android-key.php
1 day ago
android-safety-net.php
1 day ago
apple.php
1 day ago
format-base.php
1 day ago
index.php
1 day ago
none.php
1 day ago
packed.php
1 day ago
tpm.php
1 day ago
u2f.php
1 day ago
tpm.php
257 lines
| 1 | <?php |
| 2 | /** |
| 3 | * Passkeys formatters |
| 4 | * |
| 5 | * @package wp-2fa |
| 6 | * @since 3.0.0 |
| 7 | */ |
| 8 | |
| 9 | namespace WP2FA\Passkeys\Format; |
| 10 | |
| 11 | use WP2FA\Methods\Passkeys\Byte_Buffer; |
| 12 | use WP2FA\Methods\Passkeys\Web_Authn_Exception; |
| 13 | use WP2FA\Admin\Methods\passkeys\Authenticator_Data; |
| 14 | |
| 15 | /** |
| 16 | * Responsible for tpm format |
| 17 | * |
| 18 | * @since 3.0.0 |
| 19 | */ |
| 20 | class Tpm extends Format_Base { |
| 21 | |
| 22 | private const TPM_GENERATED_VALUE = "\xFF\x54\x43\x47"; |
| 23 | private const TPM_ST_ATTEST_CERTIFY = "\x80\x17"; |
| 24 | |
| 25 | /** |
| 26 | * Algorithm to be used |
| 27 | * |
| 28 | * @var string |
| 29 | * |
| 30 | * @since 3.0.0 |
| 31 | */ |
| 32 | private $alg; |
| 33 | |
| 34 | /** |
| 35 | * Signature |
| 36 | * |
| 37 | * @var string |
| 38 | * |
| 39 | * @since 3.0.0 |
| 40 | */ |
| 41 | private $signature; |
| 42 | |
| 43 | /** |
| 44 | * Public area |
| 45 | * |
| 46 | * @var Byte_Buffer |
| 47 | * |
| 48 | * @since 3.0.0 |
| 49 | */ |
| 50 | private $pub_area; |
| 51 | |
| 52 | /** |
| 53 | * X5c certificate |
| 54 | * |
| 55 | * @var string |
| 56 | * |
| 57 | * @since 3.0.0 |
| 58 | */ |
| 59 | private $x5c; |
| 60 | |
| 61 | /** |
| 62 | * Cert info |
| 63 | * |
| 64 | * @var Byte_Buffer |
| 65 | * |
| 66 | * @since 3.0.0 |
| 67 | */ |
| 68 | private $cert_info; |
| 69 | |
| 70 | /** |
| 71 | * Default constructor |
| 72 | * |
| 73 | * @param \StdClass $attestion_object - attestation object. |
| 74 | * @param \WP2FA\Admin\Methods\passkeys\Authenticator_Data $authenticator_data - Authentication data. |
| 75 | * |
| 76 | * @throws Web_Authn_Exception - if can not be created. |
| 77 | * |
| 78 | * @since 3.0.0 |
| 79 | */ |
| 80 | public function __construct( $attestion_object, Authenticator_Data $authenticator_data ) { |
| 81 | parent::__construct( $attestion_object, $authenticator_data ); |
| 82 | |
| 83 | // check packed data. |
| 84 | $att_stmt = $this->attestation_object['attStmt']; |
| 85 | |
| 86 | if ( '2.0' !== ! \array_key_exists( 'ver', $att_stmt ) || $att_stmt['ver'] ) { |
| 87 | throw new Web_Authn_Exception( 'invalid tpm version: ' . $att_stmt['ver'], Web_Authn_Exception::INVALID_DATA ); |
| 88 | } |
| 89 | |
| 90 | if ( ! \array_key_exists( 'alg', $att_stmt ) || $this->_get_cose_algorithm( $att_stmt['alg'] ) === null ) { |
| 91 | throw new Web_Authn_Exception( 'unsupported alg: ' . $att_stmt['alg'], Web_Authn_Exception::INVALID_DATA ); |
| 92 | } |
| 93 | |
| 94 | if ( ! \array_key_exists( 'sig', $att_stmt ) || ! \is_object( $att_stmt['sig'] ) || ! ( $att_stmt['sig'] instanceof Byte_Buffer ) ) { |
| 95 | throw new Web_Authn_Exception( 'signature not found', Web_Authn_Exception::INVALID_DATA ); |
| 96 | } |
| 97 | |
| 98 | if ( ! \array_key_exists( 'certInfo', $att_stmt ) || ! \is_object( $att_stmt['certInfo'] ) || ! ( $att_stmt['certInfo'] instanceof Byte_Buffer ) ) { |
