meta( $current_user->ID, '_new_email' );

			return;
		}

		$hash           = md5( $_POST['email'] . time() . wp_rand() );
		$new_user_email = array(
			'hash'     => $hash,
			'newemail' => $_POST['email'],
		);
		update_user_meta( $current_user->ID, '_new_email', $new_user_email );

		$sitename = wp_specialchars_decode( get_option( 'blogname' ), ENT_QUOTES );

		/* translators: Do not translate USERNAME, ADMIN_URL, EMAIL, SITENAME, SITEURL: those are placeholders. */
		$email_text = __( 'Howdy ###USERNAME###,

You recently requested to have the email address on your account changed.

If this is correct, please click on the following link to change it:
###ADMIN_URL###

You can safely ignore and delete this email if you do not want to
take this action.

This email has been sent to ###EMAIL###

Regards,
All at ###SITENAME###
###SITEURL###' );

		/**
		 * Filters the text of the email sent when a change of user email address is attempted.
		 *
		 * The following strings have a special meaning and will get replaced dynamically:
		 * ###USERNAME###  The current user's username.
		 * ###ADMIN_URL### The link to click on to confirm the email change.
		 * ###EMAIL###     The new email.
		 * ###SITENAME###  The name of the site.
		 * ###SITEURL###   The URL to the site.
		 *
		 * @since MU (3.0.0)
		 * @since 4.9.0 This filter is no longer Multisite specific.
		 *
		 * @param string $email_text     Text in the email.
		 * @param array  $new_user_email {
		 *     Data relating to the new user email address.
		 *
		 *     @type string $hash     The secure hash used in the confirmation link URL.
		 *     @type string $newemail The proposed new email address.
		 * }
		 */
		$content = apply_filters( 'new_user_email_content', $email_text, $new_user_email );

		$content = str_replace( '###USERNAME###', $current_user->user_login, $content );
		$content = str_replace( '###ADMIN_URL###', esc_url( admin_url( 'profile.php?newuseremail=' . $hash ) ), $content );
		$content = str_replace( '###EMAIL###', $_POST['email'], $content );
		$content = str_replace( '###SITENAME###', $sitename, $content );
		$content = str_replace( '###SITEURL###', home_url(), $content );

		wp_mail( $_POST['email'], sprintf( __( '[%s] New Email Address' ), $sitename ), $content );

		$_POST['email'] = $current_user->user_email;
	}
}

/**
 * Adds an admin notice alerting the user to check for confirmation request email
 * after email address change.
 *
 * @since 3.0.0
 * @since 4.9.0 This function was moved from wp-admin/includes/ms.php so it's no longer Multisite specific.
 *
 * @global string $pagenow
 */
function new_user_email_admin_notice() {
	global $pagenow;
	if ( 'profile.php' === $pagenow && isset( $_GET['updated'] ) && $email = get_user_meta( get_current_user_id(), '_new_email', true ) ) {
		/* translators: %s: New email address */
		echo '<div class="notice notice-info"><p>' . sprintf( __( 'Your email address has not been updated yet. Please check your inbox at %s for a confirmation email.' ), '<code>' . esc_html( $email['newemail'] ) . '</code>' ) . '</p></div>';
	}
}

/**
 * Get all user privacy request types.
 *
 * @since 4.9.6
 * @access private
 *
 * @return array List of core privacy action types.
 */
function _wp_privacy_action_request_types() {
	return array(
		'export_personal_data',
		'remove_personal_data',
	);
}

/**
 * Registers the personal data exporter for users.
 *
 * @since 4.9.6
 *
 * @param array $exporters  An array of personal data exporters.
 * @return array An array of personal data exporters.
 */
function wp_register_user_personal_data_exporter( $exporters ) {
	$exporters['wordpress-user'] = array(
		'exporter_friendly_name' => __( 'WordPress User' ),
		'callback'               => 'wp_user_personal_data_exporter',
	);

	return $exporters;
}

/**
 * Finds and exports personal data associated with an email address from the user and user_meta table.
 *
 * @since 4.9.6
 *
 * @param string $email_address  The users email address.
 * @return array An array of personal data.
 */
function wp_user_personal_data_exporter( $email_address ) {
	$email_address = trim( $email_address );

