org_fedora_oscap.common.do_chroot() - Code Metrics - Inspection of "Add support for the firstboot remediation - RHEL8" - OpenSCAP/oscap-anaconda-addon - Measure and Improve Code Quality continuously with Scrutinizer

Passed

Pull Request — rhel8-branch (#190)

by Matěj

created 2022-01-17 13:31 UTC

org_fedora_oscap.common.do_chroot() A

↳ Parent: org_fedora_oscap.common

Complexity

Conditions

Size

Total Lines	5
Code Lines	4

Duplication

Lines	0
Ratio	0 %

Importance

Changes

Metric	Value
eloc	4
dl	0
loc	5
rs	10
c	0
b	0
f	0
cc	3
nop	1

#
# Copyright (C) 2013  Red Hat, Inc.
#
# This copyrighted material is made available to anyone wishing to use,
# modify, copy, or redistribute it subject to the terms and conditions of
# the GNU General Public License v.2, or (at your option) any later version.
# This program is distributed in the hope that it will be useful, but WITHOUT
# ANY WARRANTY expressed or implied, including the implied warranties 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 Street, Fifth Floor, Boston, MA
# 02110-1301, USA.  Any Red Hat trademarks that are incorporated in the
# source code or documentation are not subject to the GNU General Public
# License and may only be used or replicated with the express permission of
# Red Hat, Inc.
#
# Red Hat Author(s): Vratislav Podzimek <[email protected]>
#

"""
Module with various classes and functions needed by the OSCAP addon that are
not specific to any installation mode (tui, gui, ks).

"""

import os
import tempfile
import subprocess
import zipfile
import tarfile

import cpioarchive
import re
import logging

from collections import namedtuple
import gettext
from functools import wraps
from pyanaconda.core import constants
from org_fedora_oscap import utils

log = logging.getLogger("anaconda")


# mimick pyanaconda/core/i18n.py
def _(string):
    if string:
        return gettext.translation("oscap-anaconda-addon", fallback=True).gettext(string)
    else:
        return ""


def N_(string): return string


# everything else should be private
__all__ = ["run_oscap_remediate", "get_fix_rules_pre",
           "extract_data", "strip_content_dir",
           "OSCAPaddonError"]

INSTALLATION_CONTENT_DIR = "/tmp/openscap_data/"
TARGET_CONTENT_DIR = "/root/openscap_data/"

SSG_DIR = "/usr/share/xml/scap/ssg/content/"

# Enable patches that set the content name at package-time
DEFAULT_SSG_CONTENT_NAME = ""
SSG_CONTENT = DEFAULT_SSG_CONTENT_NAME
if not SSG_CONTENT:
    if constants.shortProductName != 'anaconda':
        if constants.shortProductName == 'fedora':
            SSG_CONTENT = "ssg-fedora-ds.xml"
        else:
            SSG_CONTENT = (
                "ssg-{name}{version}-ds.xml"
                .format(
                    name=constants.shortProductName,
                    version=constants.productVersion.strip(".")[0]))

RESULTS_PATH = utils.join_paths(TARGET_CONTENT_DIR,
                                "eval_remediate_results.xml")
REPORT_PATH = utils.join_paths(TARGET_CONTENT_DIR,
                               "eval_remediate_report.html")

PRE_INSTALL_FIX_SYSTEM_ATTR = "urn:redhat:anaconda:pre"

THREAD_FETCH_DATA = "AnaOSCAPdataFetchThread"

SUPPORTED_ARCHIVES = (".zip", ".tar", ".tar.gz", ".tar.bz2", )

# buffer size for reading and writing out data (in bytes)
IO_BUF_SIZE = 2 * 1024 * 1024


class OSCAPaddonError(Exception):
    """Exception class for OSCAP addon related errors."""

    pass


class OSCAPaddonNetworkError(OSCAPaddonError):
    """Exception class for OSCAP addon related network errors."""

    pass


class ExtractionError(OSCAPaddonError):
    """Exception class for the extraction errors."""

    pass


MESSAGE_TYPE_FATAL = 0
MESSAGE_TYPE_WARNING = 1
MESSAGE_TYPE_INFO = 2

# namedtuple for messages returned from the rules evaluation
#   origin -- class (inherited from RuleHandler) that generated the message
#   type -- one of the MESSAGE_TYPE_* constants defined above
#   text -- the actual message that should be displayed, logged, ...
RuleMessage = namedtuple("RuleMessage", ["origin", "type", "text"])


class SubprocessLauncher(object):
    def __init__(self, args):
        self.args = args
        self.stdout = ""
        self.stderr = ""
        self.messages = []
        self.returncode = None

    def execute(self, ** kwargs):
        command_string = " ".join(self.args)
        log.info(
            "OSCAP addon: Executing subprocess: '{command_string}'"
            .format(command_string=command_string))
        try:
            proc = subprocess.Popen(self.args, stdout=subprocess.PIPE,
                                    stderr=subprocess.PIPE, ** kwargs)
        except OSError as oserr:
            msg = ("Failed to execute command '{command_string}': {oserr}"
                   .format(command_string=command_string, oserr=oserr))
            raise OSCAPaddonError(msg)

        (stdout, stderr) = proc.communicate()
        self.stdout = stdout.decode()
        self.stderr = stderr.decode(errors="replace")
        self.messages = re.findall(r'OpenSCAP Error:.*', self.stderr)
        self.messages = self.messages + re.findall(r'E: oscap:.*', self.stderr)

        self.returncode = proc.returncode

    def log_messages(self):
        for message in self.messages:
            log.warning("OSCAP addon: " + message)


def get_fix_rules_pre(profile, fpath, ds_id="", xccdf_id="", tailoring=""):
    """
    Get fix rules for the pre-installation environment for a given profile in a
    given datastream and checklist in a given file.