| 99 | throw new Web_Authn_Exception( 'certInfo not found', Web_Authn_Exception::INVALID_DATA ); |
| 100 | } |
| 101 | |
| 102 | if ( ! \array_key_exists( 'pubArea', $att_stmt ) || ! \is_object( $att_stmt['pubArea'] ) || ! ( $att_stmt['pubArea'] instanceof Byte_Buffer ) ) { |
| 103 | throw new Web_Authn_Exception( 'pubArea not found', Web_Authn_Exception::INVALID_DATA ); |
| 104 | } |
| 105 | |
| 106 | $this->alg = $att_stmt['alg']; |
| 107 | $this->signature = $att_stmt['sig']->getBinaryString(); |
| 108 | $this->cert_info = $att_stmt['certInfo']; |
| 109 | $this->pub_area = $att_stmt['pubArea']; |
| 110 | |
| 111 | // certificate for validation. |
| 112 | if ( \array_key_exists( 'x5c', $att_stmt ) && \is_array( $att_stmt['x5c'] ) && \count( $att_stmt['x5c'] ) > 0 ) { |
| 113 | |
| 114 | // The attestation certificate attestn_cert MUST be the first element in the array. |
| 115 | $attestn_cert = array_shift( $att_stmt['x5c'] ); |
| 116 | |
| 117 | if ( ! ( $attestn_cert instanceof Byte_Buffer ) ) { |
| 118 | throw new Web_Authn_Exception( 'invalid x5c certificate', Web_Authn_Exception::INVALID_DATA ); |
| 119 | } |
| 120 | |
| 121 | $this->x5c = $attestn_cert->getBinaryString(); |
| 122 | |
| 123 | // certificate chain. |
| 124 | foreach ( $att_stmt['x5c'] as $chain ) { |
| 125 | if ( $chain instanceof Byte_Buffer ) { |
| 126 | $this->x5c_chain[] = $chain->getBinaryString(); |
| 127 | } |
| 128 | } |
| 129 | } else { |
| 130 | throw new Web_Authn_Exception( 'no x5c certificate found', Web_Authn_Exception::INVALID_DATA ); |
| 131 | } |
| 132 | } |
| 133 | |
| 134 | /** |
| 135 | * Returns the key certificate in PEM format |
| 136 | * |
| 137 | * @return string|null |
| 138 | * |
| 139 | * @since 3.0.0 |
| 140 | */ |
| 141 | public function get_certificate_pem() { |
| 142 | if ( ! $this->x5c ) { |
| 143 | return null; |
| 144 | } |
| 145 | return $this->_create_certificate_pem( $this->x5c ); |
| 146 | } |
| 147 | |
| 148 | /** |
| 149 | * Validator |
| 150 | * |
| 151 | * @param string $client_data_hash - Hash collected. |
| 152 | * |
| 153 | * @throws Web_Authn_Exception - Throws exception if validation fails. |
| 154 | * |
| 155 | * @since 3.0.0 |
| 156 | */ |
| 157 | public function validate_attestation( $client_data_hash ) { |
| 158 | return $this->_validate_over_x5c( $client_data_hash ); |
| 159 | } |
| 160 | |
| 161 | /** |
| 162 | * Validates the certificate against root certificates |
| 163 | * |
| 164 | * @param array $root_cas - Array with values. |
| 165 | * |
| 166 | * @return boolean |
| 167 | * |
| 168 | * @throws Web_Authn_Exception - Throws exception. |
| 169 | * |
| 170 | * @since 3.0.0 |
| 171 | */ |
| 172 | public function validate_root_certificate( $root_cas ) { |
| 173 | if ( ! $this->x5c ) { |
| 174 | return false; |
| 175 | } |
| 176 | |
| 177 | $chain_c = $this->_create_x5c_chain_file(); |
| 178 | if ( $chain_c ) { |
| 179 | $root_cas[] = $chain_c; |
| 180 | } |
| 181 | |
| 182 | $v = \openssl_x509_checkpurpose( $this->get_certificate_pem(), -1, $root_cas ); |
| 183 | if ( -1 === $v ) { |
| 184 | throw new Web_Authn_Exception( 'error on validating root certificate: ' . \openssl_error_string(), Web_Authn_Exception::CERTIFICATE_NOT_TRUSTED ); |
