|
1
|
|
|
<?php |
|
2
|
|
|
|
|
3
|
|
|
namespace MadWizard\WebAuthn\Attestation\Verifier; |
|
4
|
|
|
|
|
5
|
|
|
use MadWizard\WebAuthn\Attestation\AttestationType; |
|
6
|
|
|
use MadWizard\WebAuthn\Attestation\AuthenticatorData; |
|
7
|
|
|
use MadWizard\WebAuthn\Attestation\Registry\AttestationFormatInterface; |
|
8
|
|
|
use MadWizard\WebAuthn\Attestation\Registry\BuiltInAttestationFormat; |
|
9
|
|
|
use MadWizard\WebAuthn\Attestation\Statement\AttestationStatementInterface; |
|
10
|
|
|
use MadWizard\WebAuthn\Attestation\Statement\FidoU2fAttestationStatement; |
|
11
|
|
|
use MadWizard\WebAuthn\Attestation\TrustPath\CertificateTrustPath; |
|
12
|
|
|
use MadWizard\WebAuthn\Crypto\Ec2Key; |
|
13
|
|
|
use MadWizard\WebAuthn\Exception\VerificationException; |
|
14
|
|
|
use function openssl_free_key; |
|
15
|
|
|
use function openssl_pkey_get_details; |
|
16
|
|
|
use function openssl_verify; |
|
17
|
|
|
use const OPENSSL_ALGO_SHA256; |
|
18
|
|
|
|
|
19
|
|
|
final class FidoU2fAttestationVerifier implements AttestationVerifierInterface |
|
20
|
|
|
{ |
|
21
|
5 |
|
public function verify(AttestationStatementInterface $attStmt, AuthenticatorData $authenticatorData, string $clientDataHash): VerificationResult |
|
22
|
|
|
{ |
|
23
|
5 |
|
if (!($attStmt instanceof FidoU2fAttestationStatement)) { |
|
24
|
1 |
|
throw new VerificationException('Expecting FidoU2fAttestationStatement'); |
|
25
|
|
|
} |
|
26
|
|
|
|
|
27
|
|
|
// AAGUID for U2F should be zeroes (not in WebAuthn spec but in FIDO2 CTAP specs and FIDO conformance tools) |
|
28
|
4 |
|
if (!$authenticatorData->getAaguid()->isZeroAaguid()) { |
|
29
|
|
|
throw new VerificationException('AAGUID should be zeroed for U2F attestations.'); |
|
30
|
|
|
} |
|
31
|
|
|
|
|
32
|
|
|
// 1. Verify that attStmt is valid CBOR conforming to the syntax defined above and perform CBOR decoding |
|
33
|
|
|
// on it to extract the contained fields. |
|
34
|
|
|
// -> This is done in FidoU2fAttestationStatement |
|
35
|
|
|
|
|
36
|
|
|
// 2 |
|
37
|
4 |
|
$key = $this->checkAttCertKey($attStmt); |
|
38
|
|
|
|
|
39
|
|
|
try { |
|
40
|
|
|
// 3. Extract the claimed rpIdHash from authenticatorData, and the claimed credentialId and credentialPublicKey |
|
41
|
|
|
// from authenticatorData.attestedCredentialData. |
|
42
|
4 |
|
$rpIdHash = $authenticatorData->getRpIdHash(); |
|
43
|
4 |
|
$credentialId = $authenticatorData->getCredentialId(); |
|
44
|
4 |
|
if ($credentialId === null) { |
|
45
|
|
|
throw new VerificationException('No credential id available.'); |
|
46
|
|
|
} |
|
47
|
|
|
|
|
48
|
|
|
// 4 |
|
49
|
4 |
|
$publicKeyU2f = $this->getPublicKeyU2f($authenticatorData); |
|
50
|
|
|
|
|
51
|
|
|
// 5. Let verificationData be the concatenation of (0x00 || rpIdHash || clientDataHash || credentialId || publicKeyU2F) |
|
52
|
4 |
|
$verificationData = "\x00" . $rpIdHash->getBinaryString() . $clientDataHash . $credentialId->getBinaryString() . $publicKeyU2f; |
|
53
|
|
|
|
|
54
|
|
|
// 6. Verify the sig using verificationData and certificate public key per [SEC1]. |
|
55
|
4 |
|
$result = openssl_verify( |
|
56
|
4 |
|
$verificationData, |
|
57
|
4 |
|
$attStmt->getSignature()->getBinaryString(), |
|
58
|
4 |
|
$key, |
|
59
|
4 |
|
OPENSSL_ALGO_SHA256 |
|
60
|
|
|
); |
|
61
|
|
|
|
|
62
|
4 |
|
if ($result === 1) { |
|
63
|
|
|
// 7. If successful, return attestation type Basic with the attestation trust path set to x5c. |
|
64
|
3 |
|
return new VerificationResult(AttestationType::BASIC, new CertificateTrustPath(...$attStmt->getCertificates())); |
|
65
|
|
|
} |
|
66
|
|
|
|
|
67
|
1 |
|
if ($result === 0) { |
|
68
|
1 |
|
throw new VerificationException('Signature invalid.'); |
|
69
|
|
|
} |
|
70
|
|
|
|
