webadmin.php

/var/www/html/wp-content/plugins/contact-form-7/includes/config-validator.php

<?php

/**
 * Configuration validator.
 *
 * @link https://contactform7.com/configuration-errors/
 */
class WPCF7_ConfigValidator {

    /**
     * The plugin version in which important updates happened last time.
     */
    const last_important_update = '5.6.1';

    const error = 100;
    const error_maybe_empty = 101;
    const error_invalid_mailbox_syntax = 102;
    const error_email_not_in_site_domain = 103;
    const error_html_in_message = 104;
    const error_multiple_controls_in_label = 105;
    const error_file_not_found = 106;
    const error_unavailable_names = 107;
    const error_invalid_mail_header = 108;
    const error_deprecated_settings = 109;
    const error_file_not_in_content_dir = 110;
    const error_unavailable_html_elements = 111;
    const error_attachments_overweight = 112;
    const error_dots_in_names = 113;
    const error_colons_in_names = 114;
    const error_upload_filesize_overlimit = 115;


    /**
     * Returns a URL linking to the documentation page for the error type.
     */
    public static function get_doc_link( $error_code = '' ) {
        $url = __( 'https://contactform7.com/configuration-errors/',
            'contact-form-7'
        );

        if ( '' !== $error_code ) {
            $error_code = strtr( $error_code, '_', '-' );

            $url = sprintf( '%s/%s', untrailingslashit( $url ), $error_code );
        }

        return esc_url( $url );
    }


    private $contact_form;
    private $errors = array();

    public function __construct( WPCF7_ContactForm $contact_form ) {
        $this->contact_form = $contact_form;
    }


    /**
     * Returns the contact form object that is tied to this validator.
     */
    public function contact_form() {
        return $this->contact_form;
    }


    /**
     * Returns true if no error has been detected.
     */
    public function is_valid() {
        return ! $this->count_errors();
    }


    /**
     * Counts detected errors.
     */
    public function count_errors( $args = '' ) {
        $args = wp_parse_args( $args, array(
            'section' => '',
            'code' => '',
        ) );

        $count = 0;

        foreach ( $this->errors as $key => $errors ) {
            if ( preg_match( '/^mail_[0-9]+\.(.*)$/', $key, $matches ) ) {
                $key = sprintf( 'mail.%s', $matches[1] );
            }

            if ( $args['section']
            and $key != $args['section']
            and preg_replace( '/\..*$/', '', $key, 1 ) != $args['section'] ) {
                continue;
            }

            foreach ( $errors as $error ) {
                if ( empty( $error ) ) {
                    continue;
                }

                if ( $args['code'] and $error['code'] != $args['code'] ) {
                    continue;
                }

                $count += 1;
            }
        }

        return $count;
    }


    /**
     * Collects messages for detected errors.
     */
    public function collect_error_messages() {
        $error_messages = array();

        foreach ( $this->errors as $section => $errors ) {
            $error_messages[$section] = array();

            foreach ( $errors as $error ) {
                if ( empty( $error['args']['message'] ) ) {
                    $message = $this->get_default_message( $error['code'] );
                } elseif ( empty( $error['args']['params'] ) ) {
                    $message = $error['args']['message'];
                } else {
                    $message = $this->build_message(
                        $error['args']['message'],
                        $error['args']['params'] );
                }

                $link = '';

                if ( ! empty( $error['args']['link'] ) ) {
                    $link = $error['args']['link'];
                }

                $error_messages[$section][] = array(
                    'message' => $message,
                    'link' => esc_url( $link ),
                );
            }
        }

        return $error_messages;
    }


    /**
     * Builds an error message by replacing placeholders.
     */
    public function build_message( $message, $params = '' ) {
        $params = wp_parse_args( $params, array() );

        foreach ( $params as $key => $val ) {
            if ( ! preg_match( '/^[0-9A-Za-z_]+$/', $key ) ) { // invalid key
                continue;
            }

