simplesamlphp /
simplesamlphp-module-webauthn
| Total Complexity | 85 |
| Total Lines | 644 |
| Duplicated Lines | 0 % |
| Changes | 8 | ||
| Bugs | 0 | Features | 0 |
Complex classes like WebAuthnRegistrationEvent often do a lot of different things. To break such a class down, we need to identify a cohesive component within that class. A common approach to find such a component is to look for fields/methods that share the same prefixes, or suffixes.
Once you have determined the fields that belong together, you can apply the Extract Class refactoring. If the component makes sense as a sub-class, Extract Subclass is also a candidate, and is often faster.
While breaking up the class, it is a good idea to analyze how other classes use WebAuthnRegistrationEvent, and based on these observations, apply Extract Interface, too.
| 1 | <?php |
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| 22 | class WebAuthnRegistrationEvent extends WebAuthnAbstractEvent { |
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| 23 | |||
| 24 | /** |
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| 25 | * Public key algorithm supported. This is -7 - ECDSA with curve P-256, or -275 (RS256) |
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| 26 | */ |
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| 27 | public const PK_ALGORITHM_ECDSA = "-7"; |
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| 28 | public const PK_ALGORITHM_RSA = "-257"; |
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| 29 | public const PK_ALGORITHM = [self::PK_ALGORITHM_ECDSA, self::PK_ALGORITHM_RSA]; |
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| 30 | public const AAGUID_ASSURANCE_LEVEL_NONE = 'None'; |
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| 31 | public const AAGUID_ASSURANCE_LEVEL_SELF = 'Self'; |
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| 32 | public const AAGUID_ASSURANCE_LEVEL_BASIC = 'Basic'; |
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| 33 | public const AAGUID_ASSURANCE_LEVEL_ATTCA = 'AttCA'; |
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| 34 | |||
| 35 | /** |
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| 36 | * the AAGUID of the newly registered authenticator |
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| 37 | * @var string |
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| 38 | */ |
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| 39 | protected string $AAGUID; |
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| 40 | |||
| 41 | /** |
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| 42 | * how sure are we about the AAGUID? |
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| 43 | * @var string |
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| 44 | */ |
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| 45 | protected string $AAGUIDAssurance; |
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| 46 | |||
| 47 | /** |
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| 48 | * An array of known hardware tokens |
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| 49 | * |
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| 50 | * @var \SimpleSAML\Module\webauthn\WebAuthn\AAGUID |
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| 51 | */ |
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| 52 | protected AAGUID $AAGUIDDictionary; |
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| 53 | protected string $AttFmt; |
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| 54 | |||
| 55 | /** |
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| 56 | * Initialize the event object. |
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| 57 | * |
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| 58 | * Validates and parses the configuration. |
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| 59 | * |
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| 60 | * @param string $pubkeyCredType PublicKeyCredential.type |
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| 61 | * @param string $scope the scope of the event |
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| 62 | * @param string $challenge the challenge which was used to trigger this event |
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| 63 | * @param string $attestationData the attestation data CBOR blob |
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| 64 | * @param string $responseId the response ID |
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| 65 | * @param string $clientDataJSON the client data JSON string which is present in all types of events |
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| 66 | * @param bool $debugMode print debugging statements? |
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| 67 | */ |
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| 68 | public function __construct( |
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| 69 | string $pubkeyCredType, |
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| 70 | string $scope, |
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| 71 | string $challenge, |
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| 72 | string $attestationData, |
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| 73 | string $responseId, |
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| 74 | string $clientDataJSON, |
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| 75 | array $acceptabilityPolicy, |
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| 76 | bool $debugMode = false |
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| 77 | ) { |
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| 78 | $this->debugBuffer .= "attestationData raw: " . $attestationData . "<br/>"; |
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| 79 | /** |
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| 80 | * §7.1 STEP 9 : CBOR decode attestationData. |
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| 81 | */ |
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| 82 | $attestationArray = $this->cborDecode($attestationData); |
