Deployer\Server\Builder::identityFile PHP Method

    public function identityFile($publicKeyFile = '~/.ssh/id_rsa.pub', $privateKeyFile = '~/.ssh/id_rsa', $passPhrase = '')
    {
        $passPhrase = $this->checkPassword($passPhrase);
        if (is_null($publicKeyFile)) {
            // Use default value
            $publicKeyFile = '~/.ssh/id_rsa.pub';
        }
        if (is_null($privateKeyFile)) {
            // Use default value
            $privateKeyFile = '~/.ssh/id_rsa';
        }
        if (is_null($passPhrase)) {
            // Ask pass phrase before connection
            $passPhrase = AskPasswordGetter::createLazyGetter();
        }
        $this->config->setAuthenticationMethod(Configuration::AUTH_BY_IDENTITY_FILE);
        $this->config->setPublicKey($publicKeyFile);
        $this->config->setPrivateKey($privateKeyFile);
        $this->config->setPassPhrase($passPhrase);
        return $this;
    }