    :see: run_oscap_remediate
    :see: _run_oscap_gen_fix
    :return: fix rules for a given profile
    :rtype: str

    """

    return _run_oscap_gen_fix(profile, fpath, PRE_INSTALL_FIX_SYSTEM_ATTR,
                              ds_id=ds_id, xccdf_id=xccdf_id,
                              tailoring=tailoring)


def _run_oscap_gen_fix(profile, fpath, template, ds_id="", xccdf_id="",
                       tailoring=""):
    """
    Run oscap tool on a given file to get the contents of fix elements with the
    'system' attribute equal to a given template for a given datastream,
    checklist and profile.

    :see: run_oscap_remediate
    :param template: the value of the 'system' attribute of the fix elements
    :type template: str
    :return: oscap tool's stdout
    :rtype: str

    """

    if not profile:
        return ""

    args = ["oscap", "xccdf", "generate", "fix"]
    args.append("--template=%s" % template)

    # oscap uses the default profile by default
    if profile.lower() != "default":
        args.append("--profile=%s" % profile)
    if ds_id:
        args.append("--datastream-id=%s" % ds_id)
    if xccdf_id:
        args.append("--xccdf-id=%s" % xccdf_id)
    if tailoring:
        args.append("--tailoring-file=%s" % tailoring)

    args.append(fpath)

    proc = SubprocessLauncher(args)
    proc.execute()
    proc.log_messages()
    if proc.returncode != 0:
        msg = "Failed to generate fix rules with the oscap tool: %s" % proc.stderr
        raise OSCAPaddonError(msg)

    return proc.stdout


def do_chroot(chroot):
    """Helper function doing the chroot if requested."""
    if chroot and chroot != "/":
        os.chroot(chroot)
        os.chdir("/")


def assert_scanner_works(chroot, executable="oscap"):
    args = [executable, "--version"]
    command = " ".join(args)

    try:
        proc = subprocess.Popen(
            args, preexec_fn=lambda: do_chroot(chroot),
            stdout=subprocess.PIPE, stderr=subprocess.PIPE)
        (stdout, stderr) = proc.communicate()
        stderr = stderr.decode(errors="replace")
    except OSError as exc:
        msg = _(f"Basic invocation '{command}' fails: {str(exc)}")
        raise OSCAPaddonError(msg)
    if proc.returncode != 0:
        msg = _(
            f"Basic scanner invocation '{command}' exited "
            "with non-zero error code {proc.returncode}: {stderr}")
        raise OSCAPaddonError(msg)
    return True


def run_oscap_remediate(profile, fpath, ds_id="", xccdf_id="", tailoring="",
                        chroot=""):
    """
    Run the evaluation and remediation with the oscap tool on a given file,
    doing the remediation as defined in a given profile defined in a given
    checklist that is a part of a given datastream. If requested, run in
    chroot.

    :param profile: id of the profile that will drive the remediation
    :type profile: str
    :param fpath: path to a file with SCAP content
    :type fpath: str
    :param ds_id: ID of the datastream that contains the checklist defining
                  the profile
    :type ds_id: str
    :param xccdf_id: ID of the checklist that defines the profile
    :type xccdf_id: str
    :param tailoring: path to a tailoring file
    :type tailoring: str
    :param chroot: path to the root the oscap tool should be run in
    :type chroot: str
    :return: oscap tool's stdout (summary of the rules, checks and fixes)
    :rtype: str

    """

    if not profile:
        return ""

    # make sure the directory for the results exists
    results_dir = os.path.dirname(RESULTS_PATH)
    if chroot:
        results_dir = os.path.normpath(chroot + "/" + results_dir)
    utils.ensure_dir_exists(results_dir)

    args = ["oscap", "xccdf", "eval"]
    args.append("--remediate")
    args.append("--results=%s" % RESULTS_PATH)
    args.append("--report=%s" % REPORT_PATH)