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| 83 | $authData = $attestationArray['authData']; |
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| 84 | $this->eventType = "REG"; |
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| 85 | parent::__construct($pubkeyCredType, $scope, $challenge, $authData, $clientDataJSON, $debugMode); |
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| 86 | |||
| 87 | $this->AAGUIDDictionary = AAGUID::getInstance(); |
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| 88 | |||
| 89 | // this function extracts the public key |
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| 90 | $this->validateAttestedCredentialData(substr($authData, 37), $responseId); |
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| 91 | // this function may need the public key to have been previously extracted |
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| 92 | $this->validateAttestationData($attestationData); |
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| 93 | // the following function sets the credential properties |
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| 94 | $this->debugBuffer .= "Attestation Data (bin2hex): " . bin2hex(substr($authData, 37)) . "<br/>"; |
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| 95 | // now check if the authenticator is acceptable as per policy |
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| 96 | $this->verifyAcceptability($acceptabilityPolicy); |
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| 97 | } |
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| 98 | |||
| 99 | private function verifyAcceptability($acceptabilityPolicy) { |
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| 100 | if (in_array($this->AAGUID, $acceptabilityPolicy['aaguidWhitelist'])) { |
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| 101 | return; |
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| 102 | } |
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| 103 | |||
| 104 | // if we care about the attestation at all, make sure we have a confidence |
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| 105 | // level beyond "None". |
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| 106 | if ($acceptabilityPolicy['minCertLevel'] != "0" && $this->AAGUIDAssurance == self::AAGUID_ASSURANCE_LEVEL_NONE) { |
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| 107 | throw new Exception("Authenticator did not provide a useful attestation level."); |
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| 108 | } |
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| 109 | |||
| 110 | if (in_array($this->AttFmt, $acceptabilityPolicy['attFmtWhitelist'])) { |
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| 111 | return; |
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| 112 | } |
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| 113 | |||
| 114 | $aaguidDb = AAGUID::getInstance(); |
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| 115 | if (!$aaguidDb->hasToken($this->AAGUID)) { |
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| 116 | throw new Exception("Authenticator with AAGUID " . $this->AAGUID . " is not known to the FIDO MDS3 database."); |
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| 117 | } |
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| 118 | $authenticatorData = $aaguidDb->get($this->AAGUID); |
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| 119 | $certification = $authenticatorData['statusReports'][0]['status']; |
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| 120 | |||
| 121 | if ($certification == "REVOKED") { |
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| 122 | throw new Exception("FIDO Alliance has REVOKED certification of this device. It cannot be registered."); |
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| 123 | } |
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| 124 | |||
| 125 | switch ($acceptabilityPolicy['minCertLevel']) { |
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| 126 | case "0": |
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| 127 | return; |
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| 128 | case "1": |
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| 129 | // note: always full string match - there is also a level NOT_FIDO_CERTIFIED ! |
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| 130 | if ($certification == "FIDO_CERTIFIED" || $certification == "FIDO_CERTIFIED_L1") { |
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| 131 | return; |
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| 132 | } |
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| 133 | // intentional fall-thorugh, higher levels are also okay |
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| 134 | case "1plus": |
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| 135 | if ($certification == "FIDO_CERTIFIED_L1plus") { |
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| 136 | return; |
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| 137 | } |
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| 138 | // intentional fall-thorugh, higher levels are also okay |
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| 139 | case "2": |
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| 140 | if ($certification == "FIDO_CERTIFIED_L2") { |
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| 141 | return; |
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| 142 | } |
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| 143 | // intentional fall-thorugh, higher levels are also okay |
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| 144 | case "3": |
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| 145 | if ($certification == "FIDO_CERTIFIED_L3") { |
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| 146 | return; |
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| 147 | } |
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| 148 | // intentional fall-thorugh, higher levels are also okay |
