• Language: en

Source code for django.views.debug

import functools
import re
import sys
import types
from pathlib import Path

from django.conf import settings
from django.http import HttpResponse, HttpResponseNotFound
from django.template import Context, Engine, TemplateDoesNotExist
from django.template.defaultfilters import pprint
from django.urls import Resolver404, resolve
from django.utils import timezone
from django.utils.datastructures import MultiValueDict
from django.utils.encoding import force_text
from django.utils.module_loading import import_string
from django.utils.version import get_docs_version

# Minimal Django templates engine to render the error templates
# regardless of the project's TEMPLATES setting. Templates are
# read directly from the filesystem so that the error handler
# works even if the template loader is broken.
DEBUG_ENGINE = Engine(
    debug=True,
    libraries={'i18n': 'django.templatetags.i18n'},
)

HIDDEN_SETTINGS = re.compile('API|TOKEN|KEY|SECRET|PASS|SIGNATURE', flags=re.IGNORECASE)

CLEANSED_SUBSTITUTE = '********************'

CURRENT_DIR = Path(__file__).parent


class CallableSettingWrapper:
    """
    Object to wrap callable appearing in settings.
    * Not to call in the debug page (#21345).
    * Not to break the debug page if the callable forbidding to set attributes
      (#23070).
    """
    def __init__(self, callable_setting):
        self._wrapped = callable_setting

    def __repr__(self):
        return repr(self._wrapped)


def cleanse_setting(key, value):
    """
    Cleanse an individual setting key/value of sensitive content. If the value
    is a dictionary, recursively cleanse the keys in that dictionary.
    """
    try:
        if HIDDEN_SETTINGS.search(key):
            cleansed = CLEANSED_SUBSTITUTE
        else:
            if isinstance(value, dict):
                cleansed = {k: cleanse_setting(k, v) for k, v in value.items()}
            else:
                cleansed = value
    except TypeError:
        # If the key isn't regex-able, just return as-is.
        cleansed = value

    if callable(cleansed):
        # For fixing #21345 and #23070
        cleansed = CallableSettingWrapper(cleansed)

    return cleansed


def get_safe_settings():
    """
    Return a dictionary of the settings module with values of sensitive
    settings replaced with stars (*********).
    """
    settings_dict = {}
    for k in dir(settings):
        if k.isupper():
            settings_dict[k] = cleanse_setting(k, getattr(settings, k))
    return settings_dict


def technical_500_response(request, exc_type, exc_value, tb, status_code=500):
    """
    Create a technical server error response. The last three arguments are
    the values returned from sys.exc_info() and friends.
    """
    reporter = ExceptionReporter(request, exc_type, exc_value, tb)
    if request.is_ajax():
        text = reporter.get_traceback_text()
        return HttpResponse(text, status=status_code, content_type='text/plain; charset=utf-8')
    else:
        html = reporter.get_traceback_html()
        return HttpResponse(html, status=status_code, content_type='text/html')


@functools.lru_cache()
def get_default_exception_reporter_filter():
    # Instantiate the default filter for the first time and cache it.
    return import_string(settings.DEFAULT_EXCEPTION_REPORTER_FILTER)()


def get_exception_reporter_filter(request):
    default_filter = get_default_exception_reporter_filter()
    return getattr(request, 'exception_reporter_filter', default_filter)


class ExceptionReporterFilter:
    """
    Base for all exception reporter filter classes. All overridable hooks
    contain lenient default behaviors.
    """

    def get_post_parameters(self, request):
        if request is None:
            return {}
        else:
            return request.POST

    def get_traceback_frame_variables(self, request, tb_frame):
        return list(tb_frame.f_locals.items())