    # oscap uses the default profile by default
    if profile.lower() != "default":
        args.append("--profile=%s" % profile)
    if ds_id:
        args.append("--datastream-id=%s" % ds_id)
    if xccdf_id:
        args.append("--xccdf-id=%s" % xccdf_id)
    if tailoring:
        args.append("--tailoring-file=%s" % tailoring)

    args.append(fpath)

    proc = SubprocessLauncher(args)
    proc.execute(preexec_fn=lambda: do_chroot(chroot))
    proc.log_messages()

    if proc.returncode not in (0, 2):
        # 0 -- success; 2 -- no error, but checks/remediation failed
        msg = "Content evaluation and remediation with the oscap tool "\
            "failed: %s" % proc.stderr
        raise OSCAPaddonError(msg)

    return proc.stdout



def _schedule_firstboot_remediation(
        chroot, profile, ds_path, results_path, report_path, ds_id, xccdf_id, tailoring_path):
    config = f"""
    OSCAP_REMEDIATE_DS={ds_path}
    OSCAP_REMEDIATE_PROFILE_ID={profile}
    OSCAP_REMEDIATE_ARF_RESULT={results_path}
    OSCAP_REMEDIATE_HTML_REPORT={report_path}
    """
    if ds_id:
        config += "OSCAP_REMEDIATE_DATASTREAM_ID={ds_id}\n"
    if xccdf_id:
        config += "OSCAP_REMEDIATE_XCCDF_ID={xccdf_id}\n"
    if tailoring_path:
        config += "OSCAP_REMEDIATE_TAILORING={tailoring_path}\n"

    local_config_filename = "/var/tmp/oscap-remediate-offline.conf.sh"
    with open(os.path.join(chroot, local_config_filename), "w") as f:
        f.write(config)
    os.symlink(os.path.join(chroot, local_config_filename),
               os.path.join(chroot, "system-update"))


def schedule_firstboot_remediation(chroot, profile, fpath, ds_id="", xccdf_id="", tailoring=""):
    if not profile:
        return ""

    # make sure the directory for the results exists
    results_dir = os.path.dirname(RESULTS_PATH)
    results_dir = os.path.normpath(chroot + "/" + results_dir)
    utils.ensure_dir_exists(results_dir)

    log.info("OSCAP addon: Scheduling firstboot remediation")
    _schedule_firstboot_remediation(
        chroot, profile, fpath, RESULTS_PATH, REPORT_PATH, ds_id, xccdf_id, tailoring)

    return ""


def extract_data(archive, out_dir, ensure_has_files=None):
    """
    Fuction that extracts the given archive to the given output directory. It
    tries to find out the archive type by the file name.

    :param archive: path to the archive file that should be extracted
    :type archive: str
    :param out_dir: output directory the archive should be extracted to
    :type out_dir: str
    :param ensure_has_files: relative paths to the files that must exist in the
                             archive
    :type ensure_has_files: iterable of strings or None
    :return: a list of files and directories extracted from the archive
    :rtype: [str]

    """

    if not ensure_has_files:
        ensure_has_files = []

    # get rid of empty file paths
    if not ensure_has_files:
        ensure_has_files = []
    else:
        ensure_has_files = [fpath for fpath in ensure_has_files if fpath]

    msg = "OSCAP addon: Extracting {archive}".format(archive=archive)
    if ensure_has_files:
        msg += ", expecting to find {files} there.".format(files=tuple(ensure_has_files))
    log.info(msg)

    result = []
    if archive.endswith(".zip"):
        # ZIP file
        try:
            zfile = zipfile.ZipFile(archive, "r")
        except Exception as exc:
            msg = _(f"Error extracting archive as a zipfile: {exc}")
            raise ExtractionError(msg)

        # generator for the paths of the files found in the archive (dirs end
        # with "/")
        files = set(info.filename for info in zfile.filelist
                    if not info.filename.endswith("/"))
        for fpath in ensure_has_files or ():
            if fpath not in files:
                msg = "File '%s' not found in the archive '%s'" % (fpath,
                                                                   archive)
                raise ExtractionError(msg)

        utils.ensure_dir_exists(out_dir)
        zfile.extractall(path=out_dir)
        result = [utils.join_paths(out_dir, info.filename) for info in zfile.filelist]
        zfile.close()
    elif archive.endswith(".tar"):
        # plain tarball
        result = _extract_tarball(archive, out_dir, ensure_has_files, None)
    elif archive.endswith(".tar.gz"):
        # gzipped tarball
        result = _extract_tarball(archive, out_dir, ensure_has_files, "gz")
    elif archive.endswith(".tar.bz2"):
        # bzipped tarball
        result = _extract_tarball(archive, out_dir, ensure_has_files, "bz2")
    elif archive.endswith(".rpm"):
        # RPM
        result = _extract_rpm(archive, out_dir, ensure_has_files)
    # elif other types of archives
    else:
        raise ExtractionError("Unsuported archive type")
    log.info("OSCAP addon: Extracted {files} from the supplied content"
             .format(files=result))
    return result


def _extract_tarball(archive, out_dir, ensure_has_files, alg):
    """
    Extract the given TAR archive to the given output directory and make sure
    the given file exists in the archive.