| 185 | } |
| 186 | return $v; |
| 187 | } |
| 188 | |
| 189 | /** |
| 190 | * Validate if x5c is present |
| 191 | * |
| 192 | * @param string $client_data_hash - Hash collected. |
| 193 | * |
| 194 | * @return bool |
| 195 | * |
| 196 | * @throws Web_Authn_Exception - Throws exception. |
| 197 | * |
| 198 | * @since 3.0.0 |
| 199 | */ |
| 200 | protected function _validate_over_x5c( $client_data_hash ) { |
| 201 | $public_key = \openssl_pkey_get_public( $this->get_certificate_pem() ); |
| 202 | |
| 203 | if ( false === $public_key ) { |
| 204 | throw new Web_Authn_Exception( 'invalid public key: ' . \openssl_error_string(), Web_Authn_Exception::INVALID_PUBLIC_KEY ); |
| 205 | } |
| 206 | |
| 207 | // Concatenate Authenticator_Data and client_data_hash to form att_to_be_signed. |
| 208 | $att_to_be_signed = $this->authenticator_data->get_binary(); |
| 209 | $att_to_be_signed .= $client_data_hash; |
| 210 | |
| 211 | // Validate that certInfo is valid:. |
| 212 | |
| 213 | // Verify that magic is set to TPM_GENERATED_VALUE. |
| 214 | if ( $this->cert_info->getBytes( 0, 4 ) !== self::TPM_GENERATED_VALUE ) { |
| 215 | throw new Web_Authn_Exception( 'tpm magic not TPM_GENERATED_VALUE', Web_Authn_Exception::INVALID_DATA ); |
| 216 | } |
| 217 | |
| 218 | // Verify that type is set to TPM_ST_ATTEST_CERTIFY. |
| 219 | if ( $this->cert_info->getBytes( 4, 2 ) !== self::TPM_ST_ATTEST_CERTIFY ) { |
| 220 | throw new Web_Authn_Exception( 'tpm type not TPM_ST_ATTEST_CERTIFY', Web_Authn_Exception::INVALID_DATA ); |
| 221 | } |
| 222 | |
| 223 | $offset = 6; |
| 224 | $qualified_signer = $this->_tpmReadLengthPrefixed( $this->cert_info, $offset ); |
| 225 | $extra_data = $this->_tpmReadLengthPrefixed( $this->cert_info, $offset ); |
| 226 | $cose_alg = $this->_get_cose_algorithm( $this->alg ); |
| 227 | |
| 228 | // Verify that extra_data is set to the hash of att_to_be_signed using the hash algorithm employed in "alg". |
| 229 | if ( $extra_data->getBinaryString() !== \hash( $cose_alg->hash, $att_to_be_signed, true ) ) { |
| 230 | throw new Web_Authn_Exception( 'certInfo:extraData not hash of attToBeSigned', Web_Authn_Exception::INVALID_DATA ); |
| 231 | } |
| 232 | |
| 233 | // Verify the sig is a valid signature over certInfo using the attestation |
| 234 | // public key in aikCert with the algorithm specified in alg. |
| 235 | return \openssl_verify( $this->cert_info->getBinaryString(), $this->signature, $public_key, $cose_alg->openssl ) === 1; |
| 236 | } |
| 237 | |
| 238 | |
| 239 | /** |
| 240 | * Returns next part of Byte_Buffer |
| 241 | * |
| 242 | * @param Byte_Buffer $buffer - Buffer to read from. |
| 243 | * @param int $offset - Offset to read. |
| 244 | * |
| 245 | * @return Byte_Buffer |
| 246 | * |
| 247 | * @since 3.0.0 |
| 248 | */ |
| 249 | protected function _tpmReadLengthPrefixed( Byte_Buffer $buffer, &$offset ) { |
| 250 | $len = $buffer->getUint16Val( $offset ); |
| 251 | $data = $buffer->getBytes( $offset + 2, $len ); |
| 252 | $offset += ( 2 + $len ); |
| 253 | |
| 254 | return new Byte_Buffer( $data ); |
| 255 | } |
| 256 | } |
| 257 |