[docs]class SafeExceptionReporterFilter(ExceptionReporterFilter): """ Use annotations made by the sensitive_post_parameters and sensitive_variables decorators to filter out sensitive information. """
[docs] def is_active(self, request): """ This filter is to add safety in production environments (i.e. DEBUG is False). If DEBUG is True then your site is not safe anyway. This hook is provided as a convenience to easily activate or deactivate the filter on a per request basis. """ return settings.DEBUG is False
def get_cleansed_multivaluedict(self, request, multivaluedict): """ Replace the keys in a MultiValueDict marked as sensitive with stars. This mitigates leaking sensitive POST parameters if something like request.POST['nonexistent_key'] throws an exception (#21098). """ sensitive_post_parameters = getattr(request, 'sensitive_post_parameters', []) if self.is_active(request) and sensitive_post_parameters: multivaluedict = multivaluedict.copy() for param in sensitive_post_parameters: if param in multivaluedict: multivaluedict[param] = CLEANSED_SUBSTITUTE return multivaluedict
[docs] def get_post_parameters(self, request): """ Replace the values of POST parameters marked as sensitive with stars (*********). """ if request is None: return {} else: sensitive_post_parameters = getattr(request, 'sensitive_post_parameters', []) if self.is_active(request) and sensitive_post_parameters: cleansed = request.POST.copy() if sensitive_post_parameters == '__ALL__': # Cleanse all parameters. for k, v in cleansed.items(): cleansed[k] = CLEANSED_SUBSTITUTE return cleansed else: # Cleanse only the specified parameters. for param in sensitive_post_parameters: if param in cleansed: cleansed[param] = CLEANSED_SUBSTITUTE return cleansed else: return request.POST
def cleanse_special_types(self, request, value): try: # If value is lazy or a complex object of another kind, this check # might raise an exception. isinstance checks that lazy # MultiValueDicts will have a return value. is_multivalue_dict = isinstance(value, MultiValueDict) except Exception as e: return '{!r} while evaluating {!r}'.format(e, value) if is_multivalue_dict: # Cleanse MultiValueDicts (request.POST is the one we usually care about) value = self.get_cleansed_multivaluedict(request, value) return value
[docs] def get_traceback_frame_variables(self, request, tb_frame): """ Replace the values of variables marked as sensitive with stars (*********). """ # Loop through the frame's callers to see if the sensitive_variables # decorator was used. current_frame = tb_frame.f_back sensitive_variables = None while current_frame is not None: if (current_frame.f_code.co_name == 'sensitive_variables_wrapper' and 'sensitive_variables_wrapper' in current_frame.f_locals): # The sensitive_variables decorator was used, so we take note # of the sensitive variables' names. wrapper = current_frame.f_locals['sensitive_variables_wrapper'] sensitive_variables = getattr(wrapper, 'sensitive_variables', None) break current_frame = current_frame.f_back cleansed = {} if self.is_active(request) and sensitive_variables: if sensitive_variables == '__ALL__': # Cleanse all variables for name, value in tb_frame.f_locals.items(): cleansed[name] = CLEANSED_SUBSTITUTE else: # Cleanse specified variables for name, value in tb_frame.f_locals.items(): if name in sensitive_variables: value = CLEANSED_SUBSTITUTE else: value = self.cleanse_special_types(request, value) cleansed[name] = value else: # Potentially cleanse the request and any MultiValueDicts if they # are one of the frame variables. for name, value in tb_frame.f_locals.items(): cleansed[name] = self.cleanse_special_types(request, value) if (tb_frame.f_code.co_name == 'sensitive_variables_wrapper' and 'sensitive_variables_wrapper' in tb_frame.f_locals): # For good measure, obfuscate the decorated function's arguments in # the sensitive_variables decorator's frame, in case the variables # associated with those arguments were meant to be obfuscated from # the decorated function's frame. cleansed['func_args'] = CLEANSED_SUBSTITUTE cleansed['func_kwargs'] = CLEANSED_SUBSTITUTE return cleansed.items()
