mitmproxy/libmproxy/protocol/http_wrappers.py
2015-08-30 03:42:11 +02:00

414 lines
12 KiB
Python

from __future__ import absolute_import
import Cookie
import copy
import time
from email.utils import parsedate_tz, formatdate, mktime_tz
from netlib import odict, encoding
from netlib.http import semantics, CONTENT_MISSING
from .. import utils, stateobject
class decoded(object):
"""
A context manager that decodes a request or response, and then
re-encodes it with the same encoding after execution of the block.
Example:
with decoded(request):
request.content = request.content.replace("foo", "bar")
"""
def __init__(self, o):
self.o = o
ce = o.headers.get_first("content-encoding")
if ce in encoding.ENCODINGS:
self.ce = ce
else:
self.ce = None
def __enter__(self):
if self.ce:
self.o.decode()
def __exit__(self, type, value, tb):
if self.ce:
self.o.encode(self.ce)
class MessageMixin(stateobject.StateObject):
_stateobject_attributes = dict(
httpversion=tuple,
headers=odict.ODictCaseless,
body=str,
timestamp_start=float,
timestamp_end=float
)
_stateobject_long_attributes = {"body"}
def get_state(self, short=False):
ret = super(MessageMixin, self).get_state(short)
if short:
if self.body:
ret["contentLength"] = len(self.body)
elif self.body == CONTENT_MISSING:
ret["contentLength"] = None
else:
ret["contentLength"] = 0
return ret
def get_decoded_content(self):
"""
Returns the decoded content based on the current Content-Encoding
header.
Doesn't change the message iteself or its headers.
"""
ce = self.headers.get_first("content-encoding")
if not self.body or ce not in encoding.ENCODINGS:
return self.body
return encoding.decode(ce, self.body)
def decode(self):
"""
Decodes body based on the current Content-Encoding header, then
removes the header. If there is no Content-Encoding header, no
action is taken.
Returns True if decoding succeeded, False otherwise.
"""
ce = self.headers.get_first("content-encoding")
if not self.body or ce not in encoding.ENCODINGS:
return False
data = encoding.decode(ce, self.body)
if data is None:
return False
self.body = data
del self.headers["content-encoding"]
return True
def encode(self, e):
"""
Encodes body with the encoding e, where e is "gzip", "deflate"
or "identity".
"""
# FIXME: Error if there's an existing encoding header?
self.body = encoding.encode(e, self.body)
self.headers["content-encoding"] = [e]
def copy(self):
c = copy.copy(self)
c.headers = self.headers.copy()
return c
def replace(self, pattern, repl, *args, **kwargs):
"""
Replaces a regular expression pattern with repl in both the headers
and the body of the message. Encoded body will be decoded
before replacement, and re-encoded afterwards.
Returns the number of replacements made.
"""
with decoded(self):
self.body, c = utils.safe_subn(
pattern, repl, self.body, *args, **kwargs
)
c += self.headers.replace(pattern, repl, *args, **kwargs)
return c
class HTTPRequest(MessageMixin, semantics.Request):
"""
An HTTP request.
Exposes the following attributes:
method: HTTP method
scheme: URL scheme (http/https)
host: Target hostname of the request. This is not neccessarily the
directy upstream server (which could be another proxy), but it's always
the target server we want to reach at the end. This attribute is either
inferred from the request itself (absolute-form, authority-form) or from
the connection metadata (e.g. the host in reverse proxy mode).
port: Destination port
path: Path portion of the URL (not present in authority-form)
httpversion: HTTP version tuple, e.g. (1,1)
headers: odict.ODictCaseless object
content: Content of the request, None, or CONTENT_MISSING if there
is content associated, but not present. CONTENT_MISSING evaluates
to False to make checking for the presence of content natural.
form_in: The request form which mitmproxy has received. The following
values are possible:
- relative (GET /index.html, OPTIONS *) (covers origin form and
asterisk form)
- absolute (GET http://example.com:80/index.html)
- authority-form (CONNECT example.com:443)
Details: http://tools.ietf.org/html/draft-ietf-httpbis-p1-messaging-25#section-5.3
form_out: The request form which mitmproxy will send out to the
destination
timestamp_start: Timestamp indicating when request transmission started
timestamp_end: Timestamp indicating when request transmission ended
"""
def __init__(
self,
form_in,
method,
scheme,
host,
port,
path,
httpversion,
headers,
body,
timestamp_start=None,
timestamp_end=None,
form_out=None,
):
semantics.Request.__init__(
self,
form_in,
method,
scheme,
host,
port,
path,
httpversion,
headers,
body,
timestamp_start,
timestamp_end,
)