	$data_to_export = array();

	$user = get_user_by( 'email', $email_address );

	if ( ! $user ) {
		return array(
			'data' => array(),
			'done' => true,
		);
	}

	$user_meta = get_user_meta( $user->ID );

	$user_prop_to_export = array(
		'ID'              => __( 'User ID' ),
		'user_login'      => __( 'User Login Name' ),
		'user_nicename'   => __( 'User Nice Name' ),
		'user_email'      => __( 'User Email' ),
		'user_url'        => __( 'User URL' ),
		'user_registered' => __( 'User Registration Date' ),
		'display_name'    => __( 'User Display Name' ),
		'nickname'        => __( 'User Nickname' ),
		'first_name'      => __( 'User First Name' ),
		'last_name'       => __( 'User Last Name' ),
		'description'     => __( 'User Description' ),
	);

	$user_data_to_export = array();

	foreach ( $user_prop_to_export as $key => $name ) {
		$value = '';

		switch ( $key ) {
			case 'ID':
			case 'user_login':
			case 'user_nicename':
			case 'user_email':
			case 'user_url':
			case 'user_registered':
			case 'display_name':
				$value = $user->data->$key;
				break;
			case 'nickname':
			case 'first_name':
			case 'last_name':
			case 'description':
				$value = $user_meta[ $key ][0];
				break;
		}

		if ( ! empty( $value ) ) {
			$user_data_to_export[] = array(
				'name'  => $name,
				'value' => $value,
			);
		}
	}

	$data_to_export[] = array(
		'group_id'    => 'user',
		'group_label' => __( 'User' ),
		'item_id'     => "user-{$user->ID}",
		'data'        => $user_data_to_export,
	);

	return array(
		'data' => $data_to_export,
		'done' => true,
	);
}

/**
 * Update log when privacy request is confirmed.
 *
 * @since 4.9.6
 * @access private
 *
 * @param int $request_id ID of the request.
 */
function _wp_privacy_account_request_confirmed( $request_id ) {
	$request_data = wp_get_user_request_data( $request_id );

	if ( ! $request_data ) {
		return;
	}

	if ( ! in_array( $request_data->status, array( 'request-pending', 'request-failed' ), true ) ) {
		return;
	}

	update_post_meta( $request_id, '_wp_user_request_confirmed_timestamp', time() );
	wp_update_post( array(
		'ID'          => $request_id,
		'post_status' => 'request-confirmed',
	) );
}

/**
 * Notify the site administrator via email when a request is confirmed.
 *
 * Without this, the admin would have to manually check the site to see if any
 * action was needed on their part yet.
 *
 * @since 4.9.6
 *
 * @param int $request_id The ID of the request.
 */
function _wp_privacy_send_request_confirmation_notification( $request_id ) {
	$request_data = wp_get_user_request_data( $request_id );

	if ( ! is_a( $request_data, 'WP_User_Request' ) || 'request-confirmed' !== $request_data->status ) {
		return;
	}

	$already_notified = (bool) get_post_meta( $request_id, '_wp_admin_notified', true );

	if ( $already_notified ) {
		return;
	}

	$manage_url         = add_query_arg( 'page', $request_data->action_name, admin_url( 'tools.php' ) );
	$action_description = wp_user_request_action_description( $request_data->action_name );

