<?php
class SignedCommunicationProvider
{

    protected $GPG;

    public function __construct($keyFile, $fingerprint = null, $passphrase = null, $tmpPath = null)
    {
        if(empty($tmpPath)) {
            $tmpPath = "/tmp/tononixOS.gpg";
        }
        if (file_exists($tmpPath)) {
            unlink($tmpPath);
        }
        $this->GPG = new GnuPG(['home-dir' => $tmpPath]);
        $keyData = file_get_contents($keyFile);
        $this->GPG->import($keyData);
        if (!empty($fingerprint)) {
            $result = $this->GPG->addsignkey($fingerprint, $passphrase);
            if ($result == false) {
                return false;
            } else {
                $this->GPG->setsignmode(GNUPG_SIG_MODE_NORMAL);
                return true;
            }
        }
    }

    public function sign($data)
    {
        if ($this->GPG == null) {
            return false;
        }
        $data = $this->GPG->sign($data);
        return $data;
    }

    public function verify($data)
    {
        $verified = "";
        $info = $this->GPG->verify($data, false, $verified);
        $result = array("data" => $verified,
                        "message" => $info);
        if ($info == false) {
            $result['message'] = "Signature Verification Failed.";
            $result['data'] = false;
            return $result;
        } else {
            return $result;
        }
    }
}