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| 149 | case "3plus": |
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| 150 | if ($certification == "FIDO_CERTIFIED_L3plus") { |
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| 151 | return; |
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| 152 | } |
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| 153 | throw new Exception("Authenticator must have Certification Level " . $acceptabilityPolicy['minCertLevel'] . " but has $certification"); |
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| 154 | default: |
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| 155 | throw new Exception("Configuration error: unknown minimum certification level " . $acceptabilityPolicy['minCertLevel']); |
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| 156 | } |
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| 157 | } |
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| 158 | |||
| 159 | /** |
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| 160 | * Validate the incoming attestation data CBOR blob and return the embedded authData |
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| 161 | * @param string $attestationData |
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| 162 | * @return void |
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| 163 | */ |
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| 164 | private function validateAttestationData(string $attestationData): void { |
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| 165 | /** |
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| 166 | * STEP 9 of the validation procedure in § 7.1 of the spec: CBOR-decode the attestationObject |
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| 167 | */ |
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| 168 | $attestationArray = $this->cborDecode($attestationData); |
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| 169 | $this->debugBuffer .= "<pre>"; |
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| 170 | $this->debugBuffer .= print_r($attestationArray, true); |
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| 171 | $this->debugBuffer .= "</pre>"; |
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| 172 | |||
| 173 | /** |
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| 174 | * STEP 15 of the validation procedure in § 7.1 of the spec: verify attStmt values |
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| 175 | */ |
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| 176 | $this->AttFmt = $attestationArray['fmt']; |
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| 177 | switch ($attestationArray['fmt']) { |
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| 178 | case "none": |
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| 179 | $this->validateAttestationFormatNone($attestationArray); |
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| 180 | break; |
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| 181 | case "packed": |
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| 182 | $this->validateAttestationFormatPacked($attestationArray); |
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| 183 | break; |
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| 184 | case "fido-u2f": |
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| 185 | $this->validateAttestationFormatFidoU2F($attestationArray); |
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| 186 | break; |
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| 187 | case "android-safetynet": |
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| 188 | $this->validateAttestationFormatAndroidSafetyNet($attestationArray); |
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| 189 | break; |
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| 190 | case "apple": |
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| 191 | $this->validateAttestationFormatApple($attestationArray); |
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| 192 | break; |
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| 193 | case "tpm": |
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| 194 | case "android-key": |
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| 195 | $this->fail("Attestation format " . $attestationArray['fmt'] . " validation not supported right now."); |
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| 196 | break; |
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| 197 | default: |
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| 198 | $this->fail("Unknown attestation format."); |
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| 199 | break; |
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| 200 | } |
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| 201 | $this->AttFmt = $attestationArray['fmt']; |
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| 202 | } |
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| 203 | |||
| 204 | /** |
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| 205 | * @param array $attestationArray |
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| 206 | * @return void |
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| 207 | */ |
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| 208 | private function validateAttestationFormatNone(array $attestationArray): void { |
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| 209 | // § 8.7 of the spec |
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| 210 | /** |
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| 211 | * § 7.1 Step 16 && §8.7 Verification Procedure: stmt must be an empty array |
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| 212 | * § 7.1 Step 17+18 are a NOOP if the format was "none" (which is acceptable as per this RPs policy) |
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| 213 | */ |
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| 214 | if (count($attestationArray['attStmt']) === 0) { |