            $placeholder = '%' . $key . '%';

            if ( false !== stripos( $message, $placeholder ) ) {
                $message = str_ireplace( $placeholder, $val, $message );
            }
        }

        return $message;
    }


    /**
     * Returns a default message that is used when the message for the error
     * is not specified.
     */
    public function get_default_message( $code ) {
        switch ( $code ) {
            case self::error_maybe_empty:
                return __( "There is a possible empty field.", 'contact-form-7' );
            case self::error_invalid_mailbox_syntax:
                return __( "Invalid mailbox syntax is used.", 'contact-form-7' );
            case self::error_email_not_in_site_domain:
                return __( "Sender email address does not belong to the site domain.", 'contact-form-7' );
            case self::error_html_in_message:
                return __( "HTML tags are used in a message.", 'contact-form-7' );
            case self::error_multiple_controls_in_label:
                return __( "Multiple form controls are in a single label element.", 'contact-form-7' );
            case self::error_invalid_mail_header:
                return __( "There are invalid mail header fields.", 'contact-form-7' );
            case self::error_deprecated_settings:
                return __( "Deprecated settings are used.", 'contact-form-7' );
            default:
                return '';
        }
    }


    /**
     * Adds a validation error.
     *
     * @param string $section The section where the error detected.
     * @param int $code The unique code of the error.
     *            This must be one of the class constants.
     * @param string|array $args Optional options for the error.
     */
    public function add_error( $section, $code, $args = '' ) {
        $args = wp_parse_args( $args, array(
            'message' => '',
            'params' => array(),
        ) );

        if ( ! isset( $this->errors[$section] ) ) {
            $this->errors[$section] = array();
        }

        $this->errors[$section][] = array( 'code' => $code, 'args' => $args );

        return true;
    }


    /**
     * Removes an error.
     */
    public function remove_error( $section, $code ) {
        if ( empty( $this->errors[$section] ) ) {
            return;
        }

        foreach ( (array) $this->errors[$section] as $key => $error ) {
            if ( isset( $error['code'] )
            and $error['code'] == $code ) {
                unset( $this->errors[$section][$key] );
            }
        }

        if ( empty( $this->errors[$section] ) ) {
            unset( $this->errors[$section] );
        }
    }


    /**
     * The main validation runner.
     *
     * @return bool True if there is no error detected.
     */
    public function validate() {
        $this->errors = array();

        $this->validate_form();
        $this->validate_mail( 'mail' );
        $this->validate_mail( 'mail_2' );
        $this->validate_messages();
        $this->validate_additional_settings();

        do_action( 'wpcf7_config_validator_validate', $this );

        return $this->is_valid();
    }


    /**
     * Saves detected errors as a post meta data.
     */
    public function save() {
        if ( $this->contact_form->initial() ) {
            return;
        }

        delete_post_meta( $this->contact_form->id(), '_config_errors' );

        if ( $this->errors ) {
            update_post_meta(
                $this->contact_form->id(), '_config_errors', $this->errors
            );
        }
    }


    /**
     * Restore errors from the database.
     */
    public function restore() {
        $config_errors = get_post_meta(
            $this->contact_form->id(), '_config_errors', true
        );

        foreach ( (array) $config_errors as $section => $errors ) {
            if ( empty( $errors ) ) {
                continue;
            }

            if ( ! is_array( $errors ) ) { // for back-compat
                $code = $errors;
                $this->add_error( $section, $code );
            } else {
                foreach ( (array) $errors as $error ) {
                    if ( ! empty( $error['code'] ) ) {
                        $code = $error['code'];
                        $args = isset( $error['args'] ) ? $error['args'] : '';
                        $this->add_error( $section, $code, $args );
                    }
                }
            }
        }
    }


    /**
     * Callback function for WPCF7_MailTaggedText. Replaces mail-tags with
     * the most conservative inputs.
     */
    public function replace_mail_tags_with_minimum_input( $matches ) {
        // allow [[foo]] syntax for escaping a tag
        if ( $matches[1] == '[' && $matches[4] == ']' ) {
            return substr( $matches[0], 1, -1 );
        }

