defender-security / vendor / web-auth / webauthn-lib / src / AttestationStatement / AndroidKeyAttestationStatementSupport.php

AndroidKeyAttestationStatementSupport.php in Defender Security – Malware Scanner, Login Security & Firewall 5.5.0, at vendor/web-auth/webauthn-lib/src/AttestationStatement/AndroidKeyAttestationStatementSupport.php

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1	<?php
2
3	declare(strict_types=1);
4
5	/*
6	* The MIT License (MIT)
7	*
8	* Copyright (c) 2014-2021 Spomky-Labs
9	*
10	* This software may be modified and distributed under the terms
11	* of the MIT license. See the LICENSE file for details.
12	*/
13
14	namespace Webauthn\AttestationStatement;
15
16	use Assert\Assertion;
17	use CBOR\Decoder;
18	use CBOR\OtherObject\OtherObjectManager;
19	use CBOR\Tag\TagObjectManager;
20	use Cose\Algorithms;
21	use Cose\Key\Ec2Key;
22	use Cose\Key\Key;
23	use Cose\Key\RsaKey;
24	use function count;
25	use FG\ASN1\ASNObject;
26	use FG\ASN1\ExplicitlyTaggedObject;
27	use FG\ASN1\Universal\OctetString;
28	use FG\ASN1\Universal\Sequence;
29	use function Safe\hex2bin;
30	use function Safe\openssl_pkey_get_public;
31	use function Safe\sprintf;
32	use Webauthn\AuthenticatorData;
33	use Webauthn\CertificateToolbox;
34	use Webauthn\StringStream;
35	use Webauthn\TrustPath\CertificateTrustPath;
36
37	final class AndroidKeyAttestationStatementSupport implements AttestationStatementSupport
38	{
39	/**
40	* @var Decoder
41	*/
42	private $decoder;
43
44	public function __construct()
45	{
46	$this->decoder = new Decoder(new TagObjectManager(), new OtherObjectManager());
47	}
48
49	public function name(): string
50	{
51	return 'android-key';
52	}
53
54	/**
55	* @param mixed[] $attestation
56	*/
57	public function load(array $attestation): AttestationStatement
58	{
59	Assertion::keyExists($attestation, 'attStmt', 'Invalid attestation object');
60	foreach (['sig', 'x5c', 'alg'] as $key) {
61	Assertion::keyExists($attestation['attStmt'], $key, sprintf('The attestation statement value "%s" is missing.', $key));
62	}
63	$certificates = $attestation['attStmt']['x5c'];
64	Assertion::isArray($certificates, 'The attestation statement value "x5c" must be a list with at least one certificate.');
65	Assertion::greaterThan(count($certificates), 0, 'The attestation statement value "x5c" must be a list with at least one certificate.');
66	Assertion::allString($certificates, 'The attestation statement value "x5c" must be a list with at least one certificate.');
67	$certificates = CertificateToolbox::convertAllDERToPEM($certificates);
68
69	return AttestationStatement::createBasic($attestation['fmt'], $attestation['attStmt'], new CertificateTrustPath($certificates));
70	}
71
72	public function isValid(string $clientDataJSONHash, AttestationStatement $attestationStatement, AuthenticatorData $authenticatorData): bool
73	{
74	$trustPath = $attestationStatement->getTrustPath();
75	Assertion::isInstanceOf($trustPath, CertificateTrustPath::class, 'Invalid trust path');
76
77	$certificates = $trustPath->getCertificates();
78
79	//Decode leaf attestation certificate
80	$leaf = $certificates[0];
81	$this->checkCertificateAndGetPublicKey($leaf, $clientDataJSONHash, $authenticatorData);
82
83	$signedData = $authenticatorData->getAuthData().$clientDataJSONHash;
84	$alg = $attestationStatement->get('alg');
85
86	return 1 === openssl_verify($signedData, $attestationStatement->get('sig'), $leaf, Algorithms::getOpensslAlgorithmFor((int) $alg));
87	}
88
89	private function checkCertificateAndGetPublicKey(string $certificate, string $clientDataHash, AuthenticatorData $authenticatorData): void