    :see: extract_data
    :param alg: compression algorithm used for the tarball
    :type alg: str (one of "gz", "bz2") or None
    :return: a list of files and directories extracted from the archive
    :rtype: [str]

    """

    if alg and alg not in ("gz", "bz2",):
        raise ExtractionError("Unsupported compression algorithm")

    mode = "r"
    if alg:
        mode += ":%s" % alg

    try:
        tfile = tarfile.TarFile.open(archive, mode)
    except tarfile.TarError as err:
        raise ExtractionError(str(err))

    # generator for the paths of the files found in the archive
    files = set(member.path for member in tfile.getmembers()
                if member.isfile())

    for fpath in ensure_has_files or ():
        if fpath not in files:
            msg = "File '%s' not found in the archive '%s'" % (fpath, archive)
            raise ExtractionError(msg)

    utils.ensure_dir_exists(out_dir)
    tfile.extractall(path=out_dir)
    result = [utils.join_paths(out_dir, member.path) for member in tfile.getmembers()]
    tfile.close()

    return result


def _extract_rpm(rpm_path, root="/", ensure_has_files=None):
    """
    Extract the given RPM into the directory tree given by the root argument
    and make sure the given file exists in the archive.

    :param rpm_path: path to the RPM file that should be extracted
    :type rpm_path: str
    :param root: root of the directory tree the RPM should be extracted into
    :type root: str
    :param ensure_has_files: relative paths to the files that must exist in the
                             RPM
    :type ensure_has_files: iterable of strings or None
    :return: a list of files and directories extracted from the archive
    :rtype: [str]

    """

    # run rpm2cpio and process the output with the cpioarchive module
    temp_fd, temp_path = tempfile.mkstemp(prefix="oscap_rpm")
    proc = subprocess.Popen(["rpm2cpio", rpm_path], stdout=temp_fd)
    proc.wait()
    if proc.returncode != 0:
        msg = "Failed to convert RPM '%s' to cpio archive" % rpm_path
        raise ExtractionError(msg)

    os.close(temp_fd)

    try:
        archive = cpioarchive.CpioArchive(temp_path)
    except cpioarchive.CpioError as err:
        raise ExtractionError(str(err))

    # get entries from the archive (supports only iteration over entries)
    entries = set(entry for entry in archive)

    # cpio entry names (paths) start with the dot
    entry_names = [entry.name.lstrip(".") for entry in entries]

    for fpath in ensure_has_files or ():
        # RPM->cpio entries have absolute paths
        if fpath not in entry_names and \
           os.path.join("/", fpath) not in entry_names:
            msg = "File '%s' not found in the archive '%s'" % (fpath, rpm_path)
            raise ExtractionError(msg)

    try:
        for entry in entries:
            if entry.size == 0:
                continue
            dirname = os.path.dirname(entry.name.lstrip("."))
            out_dir = os.path.normpath(root + dirname)
            utils.ensure_dir_exists(out_dir)

            out_fpath = os.path.normpath(root + entry.name.lstrip("."))
            if os.path.exists(out_fpath):
                continue
            with open(out_fpath, "wb") as out_file:
                buf = entry.read(IO_BUF_SIZE)
                while buf:
                    out_file.write(buf)
                    buf = entry.read(IO_BUF_SIZE)
    except (IOError, cpioarchive.CpioError) as e:
        raise ExtractionError(e)

    # cleanup
    archive.close()
    os.unlink(temp_path)

    return [os.path.normpath(root + name) for name in entry_names]


def strip_content_dir(fpaths, phase="preinst"):
    """
    Strip content directory prefix from the file paths for either
    pre-installation or post-installation phase.

    :param fpaths: iterable of file paths to strip content directory prefix
                   from
    :type fpaths: iterable of strings
    :param phase: specifies pre-installation or post-installation phase
    :type phase: "preinst" or "postinst"
    :return: the same iterable of file paths as given with the content
             directory prefix stripped
    :rtype: same type as fpaths

    """

    if phase == "preinst":
        remove_prefix = lambda x: x[len(INSTALLATION_CONTENT_DIR):]
    else:
        remove_prefix = lambda x: x[len(TARGET_CONTENT_DIR):]

    return utils.keep_type_map(remove_prefix, fpaths)


def get_ssg_path(root="/"):
    return utils.join_paths(root, SSG_DIR + SSG_CONTENT)


def ssg_available(root="/"):
    """
    Tries to find the SCAP Security Guide under the given root.

    :return: True if SSG was found under the given root, False otherwise

    """

    return os.path.exists(get_ssg_path(root))


def dry_run_skip(func):
    """
    Decorator that makes sure the decorated function is noop in the dry-run
    mode.

    :param func: a decorated function that needs to have the first parameter an
                 object with the _addon_data attribute referencing the OSCAP
                 addon's ksdata
    """

    @wraps(func)
    def decorated(self, *args, **kwargs):
        if self._addon_data.dry_run:
            return
        else:
            return func(self, *args, **kwargs)