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| 215 | $this->pass("Attestation format and statement as expected, and no attestation authorities to retrieve."); |
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| 216 | $this->AAGUIDAssurance = self::AAGUID_ASSURANCE_LEVEL_NONE; |
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| 217 | return; |
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| 218 | } else { |
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| 219 | $this->fail("Non-empty attestation authorities are not expected with 'attestationFormat = none'."); |
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| 220 | } |
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| 221 | } |
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| 222 | |||
| 223 | /** |
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| 224 | * @param array $attestationArray |
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| 225 | */ |
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| 226 | private function validateAttestationFormatApple(array $attestationArray): void { |
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| 227 | // found at: https://www.apple.com/certificateauthority/private/ |
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| 228 | |||
| 229 | $APPLE_WEBAUTHN_ROOT_CA = "-----BEGIN CERTIFICATE----- |
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| 230 | MIICEjCCAZmgAwIBAgIQaB0BbHo84wIlpQGUKEdXcTAKBggqhkjOPQQDAzBLMR8w |
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| 231 | HQYDVQQDDBZBcHBsZSBXZWJBdXRobiBSb290IENBMRMwEQYDVQQKDApBcHBsZSBJ |
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| 232 | bmMuMRMwEQYDVQQIDApDYWxpZm9ybmlhMB4XDTIwMDMxODE4MjEzMloXDTQ1MDMx |
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| 233 | NTAwMDAwMFowSzEfMB0GA1UEAwwWQXBwbGUgV2ViQXV0aG4gUm9vdCBDQTETMBEG |
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| 234 | A1UECgwKQXBwbGUgSW5jLjETMBEGA1UECAwKQ2FsaWZvcm5pYTB2MBAGByqGSM49 |
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| 235 | AgEGBSuBBAAiA2IABCJCQ2pTVhzjl4Wo6IhHtMSAzO2cv+H9DQKev3//fG59G11k |
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| 236 | xu9eI0/7o6V5uShBpe1u6l6mS19S1FEh6yGljnZAJ+2GNP1mi/YK2kSXIuTHjxA/ |
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| 237 | pcoRf7XkOtO4o1qlcaNCMEAwDwYDVR0TAQH/BAUwAwEB/zAdBgNVHQ4EFgQUJtdk |
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| 238 | 2cV4wlpn0afeaxLQG2PxxtcwDgYDVR0PAQH/BAQDAgEGMAoGCCqGSM49BAMDA2cA |
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| 239 | MGQCMFrZ+9DsJ1PW9hfNdBywZDsWDbWFp28it1d/5w2RPkRX3Bbn/UbDTNLx7Jr3 |
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| 240 | jAGGiQIwHFj+dJZYUJR786osByBelJYsVZd2GbHQu209b5RCmGQ21gpSAk9QZW4B |
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| 241 | 1bWeT0vT |
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| 242 | -----END CERTIFICATE-----"; |
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| 243 | // § 8.8 Bullet 1 of the draft spec at https://pr-preview.s3.amazonaws.com/alanwaketan/webauthn/pull/1491.html#sctn-apple-anonymous-attestation |
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| 244 | // draft implemented in state of 11 Feb 2021 |
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| 245 | // I can't help but notice that the verification procedure does NOTHING with CA certs from the chain, nor is there a root to validate to! |
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| 246 | // Found the root CA with Google, see above, and will perform chain validation even if the spec doesn't say so. |
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| 247 | // first, clear the openssl error backlog. We might need error data in case things go sideways. |
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| 248 | while (openssl_error_string() !== false); |
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| 249 | |||
| 250 | $stmtDecoded = $attestationArray['attStmt']; |
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| 251 | if (!isset($stmtDecoded['x5c'])) { |
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| 252 | $this->fail("Apple attestation statement does not contain an x5c attestation statement!"); |
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| 253 | } |
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| 254 | // § 8.8 Bullet 2 |
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| 255 | $nonceToHash = $attestationArray['authData'] . $this->clientDataHash; |
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| 256 | // § 8.8 Bullet 3 |
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| 257 | $cryptoUtils = new Utils\Crypto(); |
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| 258 | $nonce = hash("sha256", $nonceToHash, true); // does raw_output have to be FALSE or TRUE? |
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| 259 | $certProps = openssl_x509_parse($cryptoUtils->der2pem($stmtDecoded['x5c'][0])); |
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| 260 | // § 8.8 Bullet 4 |
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| 261 | if ( |
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| 262 | !isset($certProps['extensions']['1.2.840.113635.100.8.2']) || |
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| 263 | empty($certProps['extensions']['1.2.840.113635.100.8.2']) |
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| 264 | ) { |
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| 265 | $this->fail("The required nonce value is not present in the OID."); |
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| 266 | } |
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| 267 | $toCompare = substr($certProps['extensions']['1.2.840.113635.100.8.2'], 6); |
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| 268 | if ($nonce != $toCompare) { |
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| 269 | $this->fail("There is a mismatch between the nonce and the OID (XXX $nonce XXX , XXX $toCompare XXX )."); |
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| 270 | } |
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| 271 | |||