class ExceptionReporter: """Organize and coordinate reporting on exceptions.""" def __init__(self, request, exc_type, exc_value, tb, is_email=False): self.request = request self.filter = get_exception_reporter_filter(self.request) self.exc_type = exc_type self.exc_value = exc_value self.tb = tb self.is_email = is_email self.template_info = getattr(self.exc_value, 'template_debug', None) self.template_does_not_exist = False self.postmortem = None def get_traceback_data(self): """Return a dictionary containing traceback information.""" if self.exc_type and issubclass(self.exc_type, TemplateDoesNotExist): self.template_does_not_exist = True self.postmortem = self.exc_value.chain or [self.exc_value] frames = self.get_traceback_frames() for i, frame in enumerate(frames): if 'vars' in frame: frame_vars = [] for k, v in frame['vars']: v = pprint(v) # Trim large blobs of data if len(v) > 4096: v = '%s... <trimmed %d bytes string>' % (v[0:4096], len(v)) frame_vars.append((k, v)) frame['vars'] = frame_vars frames[i] = frame unicode_hint = '' if self.exc_type and issubclass(self.exc_type, UnicodeError): start = getattr(self.exc_value, 'start', None) end = getattr(self.exc_value, 'end', None) if start is not None and end is not None: unicode_str = self.exc_value.args[1] unicode_hint = force_text( unicode_str[max(start - 5, 0):min(end + 5, len(unicode_str))], 'ascii', errors='replace' ) from django import get_version if self.request is None: user_str = None else: try: user_str = str(self.request.user) except Exception: # request.user may raise OperationalError if the database is # unavailable, for example. user_str = '[unable to retrieve the current user]' c = { 'is_email': self.is_email, 'unicode_hint': unicode_hint, 'frames': frames, 'request': self.request, 'user_str': user_str, 'filtered_POST_items': list(self.filter.get_post_parameters(self.request).items()), 'settings': get_safe_settings(), 'sys_executable': sys.executable, 'sys_version_info': '%d.%d.%d' % sys.version_info[0:3], 'server_time': timezone.now(), 'django_version_info': get_version(), 'sys_path': sys.path, 'template_info': self.template_info, 'template_does_not_exist': self.template_does_not_exist, 'postmortem': self.postmortem, } if self.request is not None: c['request_GET_items'] = self.request.GET.items() c['request_FILES_items'] = self.request.FILES.items() c['request_COOKIES_items'] = self.request.COOKIES.items() # Check whether exception info is available if self.exc_type: c['exception_type'] = self.exc_type.__name__ if self.exc_value: c['exception_value'] = str(self.exc_value) if frames: c['lastframe'] = frames[-1] return c def get_traceback_html(self): """Return HTML version of debug 500 HTTP error page.""" with Path(CURRENT_DIR, 'templates', 'technical_500.html').open() as fh: t = DEBUG_ENGINE.from_string(fh.read()) c = Context(self.get_traceback_data(), use_l10n=False) return t.render(c) def get_traceback_text(self): """Return plain text version of debug 500 HTTP error page.""" with Path(CURRENT_DIR, 'templates', 'technical_500.txt').open() as fh: t = DEBUG_ENGINE.from_string(fh.read()) c = Context(self.get_traceback_data(), autoescape=False, use_l10n=False) return t.render(c) def _get_lines_from_file(self, filename, lineno, context_lines, loader=None, module_name=None): """ Return context_lines before and after lineno from file. Return (pre_context_lineno, pre_context, context_line, post_context). """ source = None if loader is not None and hasattr(loader, "get_source"): try: source = loader.get_source(module_name) except ImportError: pass if source is not None: source = source.splitlines() if source is None: try: with open(filename, 'rb') as fp: source = fp.read().splitlines() except (OSError, IOError): pass if source is None: return None, [], None, [] # If we just read the source from a file, or if the loader did not # apply tokenize.detect_encoding to decode the source into a # string, then we should do that ourselves. if isinstance(source[0], bytes): encoding = 'ascii' for line in source[:2]: # File coding may be specified. Match pattern from PEP-263 # (http://www.python.org/dev/peps/pep-0263/) match = re.search(br'coding[:=]\s*([-\w.]