    return decorated


1			#
2			# Copyright (C) 2013 Red Hat, Inc.
3			#
4			# This copyrighted material is made available to anyone wishing to use,
5			# modify, copy, or redistribute it subject to the terms and conditions of
6			# the GNU General Public License v.2, or (at your option) any later version.
7			# This program is distributed in the hope that it will be useful, but WITHOUT
8			# ANY WARRANTY expressed or implied, including the implied warranties of
9			# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
10			# Public License for more details. You should have received a copy of the
11			# GNU General Public License along with this program; if not, write to the
12			# Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
13			# 02110-1301, USA. Any Red Hat trademarks that are incorporated in the
14			# source code or documentation are not subject to the GNU General Public
15			# License and may only be used or replicated with the express permission of
16			# Red Hat, Inc.
17			#
18			# Red Hat Author(s): Vratislav Podzimek <[email protected]>
19			#
20
21			"""
22			Module with various classes and functions needed by the OSCAP addon that are
23			not specific to any installation mode (tui, gui, ks).
24
25			"""
26
27			import os
28			import tempfile
29			import subprocess
30			import zipfile
31			import tarfile
32
33			import cpioarchive
34			import re
35			import logging
36
37			from collections import namedtuple
38			import gettext
39			from functools import wraps
40			from pyanaconda.core import constants
41			from org_fedora_oscap import utils
42
43			log = logging.getLogger("anaconda")
44
45
46			# mimick pyanaconda/core/i18n.py
47			def _(string):
48			if string:
49			return gettext.translation("oscap-anaconda-addon", fallback=True).gettext(string)
50			else:
51			return ""
52
53
54			def N_(string): return string
55
56
57			# everything else should be private
58			__all__ = ["run_oscap_remediate", "get_fix_rules_pre",
59			"extract_data", "strip_content_dir",
60			"OSCAPaddonError"]
61
62			INSTALLATION_CONTENT_DIR = "/tmp/openscap_data/"
63			TARGET_CONTENT_DIR = "/root/openscap_data/"
64
65			SSG_DIR = "/usr/share/xml/scap/ssg/content/"
66
67			# Enable patches that set the content name at package-time
68			DEFAULT_SSG_CONTENT_NAME = ""
69			SSG_CONTENT = DEFAULT_SSG_CONTENT_NAME
70			if not SSG_CONTENT:
71			if constants.shortProductName != 'anaconda':
72			if constants.shortProductName == 'fedora':
73			SSG_CONTENT = "ssg-fedora-ds.xml"
74			else:
75			SSG_CONTENT = (
76			"ssg-{name}{version}-ds.xml"
77			.format(
78			name=constants.shortProductName,
79			version=constants.productVersion.strip(".")[0]))
80
81			RESULTS_PATH = utils.join_paths(TARGET_CONTENT_DIR,
82			"eval_remediate_results.xml")
83			REPORT_PATH = utils.join_paths(TARGET_CONTENT_DIR,
84			"eval_remediate_report.html")
85
86			PRE_INSTALL_FIX_SYSTEM_ATTR = "urn:redhat:anaconda:pre"
87
88			THREAD_FETCH_DATA = "AnaOSCAPdataFetchThread"
89
90			SUPPORTED_ARCHIVES = (".zip", ".tar", ".tar.gz", ".tar.bz2", )
91
92			# buffer size for reading and writing out data (in bytes)
93			IO_BUF_SIZE = 2 * 1024 * 1024
94
95
96			class OSCAPaddonError(Exception):
97			"""Exception class for OSCAP addon related errors."""
98
99			pass
100
101
102			class OSCAPaddonNetworkError(OSCAPaddonError):
103			"""Exception class for OSCAP addon related network errors."""
104
105			pass
106
107
108			class ExtractionError(OSCAPaddonError):
109			"""Exception class for the extraction errors."""
110
111			pass
112
113
114			MESSAGE_TYPE_FATAL = 0
115			MESSAGE_TYPE_WARNING = 1
116			MESSAGE_TYPE_INFO = 2
117
118			# namedtuple for messages returned from the rules evaluation
119			# origin -- class (inherited from RuleHandler) that generated the message
120			# type -- one of the MESSAGE_TYPE_* constants defined above
121			# text -- the actual message that should be displayed, logged, ...
122			RuleMessage = namedtuple("RuleMessage", ["origin", "type", "text"])
123
124
125			class SubprocessLauncher(object):
126			def __init__(self, args):
127			self.args = args
128			self.stdout = ""
129			self.stderr = ""
130			self.messages = []
131			self.returncode = None
132
133			def execute(self, ** kwargs):
134			command_string = " ".join(self.args)
135			log.info(
136			"OSCAP addon: Executing subprocess: '{command_string}'"
137			.format(command_string=command_string))
138			try:
139			proc = subprocess.Popen(self.args, stdout=subprocess.PIPE,
140			stderr=subprocess.PIPE, ** kwargs)
141			except OSError as oserr:
142			msg = ("Failed to execute command '{command_string}': {oserr}"
143			.format(command_string=command_string, oserr=oserr))
144			raise OSCAPaddonError(msg)
145
146			(stdout, stderr) = proc.communicate()
147			self.stdout = stdout.decode()
148			self.stderr = stderr.decode(errors="replace")
149			self.messages = re.findall(r'OpenSCAP Error:.*', self.stderr)
150			self.messages = self.messages + re.findall(r'E: oscap:.*', self.stderr)