| 272 | // chain validation first |
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| 273 | foreach ($stmtDecoded['x5c'] as $runIndex => $runCert) { |
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| 274 | if (isset($stmtDecoded['x5c'][$runIndex + 1])) { // there is a next cert, so follow the chain |
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| 275 | $certResource = openssl_x509_read($cryptoUtils->der2pem($runCert)); |
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| 276 | $signerPubKey = openssl_pkey_get_public($cryptoUtils->der2pem($stmtDecoded['x5c'][$runIndex + 1])); |
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| 277 | if (openssl_x509_verify($certResource, $signerPubKey) != 1) { |
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| 278 | $this->fail("Error during chain validation of the attestation certificate (while validating cert #$runIndex, which is " |
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| 279 | . $cryptoUtils->der2pem($runCert) |
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| 280 | . "; next cert was " |
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| 281 | . $cryptoUtils->der2pem($stmtDecoded['x5c'][$runIndex + 1])); |
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| 282 | } |
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| 283 | } else { // last cert, compare to the root |
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| 284 | $certResource = openssl_x509_read($cryptoUtils->der2pem($runCert)); |
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| 285 | $signerPubKey = openssl_pkey_get_public($APPLE_WEBAUTHN_ROOT_CA); |
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| 286 | if (openssl_x509_verify($certResource, $signerPubKey) != 1) { |
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| 287 | $this->fail(sprintf( |
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| 288 | "Error during root CA validation of the attestation chain certificate, which is %s", |
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| 289 | $cryptoUtils->der2pem($runCert) |
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| 290 | )); |
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| 291 | } |
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| 292 | } |
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| 293 | } |
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| 294 | |||
| 295 | $keyResource = openssl_pkey_get_public($cryptoUtils->der2pem($stmtDecoded['x5c'][0])); |
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| 296 | if ($keyResource === false) { |
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| 297 | $this->fail( |
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| 298 | "Did not get a parseable X.509 structure out of the Apple attestation statement - x5c nr. 0 statement was: XXX " |
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| 299 | . $stmtDecoded['x5c'][0] |
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| 300 | . " XXX; PEM equivalent is " |
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| 301 | . $cryptoUtils->der2pem($stmtDecoded['x5c'][0]) |
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| 302 | . ". OpenSSL error: " |
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| 303 | . openssl_error_string() |
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| 304 | ); |
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| 305 | } |
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| 306 | |||
| 307 | // $this->credential is a public key in CBOR, not "PEM". We need to convert it first. |
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| 308 | $keyArray = $this->cborDecode(hex2bin($this->credential)); |
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| 309 | $keyObject = new Ec2Key($keyArray); |
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| 310 | $credentialResource = openssl_pkey_get_public($keyObject->asPEM()); |
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| 311 | |||
| 312 | if ($credentialResource === false) { |
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| 313 | $this->fail( |
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| 314 | "Could not create a public key from CBOR credential. XXX " |
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| 315 | . $this->credential |
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| 316 | . " XXX; PEM equivalent is " |
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| 317 | . $keyObject->asPEM() |
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| 318 | . ". OpenSSL error: " |
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| 319 | . openssl_error_string() |
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| 320 | ); |
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| 321 | } |
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| 322 | |||
| 323 | // § 8.8 Bullet 5 |
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| 324 | $credentialDetails = openssl_pkey_get_details($credentialResource); |
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| 325 | $keyDetails = openssl_pkey_get_details($keyResource); |
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| 326 | if ( |
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| 327 | $credentialDetails['bits'] != $keyDetails['bits'] || |
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| 328 | $credentialDetails['key'] != $keyDetails['key'] || |
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| 329 | $credentialDetails['type'] != $keyDetails['type'] |
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| 330 | ) { |
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| 331 | $this->fail( |
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| 332 | "The credential public key does not match the certificate public key in attestationData. (" |
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| 333 | . $credentialDetails['key'] |
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| 334 | . " - " |
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| 335 | . $keyDetails['key'] |
