
|
|
// This is to differentiate if the user has multiple keys
|
|
// TODO: Check the actual key
|
|
// This request does not need to be signed. But it does need to specify that it wants a JSON response
|
|
$context = stream_context_create(
|
|
[ "http" => [ "header" => "Accept: application/activity+json" ] ]
|
|
);
|
|
$userJSON = file_get_contents( $publicKeyURL, false, $context );
|
|
$userData = json_decode( $userJSON, true );
|
|
$publicKey = $userData["publicKey"]["publicKeyPem"];
|
|
|
|
// Get the remaining parts
|
|
$signature = base64_decode( $signatureParts["signature"] );
|
|
$algorithm = $signatureParts["algorithm"];
|
|
|
|
// Finally! Calculate whether the signature is valid
|
|
// Returns 1 if verified, 0 if not, false or -1 if an error occurred
|
|
$verified = openssl_verify(
|
|
$signatureString,
|
|
$signature,
|
|
$publicKey,
|
|
$algorithm
|
|
);
|
|
|
|
// Convert to boolean
|
|
if ($verified === 1) {
|
|
$verified = true;
|
|
} elseif ($verified === 0) {
|
|
$verified = false;
|
|
} else {
|
|
$verified = null;
|
|
}
|
|
|
|
// Write a log detailing the signature verification process
|
|
$timestamp = ( new DateTime() )->format( DATE_RFC3339_EXTENDED );
|
|
// Filename for the log
|
|
$filename = "{$timestamp}.Signature.". json_encode( $verified ) . ".txt";
|
|
|
|
// Save headers and request data to the timestamped file in the logs directory
|
|
file_put_contents( $directories["logs"] . "/{$filename}",
|
|
"Original Body:\n" . print_r( $body, true ) . "\n\n" .
|
|
"Original Headers:\n" . print_r( $headers, true ) . "\n\n" .
|
|
"Signature Headers:\n" . print_r( $signatureHeaders, true ) . "\n\n" .
|
|
"Calculated signatureString:\n" . print_r( $signatureString, true ) . "\n\n" .
|
|
"Calculated algorithm:\n" . print_r( $algorithm, true ) . "\n\n" .
|
|
"publicKeyURL:\n" . print_r( $publicKeyURL, true ) . "\n\n" .
|
|
"publicKey:\n" . print_r( $publicKey, true ) . "\n"
|
|
);
|
|
|
|
return $verified;
|
|
}
|
|
|
|
// "One to stun, two to kill, three to make sure"
|
|
die();
|
|
die();
|
|
die(); |