	/**
	 * Filters the recipient of the data request confirmation notification.
	 *
	 * In a Multisite environment, this will default to the email address of the
	 * network admin because, by default, single site admins do not have the
	 * capabilities required to process requests. Some networks may wish to
	 * delegate those capabilities to a single-site admin, or a dedicated person
	 * responsible for managing privacy requests.
	 *
	 * @since 4.9.6
	 *
	 * @param string          $admin_email  The email address of the notification recipient.
	 * @param WP_User_Request $request_data The request that is initiating the notification.
	 */
	$admin_email = apply_filters( 'user_request_confirmed_email_to', get_site_option( 'admin_email' ), $request_data );

	$email_data = array(
		'request'     => $request_data,
		'user_email'  => $request_data->email,
		'description' => $action_description,
		'manage_url'  => $manage_url,
		'sitename'    => wp_specialchars_decode( get_option( 'blogname' ), ENT_QUOTES ),
		'siteurl'     => home_url(),
		'admin_email' => $admin_email,
	);

	/* translators: Do not translate SITENAME, USER_EMAIL, DESCRIPTION, MANAGE_URL, SITEURL; those are placeholders. */
	$email_text = __(
		'Howdy,

A user data privacy request has been confirmed on ###SITENAME###:

User: ###USER_EMAIL###
Request: ###DESCRIPTION###

You can view and manage these data privacy requests here:

###MANAGE_URL###

Regards,
All at ###SITENAME###
###SITEURL###'
	);

	/**
	 * Filters the body of the user request confirmation email.
	 *
	 * The email is sent to an administrator when an user request is confirmed.
	 * The following strings have a special meaning and will get replaced dynamically:
	 *
	 * ###SITENAME###    The name of the site.
	 * ###USER_EMAIL###  The user email for the request.
	 * ###DESCRIPTION### Description of the action being performed so the user knows what the email is for.
	 * ###MANAGE_URL###  The URL to manage requests.
	 * ###SITEURL###     The URL to the site.
	 *
	 * @since 4.9.6
	 *
	 * @param string $email_text Text in the email.
	 * @param array  $email_data {
	 *     Data relating to the account action email.
	 *
	 *     @type WP_User_Request $request     User request object.
	 *     @type string          $user_email  The email address confirming a request
	 *     @type string          $description Description of the action being performed so the user knows what the email is for.
	 *     @type string          $manage_url  The link to click manage privacy requests of this type.
	 *     @type string          $sitename    The site name sending the mail.
	 *     @type string          $siteurl     The site URL sending the mail.
	 *     @type string          $admin_email The administrator email receiving the mail.
	 * }
	 */
	$content = apply_filters( 'user_confirmed_action_email_content', $email_text, $email_data );

	$content = str_replace( '###SITENAME###', $email_data['sitename'], $content );
	$content = str_replace( '###USER_EMAIL###', $email_data['user_email'], $content );
	$content = str_replace( '###DESCRIPTION###', $email_data['description'], $content );
	$content = str_replace( '###MANAGE_URL###', esc_url_raw( $email_data['manage_url'] ), $content );
	$content = str_replace( '###SITEURL###', esc_url_raw( $email_data['siteurl'] ), $content );

	$subject = sprintf(
		/* translators: 1: Site name. 2: Name of the confirmed action. */
		__( '[%1$s] Action Confirmed: %2$s' ),
		$email_data['sitename'],
		$action_description
	);

	/**
	 * Filters the subject of the user request confirmation email.
	 *
	 * @since 4.9.8
	 *
	 * @param string $subject    The email subject.
	 * @param string $sitename   The name of the site.
	 * @param array  $email_data {
	 *     Data relating to the account action email.
	 *
	 *     @type WP_User_Request $request     User request object.
	 *     @type string          $user_email  The email address confirming a request
	 *     @type string          $description Description of the action being performed so the user knows what the email is for.
	 *     @type string          $manage_url  The link to click manage privacy requests of this type.
	 *     @type string          $sitename    The site name sending the mail.
	 *     @type string          $siteurl     The site URL sending the mail.
	 *     @type string          $admin_email The administrator email receiving the mail.
	 * }
	 */
	$subject = apply_filters( 'user_request_confirmed_email_subject', $subject, $email_data['sitename'], $email_data );

