/** * @param \Jose\Object\JWEInterface $jwe * @param \Jose\Object\JWKSetInterface $jwk_set * @param int $i * * @return int|null */ private function decryptRecipientKey(Object\JWEInterface &$jwe, Object\JWKSetInterface $jwk_set, $i) { $recipient = $jwe->getRecipient($i); $complete_headers = array_merge($jwe->getSharedProtectedHeaders(), $jwe->getSharedHeaders(), $recipient->getHeaders()); $this->checkCompleteHeader($complete_headers); $key_encryption_algorithm = $this->getKeyEncryptionAlgorithm($complete_headers); $content_encryption_algorithm = $this->getContentEncryptionAlgorithm($complete_headers); foreach ($jwk_set as $jwk) { try { $this->checkKeyUsage($jwk, 'decryption'); if ('dir' !== $key_encryption_algorithm->getAlgorithmName()) { $this->checkKeyAlgorithm($jwk, $key_encryption_algorithm->getAlgorithmName()); } else { $this->checkKeyAlgorithm($jwk, $content_encryption_algorithm->getAlgorithmName()); } $cek = $this->decryptCEK($key_encryption_algorithm, $content_encryption_algorithm, $jwk, $recipient, $complete_headers); if (null !== $cek) { if (true === $this->decryptPayload($jwe, $cek, $content_encryption_algorithm, $complete_headers)) { return $i; } } } catch (\Exception $e) { //We do nothing, we continue with other keys continue; } } }
/** * @param \Jose\Object\JWEInterface $jwe * * @return \Jose\Algorithm\ContentEncryptionAlgorithmInterface */ private function getContentEncryptionAlgorithm(Object\JWEInterface $jwe) { $algorithm = null; foreach ($jwe->getRecipients() as $recipient) { $complete_headers = array_merge($jwe->getSharedProtectedHeaders(), $jwe->getSharedHeaders(), $recipient->getHeaders()); Assertion::keyExists($complete_headers, 'enc', 'Parameter "enc" is missing.'); if (null === $algorithm) { $algorithm = $complete_headers['enc']; } else { Assertion::eq($algorithm, $complete_headers['enc'], 'Foreign content encryption algorithms are not allowed.'); } } $content_encryption_algorithm = $this->getJWAManager()->getAlgorithm($algorithm); Assertion::isInstanceOf($content_encryption_algorithm, Algorithm\ContentEncryptionAlgorithmInterface::class, sprintf('The content encryption algorithm "%s" is not supported or not a content encryption algorithm instance.', $algorithm)); return $content_encryption_algorithm; }
/** * @param \Jose\Object\JWEInterface $jwe * @param \Jose\Algorithm\ContentEncryptionAlgorithmInterface $content_encryption_algorithm * @param string $cek * @param string $iv * @param \Jose\Compression\CompressionInterface|null $compression_method */ private function encryptJWE(Object\JWEInterface &$jwe, Algorithm\ContentEncryptionAlgorithmInterface $content_encryption_algorithm, $cek, $iv, Compression\CompressionInterface $compression_method = null) { if (!empty($jwe->getSharedProtectedHeaders())) { $jwe = $jwe->withEncodedSharedProtectedHeaders(Base64Url::encode(json_encode($jwe->getSharedProtectedHeaders()))); } $tag = null; $payload = $this->preparePayload($jwe->getPayload(), $compression_method); $aad = null === $jwe->getAAD() ? null : Base64Url::encode($jwe->getAAD()); $ciphertext = $content_encryption_algorithm->encryptContent($payload, $cek, $iv, $aad, $jwe->getEncodedSharedProtectedHeaders(), $tag); $jwe = $jwe->withCiphertext($ciphertext); $jwe = $jwe->withIV($iv); if (null !== $tag) { $jwe = $jwe->withTag($tag); } }