151
152			self.returncode = proc.returncode
153
154			def log_messages(self):
155			for message in self.messages:
156			log.warning("OSCAP addon: " + message)
157
158
159			def get_fix_rules_pre(profile, fpath, ds_id="", xccdf_id="", tailoring=""):
160			"""
161			Get fix rules for the pre-installation environment for a given profile in a
162			given datastream and checklist in a given file.
163
164			:see: run_oscap_remediate
165			:see: _run_oscap_gen_fix
166			:return: fix rules for a given profile
167			:rtype: str
168
169			"""
170
171			return _run_oscap_gen_fix(profile, fpath, PRE_INSTALL_FIX_SYSTEM_ATTR,
172			ds_id=ds_id, xccdf_id=xccdf_id,
173			tailoring=tailoring)
174
175
176			def _run_oscap_gen_fix(profile, fpath, template, ds_id="", xccdf_id="",
177			tailoring=""):
178			"""
179			Run oscap tool on a given file to get the contents of fix elements with the
180			'system' attribute equal to a given template for a given datastream,
181			checklist and profile.
182
183			:see: run_oscap_remediate
184			:param template: the value of the 'system' attribute of the fix elements
185			:type template: str
186			:return: oscap tool's stdout
187			:rtype: str
188
189			"""
190
191			if not profile:
192			return ""
193
194			args = ["oscap", "xccdf", "generate", "fix"]
195			args.append("--template=%s" % template)
196
197			# oscap uses the default profile by default
198			if profile.lower() != "default":
199			args.append("--profile=%s" % profile)
200			if ds_id:
201			args.append("--datastream-id=%s" % ds_id)
202			if xccdf_id:
203			args.append("--xccdf-id=%s" % xccdf_id)
204			if tailoring:
205			args.append("--tailoring-file=%s" % tailoring)
206
207			args.append(fpath)
208
209			proc = SubprocessLauncher(args)
210			proc.execute()
211			proc.log_messages()
212			if proc.returncode != 0:
213			msg = "Failed to generate fix rules with the oscap tool: %s" % proc.stderr
214			raise OSCAPaddonError(msg)
215
216			return proc.stdout
217
218
219			def do_chroot(chroot):
220			"""Helper function doing the chroot if requested."""
221			if chroot and chroot != "/":
222			os.chroot(chroot)
223			os.chdir("/")
224
225
226			def assert_scanner_works(chroot, executable="oscap"):
227			args = [executable, "--version"]
228			command = " ".join(args)
229
230			try:
231			proc = subprocess.Popen(
232			args, preexec_fn=lambda: do_chroot(chroot),
233			stdout=subprocess.PIPE, stderr=subprocess.PIPE)
234			(stdout, stderr) = proc.communicate()
235			stderr = stderr.decode(errors="replace")
236			except OSError as exc:
237			msg = _(f"Basic invocation '{command}' fails: {str(exc)}")
238			raise OSCAPaddonError(msg)
239			if proc.returncode != 0:
240			msg = _(
241			f"Basic scanner invocation '{command}' exited "
242			"with non-zero error code {proc.returncode}: {stderr}")
243			raise OSCAPaddonError(msg)
244			return True
245
246
247			def run_oscap_remediate(profile, fpath, ds_id="", xccdf_id="", tailoring="",
248			chroot=""):
249			"""
250			Run the evaluation and remediation with the oscap tool on a given file,
251			doing the remediation as defined in a given profile defined in a given
252			checklist that is a part of a given datastream. If requested, run in
253			chroot.
254
255			:param profile: id of the profile that will drive the remediation
256			:type profile: str
257			:param fpath: path to a file with SCAP content
258			:type fpath: str
259			:param ds_id: ID of the datastream that contains the checklist defining
260			the profile
261			:type ds_id: str
262			:param xccdf_id: ID of the checklist that defines the profile
263			:type xccdf_id: str
264			:param tailoring: path to a tailoring file
265			:type tailoring: str
266			:param chroot: path to the root the oscap tool should be run in
267			:type chroot: str
268			:return: oscap tool's stdout (summary of the rules, checks and fixes)
269			:rtype: str
270
271			"""
272
273			if not profile:
274			return ""
275
276			# make sure the directory for the results exists
277			results_dir = os.path.dirname(RESULTS_PATH)
278			if chroot:
279			results_dir = os.path.normpath(chroot + "/" + results_dir)
280			utils.ensure_dir_exists(results_dir)
281
282			args = ["oscap", "xccdf", "eval"]
283			args.append("--remediate")
284			args.append("--results=%s" % RESULTS_PATH)
285			args.append("--report=%s" % REPORT_PATH)
286
287			# oscap uses the default profile by default
288			if profile.lower() != "default":
289			args.append("--profile=%s" % profile)
290			if ds_id:
291			args.append("--datastream-id=%s" % ds_id)
292			if xccdf_id:
293			args.append("--xccdf-id=%s" % xccdf_id)
294			if tailoring:
295			args.append("--tailoring-file=%s" % tailoring)
296
297			args.append(fpath)
298
299			proc = SubprocessLauncher(args)
300			proc.execute(preexec_fn=lambda: do_chroot(chroot))
301			proc.log_messages()
302
303			if proc.returncode not in (0, 2):
304			# 0 -- success; 2 -- no error, but checks/remediation failed