        $tag = $matches[0];
        $tagname = $matches[2];
        $values = $matches[3];

        $mail_tag = new WPCF7_MailTag( $tag, $tagname, $values );
        $field_name = $mail_tag->field_name();

        $example_email = '[email protected]';
        $example_text = 'example';
        $example_blank = '';

        $form_tags = $this->contact_form->scan_form_tags(
            array( 'name' => $field_name )
        );

        if ( $form_tags ) {
            $form_tag = new WPCF7_FormTag( $form_tags[0] );

            $is_required = ( $form_tag->is_required() || 'radio' == $form_tag->type );

            if ( ! $is_required ) {
                return $example_blank;
            }

            if ( wpcf7_form_tag_supports( $form_tag->type, 'selectable-values' ) ) {
                if ( $form_tag->pipes instanceof WPCF7_Pipes ) {
                    if ( $mail_tag->get_option( 'do_not_heat' ) ) {
                        $before_pipes = $form_tag->pipes->collect_befores();
                        $last_item = array_pop( $before_pipes );
                    } else {
                        $after_pipes = $form_tag->pipes->collect_afters();
                        $last_item = array_pop( $after_pipes );
                    }
                } else {
                    $last_item = array_pop( $form_tag->values );
                }

                if ( $last_item and wpcf7_is_mailbox_list( $last_item ) ) {
                    return $example_email;
                } else {
                    return $example_text;
                }
            }

            if ( 'email' == $form_tag->basetype ) {
                return $example_email;
            } else {
                return $example_text;
            }

        } else { // maybe special mail tag
            // for back-compat
            $field_name = preg_replace( '/^wpcf7\./', '_', $field_name );

            if ( '_site_admin_email' == $field_name ) {
                return get_bloginfo( 'admin_email', 'raw' );

            } elseif ( '_user_agent' == $field_name ) {
                return $example_text;

            } elseif ( '_user_email' == $field_name ) {
                return $this->contact_form->is_true( 'subscribers_only' )
                    ? $example_email
                    : $example_blank;

            } elseif ( '_user_' == substr( $field_name, 0, 6 ) ) {
                return $this->contact_form->is_true( 'subscribers_only' )
                    ? $example_text
                    : $example_blank;

            } elseif ( '_' == substr( $field_name, 0, 1 ) ) {
                return '_email' == substr( $field_name, -6 )
                    ? $example_email
                    : $example_text;

            }
        }

        return $tag;
    }


    /**
     * Runs error detection for the form section.
     */
    public function validate_form() {
        $section = 'form.body';
        $form = $this->contact_form->prop( 'form' );
        $this->detect_multiple_controls_in_label( $section, $form );
        $this->detect_unavailable_names( $section, $form );
        $this->detect_unavailable_html_elements( $section, $form );
        $this->detect_dots_in_names( $section, $form );
        $this->detect_colons_in_names( $section, $form );
        $this->detect_upload_filesize_overlimit( $section, $form );
    }


    /**
     * Detects errors of multiple form controls in a single label.
     *
     * @link https://contactform7.com/configuration-errors/multiple-controls-in-label/
     */
    public function detect_multiple_controls_in_label( $section, $content ) {
        $pattern = '%<label(?:[ \t\n]+.*?)?>(.+?)</label>%s';

        if ( preg_match_all( $pattern, $content, $matches ) ) {
            $form_tags_manager = WPCF7_FormTagsManager::get_instance();

            foreach ( $matches[1] as $insidelabel ) {
                $tags = $form_tags_manager->scan( $insidelabel );
                $fields_count = 0;

                foreach ( $tags as $tag ) {
                    $is_multiple_controls_container = wpcf7_form_tag_supports(
                        $tag->type, 'multiple-controls-container'
                    );