|
71
|
|
|
throw new VerificationException('Failed to check signature'); |
|
72
|
|
|
} finally { |
|
73
|
4 |
|
openssl_free_key($key); |
|
74
|
|
|
} |
|
75
|
|
|
} |
|
76
|
|
|
|
|
77
|
|
|
/** |
|
78
|
|
|
* @return resource |
|
79
|
|
|
* |
|
80
|
|
|
* @throws VerificationException |
|
81
|
|
|
*/ |
|
82
|
4 |
|
private function checkAttCertKey(FidoU2fAttestationStatement $attStmt) |
|
83
|
|
|
{ |
|
84
|
|
|
// 2. Check that x5c has exactly one element and let attCert be that element. Let certificate public key |
|
85
|
|
|
// be the public key conveyed by attCert. If certificate public key is not an Elliptic Curve (EC) public |
|
86
|
|
|
// key over the P-256 curve, terminate this algorithm and return an appropriate error. |
|
87
|
4 |
|
$certificates = $attStmt->getCertificates(); |
|
88
|
4 |
|
if (count($certificates) === 0) { |
|
89
|
|
|
throw new VerificationException('FIDO-U2F statements should contain exactly one certificate.'); |
|
90
|
|
|
} |
|
91
|
|
|
|
|
92
|
4 |
|
$attCert = $certificates[0]; |
|
93
|
|
|
|
|
94
|
4 |
|
$x509 = openssl_pkey_get_public($attCert->asPem()); |
|
95
|
4 |
|
if ($x509 === false) { |
|
96
|
|
|
throw new VerificationException('Failed to parse x509 public key.'); |
|
97
|
|
|
} |
|
98
|
|
|
|
|
99
|
4 |
|
$details = openssl_pkey_get_details($x509); |
|
100
|
|
|
|
|
101
|
4 |
|
if ($details === false || ($details['ec']['curve_name'] ?? null) !== 'prime256v1') { |
|
102
|
|
|
throw new VerificationException('Expecting first certificate to have P-256 EC key.'); |
|
103
|
|
|
} |
|
104
|
4 |
|
return $x509; |
|
|
|
|
|
|
105
|
|
|
} |
|
106
|
|
|
|
|
107
|
4 |
|
private function getPublicKeyU2f(AuthenticatorData $authData): string |
|
108
|
|
|
{ |
|
109
|
|
|
// 4. Convert the COSE_KEY formatted credentialPublicKey (see Section 7 of [RFC8152]) to Raw ANSI X9.62 public |
|
110
|
|
|
// key format (see ALG_KEY_ECC_X962_RAW in Section 3.6.2 Public Key Representation Formats of [FIDO-Registry]). |
|
111
|
|
|
// |
|
112
|
|
|
// Let x be the value corresponding to the "-2" key (representing x coordinate) in credentialPublicKey, |
|
113
|
|
|
// and confirm its size to be of 32 bytes. If size differs or "-2" key is not found, terminate this algorithm |
|
114
|
|
|
// |
|
115
|
|
|
// Let y be the value corresponding to the "-3" key (representing y coordinate) in credentialPublicKey, |
|
116
|
|
|
// and confirm its size to be of 32 bytes. If size differs or "-3" key is not found, terminate this algorithm |
|
117
|
|
|
// and return an appropriate error. |
|
118
|
|
|
// |
|
119
|
|
|
|
|
120
|
4 |
|
$credentialPublicKey = $authData->getKey(); |
|
121
|
|
|
|
|
122
|
4 |
|
if (!($credentialPublicKey instanceof Ec2Key)) { |
|
123
|
|
|
throw new VerificationException('Public key is not EC2 key.'); |
|
124
|
|
|
} |
|
125
|
|
|
|
|
126
|
4 |
|
$x = $credentialPublicKey->getX(); |
|
127
|
4 |
|
$y = $credentialPublicKey->getY(); |
|
128
|
|
|
|
|
129
|
4 |
|
if ($x->getLength() !== 32 || $y->getLength() !== 32) { |
|
130
|
|
|
throw new VerificationException('Unexpected key size.'); |
|
131
|
|
|
} |
|
132
|
|
|
|
|
133
|
|
|
// Let publicKeyU2F be the concatenation 0x04 || x || y. This signifies uncompressed ECC key format. |
|
134
|
4 |
|
return "\x04" . $x->getBinaryString() . $y->getBinaryString(); |
|
135
|
|
|
} |
|
136
|
|
|
|
|
137
|
19 |
|
public function getSupportedFormat(): AttestationFormatInterface |
|
138
|
|
|
{ |
|
139
|
19 |
|
return new BuiltInAttestationFormat( |
|
140
|
19 |
|
FidoU2fAttestationStatement::FORMAT_ID, |
|
141
|
19 |
|
FidoU2fAttestationStatement::class, |
|
142
|
|
|
$this |
|
143
|
|
|
); |
|
144
|
|
|
} |
|
145
|
|
|
} |
|
146
|
|
|
|
madwizard-org /
webauthn-server
Loading history...