	$email_sent = wp_mail( $email_data['admin_email'], $subject, $content );

	if ( $email_sent ) {
		update_post_meta( $request_id, '_wp_admin_notified', true );
	}
}

/**
 * Notify the user when their erasure request is fulfilled.
 *
 * Without this, the user would never know if their data was actually erased.
 *
 * @since 4.9.6
 *
 * @param int $request_id The privacy request post ID associated with this request.
 */
function _wp_privacy_send_erasure_fulfillment_notification( $request_id ) {
	$request_data = wp_get_user_request_data( $request_id );

	if ( ! is_a( $request_data, 'WP_User_Request' ) || 'request-completed' !== $request_data->status ) {
		return;
	}

	$already_notified = (bool) get_post_meta( $request_id, '_wp_user_notified', true );

	if ( $already_notified ) {
		return;
	}

	/**
	 * Filters the recipient of the data erasure fulfillment notification.
	 *
	 * @since 4.9.6
	 *
	 * @param string          $user_email   The email address of the notification recipient.
	 * @param WP_User_Request $request_data The request that is initiating the notification.
	 */
	$user_email = apply_filters( 'user_erasure_fulfillment_email_to', $request_data->email, $request_data );

	$email_data = array(
		'request'            => $request_data,
		'message_recipient'  => $user_email,
		'privacy_policy_url' => get_privacy_policy_url(),
		'sitename'           => wp_specialchars_decode( get_option( 'blogname' ), ENT_QUOTES ),
		'siteurl'            => home_url(),
	);

	$subject  = sprintf(
		/* translators: %s: Site name. */
		__( '[%s] Erasure Request Fulfilled' ),
		$email_data['sitename']
	);

	/**
	 * Filters the subject of the email sent when an erasure request is completed.
	 *
	 * @since 4.9.8
	 *
	 * @param string $subject    The email subject.
	 * @param string $sitename   The name of the site.
	 * @param array  $email_data {
	 *     Data relating to the account action email.
	 *
	 *     @type WP_User_Request $request            User request object.
	 *     @type string          $message_recipient  The address that the email will be sent to. Defaults
	 *                                               to the value of `$request->email`, but can be changed
	 *                                               by the `user_erasure_fulfillment_email_to` filter.
	 *     @type string          $privacy_policy_url Privacy policy URL.
	 *     @type string          $sitename           The site name sending the mail.
	 *     @type string          $siteurl            The site URL sending the mail.
	 * }
	 */
	$subject = apply_filters( 'user_erasure_complete_email_subject', $subject, $email_data['sitename'], $email_data );

	if ( empty( $email_data['privacy_policy_url'] ) ) {
		/* translators: Do not translate SITENAME, SITEURL; those are placeholders. */
		$email_text = __(
			'Howdy,

Your request to erase your personal data on ###SITENAME### has been completed.

If you have any follow-up questions or concerns, please contact the site administrator.

Regards,
All at ###SITENAME###
###SITEURL###'
		);
	} else {
		/* translators: Do not translate SITENAME, SITEURL, PRIVACY_POLICY_URL; those are placeholders. */
		$email_text = __(
			'Howdy,

Your request to erase your personal data on ###SITENAME### has been completed.

If you have any follow-up questions or concerns, please contact the site administrator.