+)', line) if match: encoding = match.group(1).decode('ascii') break source = [str(sline, encoding, 'replace') for sline in source] lower_bound = max(0, lineno - context_lines) upper_bound = lineno + context_lines pre_context = source[lower_bound:lineno] context_line = source[lineno] post_context = source[lineno + 1:upper_bound] return lower_bound, pre_context, context_line, post_context def get_traceback_frames(self): def explicit_or_implicit_cause(exc_value): explicit = getattr(exc_value, '__cause__', None) implicit = getattr(exc_value, '__context__', None) return explicit or implicit # Get the exception and all its causes exceptions = [] exc_value = self.exc_value while exc_value: exceptions.append(exc_value) exc_value = explicit_or_implicit_cause(exc_value) frames = [] # No exceptions were supplied to ExceptionReporter if not exceptions: return frames # In case there's just one exception, take the traceback from self.tb exc_value = exceptions.pop() tb = self.tb if not exceptions else exc_value.__traceback__ while tb is not None: # Support for __traceback_hide__ which is used by a few libraries # to hide internal frames. if tb.tb_frame.f_locals.get('__traceback_hide__'): tb = tb.tb_next continue filename = tb.tb_frame.f_code.co_filename function = tb.tb_frame.f_code.co_name lineno = tb.tb_lineno - 1 loader = tb.tb_frame.f_globals.get('__loader__') module_name = tb.tb_frame.f_globals.get('__name__') or '' pre_context_lineno, pre_context, context_line, post_context = self._get_lines_from_file( filename, lineno, 7, loader, module_name, ) if pre_context_lineno is None: pre_context_lineno = lineno pre_context = [] context_line = '<source code not available>' post_context = [] frames.append({ 'exc_cause': explicit_or_implicit_cause(exc_value), 'exc_cause_explicit': getattr(exc_value, '__cause__', True), 'tb': tb, 'type': 'django' if module_name.startswith('django.') else 'user', 'filename': filename, 'function': function, 'lineno': lineno + 1, 'vars': self.filter.get_traceback_frame_variables(self.request, tb.tb_frame), 'id': id(tb), 'pre_context': pre_context, 'context_line': context_line, 'post_context': post_context, 'pre_context_lineno': pre_context_lineno + 1, }) # If the traceback for current exception is consumed, try the # other exception. if not tb.tb_next and exceptions: exc_value = exceptions.pop() tb = exc_value.__traceback__ else: tb = tb.tb_next return frames def technical_404_response(request, exception): """Create a technical 404 error response. `exception` is the Http404.""" try: error_url = exception.args[0]['path'] except (IndexError, TypeError, KeyError): error_url = request.path_info[1:] # Trim leading slash try: tried = exception.args[0]['tried'] except (IndexError, TypeError, KeyError): tried = [] else: if (not tried or ( # empty URLconf request.path == '/' and len(tried) == 1 and # default URLconf len(tried[0]) == 1 and getattr(tried[0][0], 'app_name', '') == getattr(tried[0][0], 'namespace', '') == 'admin' )): return default_urlconf(request) urlconf = getattr(request, 'urlconf', settings.ROOT_URLCONF) if isinstance(urlconf, types.ModuleType): urlconf = urlconf.__name__ caller = '' try: resolver_match = resolve(request.path) except Resolver404: pass else: obj = resolver_match.func if hasattr(obj, '__name__'): caller = obj.__name__ elif hasattr(obj, '__class__') and hasattr(obj.__class__, '__name__'): caller = obj.__class__.__name__ if hasattr(obj, '__module__'): module = obj.__module__ caller = '%s.%s' % (module, caller) with Path(CURRENT_DIR, 'templates', 'technical_404.html').open() as fh: t = DEBUG_ENGINE.from_string(fh.read()) c = Context({ 'urlconf': urlconf, 'root_urlconf': settings.ROOT_URLCONF, 'request_path': error_url, 'urlpatterns': tried, 'reason': str(exception), 'request': request, 'settings': get_safe_settings(), 'raising_view_name': caller, }) return HttpResponseNotFound(t.render(c), content_type='text/html') def default_urlconf(request): """Create an empty URLconf 404 error response.""" with Path(CURRENT_DIR, 'templates', 'default_urlconf.html').open() as fh: t = DEBUG_ENGINE.from_string(fh.read()) c = Context({ 'version': get_docs_version(), }) return HttpResponse(t.render(c), content_type='text/html')
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