PocketMine-MP/src/network/mcpe/JwtUtils.php
2022-06-04 17:34:49 +01:00

209 lines
6.5 KiB
PHP

<?php
/*
*
* ____ _ _ __ __ _ __ __ ____
* | _ \ ___ ___| | _____| |_| \/ (_)_ __ ___ | \/ | _ \
* | |_) / _ \ / __| |/ / _ \ __| |\/| | | '_ \ / _ \_____| |\/| | |_) |
* | __/ (_) | (__| < __/ |_| | | | | | | | __/_____| | | | __/
* |_| \___/ \___|_|\_\___|\__|_| |_|_|_| |_|\___| |_| |_|_|
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* @author PocketMine Team
* @link http://www.pocketmine.net/
*
*
*/
declare(strict_types=1);
namespace pocketmine\network\mcpe;
use FG\ASN1\Exception\ParserException;
use FG\ASN1\Universal\Integer;
use FG\ASN1\Universal\Sequence;
use pocketmine\utils\AssumptionFailedError;
use pocketmine\utils\Utils;
use function base64_decode;
use function base64_encode;
use function count;
use function explode;
use function gmp_export;
use function gmp_import;
use function gmp_init;
use function gmp_strval;
use function is_array;
use function json_decode;
use function json_encode;
use function json_last_error_msg;
use function openssl_error_string;
use function openssl_pkey_get_details;
use function openssl_pkey_get_public;
use function openssl_sign;
use function openssl_verify;
use function preg_match;
use function rtrim;
use function sprintf;
use function str_pad;
use function str_repeat;
use function str_replace;
use function str_split;
use function strlen;
use function strtr;
use const GMP_BIG_ENDIAN;
use const GMP_MSW_FIRST;
use const JSON_THROW_ON_ERROR;
use const OPENSSL_ALGO_SHA384;
use const STR_PAD_LEFT;
final class JwtUtils{
/**
* @return string[]
* @phpstan-return array{string, string, string}
* @throws JwtException
*/
public static function split(string $jwt) : array{
$v = explode(".", $jwt);
if(count($v) !== 3){
throw new JwtException("Expected exactly 3 JWT parts, got " . count($v));
}
return [$v[0], $v[1], $v[2]]; //workaround phpstan bug
}
/**
* TODO: replace this result with an object
*
* @return mixed[]
* @phpstan-return array{mixed[], mixed[], string}
*
* @throws JwtException
*/
public static function parse(string $token) : array{
$v = self::split($token);
$header = json_decode(self::b64UrlDecode($v[0]), true);
if(!is_array($header)){
throw new JwtException("Failed to decode JWT header JSON: " . json_last_error_msg());
}
$body = json_decode(self::b64UrlDecode($v[1]), true);
if(!is_array($body)){
throw new JwtException("Failed to decode JWT payload JSON: " . json_last_error_msg());
}
$signature = self::b64UrlDecode($v[2]);
return [$header, $body, $signature];
}
/**
* @throws JwtException
*/
public static function verify(string $jwt, \OpenSSLAsymmetricKey $signingKey) : bool{
[$header, $body, $signature] = self::split($jwt);
$plainSignature = self::b64UrlDecode($signature);
if(strlen($plainSignature) !== 96){
throw new JwtException("JWT signature has unexpected length, expected 96, got " . strlen($plainSignature));
}
[$rString, $sString] = str_split($plainSignature, 48);
$convert = fn(string $str) => gmp_strval(gmp_import($str, 1, GMP_BIG_ENDIAN | GMP_MSW_FIRST), 10);
$sequence = new Sequence(
new Integer($convert($rString)),
new Integer($convert($sString))
);
$v = openssl_verify(
$header . '.' . $body,
$sequence->getBinary(),
$signingKey,
OPENSSL_ALGO_SHA384
);
switch($v){
case 0: return false;
case 1: return true;
case -1: throw new JwtException("Error verifying JWT signature: " . openssl_error_string());
default: throw new AssumptionFailedError("openssl_verify() should only return -1, 0 or 1");
}
}
/**
* @phpstan-param array<string, mixed> $header
* @phpstan-param array<string, mixed> $claims
*/
public static function create(array $header, array $claims, \OpenSSLAsymmetricKey $signingKey) : string{
$jwtBody = JwtUtils::b64UrlEncode(json_encode($header, JSON_THROW_ON_ERROR)) . "." . JwtUtils::b64UrlEncode(json_encode($claims, JSON_THROW_ON_ERROR));
openssl_sign(
$jwtBody,
$rawDerSig,
$signingKey,
OPENSSL_ALGO_SHA384
);
try{
$asnObject = Sequence::fromBinary($rawDerSig);
}catch(ParserException $e){
throw new AssumptionFailedError("Failed to parse OpenSSL signature: " . $e->getMessage(), 0, $e);
}
if(count($asnObject) !== 2){
throw new AssumptionFailedError("OpenSSL produced invalid signature, expected exactly 2 parts");
}
[$r, $s] = [$asnObject[0], $asnObject[1]];
if(!($r instanceof Integer) || !($s instanceof Integer)){
throw new AssumptionFailedError("OpenSSL produced invalid signature, expected 2 INTEGER parts");
}
$rString = $r->getContent();
$sString = $s->getContent();
$toBinary = fn($str) => str_pad(
gmp_export(gmp_init($str, 10), 1, GMP_BIG_ENDIAN | GMP_MSW_FIRST),
48,
"\x00",
STR_PAD_LEFT
);
$jwtSig = JwtUtils::b64UrlEncode($toBinary($rString) . $toBinary($sString));
return "$jwtBody.$jwtSig";
}
public static function b64UrlEncode(string $str) : string{
return rtrim(strtr(base64_encode($str), '+/', '-_'), '=');
}
public static function b64UrlDecode(string $str) : string{
if(($len = strlen($str) % 4) !== 0){
$str .= str_repeat('=', 4 - $len);
}
$decoded = base64_decode(strtr($str, '-_', '+/'), true);
if($decoded === false){
throw new JwtException("Malformed base64url encoded payload could not be decoded");
}
return $decoded;
}
public static function emitDerPublicKey(\OpenSSLAsymmetricKey $opensslKey) : string{
$details = Utils::assumeNotFalse(openssl_pkey_get_details($opensslKey), "Failed to get details from OpenSSL key resource");
/** @var string $pemKey */
$pemKey = $details['key'];
if(preg_match("@^-----BEGIN[A-Z\d ]+PUBLIC KEY-----\n([A-Za-z\d+/\n]+)\n-----END[A-Z\d ]+PUBLIC KEY-----\n$@", $pemKey, $matches) === 1){
$derKey = base64_decode(str_replace("\n", "", $matches[1]), true);
if($derKey !== false){
return $derKey;
}
}
throw new AssumptionFailedError("OpenSSL resource contains invalid public key");
}
public static function parseDerPublicKey(string $derKey) : \OpenSSLAsymmetricKey{
$signingKeyOpenSSL = openssl_pkey_get_public(sprintf("-----BEGIN PUBLIC KEY-----\n%s\n-----END PUBLIC KEY-----\n", base64_encode($derKey)));
if($signingKeyOpenSSL === false){
throw new JwtException("OpenSSL failed to parse key: " . openssl_error_string());
}
return $signingKeyOpenSSL;
}
}