                    $is_zero_controls_container = wpcf7_form_tag_supports(
                        $tag->type, 'zero-controls-container'
                    );

                    if ( $is_multiple_controls_container ) {
                        $fields_count += count( $tag->values );

                        if ( $tag->has_option( 'free_text' ) ) {
                            $fields_count += 1;
                        }
                    } elseif ( $is_zero_controls_container ) {
                        $fields_count += 0;
                    } elseif ( ! empty( $tag->name ) ) {
                        $fields_count += 1;
                    }

                    if ( 1 < $fields_count ) {
                        return $this->add_error( $section,
                            self::error_multiple_controls_in_label, array(
                                'link' => self::get_doc_link( 'multiple_controls_in_label' ),
                            )
                        );
                    }
                }
            }
        }

        return false;
    }


    /**
     * Detects errors of unavailable form-tag names.
     *
     * @link https://contactform7.com/configuration-errors/unavailable-names/
     */
    public function detect_unavailable_names( $section, $content ) {
        $public_query_vars = array( 'm', 'p', 'posts', 'w', 'cat',
            'withcomments', 'withoutcomments', 's', 'search', 'exact', 'sentence',
            'calendar', 'page', 'paged', 'more', 'tb', 'pb', 'author', 'order',
            'orderby', 'year', 'monthnum', 'day', 'hour', 'minute', 'second',
            'name', 'category_name', 'tag', 'feed', 'author_name', 'static',
            'pagename', 'page_id', 'error', 'attachment', 'attachment_id',
            'subpost', 'subpost_id', 'preview', 'robots', 'taxonomy', 'term',
            'cpage', 'post_type', 'embed',
        );

        $form_tags_manager = WPCF7_FormTagsManager::get_instance();

        $ng_named_tags = $form_tags_manager->filter( $content, array(
            'name' => $public_query_vars,
        ) );

        $ng_names = array();

        foreach ( $ng_named_tags as $tag ) {
            $ng_names[] = sprintf( '"%s"', $tag->name );
        }

        if ( $ng_names ) {
            $ng_names = array_unique( $ng_names );

            return $this->add_error( $section,
                self::error_unavailable_names,
                array(
                    'message' =>
                        /* translators: %names%: a list of form control names */
                        __( "Unavailable names (%names%) are used for form controls.", 'contact-form-7' ),
                    'params' => array( 'names' => implode( ', ', $ng_names ) ),
                    'link' => self::get_doc_link( 'unavailable_names' ),
                )
            );
        }

        return false;
    }


    /**
     * Detects errors of unavailable HTML elements.
     *
     * @link https://contactform7.com/configuration-errors/unavailable-html-elements/
     */
    public function detect_unavailable_html_elements( $section, $content ) {
        $pattern = '%(?:<form[\s\t>]|</form>)%i';

        if ( preg_match( $pattern, $content ) ) {
            return $this->add_error( $section,
                self::error_unavailable_html_elements,
                array(
                    'message' => __( "Unavailable HTML elements are used in the form template.", 'contact-form-7' ),
                    'link' => self::get_doc_link( 'unavailable_html_elements' ),
                )
            );
        }

        return false;
    }


    /**
     * Detects errors of dots in form-tag names.
     *
     * @link https://contactform7.com/configuration-errors/dots-in-names/
     */
    public function detect_dots_in_names( $section, $content ) {
        $form_tags_manager = WPCF7_FormTagsManager::get_instance();

        $tags = $form_tags_manager->filter( $content, array(
            'feature' => 'name-attr',
        ) );

        foreach ( $tags as $tag ) {
            if ( false !== strpos( $tag->raw_name, '.' ) ) {
                return $this->add_error( $section,
                    self::error_dots_in_names,
                    array(
                        'message' => __( "Dots are used in form-tag names.", 'contact-form-7' ),
                        'link' => self::get_doc_link( 'dots_in_names' ),
                    )
                );
            }
        }

        return false;
    }


    /**
     * Detects errors of colons in form-tag names.
     *
     * @link https://contactform7.com/configuration-errors/colons-in-names/
     */
    public function detect_colons_in_names( $section, $content ) {
        $form_tags_manager = WPCF7_FormTagsManager::get_instance();

