import datetime import json import mimetypes import os import re import sys import time from email.header import Header from http.client import responses from urllib.parse import quote, urlparse from django.conf import settings from django.core import signals, signing from django.core.exceptions import DisallowedRedirect from django.core.serializers.json import DjangoJSONEncoder from django.http.cookie import SimpleCookie from django.utils import timezone from django.utils.encoding import iri_to_uri from django.utils.http import http_date _charset_from_content_type_re = re.compile(r';\s*charset=(?P[^\s;]+)', re.I) class BadHeaderError(ValueError): pass class HttpResponseBase: """ An HTTP response base class with dictionary-accessed headers. This class doesn't handle content. It should not be used directly. Use the HttpResponse and StreamingHttpResponse subclasses instead. """ status_code = 200 def __init__(self, content_type=None, status=None, reason=None, charset=None): # _headers is a mapping of the lowercase name to the original case of # the header (required for working with legacy systems) and the header # value. Both the name of the header and its value are ASCII strings. self._headers = {} self._resource_closers = [] # This parameter is set by the handler. It's necessary to preserve the # historical behavior of request_finished. self._handler_class = None self.cookies = SimpleCookie() self.closed = False if status is not None: try: self.status_code = int(status) except (ValueError, TypeError): raise TypeError('HTTP status code must be an integer.') if not 100 <= self.status_code <= 599: raise ValueError('HTTP status code must be an integer from 100 to 599.') self._reason_phrase = reason self._charset = charset if content_type is None: content_type = 'text/html; charset=%s' % self.charset self['Content-Type'] = content_type @property def reason_phrase(self): if self._reason_phrase is not None: return self._reason_phrase # Leave self._reason_phrase unset in order to use the default # reason phrase for status code. return responses.get(self.status_code, 'Unknown Status Code') @reason_phrase.setter def reason_phrase(self, value): self._reason_phrase = value @property def charset(self): if self._charset is not None: return self._charset content_type = self.get('Content-Type', '') matched = _charset_from_content_type_re.search(content_type) if matched: # Extract the charset and strip its double quotes return matched.group('charset').replace('"', '') return settings.DEFAULT_CHARSET @charset.setter def charset(self, value): self._charset = value def serialize_headers(self): """HTTP headers as a bytestring.""" def to_bytes(val, encoding): return val if isinstance(val, bytes) else val.encode(encoding) headers = [ (to_bytes(key, 'ascii') + b': ' + to_bytes(value, 'latin-1')) for key, value in self._headers.values() ] return b'\r\n'.join(headers) __bytes__ = serialize_headers @property def _content_type_for_repr(self): return ', "%s"' % self['Content-Type'] if 'Content-Type' in self else '' def _convert_to_charset(self, value, charset, mime_encode=False): """ Convert headers key/value to ascii/latin-1 native strings. `charset` must be 'ascii' or 'latin-1'. If `mime_encode` is True and `value` can't be represented in the given charset, apply MIME-encoding. """ if not isinstance(value, (bytes, str)): value = str(value) if ((isinstance(value, bytes) and (b'\n' in value or b'\r' in value)) or isinstance(value, str) and ('\n' in value or '\r' in value)): raise BadHeaderError("Header values can't contain newlines (got %r)" % value) try: if isinstance(value, str): # Ensure string is valid in given charset value.encode(charset) else: # Convert bytestring using given charset value = value.decode(charset) except UnicodeError as e: if mime_encode: value = Header(value, 'utf-8', maxlinelen=sys.maxsize).encode() else: e.reason += ', HTTP response headers must be in %s format' % charset raise return value def __setitem__(self, header, value): header = self._convert_to_charset(header, 'ascii') value = self._convert_to_charset(value, 'latin-1', mime_encode=True) self._headers[header.lower()] = (header, value) def __delitem__(self, header): self._headers.pop(header.lower(), False) def __getitem__(self, header): return self._headers[header.lower()][1] def has_header(self, header): """Case-insensitive check for a header.""" return header.lower() in self._headers __contains__ = has_header def items(self): return self._headers.values() def get(self, header, alternate=None): return self._headers.get(header.lower(), (None, alternate))[1] def set_cookie(self, key, value='', max_age=None, expires=None, path='/', domain=None, secure=False, httponly=False, samesite=None): """ Set a cookie. ``expires`` can be: - a string in the correct format, - a naive ``datetime.datetime`` object in UTC, - an aware ``datetime.datetime`` object in any time zone. If it is a ``datetime.datetime`` object then calculate ``max_age``. """ self.cookies[key] = value if expires is not None: if isinstance(expires, datetime.datetime): if timezone.is_aware(expires): expires = timezone.make_naive(expires, timezone.utc) delta = expires - expires.utcnow() # Add one second so the date matches exactly (a fraction of # time gets lost between converting to a timedelta and # then the date string). delta = delta + datetime.timedelta(seconds=1) # Just set max_age - the max_age logic will set expires. expires = None