For more information, you can also read our privacy policy: ###PRIVACY_POLICY_URL###

Regards,
All at ###SITENAME###
###SITEURL###'
		);
	}

	/**
	 * Filters the body of the data erasure fulfillment notification.
	 *
	 * The email is sent to a user when a their data erasure request is fulfilled
	 * by an administrator.
	 *
	 * The following strings have a special meaning and will get replaced dynamically:
	 *
	 * ###SITENAME###           The name of the site.
	 * ###PRIVACY_POLICY_URL### Privacy policy page URL.
	 * ###SITEURL###            The URL to the site.
	 *
	 * @since 4.9.6
	 *
	 * @param string $email_text Text in the email.
	 * @param array  $email_data {
	 *     Data relating to the account action email.
	 *
	 *     @type WP_User_Request $request            User request object.
	 *     @type string          $message_recipient  The address that the email will be sent to. Defaults
	 *                                               to the value of `$request->email`, but can be changed
	 *                                               by the `user_erasure_fulfillment_email_to` filter.
	 *     @type string          $privacy_policy_url Privacy policy URL.
	 *     @type string          $sitename           The site name sending the mail.
	 *     @type string          $siteurl            The site URL sending the mail.
	 * }
	 */
	$content = apply_filters( 'user_confirmed_action_email_content', $email_text, $email_data );

	$content = str_replace( '###SITENAME###', $email_data['sitename'], $content );
	$content = str_replace( '###PRIVACY_POLICY_URL###', $email_data['privacy_policy_url'], $content );
	$content = str_replace( '###SITEURL###', esc_url_raw( $email_data['siteurl'] ), $content );

	$email_sent = wp_mail( $user_email, $subject, $content );

	if ( $email_sent ) {
		update_post_meta( $request_id, '_wp_user_notified', true );
	}
}

/**
 * Return request confirmation message HTML.
 *
 * @since 4.9.6
 * @access private
 *
 * @param int $request_id The request ID being confirmed.
 * @return string $message The confirmation message.
 */
function _wp_privacy_account_request_confirmed_message( $request_id ) {
	$request = wp_get_user_request_data( $request_id );

	$message = '<p class="success">' . __( 'Action has been confirmed.' ) . '</p>';
	$message .= '<p>' . __( 'The site administrator has been notified and will fulfill your request as soon as possible.' ) . '</p>';

	if ( $request && in_array( $request->action_name, _wp_privacy_action_request_types(), true ) ) {
		if ( 'export_personal_data' === $request->action_name ) {
			$message = '<p class="success">' . __( 'Thanks for confirming your export request.' ) . '</p>';
			$message .= '<p>' . __( 'The site administrator has been notified. You will receive a link to download your export via email when they fulfill your request.' ) . '</p>';
		} elseif ( 'remove_personal_data' === $request->action_name ) {
			$message = '<p class="success">' . __( 'Thanks for confirming your erasure request.' ) . '</p>';
			$message .= '<p>' . __( 'The site administrator has been notified. You will receive an email confirmation when they erase your data.' ) . '</p>';
		}
	}

	/**
	 * Filters the message displayed to a user when they confirm a data request.
	 *
	 * @since 4.9.6
	 *
	 * @param string $message    The message to the user.
	 * @param int    $request_id The ID of the request being confirmed.
	 */
	$message = apply_filters( 'user_request_action_confirmed_message', $message, $request_id );

	return $message;
}

/**
 * Create and log a user request to perform a specific action.
 *
 * Requests are stored inside a post type named `user_request` since they can apply to both
 * users on the site, or guests without a user account.
 *
 * @since 4.9.6
 *
 * @param string $email_address User email address. This can be the address of a registered or non-registered user.
 * @param string $action_name   Name of the action that is being confirmed. Required.
 * @param array  $request_data  Misc data you want to send with the verification request and pass to the actions once the request is confirmed.
 * @return int|WP_Error Returns the request ID if successful, or a WP_Error object on failure.
 */
function wp_create_user_request( $email_address = '', $action_name = '', $request_data = array() ) {
	$email_address = sanitize_email( $email_address );
	$action_name   = sanitize_key( $action_name );

	if ( ! is_email( $email_address ) ) {
		return new WP_Error( 'invalid_email', __( 'Invalid email address.' ) );
	}

	if ( ! $action_name ) {
		return new WP_Error( 'invalid_action', __( 'Invalid action name.' ) );
	}

