lcobucci/jwt

事实及其依据的检查

以下内容均非抄自文档。检查脚本 content/libraries/verify/lcobucci-jwt/run.sh 于2026年10月20日在容器镜像 php:8.5.11-cli-trixie 中运行了 lcobucci/jwt 5.6.1；本页内容必须与它的输出一致，每条事实都列出了对应的输出行。

• JWS 算法

  HS256HS384HS512RS256RS384RS512ES256ES384ES512EdDSA

  256/384/512 的 HS、RS、ES 以及 EdDSA 的签名与验证均成功；没有 RSA-PSS 或 ES256K 的签名器类。

  检查记录

  fact jws-algorithms = HS256, HS384, HS512, RS256, RS384, RS512, ES256, ES384, ES512, EdDSA
  evidence jws-algorithms: PS256 signer class Lcobucci\JWT\Signer\Rsa\Pss\Sha256 exists: false
  evidence jws-algorithms: ES256K signer class Lcobucci\JWT\Signer\Ecdsa\Sha256K exists: false

• ES256 签名编码

  raw

  ES256 签名是 64 字节的原始 r‖s。

  检查记录

  fact jws-ecdsa-encoding = raw

• JWS 中的 DER 签名

  rejected

  DER 编码的 ES256 签名会报错 Token signature mismatch。

  检查记录

  fact jws-der-signature = rejected
  evidence jws-der-signature: Lcobucci\JWT\Validation\RequiredConstraintsViolated: The token violates some mandatory constraints, details: - Token signature mismatch

• 算法允许列表

  required

  SignedWith 锁定签名器：用 ES256 签名器验证 RS256 令牌，报错 Token signer mismatch；不带约束调用 assert() 会抛出 NoConstraintsGiven。

  检查记录

  fact jwt-algorithm-allowlist = required
  evidence jwt-algorithm-allowlist: RS256 token with SignedWith(ES256 signer, EC key): Lcobucci\JWT\Validation\RequiredConstraintsViolated: The token violates some mandatory constraints, details: - Token signer mismatch
  evidence jwt-algorithm-allowlist: assert() with no constraints: Lcobucci\JWT\Validation\NoConstraintsGiven: No constraint given.

• 未签名的令牌（alg none）

  rejected

  未签名的令牌无法解析：The JWT string is missing the Signature part。

  检查记录

  fact jwt-alg-none = rejected
  evidence jwt-alg-none: parsing an unsigned token: Lcobucci\JWT\Token\InvalidTokenStructure: The JWT string is missing the Signature part

• 把公钥用作 HMAC 密钥

  rejected

  以 PEM 文本为密钥的 HS256 令牌，未通过 ES256 签名器的 SignedWith 检查，报错 Token signer mismatch。

  检查记录

  fact jwt-hmac-public-key = rejected
  evidence jwt-hmac-public-key: SignedWith(ES256 signer, EC key): Lcobucci\JWT\Validation\RequiredConstraintsViolated: The token violates some mandatory constraints, details: - Token signer mismatch

• 按 alg 检查曲线

  enforced

  ES256 签名器拒绝了 P-384 密钥：The length of the provided key is different than 256 bits, 384 bits provided。

  检查记录

  fact jwt-ecdsa-curve-check = enforced
  evidence jwt-ecdsa-curve-check: ES256 signer with a P-384 key: Lcobucci\JWT\Signer\InvalidKeyProvided: The length of the provided key is different than 256 bits, 384 bits provided

• 解码时校验声明

  no

  解析和 SignedWith 都不检查时间：一小时前就已过期的令牌照样通过。

  检查记录

  fact jwt-claims-validated-on-decode = no
  evidence jwt-claims-validated-on-decode: SignedWith only, token expired an hour ago: ok

• 默认时钟偏差

  0s

  除非传入时间间隔，否则 LooseValidAt 和 StrictValidAt 都不留任何容差。

  检查记录

  fact jwt-clock-skew = 0s

• 是否要求过期时间声明

  no

  LooseValidAt 接受了不含 exp 的令牌；StrictValidAt 要求 iat、nbf 和 exp 都存在。

  检查记录

  fact jwt-exp-required = no
  evidence jwt-exp-required: LooseValidAt without exp: ok; StrictValidAt: Lcobucci\JWT\Validation\RequiredConstraintsViolated: The token violates some mandatory constraints, details: - "Issued At" claim missing
  evidence jwt-exp-required: StrictValidAt with iat and exp but no nbf: Lcobucci\JWT\Validation\RequiredConstraintsViolated: The token violates some mandatory constraints, details: - "Not Before" claim missing

• 过短的 HMAC 密钥

  rejected

  HS256 拒绝了 5 字节的密钥：Key provided is shorter than 256 bits, only 40 bits provided。

  检查记录

  fact jwt-hmac-short-secret = rejected
  evidence jwt-hmac-short-secret: 5-byte HS256 key: Lcobucci\JWT\Signer\InvalidKeyProvided: Key provided is shorter than 256 bits, only 40 bits provided

用法

<?php
require 'vendor/autoload.php';

use Lcobucci\Clock\SystemClock;
use Lcobucci\JWT\Configuration;
use Lcobucci\JWT\Signer\Ecdsa\Sha256;
use Lcobucci\JWT\Signer\Key\InMemory;
use Lcobucci\JWT\Validation\Constraint\{IssuedBy, SignedWith, StrictValidAt};

$key = openssl_pkey_new(['private_key_type' => OPENSSL_KEYTYPE_EC, 'curve_name' => 'prime256v1']);
openssl_pkey_export($key, $privatePem);
$private = InMemory::plainText($privatePem);
$public = InMemory::plainText(openssl_pkey_get_details($key)['key']);

$config = Configuration::forAsymmetricSigner(new Sha256(), $private, $public);
$now = new DateTimeImmutable();
$token = $config->builder()->issuedBy('https://auth.example.com')->relatedTo('user-42')
    ->issuedAt($now)->canOnlyBeUsedAfter($now)->expiresAt($now->modify('+10 minutes'))
    ->getToken($config->signer(), $config->signingKey());

// Every check is an explicit constraint; StrictValidAt requires iat, nbf and exp.
$parsed = $config->parser()->parse($token->toString());
$config->validator()->assert($parsed,
    new SignedWith($config->signer(), $config->verificationKey()),
    new IssuedBy('https://auth.example.com'),
    new StrictValidAt(SystemClock::fromUTC(), new DateInterval('PT30S')));
echo 'sub: ', $parsed->claims()->get('sub'), "\n";