max_age = max(0, delta.days * 86400 + delta.seconds) else: self.cookies[key]['expires'] = expires else: self.cookies[key]['expires'] = '' if max_age is not None: self.cookies[key]['max-age'] = max_age # IE requires expires, so set it if hasn't been already. if not expires: self.cookies[key]['expires'] = http_date(time.time() + max_age) if path is not None: self.cookies[key]['path'] = path if domain is not None: self.cookies[key]['domain'] = domain if secure: self.cookies[key]['secure'] = True if httponly: self.cookies[key]['httponly'] = True if samesite: if samesite.lower() not in ('lax', 'strict'): raise ValueError('samesite must be "lax" or "strict".') self.cookies[key]['samesite'] = samesite def setdefault(self, key, value): """Set a header unless it has already been set.""" if key not in self: self[key] = value def set_signed_cookie(self, key, value, salt='', **kwargs): value = signing.get_cookie_signer(salt=key + salt).sign(value) return self.set_cookie(key, value, **kwargs) def delete_cookie(self, key, path='/', domain=None): # Most browsers ignore the Set-Cookie header if the cookie name starts # with __Host- or __Secure- and the cookie doesn't use the secure flag. secure = key.startswith(('__Secure-', '__Host-')) self.set_cookie( key, max_age=0, path=path, domain=domain, secure=secure, expires='Thu, 01 Jan 1970 00:00:00 GMT', ) # Common methods used by subclasses def make_bytes(self, value): """Turn a value into a bytestring encoded in the output charset.""" # Per PEP 3333, this response body must be bytes. To avoid returning # an instance of a subclass, this function returns `bytes(value)`. # This doesn't make a copy when `value` already contains bytes. # Handle string types -- we can't rely on force_bytes here because: # - Python attempts str conversion first # - when self._charset != 'utf-8' it re-encodes the content if isinstance(value, (bytes, memoryview)): return bytes(value) if isinstance(value, str): return bytes(value.encode(self.charset)) # Handle non-string types. return str(value).encode(self.charset) # These methods partially implement the file-like object interface. # See https://docs.python.org/library/io.html#io.IOBase # The WSGI server must call this method upon completion of the request. # See http://blog.dscpl.com.au/2012/10/obligations-for-calling-close-on.html def close(self): for closer in self._resource_closers: try: closer() except Exception: pass # Free resources that were still referenced. self._resource_closers.clear() self.closed = True signals.request_finished.send(sender=self._handler_class) def write(self, content): raise OSError('This %s instance is not writable' % self.__class__.__name__) def flush(self): pass def tell(self): raise OSError('This %s instance cannot tell its position' % self.__class__.__name__) # These methods partially implement a stream-like object interface. # See https://docs.python.org/library/io.html#io.IOBase def readable(self): return False def seekable(self): return False def writable(self): return False def writelines(self, lines): raise OSError('This %s instance is not writable' % self.__class__.__name__) class HttpResponse(HttpResponseBase): """ An HTTP response class with a string as content. This content that can be read, appended to, or replaced. """ streaming = False def __init__(self, content=b'', *args, **kwargs): super().__init__(*args, **kwargs) # Content is a bytestring. See the `content` property methods. self.content = content def __repr__(self): return '<%(cls)s status_code=%(status_code)d%(content_type)s>' % { 'cls': self.__class__.__name__, 'status_code': self.status_code, 'content_type': self._content_type_for_repr, } def serialize(self): """Full HTTP message, including headers, as a bytestring.""" return self.serialize_headers() + b'\r\n\r\n' + self.content __bytes__ = serialize @property def content(self): return b''.join(self._container) @content.setter def content(self, value): # Consume iterators upon assignment to allow repeated iteration. if hasattr(value, '__iter__') and not isinstance(value, (bytes, str)): content = b''.join(self.make_bytes(chunk) for chunk in value) if hasattr(value, 'close'): try: value.close() except Exception: pass else: content = self.make_bytes(value) # Create a list of properly encoded bytestrings to support write(). self._container = [content] def __iter__(self): return iter(self._container) def write(self, content): self._container.append(self.make_bytes(content)) def tell(self): return len(self.content) def getvalue(self): return self.content def writable(self): return True def writelines(self, lines): for line in lines: self.write(line) class StreamingHttpResponse(HttpResponseBase): """ A streaming HTTP response class with an iterator as content. This should only be iterated once, when the response is streamed to the client. However, it can be appended to or replaced with a new iterator that wraps the original content (or yields entirely new content). """ streaming = True def __init__(self, streaming_content=(), *args, **kwargs): super().__init__(*args, **kwargs) # `streaming_content` should be an iterable of bytestrings. # See the `streaming_content` property methods. self.streaming_content = streaming_content @property def content(self): raise AttributeError( "This %s instance has no `content` attribute. Use " "`streaming_content` instead." % self.__class__.