305			msg = "Content evaluation and remediation with the oscap tool "\
306			"failed: %s" % proc.stderr
307			raise OSCAPaddonError(msg)
308
309			return proc.stdout
310
311
312
313			def _schedule_firstboot_remediation(
314			chroot, profile, ds_path, results_path, report_path, ds_id, xccdf_id, tailoring_path):
315			config = f"""
316			OSCAP_REMEDIATE_DS={ds_path}
317			OSCAP_REMEDIATE_PROFILE_ID={profile}
318			OSCAP_REMEDIATE_ARF_RESULT={results_path}
319			OSCAP_REMEDIATE_HTML_REPORT={report_path}
320			"""
321			if ds_id:
322			config += "OSCAP_REMEDIATE_DATASTREAM_ID={ds_id}\n"
323			if xccdf_id:
324			config += "OSCAP_REMEDIATE_XCCDF_ID={xccdf_id}\n"
325			if tailoring_path:
326			config += "OSCAP_REMEDIATE_TAILORING={tailoring_path}\n"
327
328			local_config_filename = "/var/tmp/oscap-remediate-offline.conf.sh"
329			with open(os.path.join(chroot, local_config_filename), "w") as f:
330			f.write(config)
331			os.symlink(os.path.join(chroot, local_config_filename),
332			os.path.join(chroot, "system-update"))
333
334
335			def schedule_firstboot_remediation(chroot, profile, fpath, ds_id="", xccdf_id="", tailoring=""):
336			if not profile:
337			return ""
338
339			# make sure the directory for the results exists
340			results_dir = os.path.dirname(RESULTS_PATH)
341			results_dir = os.path.normpath(chroot + "/" + results_dir)
342			utils.ensure_dir_exists(results_dir)
343
344			log.info("OSCAP addon: Scheduling firstboot remediation")
345			_schedule_firstboot_remediation(
346			chroot, profile, fpath, RESULTS_PATH, REPORT_PATH, ds_id, xccdf_id, tailoring)
347
348			return ""
349
350
351			def extract_data(archive, out_dir, ensure_has_files=None):
352			"""
353			Fuction that extracts the given archive to the given output directory. It
354			tries to find out the archive type by the file name.
355
356			:param archive: path to the archive file that should be extracted
357			:type archive: str
358			:param out_dir: output directory the archive should be extracted to
359			:type out_dir: str
360			:param ensure_has_files: relative paths to the files that must exist in the
361			archive
362			:type ensure_has_files: iterable of strings or None
363			:return: a list of files and directories extracted from the archive
364			:rtype: [str]
365
366			"""
367
368			if not ensure_has_files:
369			ensure_has_files = []
370
371			# get rid of empty file paths
372			if not ensure_has_files:
373			ensure_has_files = []
374			else:
375			ensure_has_files = [fpath for fpath in ensure_has_files if fpath]
376
377			msg = "OSCAP addon: Extracting {archive}".format(archive=archive)
378			if ensure_has_files:
379			msg += ", expecting to find {files} there.".format(files=tuple(ensure_has_files))
380			log.info(msg)
381
382			result = []
383			if archive.endswith(".zip"):
384			# ZIP file
385			try:
386			zfile = zipfile.ZipFile(archive, "r")
387			except Exception as exc:
388			msg = _(f"Error extracting archive as a zipfile: {exc}")
389			raise ExtractionError(msg)
390
391			# generator for the paths of the files found in the archive (dirs end
392			# with "/")
393			files = set(info.filename for info in zfile.filelist
394			if not info.filename.endswith("/"))
395			for fpath in ensure_has_files or ():
396			if fpath not in files:
397			msg = "File '%s' not found in the archive '%s'" % (fpath,
398			archive)
399			raise ExtractionError(msg)
400
401			utils.ensure_dir_exists(out_dir)
402			zfile.extractall(path=out_dir)
403			result = [utils.join_paths(out_dir, info.filename) for info in zfile.filelist]
404			zfile.close()
405			elif archive.endswith(".tar"):
406			# plain tarball
407			result = _extract_tarball(archive, out_dir, ensure_has_files, None)
408			elif archive.endswith(".tar.gz"):
409			# gzipped tarball
410			result = _extract_tarball(archive, out_dir, ensure_has_files, "gz")
411			elif archive.endswith(".tar.bz2"):
412			# bzipped tarball
413			result = _extract_tarball(archive, out_dir, ensure_has_files, "bz2")
414			elif archive.endswith(".rpm"):
415			# RPM
416			result = _extract_rpm(archive, out_dir, ensure_has_files)
417			# elif other types of archives
418			else:
419			raise ExtractionError("Unsuported archive type")
420			log.info("OSCAP addon: Extracted {files} from the supplied content"
421			.format(files=result))
422			return result
423
424
425			def _extract_tarball(archive, out_dir, ensure_has_files, alg):
426			"""
427			Extract the given TAR archive to the given output directory and make sure
428			the given file exists in the archive.
429
430			:see: extract_data
431			:param alg: compression algorithm used for the tarball
432			:type alg: str (one of "gz", "bz2") or None
433			:return: a list of files and directories extracted from the archive
434			:rtype: [str]
435
436			"""
437
438			if alg and alg not in ("gz", "bz2",):
439			raise ExtractionError("Unsupported compression algorithm")
440
441			mode = "r"
442			if alg:
443			mode += ":%s" % alg
444
445			try:
446			tfile = tarfile.TarFile.open(archive, mode)
