android-key.php
1 day ago
android-safety-net.php
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apple.php
1 day ago
format-base.php
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index.php
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none.php
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packed.php
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tpm.php
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u2f.php
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android-safety-net.php
227 lines
| 1 | <?php |
| 2 | /** |
| 3 | * Passkeys formatters |
| 4 | * |
| 5 | * @package wp-2fa |
| 6 | * @since 3.0.0 |
| 7 | * @copyright 2026 Melapress |
| 8 | * @license https://www.apache.org/licenses/LICENSE-2.0 Apache License 2.0 |
| 9 | * @link https://wordpress.org/plugins/wp-2fa/ |
| 10 | */ |
| 11 | |
| 12 | namespace WP2FA\Passkeys\Format; |
| 13 | |
| 14 | use WP2FA\Methods\Passkeys\Byte_Buffer; |
| 15 | use WP2FA\Methods\Passkeys\Web_Authn_Exception; |
| 16 | use WP2FA\Admin\Methods\passkeys\Authenticator_Data; |
| 17 | |
| 18 | /** |
| 19 | * Responsible for android format |
| 20 | * |
| 21 | * @since 3.0.0 |
| 22 | */ |
| 23 | class Android_Safety_Net extends Format_Base { |
| 24 | |
| 25 | /** |
| 26 | * Signature chain |
| 27 | * |
| 28 | * @var string |
| 29 | * |
| 30 | * @since 3.0.0 |
| 31 | */ |
| 32 | private $signature; |
| 33 | |
| 34 | /** |
| 35 | * Signed value |
| 36 | * |
| 37 | * @var string |
| 38 | * |
| 39 | * @since 3.0.0 |
| 40 | */ |
| 41 | private $signed_value; |
| 42 | |
| 43 | /** |
| 44 | * X5c certificate |
| 45 | * |
| 46 | * @var string |
| 47 | * |
| 48 | * @since 3.0.0 |
| 49 | */ |
| 50 | private $x5c; |
| 51 | |
| 52 | /** |
| 53 | * Payload |
| 54 | * |
| 55 | * @var \stdClass |
| 56 | * |
| 57 | * @since 3.0.0 |
| 58 | */ |
| 59 | private $payload; |
| 60 | |
| 61 | /** |
| 62 | * Default constructor |
| 63 | * |
| 64 | * @param mixed $attestation_object - attestation object. |
| 65 | * @param \WP2FA\Admin\Methods\passkeys\Authenticator_Data $authenticator_data - Authentication data. |
| 66 | * |
| 67 | * @throws Web_Authn_Exception - if can not be created. |
| 68 | * |
| 69 | * @since 3.0.0 |
| 70 | */ |
| 71 | public function __construct( $attestation_object, Authenticator_Data $authenticator_data ) { |
| 72 | parent::__construct( $attestation_object, $authenticator_data ); |
| 73 | |
| 74 | // check data. |
| 75 | $att_stmt = $this->attestation_object['attStmt']; |
| 76 | |
| 77 | if ( ! \array_key_exists( 'ver', $att_stmt ) || ! $att_stmt['ver'] ) { |
| 78 | throw new Web_Authn_Exception( 'invalid Android Safety Net Format', Web_Authn_Exception::INVALID_DATA ); |
| 79 | } |
| 80 | |
| 81 | if ( ! \array_key_exists( 'response', $att_stmt ) || ! ( $att_stmt['response'] instanceof Byte_Buffer ) ) { |
| 82 | throw new Web_Authn_Exception( 'invalid Android Safety Net Format', Web_Authn_Exception::INVALID_DATA ); |
| 83 | } |
| 84 | |
| 85 | $response = $att_stmt['response']->getBinaryString(); |
| 86 | |
| 87 | // Response is a JWS [RFC7515] object in Compact Serialization. |
| 88 | // JWSs have three segments separated by two period ('.') characters. |
| 89 | $parts = \explode( '.', $response ); |
| 90 | unset( $response ); |
| 91 | if ( \count( $parts ) !== 3 ) { |
| 92 | throw new Web_Authn_Exception( 'invalid JWS data', Web_Authn_Exception::INVALID_DATA ); |
| 93 | } |
| 94 | |
| 95 | $header = $this->_base64url_decode( $parts[0] ); |
| 96 | $payload = $this->_base64url_decode( $parts[1] ); |
| 97 | $this->signature = $this->_base64url_decode( $parts[2] ); |
| 98 | $this->signed_value = $parts[0] . '.' . $parts[1]; |
| 99 | unset( $parts ); |
| 100 | |
| 101 | $header = \json_decode( $header ); |
| 102 | $payload = \json_decode( $payload ); |
| 103 | |
| 104 | if ( ! ( $header instanceof \stdClass ) ) { |
| 105 | throw new Web_Authn_Exception( 'invalid JWS header', Web_Authn_Exception::INVALID_DATA ); |
| 106 | } |
| 107 | if ( ! ( $payload instanceof \stdClass ) ) { |
| 108 | throw new Web_Authn_Exception( 'invalid JWS payload', Web_Authn_Exception::INVALID_DATA ); |
| 109 | } |
| 110 | |
| 111 | if ( ! isset( $header->x5c ) || ! is_array( $header->x5c ) || count( $header->x5c ) === 0 ) { |
| 112 | throw new Web_Authn_Exception( 'No X.509 signature in JWS Header', Web_Authn_Exception::INVALID_DATA ); |
| 113 | } |
| 114 | |
| 115 | // algorithm. |
| 116 | if ( ! \in_array( $header->alg, array( 'RS256', 'ES256' ) ) ) { |
