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<charset>[^\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 lower-case 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._closable_objects = []
# 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 = '%s; charset=%s' % (settings.DEFAULT_CONTENT_TYPE,
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):
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 closable in self._closable_objects:
try:
closable.close()
except Exception:
pass
self.closed = True
signals.request_finished.send(sender=self._handler_class)
def write(self, content):
raise IOError("This %s instance is not writable" % self.__class__.__name__)
def flush(self):
pass
def tell(self):
raise IOError("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 IOError("This %s instance is not writable" % self.__class__.__name__)
[docs]class HttpResponse(HttpResponseBase):
"""
An HTTP response class with a string as content.
This content that can be read, appended to, or replaced.
"""
streaming = False
[docs] 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)
[docs]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._closable_objects.append(value)
def __iter__(self):
return self.streaming_content
def getvalue(self):
return b''.join(self.streaming_content)
[docs]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._closable_objects.append(filelike)
value = iter(lambda: filelike.read(self.block_size), b'')
self.set_headers(filelike)
super()._set_streaming_content(value)
[docs] 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(settings.DEFAULT_CONTENT_TYPE):
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'
if self.as_attachment:
filename = self.filename or os.path.basename(filename)
if filename:
try:
filename.encode('ascii')
file_expr = 'filename="{}"'.format(filename)
except UnicodeEncodeError:
file_expr = "filename*=utf-8''{}".format(quote(filename))
self['Content-Disposition'] = 'attachment; {}'.format(file_expr)
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,
}
[docs]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 = []
[docs]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 Http404(Exception):
pass
[docs]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)
Oct 31, 2018