__name__ ) @property def streaming_content(self): return map(self.make_bytes, self._iterator) @streaming_content.setter def streaming_content(self, value): self._set_streaming_content(value) def _set_streaming_content(self, value): # Ensure we can never iterate on "value" more than once. self._iterator = iter(value) if hasattr(value, 'close'): self._resource_closers.append(value.close) def __iter__(self): return self.streaming_content def getvalue(self): return b''.join(self.streaming_content) class FileResponse(StreamingHttpResponse): """ A streaming HTTP response class optimized for files. """ block_size = 4096 def __init__(self, *args, as_attachment=False, filename='', **kwargs): self.as_attachment = as_attachment self.filename = filename super().__init__(*args, **kwargs) def _set_streaming_content(self, value): if not hasattr(value, 'read'): self.file_to_stream = None return super()._set_streaming_content(value) self.file_to_stream = filelike = value if hasattr(filelike, 'close'): self._resource_closers.append(filelike.close) value = iter(lambda: filelike.read(self.block_size), b'') self.set_headers(filelike) super()._set_streaming_content(value) def set_headers(self, filelike): """ Set some common response headers (Content-Length, Content-Type, and Content-Disposition) based on the `filelike` response content. """ encoding_map = { 'bzip2': 'application/x-bzip', 'gzip': 'application/gzip', 'xz': 'application/x-xz', } filename = getattr(filelike, 'name', None) filename = filename if (isinstance(filename, str) and filename) else self.filename if os.path.isabs(filename): self['Content-Length'] = os.path.getsize(filelike.name) elif hasattr(filelike, 'getbuffer'): self['Content-Length'] = filelike.getbuffer().nbytes if self.get('Content-Type', '').startswith('text/html'): if filename: content_type, encoding = mimetypes.guess_type(filename) # Encoding isn't set to prevent browsers from automatically # uncompressing files. content_type = encoding_map.get(encoding, content_type) self['Content-Type'] = content_type or 'application/octet-stream' else: self['Content-Type'] = 'application/octet-stream' filename = self.filename or os.path.basename(filename) if filename: disposition = 'attachment' if self.as_attachment else 'inline' try: filename.encode('ascii') file_expr = 'filename="{}"'.format(filename) except UnicodeEncodeError: file_expr = "filename*=utf-8''{}".format(quote(filename)) self['Content-Disposition'] = '{}; {}'.format(disposition, file_expr) elif self.as_attachment: self['Content-Disposition'] = 'attachment' class HttpResponseRedirectBase(HttpResponse): allowed_schemes = ['http', 'https', 'ftp'] def __init__(self, redirect_to, *args, **kwargs): super().__init__(*args, **kwargs) self['Location'] = iri_to_uri(redirect_to) parsed = urlparse(str(redirect_to)) if parsed.scheme and parsed.scheme not in self.allowed_schemes: raise DisallowedRedirect("Unsafe redirect to URL with protocol '%s'" % parsed.scheme) url = property(lambda self: self['Location']) def __repr__(self): return '<%(cls)s status_code=%(status_code)d%(content_type)s, url="%(url)s">' % { 'cls': self.__class__.__name__, 'status_code': self.status_code, 'content_type': self._content_type_for_repr, 'url': self.url, } class HttpResponseRedirect(HttpResponseRedirectBase): status_code = 302 class HttpResponsePermanentRedirect(HttpResponseRedirectBase): status_code = 301 class HttpResponseNotModified(HttpResponse): status_code = 304 def __init__(self, *args, **kwargs): super().__init__(*args, **kwargs) del self['content-type'] @HttpResponse.content.setter def content(self, value): if value: raise AttributeError("You cannot set content to a 304 (Not Modified) response") self._container = [] class HttpResponseBadRequest(HttpResponse): status_code = 400 class HttpResponseNotFound(HttpResponse): status_code = 404 class HttpResponseForbidden(HttpResponse): status_code = 403 class HttpResponseNotAllowed(HttpResponse): status_code = 405 def __init__(self, permitted_methods, *args, **kwargs): super().__init__(*args, **kwargs) self['Allow'] = ', '.join(permitted_methods) def __repr__(self): return '<%(cls)s [%(methods)s] status_code=%(status_code)d%(content_type)s>' % { 'cls': self.__class__.__name__, 'status_code': self.status_code, 'content_type': self._content_type_for_repr, 'methods': self['Allow'], } class HttpResponseGone(HttpResponse): status_code = 410 class HttpResponseServerError(HttpResponse): status_code = 500 class Http404(Exception): pass class JsonResponse(HttpResponse): """ An HTTP response class that consumes data to be serialized to JSON. :param data: Data to be dumped into json. By default only ``dict`` objects are allowed to be passed due to a security flaw before EcmaScript 5. See the ``safe`` parameter for more information. :param encoder: Should be a json encoder class. Defaults to ``django.core.serializers.json.DjangoJSONEncoder``. :param safe: Controls if only ``dict`` objects may be serialized. Defaults to ``True``. :param json_dumps_params: A dictionary of kwargs passed to json.dumps(). """ def __init__(self, data, encoder=DjangoJSONEncoder, safe=True, json_dumps_params=None, **kwargs): if safe and not isinstance(data, dict): raise TypeError( 'In order to allow non-dict objects to be serialized set the ' 'safe parameter to False.' ) if json_dumps_params is None: json_dumps_params = {} kwargs.setdefault('content_type', 'application/json') data = json.dumps(data, cls=encoder, **json_dumps_params) super().__init__(content=data, **kwargs)