[Web] Feature (beta): Add WebAuthn support for administrators and domain administrators

2020-11-15 19:32:37 +01:00
parent 58cce74bc9
commit c150ac7b37
43 changed files with 33820 additions and 1502 deletions
--- a/data/web/inc/lib/WebAuthn/Attestation/Format/AndroidSafetyNet.php
+++ b/data/web/inc/lib/WebAuthn/Attestation/Format/AndroidSafetyNet.php
@@ -0,0 +1,140 @@
+<?php
+
+
+namespace WebAuthn\Attestation\Format;
+use WebAuthn\WebAuthnException;
+use WebAuthn\Binary\ByteBuffer;
+
+class AndroidSafetyNet extends FormatBase {
+    private $_signature;
+    private $_signedValue;
+    private $_x5c;
+    private $_payload;
+
+    public function __construct($AttestionObject, \WebAuthn\Attestation\AuthenticatorData $authenticatorData) {
+        parent::__construct($AttestionObject, $authenticatorData);
+
+        // check data
+        $attStmt = $this->_attestationObject['attStmt'];
+
+        if (!\array_key_exists('ver', $attStmt) || !$attStmt['ver']) {
+            throw new WebAuthnException('invalid Android Safety Net Format', WebAuthnException::INVALID_DATA);
+        }
+
+        if (!\array_key_exists('response', $attStmt) || !($attStmt['response'] instanceof ByteBuffer)) {
+            throw new WebAuthnException('invalid Android Safety Net Format', WebAuthnException::INVALID_DATA);
+        }
+
+        $response = $attStmt['response']->getBinaryString();
+
+        // Response is a JWS [RFC7515] object in Compact Serialization.
+        // JWSs have three segments separated by two period ('.') characters
+        $parts = \explode('.', $response);
+        unset ($response);
+        if (\count($parts) !== 3) {
+            throw new WebAuthnException('invalid JWS data', WebAuthnException::INVALID_DATA);
+        }
+
+        $header = $this->_base64url_decode($parts[0]);
+        $payload = $this->_base64url_decode($parts[1]);
+        $this->_signature = $this->_base64url_decode($parts[2]);
+        $this->_signedValue = $parts[0] . '.' . $parts[1];
+        unset ($parts);
+
+        $header = \json_decode($header);
+        $payload = \json_decode($payload);
+
+        if (!($header instanceof \stdClass)) {
+            throw new WebAuthnException('invalid JWS header', WebAuthnException::INVALID_DATA);
+        }
+        if (!($payload instanceof \stdClass)) {
+            throw new WebAuthnException('invalid JWS payload', WebAuthnException::INVALID_DATA);
+        }
+
+        if (!$header->x5c || !is_array($header->x5c) || count($header->x5c) === 0) {
+            throw new WebAuthnException('No X.509 signature in JWS Header', WebAuthnException::INVALID_DATA);
+        }
+
+        // algorithm
+        if (!\in_array($header->alg, array('RS256', 'ES256'))) {
+            throw new WebAuthnException('invalid JWS algorithm ' . $header->alg, WebAuthnException::INVALID_DATA);
+        }
+
+        $this->_x5c = \base64_decode($header->x5c[0]);
+        $this->_payload = $payload;
+
+        if (count($header->x5c) > 1) {
+            for ($i=1; $i<count($header->x5c); $i++) {
+                $this->_x5c_chain[] = \base64_decode($header->x5c[$i]);
+            }
+            unset ($i);
+        }
+    }
+
+
+    /*
+     * returns the key certificate in PEM format
+     * @return string
+     */
+    public function getCertificatePem() {
+        return $this->_createCertificatePem($this->_x5c);
+    }
+
+    /**
+     * @param string $clientDataHash
+     */
+    public function validateAttestation($clientDataHash) {
+        $publicKey = \openssl_pkey_get_public($this->getCertificatePem());
+
+        // Verify that the nonce in the response is identical to the Base64 encoding
+        // of the SHA-256 hash of the concatenation of authenticatorData and clientDataHash.
+        if (!$this->_payload->nonce || $this->_payload->nonce !== \base64_encode(\hash('SHA256', $this->_authenticatorData->getBinary() . $clientDataHash, true))) {
+            throw new WebAuthnException('invalid nonce in JWS payload', WebAuthnException::INVALID_DATA);
+        }
+
+        // Verify that attestationCert is issued to the hostname "attest.android.com"
+        $certInfo = \openssl_x509_parse($this->getCertificatePem());
+        if (!\is_array($certInfo) || !$certInfo['subject'] || $certInfo['subject']['CN'] !== 'attest.android.com') {
+            throw new WebAuthnException('invalid certificate CN in JWS (' . $certInfo['subject']['CN']. ')', WebAuthnException::INVALID_DATA);
+        }
+
+        // Verify that the ctsProfileMatch attribute in the payload of response is true.
+        if (!$this->_payload->ctsProfileMatch) {
+            throw new WebAuthnException('invalid ctsProfileMatch in payload', WebAuthnException::INVALID_DATA);
+        }
+
+        // check certificate
+        return \openssl_verify($this->_signedValue, $this->_signature, $publicKey, OPENSSL_ALGO_SHA256) === 1;
+    }
+
+
+    /**
+     * validates the certificate against root certificates
+     * @param array $rootCas
+     * @return boolean
+     * @throws WebAuthnException
+     */
+    public function validateRootCertificate($rootCas) {
+        $chainC = $this->_createX5cChainFile();
+        if ($chainC) {
+            $rootCas[] = $chainC;
+        }
+
+        $v = \openssl_x509_checkpurpose($this->getCertificatePem(), -1, $rootCas);
+        if ($v === -1) {
+            throw new WebAuthnException('error on validating root certificate: ' . \openssl_error_string(), WebAuthnException::CERTIFICATE_NOT_TRUSTED);
+        }
+        return $v;
+    }
+
+
+    /**
+     * decode base64 url
+     * @param string $data
+     * @return string
+     */
+    private function _base64url_decode($data) {
+        return \base64_decode(\strtr($data, '-_', '+/') . \str_repeat('=', 3 - (3 + \strlen($data)) % 4));
+    }
+}
+