ospd.xml

Complexity

Total Complexity

43

Size/Duplication

Total Lines	288
Duplicated Lines	0 %

Importance

Changes

0

6 Functions

Rating	Name	Duplication	Size	Complexity
A	escape_ctrl_chars()	0	12	3
A	split_invalid_xml()	0	21	4
A	elements_as_text()	0	20	4
A	get_result_xml()	0	26	3
B	get_elements_from_dict()	0	26	6
B	simple_response_str()	0	32	7

# Copyright (C) 2014-2020 Greenbone Networks GmbH
#
# SPDX-License-Identifier: GPL-2.0-or-later
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

""" OSP XML utils class.
"""

import re

from typing import List, Dict, Any, Union

from xml.sax.saxutils import escape, quoteattr
from xml.etree.ElementTree import tostring, Element

from ospd.misc import ResultType


r = re.compile(
    r'(.*?)(?:([^\x09\x0A\x0D\x20-\x7E\x85\xA0-\xFF'
    + r'\u0100-\uD7FF\uE000-\uFDCF\uFDE0-\uFFFD])|([\n])|$)'
)


def split_invalid_xml(result_text: str) -> Union[List[Union[str, int]], str]:
    """ Search for occurence of non printable chars and replace them
    with the integer representation the Unicode code. The original string
    is splitted where a non printable char is found.
    """
    splitted_string = []

    def replacer(match):
        regex_g1 = match.group(1)
        if len(regex_g1) > 0:
            splitted_string.append(regex_g1)
        regex_g2 = match.group(2)
        if regex_g2 is not None:
            splitted_string.append(ord(regex_g2))
        regex_g3 = match.group(3)
        if regex_g3 is not None:
            splitted_string.append(regex_g3)
        return ""

    re.sub(r, replacer, result_text)
    return splitted_string


def escape_ctrl_chars(result_text):
    """ Replace non printable chars in result_text with an hexa code
    in string format.
    """
    escaped_str = ''
    for fragment in split_invalid_xml(result_text):
        if isinstance(fragment, int):
            escaped_str += '\\x%04X' % fragment
        else:
            escaped_str += fragment

    return escaped_str


def get_result_xml(result):
    """ Formats a scan result to XML format.

    Arguments:
        result (dict): Dictionary with a scan result.

    Return:
        Result as xml element object.
    """

    result_xml = Element('result')
    for name, value in [
        ('name', result['name']),
        ('type', ResultType.get_str(result['type'])),
        ('severity', result['severity']),
        ('host', result['host']),
        ('hostname', result['hostname']),
        ('test_id', result['test_id']),
        ('port', result['port']),
        ('qod', result['qod']),
    ]:
        result_xml.set(name, escape(str(value)))
    if result['value'] is not None:
        result_xml.text = escape_ctrl_chars(result['value'])

    return result_xml


def simple_response_str(
    command: str,
    status: int,
    status_text: str,
    content: Union[str, Element, List[str], List[Element]] = "",
) -> bytes:
    """ Creates an OSP response XML string.

    Arguments:
        command (str): OSP Command to respond to.
        status (int): Status of the response.
        status_text (str): Status text of the response.
        content (str): Text part of the response XML element.

    Return:
        String of response in xml format.
    """
    response = Element('%s_response' % command)

    for name, value in [('status', str(status)), ('status_text', status_text)]:
        response.set(name, escape(str(value)))

    if isinstance(content, list):
        for elem in content:
            if isinstance(elem, Element):
                response.append(elem)
    elif isinstance(content, Element):
        response.append(content)
    elif content is not None:
        response.text = escape_ctrl_chars(content)

    return tostring(response, encoding='utf-8')


def get_elements_from_dict(data: Dict[str, Any]) -> List[Element]:
    """ Creates a list of etree elements from a dictionary

    Args:
        Dictionary of tags and their elements.

    Return:
        List of xml elements.
    """

    responses = []

    for tag, value in data.items():
        elem = Element(tag)

        if isinstance(value, dict):
            for val in get_elements_from_dict(value):
                elem.append(val)
        elif isinstance(value, list):
            elem.text = ', '.join(value)
        elif value is not None:
            elem.text = escape_ctrl_chars(value)

        responses.append(elem)

    return responses


def elements_as_text(
    elements: Dict[str, Union[str, Dict]], indent: int = 2
) -> str:
    """ Returns the elements dictionary as formatted plain text. """

    text = ""
    for elename, eledesc in elements.items():
        if isinstance(eledesc, dict):
            desc_txt = elements_as_text(eledesc, indent + 2)
            desc_txt = ''.join(['\n', desc_txt])
        elif isinstance(eledesc, str):
            desc_txt = ''.join([eledesc, '\n'])
        else:
            assert False, "Only string or dictionary"

        ele_txt = "\t{0}{1: <22} {2}".format(' ' * indent, elename, desc_txt)

The variable desc_txt does not seem to be defined for all execution paths.

        text = ''.join([text, ele_txt])

    return text


class XmlStringHelper:
    """ Class with methods to help the creation of a xml object in
    string format.
    """

    def create_element(self, elem_name: str, end: bool = False) -> bytes:
        """ Get a name and create the open element of an entity.

        Arguments:
            elem_name (str): The name of the tag element.
            end (bool): Create a initial tag if False, otherwise the end tag.

        Return:
            Encoded string representing a part of an xml element.
        """
        if end:
            ret = "</%s>" % elem_name
        else:
            ret = "<%s>" % elem_name

        return ret.encode('utf-8')

    def create_response(self, command: str, end: bool = False) -> bytes:
        """ Create or end an xml response.

        Arguments:
            command (str): The name of the command for the response element.
            end (bool): Create a initial tag if False, otherwise the end tag.

        Return:
            Encoded string representing a part of an xml element.
        """
        if not command:
            return

        if end:
            return ('</%s_response>' % command).encode('utf-8')

        return ('<%s_response status="200" status_text="OK">' % command).encode(
            'utf-8'
        )

    def add_element(
        self,
        content: Union[Element, str, list],
        xml_str: bytes = None,
        end: bool = False,
    ) -> bytes:
        """Create the initial or ending tag for a subelement, or add
        one or many xml elements

        Arguments:
            content (Element, str, list): Content to add.
            xml_str (bytes): Initial string where content to be added to.
            end (bool): Create a initial tag if False, otherwise the end tag.
                        It will be added to the xml_str.

        Return:
            Encoded string representing a part of an xml element.
        """

        if not xml_str:
            xml_str = b''

        if content:
            if isinstance(content, list):
                for elem in content:
                    xml_str = xml_str + tostring(elem, encoding='utf-8')
            elif isinstance(content, Element):
                xml_str = xml_str + tostring(content, encoding='utf-8')
            else:
                if end:
                    xml_str = xml_str + self.create_element(content, False)
                else:
                    xml_str = xml_str + self.create_element(content)

        return xml_str

    def add_attr(
        self, tag: bytes, attribute: str, value: Union[str, int] = None
    ) -> bytes:
        """ Add an attribute to the beginnig tag of an xml element.
        Arguments:
            tag (bytes): Tag to add the attrubute to.
            attribute (str): Attribute name
            value (str): Attribute value
        Return:
            Tag in encoded string format with the given attribute
        """
        if not tag:
            return None

        if not attribute:
            return tag

        if not value:
            value = ''

        return tag[:-1] + (
            " %s=%s>" % (attribute, quoteattr(str(value)))
        ).encode('utf-8')