leftypol/inc/functions/net.php

77 lines
2.1 KiB
PHP

<?php
namespace Vichan\Functions\Net;
/**
* @return bool Returns if the client-server connection is an HTTPS one.
*/
function is_connection_https(): bool {
return !empty($_SERVER['HTTPS']) && $_SERVER['HTTPS'] != 'off';
}
/**
* @return bool Returns if the client-server connection is an encrypted one (HTTPS or Tor loopback).
*/
function is_connection_secure(): bool {
return is_connection_https() || (!empty($_SERVER['REMOTE_ADDR']) && $_SERVER['REMOTE_ADDR'] === '127.0.0.1');
}
/**
* Encodes a string into a base64 variant without characters illegal in urls.
*/
function base64_url_encode(string $input): string {
return strtr(base64_encode($input), '+/=', '-_.');
}
/**
* Decodes a string from a base64 variant without characters illegal in urls.
*/
function base64_url_decode(string $input): string {
return base64_decode(strtr($input, '-_.', '+/='));
}
/**
* Encodes a typed cursor.
*
* @param string $type The type for the cursor. Only the first character is considered.
* @param array $map A map of key-value pairs to encode.
* @return string An encoded string that can be sent through urls. Empty if either parameter is empty.
*/
function encode_cursor(string $type, array $map): string {
if (empty($type) || empty($map)) {
return '';
}
$acc = $type[0];
foreach ($map as $key => $value) {
$acc .= "|$key#$value";
}
return base64_url_encode($acc);
}
/**
* Decodes a typed cursor.
*
* @param string $cursor A string emitted by `encode_cursor`.
* @return array An array with the type of the cursor and an array of key-value pairs. The type is null and the map
* empty if either there are no key-value pairs or the encoding is incorrect.
*/
function decode_cursor(string $cursor): array {
$map = [];
$type = '';
$acc = base64_url_decode($cursor);
if ($acc === false || empty($acc)) {
return [ null, [] ];
}
$type = $acc[0];
foreach (explode('|', substr($acc, 2)) as $pair) {
$pair = explode('#', $pair);
if (count($pair) >= 2) {
$key = $pair[0];
$value = $pair[1];
$map[$key] = $value;
}
}
return [ $type, $map ];
}