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| 336 | . ")" |
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| 337 | ); |
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| 338 | } |
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| 339 | $this->pass("Apple attestation format verification passed."); |
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| 340 | return; |
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| 341 | } |
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| 342 | |||
| 343 | /** |
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| 344 | * @param array $attestationArray |
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| 345 | */ |
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| 346 | private function validateAttestationFormatPacked(array $attestationArray): void { |
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| 347 | $stmtDecoded = $attestationArray['attStmt']; |
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| 348 | $this->debugBuffer .= "AttStmt: " . print_r($stmtDecoded, true) . "<br/>"; |
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| 349 | /** |
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| 350 | * §7.1 Step 16: attestation is either done with x5c or ecdaa. |
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| 351 | */ |
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| 352 | if (isset($stmtDecoded['x5c'])) { |
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| 353 | $this->validateAttestationFormatPackedX5C($attestationArray); |
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| 354 | } elseif (isset($stmtDecoded['ecdaa'])) { |
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| 355 | $this->fail("ecdaa attestation not supported right now."); |
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| 356 | } else { |
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| 357 | // if we are still here, we are in the "self" type. |
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| 358 | $this->validateAttestationFormatPackedSelf($attestationArray); |
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| 359 | } |
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| 360 | } |
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| 361 | |||
| 362 | /** |
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| 363 | * @param array $attestationArray |
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| 364 | * @return void |
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| 365 | */ |
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| 366 | private function validateAttestationFormatPackedX5C(array $attestationArray): void { |
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| 367 | $stmtDecoded = $attestationArray['attStmt']; |
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| 368 | /** |
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| 369 | * §8.2 Step 2: check x5c attestation |
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| 370 | */ |
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| 371 | $sigdata = $attestationArray['authData'] . $this->clientDataHash; |
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| 372 | $keyResource = openssl_pkey_get_public($this->der2pem($stmtDecoded['x5c'][0])); |
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| 373 | if ($keyResource === false) { |
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| 374 | $this->fail("Unable to construct public key resource from PEM."); |
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| 375 | } |
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| 376 | /** |
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| 377 | * §8.2 Step 2 Bullet 1: check signature |
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| 378 | */ |
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| 379 | if (openssl_verify($sigdata, $stmtDecoded['sig'], $keyResource, OPENSSL_ALGO_SHA256) !== 1) { |
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| 380 | $this->fail("x5c attestation failed."); |
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| 381 | } |
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| 382 | $this->pass("x5c sig check passed."); |
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| 383 | // still need to perform sanity checks on the attestation certificate |
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| 384 | /** |
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| 385 | * §8.2 Step 2 Bullet 2: check certificate properties listed in §8.2.1 |
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| 386 | */ |
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| 387 | $certProps = openssl_x509_parse($this->der2pem($stmtDecoded['x5c'][0])); |
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| 388 | $this->debugBuffer .= "Attestation Certificate:" . print_r($certProps, true) . "<br/>"; |
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| 389 | if ( |
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| 390 | $certProps['version'] !== 2 || /** §8.2.1 Bullet 1 */ |
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| 391 | $certProps['subject']['OU'] !== "Authenticator Attestation" || /** §8.2.1 Bullet 2 [Subject-OU] */ |
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| 392 | !isset($certProps['subject']['CN']) || /** §8.2.1 Bullet 2 [Subject-CN] */ |
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| 393 | !isset($certProps['extensions']['basicConstraints']) || |
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| 394 | strstr("CA:FALSE", $certProps['extensions']['basicConstraints']) === false /** §8.2.1 Bullet 4 */ |
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| 395 | ) { |
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| 396 | $this->fail("Attestation certificate properties are no good."); |
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| 397 | } |
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| 398 | |||
| 399 | if ($this->AAGUIDDictionary->hasToken($this->AAGUID)) { |
