ssg/checks.py
"""
Common functions for processing Checks in SSG
"""
from __future__ import absolute_import
from __future__ import print_function
import os
from .constants import XCCDF12_NS
from .oval import parse_affected
from .utils import read_file_list
def get_content_ref_if_exists_and_not_remote(check):
"""
Given an OVAL check element, examine the ``xccdf_ns:check-content-ref``.
If the check-content-ref element exists and it isn't remote, return it.
Args:
check (Element): An OVAL check element to be examined.
Returns:
Element or None: The check-content-ref element if it exists and is not remote, otherwise None.
See Also:
is_content_href_remote: Function to determine if the content reference is remote.
"""
checkcontentref = check.find("./{%s}check-content-ref" % XCCDF12_NS)
if checkcontentref is None:
return None
if is_content_href_remote(checkcontentref):
return None
return checkcontentref
def is_content_href_remote(check_content_ref):
"""
Given an OVAL check-content-ref element, examine the 'href' attribute.
Args:
check_content_ref (Element): An XML element representing the OVAL check-content-ref.
Returns:
bool: True if the 'href' attribute starts with 'http://' or 'https://', otherwise False.
Raises:
RuntimeError: If the 'href' attribute does not exist in the check_content_ref element.
"""
hrefattr = check_content_ref.get("href")
if hrefattr is None:
# @href attribute of <check-content-ref> is required by XCCDF standard
msg = "Invalid OVAL <check-content-ref> detected - missing the " \
"'href' attribute!"
raise RuntimeError(msg)
return hrefattr.startswith("http://") or hrefattr.startswith("https://")
def get_oval_path(rule_obj, oval_id):
"""
Returns the full path to the OVAL check file for the given rule object and OVAL ID.
Args:
rule_obj (dict): A dictionary containing rule information.
It must include the keys 'dir', 'id', and 'ovals'.
oval_id (str): A string representing the ID of the OVAL check file.
If it does not end with ".xml", the extension will be appended.
Returns:
str: The full path to the OVAL check file.
Raises:
ValueError: If the rule_obj is malformed or if the oval_id is unknown for the given rule.
"""
if not oval_id.endswith(".xml"):
oval_id += ".xml"
if 'dir' not in rule_obj or 'id' not in rule_obj:
raise ValueError("Malformed rule_obj")
if 'ovals' not in rule_obj or oval_id not in rule_obj['ovals']:
raise ValueError("Unknown oval_id:%s for rule_id" % oval_id)
return os.path.join(rule_obj['dir'], 'oval', oval_id)
def get_oval_contents(rule_obj, oval_id):
"""
Returns the tuple (path, contents) of the check described by the given oval_id or product.
Parameters:
rule_obj (object): The rule object containing the OVAL definitions.
oval_id (str): The identifier of the OVAL check.
Returns:
tuple: A tuple containing the path to the OVAL file and its contents.
"""
oval_path = get_oval_path(rule_obj, oval_id)
oval_contents = read_file_list(oval_path)
return oval_path, oval_contents
def set_applicable_platforms(oval_contents, new_platforms):
"""
Modifies the given OVAL contents to update the platforms to the new platforms.
Args:
oval_contents (list of str): The original OVAL content lines.
new_platforms (list of str): The new platforms to be set in the OVAL content.
Returns:
list of str: The modified OVAL content lines with updated platforms.
"""
start_affected, end_affected, indent = parse_affected(oval_contents)
platforms = sorted(new_platforms)
new_platforms_xml = map(lambda x: indent + "<platform>%s</platform>" % x, platforms)
new_platforms_xml = list(new_platforms_xml)
new_contents = oval_contents[0:start_affected+1]
new_contents.extend(new_platforms_xml)
new_contents.extend(oval_contents[end_affected:])
return new_contents