90	{
91	$resource = openssl_pkey_get_public($certificate);
92	$details = openssl_pkey_get_details($resource);
93	Assertion::isArray($details, 'Unable to read the certificate');
94
95	//Check that authData publicKey matches the public key in the attestation certificate
96	$attestedCredentialData = $authenticatorData->getAttestedCredentialData();
97	Assertion::notNull($attestedCredentialData, 'No attested credential data found');
98	$publicKeyData = $attestedCredentialData->getCredentialPublicKey();
99	Assertion::notNull($publicKeyData, 'No attested public key found');
100	$publicDataStream = new StringStream($publicKeyData);
101	$coseKey = $this->decoder->decode($publicDataStream)->getNormalizedData(false);
102	Assertion::true($publicDataStream->isEOF(), 'Invalid public key data. Presence of extra bytes.');
103	$publicDataStream->close();
104	$publicKey = Key::createFromData($coseKey);
105
106	Assertion::true(($publicKey instanceof Ec2Key) \|\| ($publicKey instanceof RsaKey), 'Unsupported key type');
107	Assertion::eq($publicKey->asPEM(), $details['key'], 'Invalid key');
108
109	/---------------------------/
110	$certDetails = openssl_x509_parse($certificate);
111
112	//Find Android KeyStore Extension with OID “1.3.6.1.4.1.11129.2.1.17” in certificate extensions
113	Assertion::isArray($certDetails, 'The certificate is not valid');
114	Assertion::keyExists($certDetails, 'extensions', 'The certificate has no extension');
115	Assertion::isArray($certDetails['extensions'], 'The certificate has no extension');
116	Assertion::keyExists($certDetails['extensions'], '1.3.6.1.4.1.11129.2.1.17', 'The certificate extension "1.3.6.1.4.1.11129.2.1.17" is missing');
117	$extension = $certDetails['extensions']['1.3.6.1.4.1.11129.2.1.17'];
118	$extensionAsAsn1 = ASNObject::fromBinary($extension);
119	Assertion::isInstanceOf($extensionAsAsn1, Sequence::class, 'The certificate extension "1.3.6.1.4.1.11129.2.1.17" is invalid');
120	$objects = $extensionAsAsn1->getChildren();
121
122	//Check that attestationChallenge is set to the clientDataHash.
123	Assertion::keyExists($objects, 4, 'The certificate extension "1.3.6.1.4.1.11129.2.1.17" is invalid');
124	Assertion::isInstanceOf($objects[4], OctetString::class, 'The certificate extension "1.3.6.1.4.1.11129.2.1.17" is invalid');
125	Assertion::eq($clientDataHash, hex2bin(($objects[4])->getContent()), 'The client data hash is not valid');
126
127	//Check that both teeEnforced and softwareEnforced structures don’t contain allApplications(600) tag.
128	Assertion::keyExists($objects, 6, 'The certificate extension "1.3.6.1.4.1.11129.2.1.17" is invalid');
129	$softwareEnforcedFlags = $objects[6];
130	Assertion::isInstanceOf($softwareEnforcedFlags, Sequence::class, 'The certificate extension "1.3.6.1.4.1.11129.2.1.17" is invalid');
131	$this->checkAbsenceOfAllApplicationsTag($softwareEnforcedFlags);
132
133	Assertion::keyExists($objects, 7, 'The certificate extension "1.3.6.1.4.1.11129.2.1.17" is invalid');
134	$teeEnforcedFlags = $objects[6];
135	Assertion::isInstanceOf($teeEnforcedFlags, Sequence::class, 'The certificate extension "1.3.6.1.4.1.11129.2.1.17" is invalid');
136	$this->checkAbsenceOfAllApplicationsTag($teeEnforcedFlags);
137	}
138
139	private function checkAbsenceOfAllApplicationsTag(Sequence $sequence): void
140	{
141	foreach ($sequence->getChildren() as $tag) {
142	Assertion::isInstanceOf($tag, ExplicitlyTaggedObject::class, 'Invalid tag');
143	/* @var ExplicitlyTaggedObject $tag */
144	Assertion::notEq(600, (int) $tag->getTag(), 'Forbidden tag 600 found');
145	}
146	}
147	}
148