private static function createPemFromModulusAndExponent()

in src/JWK.php [122:157]
29 lines of code
1 McCabe index (conditional complexity)

    private static function createPemFromModulusAndExponent($n, $e)
    {
        $modulus = JWT::urlsafeB64Decode($n);
        $publicExponent = JWT::urlsafeB64Decode($e);

        $components = array(
            'modulus' => \pack('Ca*a*', 2, self::encodeLength(\strlen($modulus)), $modulus),
            'publicExponent' => \pack('Ca*a*', 2, self::encodeLength(\strlen($publicExponent)), $publicExponent)
        );

        $rsaPublicKey = \pack(
            'Ca*a*a*',
            48,
            self::encodeLength(\strlen($components['modulus']) + \strlen($components['publicExponent'])),
            $components['modulus'],
            $components['publicExponent']
        );

        // sequence(oid(1.2.840.113549.1.1.1), null)) = rsaEncryption.
        $rsaOID = \pack('H*', '300d06092a864886f70d0101010500'); // hex version of MA0GCSqGSIb3DQEBAQUA
        $rsaPublicKey = \chr(0) . $rsaPublicKey;
        $rsaPublicKey = \chr(3) . self::encodeLength(\strlen($rsaPublicKey)) . $rsaPublicKey;

        $rsaPublicKey = \pack(
            'Ca*a*',
            48,
            self::encodeLength(\strlen($rsaOID . $rsaPublicKey)),
            $rsaOID . $rsaPublicKey
        );

        $rsaPublicKey = "-----BEGIN PUBLIC KEY-----\r\n" .
            \chunk_split(\base64_encode($rsaPublicKey), 64) .
            '-----END PUBLIC KEY-----';

        return $rsaPublicKey;
    }