	$user    = get_user_by( 'email', $email_address );
	$user_id = $user && ! is_wp_error( $user ) ? $user->ID : 0;

	// Check for duplicates.
	$requests_query = new WP_Query( array(
		'post_type'     => 'user_request',
		'post_name__in' => array( $action_name ),  // Action name stored in post_name column.
		'title'         => $email_address, // Email address stored in post_title column.
		'post_status'   => 'any',
		'fields'        => 'ids',
	) );

	if ( $requests_query->found_posts ) {
		return new WP_Error( 'duplicate_request', __( 'A request for this email address already exists.' ) );
	}

	$request_id = wp_insert_post( array(
		'post_author'   => $user_id,
		'post_name'     => $action_name,
		'post_title'    => $email_address,
		'post_content'  => wp_json_encode( $request_data ),
		'post_status'   => 'request-pending',
		'post_type'     => 'user_request',
		'post_date'     => current_time( 'mysql', false ),
		'post_date_gmt' => current_time( 'mysql', true ),
	), true );

	return $request_id;
}

/**
 * Get action description from the name and return a string.
 *
 * @since 4.9.6
 *
 * @param string $action_name Action name of the request.
 * @return string Human readable action name.
 */
function wp_user_request_action_description( $action_name ) {
	switch ( $action_name ) {
		case 'export_personal_data':
			$description = __( 'Export Personal Data' );
			break;
		case 'remove_personal_data':
			$description = __( 'Erase Personal Data' );
			break;
		default:
			/* translators: %s: action name */
			$description = sprintf( __( 'Confirm the "%s" action' ), $action_name );
			break;
	}

	/**
	 * Filters the user action description.
	 *
	 * @since 4.9.6
	 *
	 * @param string $description The default description.
	 * @param string $action_name The name of the request.
	 */
	return apply_filters( 'user_request_action_description', $description, $action_name );
}

/**
 * Send a confirmation request email to confirm an action.
 *
 * If the request is not already pending, it will be updated.
 *
 * @since 4.9.6
 *
 * @param string $request_id ID of the request created via wp_create_user_request().
 * @return WP_Error|bool Will return true/false based on the success of sending the email, or a WP_Error object.
 */
function wp_send_user_request( $request_id ) {
	$request_id = absint( $request_id );
	$request    = wp_get_user_request_data( $request_id );

	if ( ! $request ) {
		return new WP_Error( 'user_request_error', __( 'Invalid request.' ) );
	}

	$email_data = array(
		'request'     => $request,
		'email'       => $request->email,
		'description' => wp_user_request_action_description( $request->action_name ),
		'confirm_url' => add_query_arg( array(
			'action'      => 'confirmaction',
			'request_id'  => $request_id,
			'confirm_key' => wp_generate_user_request_key( $request_id ),
		), wp_login_url() ),
		'sitename'    => wp_specialchars_decode( get_option( 'blogname' ), ENT_QUOTES ),
		'siteurl'     => home_url(),
	);

	/* translators: Do not translate DESCRIPTION, CONFIRM_URL, SITENAME, SITEURL: those are placeholders. */
	$email_text = __(
		'Howdy,

A request has been made to perform the following action on your account:

     ###DESCRIPTION###

To confirm this, please click on the following link:
###CONFIRM_URL###

You can safely ignore and delete this email if you do not want to
take this action.