| 117 | throw new Web_Authn_Exception( 'invalid JWS algorithm ' . $header->alg, Web_Authn_Exception::INVALID_DATA ); |
| 118 | } |
| 119 | |
| 120 | $this->x5c = \base64_decode( $header->x5c[0] ); |
| 121 | $this->payload = $payload; |
| 122 | |
| 123 | if ( count( $header->x5c ) > 1 ) { |
| 124 | for ( $i = 1; $i < count( $header->x5c ); $i++ ) { // phpcs:ignore Squiz.PHP.DisallowSizeFunctionsInLoops.Found |
| 125 | $this->x5c_chain[] = \base64_decode( $header->x5c[ $i ] ); |
| 126 | } |
| 127 | unset( $i ); |
| 128 | } |
| 129 | } |
| 130 | |
| 131 | /** |
| 132 | * A stricter verdict of device integrity. |
| 133 | * If the value of ctsProfileMatch is true, then the profile of the device running your app matches |
| 134 | * the profile of a device that has passed Android compatibility testing and |
| 135 | * has been approved as a Google-certified Android device. |
| 136 | * |
| 137 | * @return bool |
| 138 | * |
| 139 | * @since 3.0.0 |
| 140 | */ |
| 141 | public function ctsProfileMatch() { |
| 142 | return isset( $this->payload->ctsProfileMatch ) ? ! ! $this->payload->ctsProfileMatch : false; |
| 143 | } |
| 144 | |
| 145 | /** |
| 146 | * Returns the key certificate in PEM format |
| 147 | * |
| 148 | * @return string |
| 149 | * |
| 150 | * @since 3.0.0 |
| 151 | */ |
| 152 | public function getCertificatePem() { |
| 153 | return $this->_create_certificate_pem( $this->x5c ); |
| 154 | } |
| 155 | |
| 156 | /** |
| 157 | * Validates the attestation |
| 158 | * |
| 159 | * @param string $client_data_hash - Hash collected. |
| 160 | * |
| 161 | * @throws Web_Authn_Exception - Throws exception if validation fails. |
| 162 | * |
| 163 | * @since 3.0.0 |
| 164 | */ |
| 165 | public function validate_attestation( $client_data_hash ) { |
| 166 | $public_key = \openssl_pkey_get_public( $this->getCertificatePem() ); |
| 167 | |
| 168 | // Verify that the nonce in the response is identical to the Base64 encoding |
| 169 | // of the SHA-256 hash of the concatenation of Authenticator_Data and client_data_hash. |
| 170 | if ( empty( $this->payload->nonce ) || \base64_encode( \hash( 'SHA256', $this->authenticator_data->get_binary() . $client_data_hash, true ) ) !== $this->payload->nonce ) { |
| 171 | throw new Web_Authn_Exception( 'invalid nonce in JWS payload', Web_Authn_Exception::INVALID_DATA ); |
| 172 | } |
| 173 | |
| 174 | // Verify that attestationCert is issued to the hostname "attest.android.com". |
| 175 | $cert_info = \openssl_x509_parse( $this->getCertificatePem() ); |
| 176 | if ( ! \is_array( $cert_info ) || ( $cert_info['subject']['CN'] ?? '' ) !== 'attest.android.com' ) { |
| 177 | throw new Web_Authn_Exception( 'invalid certificate CN in JWS (' . ( $cert_info['subject']['CN'] ?? '-' ) . ')', Web_Authn_Exception::INVALID_DATA ); |
| 178 | } |
| 179 | |
| 180 | // Verify that the basicIntegrity attribute in the payload of response is true. |
| 181 | if ( empty( $this->payload->basicIntegrity ) ) { |
| 182 | throw new Web_Authn_Exception( 'invalid basicIntegrity in payload', Web_Authn_Exception::INVALID_DATA ); |
| 183 | } |
| 184 | |
| 185 | // check certificate. |
| 186 | return \openssl_verify( $this->signed_value, $this->signature, $public_key, OPENSSL_ALGO_SHA256 ) === 1; |
| 187 | } |
| 188 | |
| 189 | |
| 190 | /** |
| 191 | * Validates the certificate against root certificates |
| 192 | * |
| 193 | * @param array $root_cas - Array with values. |
| 194 | * |
| 195 | * @return boolean |
| 196 | * |
| 197 | * @throws Web_Authn_Exception - Throws exception. |
| 198 | * |
| 199 | * @since 3.0.0 |
| 200 | */ |
| 201 | public function validate_root_certificate( $root_cas ) { |
| 202 | $chain_c = $this->_create_x5c_chain_file(); |
| 203 | if ( $chain_c ) { |
| 204 | $root_cas[] = $chain_c; |
| 205 | } |
| 206 | |
| 207 | $v = \openssl_x509_checkpurpose( $this->get_certificate_pem(), -1, $root_cas ); |
| 208 | if ( -1 === $v ) { |
| 209 | throw new Web_Authn_Exception( 'error on validating root certificate: ' . \openssl_error_string(), Web_Authn_Exception::CERTIFICATE_NOT_TRUSTED ); |
| 210 | } |
| 211 | return $v; |
| 212 | } |
| 213 | |
| 214 | /** |
| 215 | * Decode base64 url |
| 216 | * |
| 217 | * @param string $data - Data to decode. |
| 218 | * |
| 219 | * @return string |
| 220 | * |
| 221 | * @since 3.0.0 |
| 222 | */ |
| 223 | private function _base64url_decode( $data ) { |
| 224 | return \base64_decode( \strtr( $data, '-_', '+/' ) . \str_repeat( '=', 3 - ( 3 + \strlen( $data ) ) % 4 ) ); |
| 225 | } |
| 226 | } |
| 227 |