447			except tarfile.TarError as err:
448			raise ExtractionError(str(err))
449
450			# generator for the paths of the files found in the archive
451			files = set(member.path for member in tfile.getmembers()
452			if member.isfile())
453
454			for fpath in ensure_has_files or ():
455			if fpath not in files:
456			msg = "File '%s' not found in the archive '%s'" % (fpath, archive)
457			raise ExtractionError(msg)
458
459			utils.ensure_dir_exists(out_dir)
460			tfile.extractall(path=out_dir)
461			result = [utils.join_paths(out_dir, member.path) for member in tfile.getmembers()]
462			tfile.close()
463
464			return result
465
466
467			def _extract_rpm(rpm_path, root="/", ensure_has_files=None):
468			"""
469			Extract the given RPM into the directory tree given by the root argument
470			and make sure the given file exists in the archive.
471
472			:param rpm_path: path to the RPM file that should be extracted
473			:type rpm_path: str
474			:param root: root of the directory tree the RPM should be extracted into
475			:type root: str
476			:param ensure_has_files: relative paths to the files that must exist in the
477			RPM
478			:type ensure_has_files: iterable of strings or None
479			:return: a list of files and directories extracted from the archive
480			:rtype: [str]
481
482			"""
483
484			# run rpm2cpio and process the output with the cpioarchive module
485			temp_fd, temp_path = tempfile.mkstemp(prefix="oscap_rpm")
486			proc = subprocess.Popen(["rpm2cpio", rpm_path], stdout=temp_fd)
487			proc.wait()
488			if proc.returncode != 0:
489			msg = "Failed to convert RPM '%s' to cpio archive" % rpm_path
490			raise ExtractionError(msg)
491
492			os.close(temp_fd)
493
494			try:
495			archive = cpioarchive.CpioArchive(temp_path)
496			except cpioarchive.CpioError as err:
497			raise ExtractionError(str(err))
498
499			# get entries from the archive (supports only iteration over entries)
500			entries = set(entry for entry in archive)
501
502			# cpio entry names (paths) start with the dot
503			entry_names = [entry.name.lstrip(".") for entry in entries]
504
505			for fpath in ensure_has_files or ():
506			# RPM->cpio entries have absolute paths
507			if fpath not in entry_names and \
508			os.path.join("/", fpath) not in entry_names:
509			msg = "File '%s' not found in the archive '%s'" % (fpath, rpm_path)
510			raise ExtractionError(msg)
511
512			try:
513			for entry in entries:
514			if entry.size == 0:
515			continue
516			dirname = os.path.dirname(entry.name.lstrip("."))
517			out_dir = os.path.normpath(root + dirname)
518			utils.ensure_dir_exists(out_dir)
519
520			out_fpath = os.path.normpath(root + entry.name.lstrip("."))
521			if os.path.exists(out_fpath):
522			continue
523			with open(out_fpath, "wb") as out_file:
524			buf = entry.read(IO_BUF_SIZE)
525			while buf:
526			out_file.write(buf)
527			buf = entry.read(IO_BUF_SIZE)
528			except (IOError, cpioarchive.CpioError) as e:
529			raise ExtractionError(e)
530
531			# cleanup
532			archive.close()
533			os.unlink(temp_path)
534
535			return [os.path.normpath(root + name) for name in entry_names]
536
537
538			def strip_content_dir(fpaths, phase="preinst"):
539			"""
540			Strip content directory prefix from the file paths for either
541			pre-installation or post-installation phase.
542
543			:param fpaths: iterable of file paths to strip content directory prefix
544			from
545			:type fpaths: iterable of strings
546			:param phase: specifies pre-installation or post-installation phase
547			:type phase: "preinst" or "postinst"
548			:return: the same iterable of file paths as given with the content
549			directory prefix stripped
550			:rtype: same type as fpaths
551
552			"""
553
554			if phase == "preinst":
555			remove_prefix = lambda x: x[len(INSTALLATION_CONTENT_DIR):]
556			else:
557			remove_prefix = lambda x: x[len(TARGET_CONTENT_DIR):]
558
559			return utils.keep_type_map(remove_prefix, fpaths)
560
561
562			def get_ssg_path(root="/"):
563			return utils.join_paths(root, SSG_DIR + SSG_CONTENT)
564
565
566			def ssg_available(root="/"):
567			"""
568			Tries to find the SCAP Security Guide under the given root.
569
570			:return: True if SSG was found under the given root, False otherwise
571
572			"""
573
574			return os.path.exists(get_ssg_path(root))
575
576
577			def dry_run_skip(func):
578			"""
579			Decorator that makes sure the decorated function is noop in the dry-run
580			mode.
581
582			:param func: a decorated function that needs to have the first parameter an
583			object with the _addon_data attribute referencing the OSCAP
584			addon's ksdata
585			"""
586
587			@wraps(func)
588			def decorated(self, args, *kwargs):
589			if self._addon_data.dry_run:
590			return
591			else:
592			return func(self, args, *kwargs)
593
594			return decorated
595

OpenSCAP / oscap-anaconda-addon

Pull Request — rhel8-branch (#190)

org_fedora_oscap.common.do_chroot() A

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