        $tags = $form_tags_manager->filter( $content, array(
            'feature' => 'name-attr',
        ) );

        foreach ( $tags as $tag ) {
            if ( false !== strpos( $tag->raw_name, ':' ) ) {
                return $this->add_error( $section,
                    self::error_colons_in_names,
                    array(
                        'message' => __( "Colons are used in form-tag names.", 'contact-form-7' ),
                        'link' => self::get_doc_link( 'colons_in_names' ),
                    )
                );
            }
        }

        return false;
    }


    /**
     * Detects errors of uploadable file size overlimit.
     *
     * @link https://contactform7.com/configuration-errors/upload-filesize-overlimit
     */
    public function detect_upload_filesize_overlimit( $section, $content ) {
        $upload_max_filesize = ini_get( 'upload_max_filesize' );

        if ( ! $upload_max_filesize ) {
            return false;
        }

        $upload_max_filesize = strtolower( $upload_max_filesize );
        $upload_max_filesize = trim( $upload_max_filesize );

        if ( ! preg_match( '/^(\d+)([kmg]?)$/', $upload_max_filesize, $matches ) ) {
            return false;
        }

        if ( 'k' === $matches[2] ) {
            $upload_max_filesize = (int) $matches[1] * KB_IN_BYTES;
        } elseif ( 'm' === $matches[2] ) {
            $upload_max_filesize = (int) $matches[1] * MB_IN_BYTES;
        } elseif ( 'g' === $matches[2] ) {
            $upload_max_filesize = (int) $matches[1] * GB_IN_BYTES;
        } else {
            $upload_max_filesize = (int) $matches[1];
        }

        $form_tags_manager = WPCF7_FormTagsManager::get_instance();

        $tags = $form_tags_manager->filter( $content, array(
            'basetype' => 'file',
        ) );

        foreach ( $tags as $tag ) {
            if ( $upload_max_filesize < $tag->get_limit_option() ) {
                return $this->add_error( $section,
                    self::error_upload_filesize_overlimit,
                    array(
                        'message' => __( "Uploadable file size exceeds PHP’s maximum acceptable size.", 'contact-form-7' ),
                        'link' => self::get_doc_link( 'upload_filesize_overlimit' ),
                    )
                );
            }
        }

        return false;
    }


    /**
     * Runs error detection for the mail sections.
     */
    public function validate_mail( $template = 'mail' ) {
        $components = (array) $this->contact_form->prop( $template );

        if ( ! $components ) {
            return;
        }

        if ( 'mail' !== $template and empty( $components['active'] ) ) {
            return;
        }

        $components = wp_parse_args( $components, array(
            'subject' => '',
            'sender' => '',
            'recipient' => '',
            'additional_headers' => '',
            'body' => '',
            'attachments' => '',
        ) );

        $callback = array( $this, 'replace_mail_tags_with_minimum_input' );

        $subject = new WPCF7_MailTaggedText(
            $components['subject'],
            array( 'callback' => $callback )
        );

        $subject = $subject->replace_tags();
        $subject = wpcf7_strip_newline( $subject );

        $this->detect_maybe_empty( sprintf( '%s.subject', $template ), $subject );

        $sender = new WPCF7_MailTaggedText(
            $components['sender'],
            array( 'callback' => $callback )
        );

        $sender = $sender->replace_tags();
        $sender = wpcf7_strip_newline( $sender );

        $invalid_mailbox = $this->detect_invalid_mailbox_syntax(
            sprintf( '%s.sender', $template ),
            $sender
        );

        if ( ! $invalid_mailbox and ! wpcf7_is_email_in_site_domain( $sender ) ) {
            $this->add_error( sprintf( '%s.sender', $template ),
                self::error_email_not_in_site_domain, array(
                    'link' => self::get_doc_link( 'email_not_in_site_domain' ),
                )
            );
        }