Regards,
All at ###SITENAME###
###SITEURL###'
	);

	/**
	 * Filters the text of the email sent when an account action is attempted.
	 *
	 * The following strings have a special meaning and will get replaced dynamically:
	 *
	 * ###DESCRIPTION### Description of the action being performed so the user knows what the email is for.
	 * ###CONFIRM_URL### The link to click on to confirm the account action.
	 * ###SITENAME###    The name of the site.
	 * ###SITEURL###     The URL to the site.
	 *
	 * @since 4.9.6
	 *
	 * @param string $email_text Text in the email.
	 * @param array  $email_data {
	 *     Data relating to the account action email.
	 *
	 *     @type WP_User_Request $request     User request object.
	 *     @type string          $email       The email address this is being sent to.
	 *     @type string          $description Description of the action being performed so the user knows what the email is for.
	 *     @type string          $confirm_url The link to click on to confirm the account action.
	 *     @type string          $sitename    The site name sending the mail.
	 *     @type string          $siteurl     The site URL sending the mail.
	 * }
	 */
	$content = apply_filters( 'user_request_action_email_content', $email_text, $email_data );

	$content = str_replace( '###DESCRIPTION###', $email_data['description'], $content );
	$content = str_replace( '###CONFIRM_URL###', esc_url_raw( $email_data['confirm_url'] ), $content );
	$content = str_replace( '###EMAIL###', $email_data['email'], $content );
	$content = str_replace( '###SITENAME###', $email_data['sitename'], $content );
	$content = str_replace( '###SITEURL###', esc_url_raw( $email_data['siteurl'] ), $content );

	/* translators: Privacy data request subject. 1: Site name, 2: Name of the action */
	$subject = sprintf( __( '[%1$s] Confirm Action: %2$s' ), $email_data['sitename'], $email_data['description'] );

	/**
	 * Filters the subject of the email sent when an account action is attempted.
	 *
	 * @since 4.9.6
	 *
	 * @param string $subject    The email subject.
	 * @param string $sitename   The name of the site.
	 * @param array  $email_data {
	 *     Data relating to the account action email.
	 *
	 *     @type WP_User_Request $request     User request object.
	 *     @type string          $email       The email address this is being sent to.
	 *     @type string          $description Description of the action being performed so the user knows what the email is for.
	 *     @type string          $confirm_url The link to click on to confirm the account action.
	 *     @type string          $sitename    The site name sending the mail.
	 *     @type string          $siteurl     The site URL sending the mail.
	 * }
	 */
	$subject = apply_filters( 'user_request_action_email_subject', $subject, $email_data['sitename'], $email_data );

	return wp_mail( $email_data['email'], $subject, $content );
}

/**
 * Returns a confirmation key for a user action and stores the hashed version for future comparison.
 *
 * @since 4.9.6
 *
 * @param int $request_id Request ID.
 * @return string Confirmation key.
 */
function wp_generate_user_request_key( $request_id ) {
	global $wp_hasher;

	// Generate something random for a confirmation key.
	$key = wp_generate_password( 20, false );

	// Return the key, hashed.
	if ( empty( $wp_hasher ) ) {
		require_once ABSPATH . WPINC . '/class-phpass.php';
		$wp_hasher = new PasswordHash( 8, true );
	}

	wp_update_post( array(
		'ID'                => $request_id,
		'post_status'       => 'request-pending',
		'post_password'     => $wp_hasher->HashPassword( $key ),
		'post_modified'     => current_time( 'mysql', false ),
		'post_modified_gmt' => current_time( 'mysql', true ),
	) );

	return $key;
}

/**
 * Validate a user request by comparing the key with the request's key.
 *
 * @since 4.9.6
 *
 * @param string $request_id ID of the request being confirmed.
 * @param string $key        Provided key to validate.
 * @return bool|WP_Error WP_Error on failure, true on success.
 */
function wp_validate_user_request_key( $request_id, $key ) {
	global $wp_hasher;

	$request_id = absint( $request_id );
	$request    = wp_get_user_request_data( $request_id );

	if ( ! $request ) {
		return new WP_Error( 'user_request_error', __( 'Invalid request.' ) );
	}

	if ( ! in_array( $request->status, array( 'request-pending', 'request-failed' ), true ) ) {
		return __( 'This link has expired.' );
	}

	if ( empty( $key ) ) {
		return new WP_Error( 'invalid_key', __( 'Invalid key' ) );
	}

	if ( empty( $wp_hasher ) ) {
		require_once ABSPATH . WPINC . '/class-phpass.php';
		$wp_hasher = new PasswordHash( 8, true );
	}