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| 400 | $token = $this->AAGUIDDictionary->get($this->AAGUID); |
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| 401 | /** |
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| 402 | * Checking the OID is not programmatically possible. Text per spec: |
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| 403 | * "If the related attetation root certificate is used for multiple |
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| 404 | * authenticator models, the Extension OID ... MUST be present." |
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| 405 | * |
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| 406 | * FIDO MDS3 metadata does not disclose whether the root CAs are |
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| 407 | * used for multiple models. |
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| 408 | */ |
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| 409 | /* if ($token['multi'] === true) { // need to check the OID |
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| 410 | if ( |
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| 411 | !isset($certProps['extensions']['1.3.6.1.4.1.45724.1.1.4']) || empty($certProps['extensions']['1.3.6.1.4.1.45724.1.1.4']) |
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| 412 | ) { // §8.2.1 Bullet 3 |
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| 413 | $this->fail( |
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| 414 | "This vendor uses one cert for multiple authenticator model attestations, but lacks the AAGUID OID." |
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| 415 | ); |
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| 416 | } |
||
| 417 | /** |
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| 418 | * §8.2 Step 2 Bullet 3: compare AAGUID values |
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| 419 | */ |
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| 420 | /* $AAGUIDFromOid = substr(bin2hex($certProps['extensions']['1.3.6.1.4.1.45724.1.1.4']), 4); |
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| 421 | $this->debugBuffer .= "AAGUID from OID = $AAGUIDFromOid<br/>"; |
||
| 422 | if (strtolower($AAGUIDFromOid) !== strtolower($this->AAGUID)) { |
||
| 423 | $this->fail("AAGUID mismatch between attestation certificate and attestation statement."); |
||
| 424 | } |
||
| 425 | }*/ |
||
| 426 | // we would need to verify the attestation certificate against a known-good |
||
| 427 | // root CA certificate to get more than basic |
||
| 428 | /* |
||
| 429 | * §7.1 Step 17 is to look at $token['RootPEMs'] |
||
| 430 | */ |
||
| 431 | foreach ($token['metadataStatement']['attestationRootCertificates'] as $oneRoot) { |
||
| 432 | $caData = openssl_x509_parse("-----BEGIN CERTIFICATE-----\n$oneRoot\n-----END CERTIFICATE-----", true); |
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| 433 | |||
| 434 | } |
||
| 435 | /* |
||
| 436 | * §7.1 Step 18 is skipped, and we unconditionally return "only" Basic. |
||
| 437 | */ |
||
| 438 | $this->AAGUIDAssurance = self::AAGUID_ASSURANCE_LEVEL_BASIC; |
||
| 439 | } else { |
||
| 440 | $this->warn("Unknown authenticator model found: " . $this->AAGUID . "."); |
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| 441 | // unable to verify all cert properties, so this is not enough for BASIC. |
||
| 442 | // but it's our own fault, we should add the device to our DB. |
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| 443 | $this->AAGUIDAssurance = self::AAGUID_ASSURANCE_LEVEL_SELF; |
||
| 444 | } |
||
| 445 | $this->pass("x5c attestation passed."); |
||
| 446 | return; |
||
| 447 | } |
||
| 448 | |||
| 449 | /** |
||
| 450 | * @param array $attestationArray |
||
| 451 | * @return void |
||
| 452 | */ |
||
| 453 | private function validateAttestationFormatPackedSelf(array $attestationArray): void { |
||
| 492 | } |
||
| 493 | } |
||
| 494 | |||
| 495 | /** |
||
| 496 | * support legacy U2F tokens |
||
| 497 | * |
||
| 498 | * @param array $attestationData the incoming attestation data |
||
| 499 | * @return void |
||
| 500 | */ |
||
| 501 | private function validateAttestationFormatFidoU2F(array $attestationData): void { |
||
| 502 | /** |
||
| 503 | * §8.6 Verification Step 1 is a NOOP: if we're here, the attStmt was |
||
| 504 | * already successfully CBOR decoded |
||
| 505 | */ |
||
| 506 | $stmtDecoded = $attestationData['attStmt']; |
||
| 507 | if (!isset($stmtDecoded['x5c'])) { |
||
| 508 | $this->fail("FIDO U2F attestation needs to have the 'x5c' key"); |
||
| 509 | } |
||
| 510 | /** |
||
| 511 | * §8.6 Verification Step 2: extract attCert and sanity check it |
||
| 512 | */ |
||
| 513 | if (count($stmtDecoded['x5c']) !== 1) { |
||
| 514 | $this->fail("FIDO U2F attestation requires 'x5c' to have only exactly one key."); |
||
| 515 | } |
||
| 516 | $attCert = $this->der2pem($stmtDecoded['x5c'][0]); |
||
| 517 | $key = openssl_pkey_get_public($attCert); |
||
| 518 | $keyProps = openssl_pkey_get_details($key); |
||
| 519 | if (!isset($keyProps['ec']['curve_name']) || $keyProps['ec']['curve_name'] !== "prime256v1") { |
||
| 520 | $this->fail("FIDO U2F attestation public key is not P-256!"); |
||
| 521 | } |
||
| 522 | /** |
||
| 523 | * §8.6 Verification Step 3 is a NOOP as these properties are already |
||
| 524 | * available as class members: |
||
| 525 | * |
||
| 526 | * $this->rpIdHash; |
||
| 527 | * $this->credentialId; |
||
| 528 | * $this->credential; |
||
| 529 | */ |
||
| 530 | /** |
||
| 531 | * §8.6 Verification Step 4: encode the public key in ANSI X9.62 format |
||
| 532 | */ |
||
| 533 | if ( |
||
| 534 | isset($this->credential[-2]) && |
||
| 535 | strlen($this->credential[-2]) === 32 && |
||
| 536 | isset($this->credential[-3]) && |
||
| 537 | strlen($this->credential[-3]) === 32 |
||
| 538 | ) { |
||
| 539 | $publicKeyU2F = chr(4) . $this->credential[-2] . $this->credential[-3]; |
||
| 540 | } else { |
||
| 541 | $publicKeyU2F = false; |
||
| 542 | $this->fail("FIDO U2F attestation: the public key is not as expected."); |
||
| 543 | } |
||
| 544 | /** |
||
| 545 | * §8.6 Verification Step 5: create verificationData |