        $recipient = new WPCF7_MailTaggedText(
            $components['recipient'],
            array( 'callback' => $callback )
        );

        $recipient = $recipient->replace_tags();
        $recipient = wpcf7_strip_newline( $recipient );

        $this->detect_invalid_mailbox_syntax(
            sprintf( '%s.recipient', $template ),
            $recipient
        );

        $additional_headers = new WPCF7_MailTaggedText(
            $components['additional_headers'],
            array( 'callback' => $callback )
        );

        $additional_headers = $additional_headers->replace_tags();
        $additional_headers = explode( "\n", $additional_headers );
        $mailbox_header_types = array( 'reply-to', 'cc', 'bcc' );
        $invalid_mail_header_exists = false;

        foreach ( $additional_headers as $header ) {
            $header = trim( $header );

            if ( '' === $header ) {
                continue;
            }

            if ( ! preg_match( '/^([0-9A-Za-z-]+):(.*)$/', $header, $matches ) ) {
                $invalid_mail_header_exists = true;
            } else {
                $header_name = $matches[1];
                $header_value = trim( $matches[2] );

                if ( in_array( strtolower( $header_name ), $mailbox_header_types )
                and '' !== $header_value ) {
                    $this->detect_invalid_mailbox_syntax(
                        sprintf( '%s.additional_headers', $template ),
                        $header_value,
                        array(
                            'message' =>
                                __( "Invalid mailbox syntax is used in the %name% field.", 'contact-form-7' ),
                            'params' => array( 'name' => $header_name )
                        )
                    );
                }
            }
        }

        if ( $invalid_mail_header_exists ) {
            $this->add_error( sprintf( '%s.additional_headers', $template ),
                self::error_invalid_mail_header, array(
                    'link' => self::get_doc_link( 'invalid_mail_header' ),
                )
            );
        }

        $body = new WPCF7_MailTaggedText(
            $components['body'],
            array( 'callback' => $callback )
        );

        $body = $body->replace_tags();

        $this->detect_maybe_empty( sprintf( '%s.body', $template ), $body );

        if ( '' !== $components['attachments'] ) {
            $attachables = array();

            $tags = $this->contact_form->scan_form_tags(
                array( 'type' => array( 'file', 'file*' ) )
            );

            foreach ( $tags as $tag ) {
                $name = $tag->name;

                if ( false === strpos( $components['attachments'], "[{$name}]" ) ) {
                    continue;
                }

                $limit = (int) $tag->get_limit_option();

                if ( empty( $attachables[$name] )
                or $attachables[$name] < $limit ) {
                    $attachables[$name] = $limit;
                }
            }

            $total_size = array_sum( $attachables );

            $has_file_not_found = false;
            $has_file_not_in_content_dir = false;

            foreach ( explode( "\n", $components['attachments'] ) as $line ) {
                $line = trim( $line );

                if ( '' === $line or '[' == substr( $line, 0, 1 ) ) {
                    continue;
                }

                $has_file_not_found = $this->detect_file_not_found(
                    sprintf( '%s.attachments', $template ), $line
                );

                if ( ! $has_file_not_found and ! $has_file_not_in_content_dir ) {
                    $has_file_not_in_content_dir = $this->detect_file_not_in_content_dir(
                        sprintf( '%s.attachments', $template ), $line
                    );
                }

                if ( ! $has_file_not_found ) {
                    $path = path_join( WP_CONTENT_DIR, $line );
                    $total_size += (int) @filesize( $path );
                }
            }

            $max = 25 * MB_IN_BYTES; // 25 MB

            if ( $max < $total_size ) {
                $this->add_error( sprintf( '%s.attachments', $template ),
                    self::error_attachments_overweight,
                    array(
                        'message' => __( "The total size of attachment files is too large.", 'contact-form-7' ),
                        'link' => self::get_doc_link( 'attachments_overweight' ),
                    )
                );
            }
        }
    }