	$key_request_time = $request->modified_timestamp;
	$saved_key        = $request->confirm_key;

	if ( ! $saved_key ) {
		return new WP_Error( 'invalid_key', __( 'Invalid key' ) );
	}

	if ( ! $key_request_time ) {
		return new WP_Error( 'invalid_key', __( 'Invalid action' ) );
	}

	/**
	 * Filters the expiration time of confirm keys.
	 *
	 * @since 4.9.6
	 *
	 * @param int $expiration The expiration time in seconds.
	 */
	$expiration_duration = (int) apply_filters( 'user_request_key_expiration', DAY_IN_SECONDS );
	$expiration_time     = $key_request_time + $expiration_duration;

	if ( ! $wp_hasher->CheckPassword( $key, $saved_key ) ) {
		return new WP_Error( 'invalid_key', __( 'Invalid key' ) );
	}

	if ( ! $expiration_time || time() > $expiration_time ) {
		return new WP_Error( 'expired_key', __( 'The confirmation email has expired.' ) );
	}

	return true;
}

/**
 * Return data about a user request.
 *
 * @since 4.9.6
 *
 * @param int $request_id Request ID to get data about.
 * @return WP_User_Request|false
 */
function wp_get_user_request_data( $request_id ) {
	$request_id = absint( $request_id );
	$post       = get_post( $request_id );

	if ( ! $post || 'user_request' !== $post->post_type ) {
		return false;
	}

	return new WP_User_Request( $post );
}

/**
 * WP_User_Request class.
 *
 * Represents user request data loaded from a WP_Post object.
 *
 * @since 4.9.6
 */
final class WP_User_Request {
	/**
	 * Request ID.
	 *
	 * @var int
	 */
	public $ID = 0;

	/**
	 * User ID.
	 *
	 * @var int
	 */

	public $user_id = 0;

	/**
	 * User email.
	 *
	 * @var int
	 */
	public $email = '';

	/**
	 * Action name.
	 *
	 * @var string
	 */
	public $action_name = '';

	/**
	 * Current status.
	 *
	 * @var string
	 */
	public $status = '';

	/**
	 * Timestamp this request was created.
	 *
	 * @var int|null
	 */
	public $created_timestamp = null;

	/**
	 * Timestamp this request was last modified.
	 *
	 * @var int|null
	 */
	public $modified_timestamp = null;

	/**
	 * Timestamp this request was confirmed.
	 *
	 * @var int
	 */
	public $confirmed_timestamp = null;

	/**
	 * Timestamp this request was completed.
	 *
	 * @var int
	 */
	public $completed_timestamp = null;

	/**
	 * Misc data assigned to this request.
	 *
	 * @var array
	 */
	public $request_data = array();

	/**
	 * Key used to confirm this request.
	 *
	 * @var string
	 */
	public $confirm_key = '';

	/**
	 * Constructor.
	 *
	 * @since 4.9.6
	 *
	 * @param WP_Post|object $post Post object.
	 */
	public function __construct( $post ) {
		$this->ID                  = $post->ID;
		$this->user_id             = $post->post_author;
		$this->email               = $post->post_title;
		$this->action_name         = $post->post_name;
		$this->status              = $post->post_status;
		$this->created_timestamp   = strtotime( $post->post_date_gmt );
		$this->modified_timestamp  = strtotime( $post->post_modified_gmt );
		$this->confirmed_timestamp = (int) get_post_meta( $post->ID, '_wp_user_request_confirmed_timestamp', true );
		$this->completed_timestamp = (int) get_post_meta( $post->ID, '_wp_user_request_completed_timestamp', true );
		$this->request_data        = json_decode( $post->post_content, true );
		$this->confirm_key         = $post->post_password;
	}
}