||
| 546 | * |
||
| 547 | * @psalm-var string $publicKeyU2F |
||
| 548 | */ |
||
| 549 | $verificationData = chr(0) . $this->rpIdHash . $this->clientDataHash . $this->credentialId . $publicKeyU2F; |
||
| 550 | /** |
||
| 551 | * §8.6 Verification Step 6: verify signature |
||
| 552 | */ |
||
| 553 | if (openssl_verify($verificationData, $stmtDecoded['sig'], $attCert, OPENSSL_ALGO_SHA256) !== 1) { |
||
| 554 | $this->fail("FIDO U2F Attestation verification failed."); |
||
| 555 | } else { |
||
| 556 | $this->pass("Successfully verified FIDO U2F signature."); |
||
| 557 | } |
||
| 558 | /** |
||
| 559 | * §8.6 Verification Step 7: not performed, this is optional as per spec |
||
| 560 | */ |
||
| 561 | /** |
||
| 562 | * §8.6 Verification Step 8: so we always settle for "Basic" |
||
| 563 | */ |
||
| 564 | $this->AAGUIDAssurance = self::AAGUID_ASSURANCE_LEVEL_BASIC; |
||
| 565 | } |
||
| 566 | |||
| 567 | /** |
||
| 568 | * support Android authenticators (fingerprint etc.) |
||
| 569 | * |
||
| 570 | * @param array $attestationData the incoming attestation data |
||
| 571 | * @return void |
||
| 572 | */ |
||
| 573 | private function validateAttestationFormatAndroidSafetyNet(array $attestationData): void { |
||
| 574 | |||
| 575 | } |
||
| 576 | |||
| 577 | /** |
||
| 578 | * The registration contains the actual credential. This function parses it. |
||
| 579 | * @param string $attData the attestation data binary blob |
||
| 580 | * @param string $responseId the response ID |
||
| 581 | * @return void |
||
| 582 | */ |
||
| 583 | private function validateAttestedCredentialData(string $attData, string $responseId): void { |
||
| 584 | $aaguid = substr($attData, 0, 16); |
||
| 585 | $credIdLenBytes = substr($attData, 16, 2); |
||
| 586 | $credIdLen = intval(bin2hex($credIdLenBytes), 16); |
||
| 587 | $credId = substr($attData, 18, $credIdLen); |
||
| 588 | $this->debugBuffer .= "AAGUID (hex) = " . bin2hex($aaguid) . "</br/>"; |
||
| 589 | $this->AAGUID = bin2hex($aaguid); |
||
| 590 | $this->debugBuffer .= "Length Raw = " . bin2hex($credIdLenBytes) . "<br/>"; |
||
| 591 | $this->debugBuffer .= "Credential ID Length (decimal) = " . $credIdLen . "<br/>"; |
||
| 592 | $this->debugBuffer .= "Credential ID (hex) = " . bin2hex($credId) . "<br/>"; |
||
| 593 | if (bin2hex(WebAuthnAbstractEvent::base64urlDecode($responseId)) === bin2hex($credId)) { |
||
| 594 | $this->pass("Credential IDs in authenticator response and in attestation data match."); |
||
| 595 | } else { |
||
| 596 | $this->fail( |
||
| 597 | "Mismatch of credentialId (" . bin2hex($credId) . ") vs. response ID (" . |
||
| 598 | bin2hex(WebAuthnAbstractEvent::base64urlDecode($responseId)) . ")." |
||
| 599 | ); |
||
| 600 | } |
||
| 601 | // so far so good. Now extract the actual public key from its COSE |
||
| 602 | // encoding. |
||
| 603 | // finding out the number of bytes to CBOR decode appears non-trivial. |
||
| 604 | // The simple case is if no ED is present as the CBOR data then goes to |
||
| 605 | // the end of the byte sequence. |
||
| 606 | // since we don't know the algoritm yet, we don't know how many bytes |
||
| 607 | // of credential CBOR follow. Let's read to the end; the CBOR decoder |
||
| 608 | // silently ignores trailing extensions (if any) |
||
| 609 | $pubKeyCBOR = substr($attData, 18 + $credIdLen); |
||
| 610 | $arrayPK = $this->cborDecode($pubKeyCBOR); |
||
| 611 | $this->debugBuffer .= "pubKey in canonical form: <pre>" . print_r($arrayPK, true) . "</pre>"; |
||
| 612 | /** |
||
| 613 | * STEP 13 of the validation procedure in § 7.1 of the spec: is the algorithm the expected one? |
||
| 614 | */ |
||
| 615 | if (in_array($arrayPK['3'], self::PK_ALGORITHM)) { // we requested -7 or -257, so want to see it here |
||
| 616 | $this->algo = $arrayPK['3']; |
||
| 617 | $this->pass("Public Key Algorithm is expected (" . implode(' or ', WebAuthnRegistrationEvent::PK_ALGORITHM) . ")."); |
||
| 618 | } else { |
||
| 619 | $this->fail("Public Key Algorithm mismatch!"); |
||
| 620 | } |
||
| 621 | $this->credentialId = bin2hex($credId); |
||
| 622 | $this->credential = bin2hex($pubKeyCBOR); |
||
| 623 | |||
| 624 | // now that we know credential and its length, we can CBOR-decode the |
||
| 625 | // trailing extensions |
||
| 626 | switch ($this->algo) { |
||
| 627 | case self::PK_ALGORITHM_ECDSA: |
||
| 628 | $credentialLength = 77; |
||
| 629 | break; |
||
| 630 | case self::PK_ALGORITHM_RSA: |
||
| 631 | $credentialLength = 272; |
||
| 632 | break; |
||
| 633 | default: |
||
| 634 | $this->fail("No credential length information for $this->algo"); |
||
| 635 | } |
||
| 636 | $extensions = substr($attData, 18 + $credIdLen + $credentialLength); |
||
| 637 | if (strlen($extensions) !== 0) { |
||
| 638 | $this->pass("Found the following extensions (" . strlen($extensions) . " bytes) during registration ceremony: "); |
||
| 639 | } |
||
| 640 | } |
||
| 641 | |||
| 642 | /** |
||
| 643 | * transform DER formatted certificate to PEM format |
||
| 644 | * |
||
| 645 | * @param string $derData blob of DER data |
||
| 646 | * @return string the PEM representation of the certificate |
||
| 647 | */ |
||
| 648 | private function der2pem(string $derData): string { |
||
| 649 | $pem = chunk_split(base64_encode($derData), 64, "\n"); |
||
| 650 | $pem = "-----BEGIN CERTIFICATE-----\n" . $pem . "-----END CERTIFICATE-----\n"; |
||
| 651 | return $pem; |
||
| 652 | } |
||
| 653 | |||
| 654 | /** |
||
| 655 | * @return string |
||
| 656 | */ |
||
| 657 | public function getAAGUID() { |
||
| 658 | return $this->AAGUID; |
||
| 659 | } |
||
| 660 | |||
| 661 | /** |
||
| 662 | * @return string |
||
| 663 | */ |
||
| 664 | public function getAttestationLevel() { |
||
| 666 | } |
||
| 667 | |||
| 668 | } |
||
| 669 |
Loading history...
The issue could also be caused by a filter entry in the build configuration. If the path has been excluded in your configuration, e.g.
excluded_paths: ["lib/*"], you can move it to the dependency path list as follows:For further information see https://scrutinizer-ci.com/docs/tools/php/php-scrutinizer/#list-dependency-paths