<?php
class Auth_Internal extends Plugin implements IAuthModule {

	private $host;

	function about() {
		return array(1.0,
			"Authenticates against internal tt-rss database",
			"fox",
			true);
	}

    /* @var PluginHost $host */
    function init($host) {
		$this->host = $host;
		$this->pdo = Db::pdo();

		$host->add_hook($host::HOOK_AUTH_USER, $this);
	}

	function authenticate($login, $password) {

		$pwd_hash1 = encrypt_password($password);
		$pwd_hash2 = encrypt_password($password, $login);
		$otp = $_REQUEST["otp"];

		if (get_schema_version() > 96) {
			if (!defined('AUTH_DISABLE_OTP') || !AUTH_DISABLE_OTP) {

				$sth = $this->pdo->prepare("SELECT otp_enabled,salt FROM ttrss_users WHERE
					login = ?");
				$sth->execute([$login]);

				if ($row = $sth->fetch()) {

					$base32 = new \OTPHP\Base32();

					$otp_enabled = $row['otp_enabled'];
					$secret = $base32->encode(sha1($row['salt']));

					$topt = new \OTPHP\TOTP($secret);
					$otp_check = $topt->now();

					if ($otp_enabled) {
						if ($otp) {
							if ($otp != $otp_check) {
								return false;
							}
						} else {
							$return = urlencode($_REQUEST["return"]);
							?>
							<!DOCTYPE html>
							<html>
								<head>
									<title>Agriget</title>
									<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
								</head>
								<?php echo stylesheet_tag("css/default.css") ?>
							<body class="ttrss_utility otp">
							<h1><?php echo __("Authentication") ?></h1>
							<div class="content">
							<form action="public.php?return=<?php echo $return ?>"
									method="POST" class="otpform">
								<input type="hidden" name="op" value="login">
								<input type="hidden" name="login" value="<?php echo htmlspecialchars($login) ?>">
								<input type="hidden" name="password" value="<?php echo htmlspecialchars($password) ?>">
								<input type="hidden" name="bw_limit" value="<?php echo htmlspecialchars($_POST["bw_limit"]) ?>">
								<input type="hidden" name="remember_me" value="<?php echo htmlspecialchars($_POST["remember_me"]) ?>">
								<input type="hidden" name="profile" value="<?php echo htmlspecialchars($_POST["profile"]) ?>">

								<fieldset>
									<label><?php echo __("Please enter your one time password:") ?></label>
									<input autocomplete="off" size="6" name="otp" value=""/>
									<input type="submit" value="Continue"/>
								</fieldset>
							</form></div>
							<script type="text/javascript">
								document.forms[0].otp.focus();
							</script>
							<?php
							exit;
						}
					}
				}
			}
		}

		if (get_schema_version() > 87) {

			$sth = $this->pdo->prepare("SELECT salt FROM ttrss_users WHERE login = ?");
			$sth->execute([$login]);

			if ($row = $sth->fetch()) {
				$salt = $row['salt'];

				if ($salt == "") {

					$sth = $this->pdo->prepare("SELECT id FROM ttrss_users WHERE
                        login = ? AND (pwd_hash = ? OR pwd_hash = ?)");

					$sth->execute([$login, $pwd_hash1, $pwd_hash2]);

					// verify and upgrade password to new salt base

					if ($row = $sth->fetch()) {
						// upgrade password to MODE2

						$user_id = $row['id'];

						$salt = substr(bin2hex(get_random_bytes(125)), 0, 250);
						$pwd_hash = encrypt_password($password, $salt, true);

						$sth = $this->pdo->prepare("UPDATE ttrss_users SET
					        pwd_hash = ?, salt = ? WHERE login = ?");

						$sth->execute([$pwd_hash, $salt, $login]);

						return $user_id;

					} else {
						return false;
					}

				} else {
					$pwd_hash = encrypt_password($password, $salt, true);

					$sth = $this->pdo->prepare("SELECT id
  		                  FROM ttrss_users WHERE
					      login = ? AND pwd_hash = ?");
					$sth->execute([$login, $pwd_hash]);

					if ($row = $sth->fetch()) {
						return $row['id'];
					}
				}

			} else {
				$sth = $this->pdo->prepare("SELECT id
                    FROM ttrss_users WHERE
                      login = ? AND (pwd_hash = ? OR pwd_hash = ?)");

				$sth->execute([$login, $pwd_hash1, $pwd_hash2]);

				if ($row = $sth->fetch()) {
					return $row['id'];
				}
			}
		} else {
			$sth = $this->pdo->prepare("SELECT id
                    FROM ttrss_users WHERE
                      login = ? AND (pwd_hash = ? OR pwd_hash = ?)");

			$sth->execute([$login, $pwd_hash1, $pwd_hash2]);

			if ($row = $sth->fetch()) {
				return $row['id'];
			}
        }

		return false;
	}

	function check_password($owner_uid, $password) {

		$sth = $this->pdo->prepare("SELECT salt,login FROM ttrss_users WHERE
			id = ?");
		$sth->execute([$owner_uid]);

		if ($row = $sth->fetch()) {

			$salt = $row['salt'];
			$login = $row['login'];

			if (!$salt) {
				$password_hash1 = encrypt_password($password);
				$password_hash2 = encrypt_password($password, $login);

				$sth = $this->pdo->prepare("SELECT id FROM ttrss_users WHERE
                    id = ? AND (pwd_hash = ? OR pwd_hash = ?)");

				$sth->execute([$owner_uid, $password_hash1, $password_hash2]);

				return $sth->fetch();

			} else {
				$password_hash = encrypt_password($password, $salt, true);

				$sth = $this->pdo->prepare("SELECT id FROM ttrss_users WHERE
                    id = ? AND pwd_hash = ?");

				$sth->execute([$owner_uid, $password_hash]);

				return $sth->fetch();
			}
		}

        return false;
	}

	function change_password($owner_uid, $old_password, $new_password) {

		if ($this->check_password($owner_uid, $old_password)) {

			$new_salt = substr(bin2hex(get_random_bytes(125)), 0, 250);
			$new_password_hash = encrypt_password($new_password, $new_salt, true);

			$sth = $this->pdo->prepare("UPDATE ttrss_users SET
				pwd_hash = ?, salt = ?, otp_enabled = false
					WHERE id = ?");
			$sth->execute([$new_password_hash, $new_salt, $owner_uid]);

			$_SESSION["pwd_hash"] = $new_password_hash;

			return __("Password has been changed.");
		} else {
			return "ERROR: ".__('Old password is incorrect.');
		}
	}

	function api_version() {
		return 2;
	}

}
?>