    /**
     * Detects errors of invalid mailbox syntax.
     *
     * @link https://contactform7.com/configuration-errors/invalid-mailbox-syntax/
     */
    public function detect_invalid_mailbox_syntax( $section, $content, $args = '' ) {
        $args = wp_parse_args( $args, array(
            'link' => self::get_doc_link( 'invalid_mailbox_syntax' ),
            'message' => '',
            'params' => array(),
        ) );

        if ( ! wpcf7_is_mailbox_list( $content ) ) {
            return $this->add_error( $section,
                self::error_invalid_mailbox_syntax, $args
            );
        }

        return false;
    }


    /**
     * Detects errors of empty message fields.
     *
     * @link https://contactform7.com/configuration-errors/maybe-empty/
     */
    public function detect_maybe_empty( $section, $content ) {
        if ( '' === $content ) {
            return $this->add_error( $section,
                self::error_maybe_empty, array(
                    'link' => self::get_doc_link( 'maybe_empty' ),
                )
            );
        }

        return false;
    }


    /**
     * Detects errors of nonexistent attachment files.
     *
     * @link https://contactform7.com/configuration-errors/file-not-found/
     */
    public function detect_file_not_found( $section, $content ) {
        $path = path_join( WP_CONTENT_DIR, $content );

        if ( ! is_readable( $path ) or ! is_file( $path ) ) {
            return $this->add_error( $section,
                self::error_file_not_found,
                array(
                    'message' =>
                        __( "Attachment file does not exist at %path%.", 'contact-form-7' ),
                    'params' => array( 'path' => $content ),
                    'link' => self::get_doc_link( 'file_not_found' ),
                )
            );
        }

        return false;
    }


    /**
     * Detects errors of attachment files out of the content directory.
     *
     * @link https://contactform7.com/configuration-errors/file-not-in-content-dir/
     */
    public function detect_file_not_in_content_dir( $section, $content ) {
        $path = path_join( WP_CONTENT_DIR, $content );

        if ( ! wpcf7_is_file_path_in_content_dir( $path ) ) {
            return $this->add_error( $section,
                self::error_file_not_in_content_dir,
                array(
                    'message' =>
                        __( "It is not allowed to use files outside the wp-content directory.", 'contact-form-7' ),
                    'link' => self::get_doc_link( 'file_not_in_content_dir' ),
                )
            );
        }

        return false;
    }


    /**
     * Runs error detection for the messages section.
     */
    public function validate_messages() {
        $messages = (array) $this->contact_form->prop( 'messages' );

        if ( ! $messages ) {
            return;
        }

        if ( isset( $messages['captcha_not_match'] )
        and ! wpcf7_use_really_simple_captcha() ) {
            unset( $messages['captcha_not_match'] );
        }

        foreach ( $messages as $key => $message ) {
            $section = sprintf( 'messages.%s', $key );
            $this->detect_html_in_message( $section, $message );
        }
    }


    /**
     * Detects errors of HTML uses in a message.
     *
     * @link https://contactform7.com/configuration-errors/html-in-message/
     */
    public function detect_html_in_message( $section, $content ) {
        $stripped = wp_strip_all_tags( $content );

        if ( $stripped != $content ) {
            return $this->add_error( $section,
                self::error_html_in_message,
                array(
                    'link' => self::get_doc_link( 'html_in_message' ),
                )
            );
        }

        return false;
    }


    /**
     * Runs error detection for the additional settings section.
     */
    public function validate_additional_settings() {
        $deprecated_settings_used =
            $this->contact_form->additional_setting( 'on_sent_ok' ) ||
            $this->contact_form->additional_setting( 'on_submit' );

        if ( $deprecated_settings_used ) {
            return $this->add_error( 'additional_settings.body',
                self::error_deprecated_settings,
                array(
                    'link' => self::get_doc_link( 'deprecated_settings' ),
                )
            );
        }
    }

}