self.form_out = form_out or form_in
# Have this request's cookies been modified by sticky cookies or auth?
self.stickycookie = False
self.stickyauth = False
# Is this request replayed?
self.is_replay = False
_stateobject_attributes = MessageMixin._stateobject_attributes.copy()
_stateobject_attributes.update(
form_in=str,
method=str,
scheme=str,
host=str,
port=int,
path=str,
form_out=str,
is_replay=bool
)
@classmethod
def from_state(cls, state):
f = cls(
None,
None,
None,
None,
None,
None,
None,
None,
None,
None,
None)
f.load_state(state)
return f
@classmethod
def from_protocol(
self,
protocol,
*args,
**kwargs
):
req = protocol.read_request(*args, **kwargs)
return self.wrap(req)
@classmethod
def wrap(self, request):
req = HTTPRequest(
form_in=request.form_in,
method=request.method,
scheme=request.scheme,
host=request.host,
port=request.port,
path=request.path,
httpversion=request.httpversion,
headers=request.headers,
body=request.body,
timestamp_start=request.timestamp_start,
timestamp_end=request.timestamp_end,
form_out=(request.form_out if hasattr(request, 'form_out') else None),
)
if hasattr(request, 'stream_id'):
req.stream_id = request.stream_id
return req
def __hash__(self):
return id(self)
def replace(self, pattern, repl, *args, **kwargs):
"""
Replaces a regular expression pattern with repl in the headers, the
request path and the body of the request. Encoded content will be
decoded before replacement, and re-encoded afterwards.
Returns the number of replacements made.
"""
c = MessageMixin.replace(self, pattern, repl, *args, **kwargs)
self.path, pc = utils.safe_subn(
pattern, repl, self.path, *args, **kwargs
)
c += pc
return c
class HTTPResponse(MessageMixin, semantics.Response):
"""
An HTTP response.
Exposes the following attributes:
httpversion: HTTP version tuple, e.g. (1, 0), (1, 1), or (2, 0)
status_code: HTTP response status code
msg: HTTP response message
headers: ODict Caseless object
content: Content of the request, None, or CONTENT_MISSING if there
is content associated, but not present. CONTENT_MISSING evaluates
to False to make checking for the presence of content natural.
timestamp_start: Timestamp indicating when request transmission started
timestamp_end: Timestamp indicating when request transmission ended
"""
def __init__(
self,
httpversion,
status_code,
msg,
headers,
body,
timestamp_start=None,
timestamp_end=None,
):
semantics.Response.__init__(
self,
httpversion,
status_code,
msg,
headers,
body,
timestamp_start=timestamp_start,
timestamp_end=timestamp_end,
)
# Is this request replayed?
self.is_replay = False
self.stream = False
_stateobject_attributes = MessageMixin._stateobject_attributes.copy()
_stateobject_attributes.update(
status_code=int,
msg=str
)
@classmethod
def from_state(cls, state):
f = cls(None, None, None, None, None)
f.load_state(state)
return f
@classmethod
def from_protocol(
self,
protocol,
*args,
**kwargs
):
resp = protocol.read_response(*args, **kwargs)
return self.wrap(resp)
@classmethod
def wrap(self, response):
resp = HTTPResponse(
httpversion=response.httpversion,
status_code=response.status_code,
msg=response.msg,
headers=response.headers,
body=response.body,
timestamp_start=response.timestamp_start,
timestamp_end=response.timestamp_end,
)
if hasattr(response, 'stream_id'):
resp.stream_id = response.stream_id
return resp
def _refresh_cookie(self, c, delta):
"""
Takes a cookie string c and a time delta in seconds, and returns
a refreshed cookie string.
"""
c = Cookie.SimpleCookie(str(c))
for i in c.values():
if "expires" in i:
d = parsedate_tz(i["expires"])
if d:
d = mktime_tz(d) + delta
i["expires"] = formatdate(d)
else:
# This can happen when the expires tag is invalid.
# reddit.com sends a an expires tag like this: "Thu, 31 Dec
# 2037 23:59:59 GMT", which is valid RFC 1123, but not
# strictly correct according to the cookie spec. Browsers
# appear to parse this tolerantly - maybe we should too.
# For now, we just ignore this.
del i["expires"]
return c.output(header="").strip()
def refresh(self, now=None):
"""
This fairly complex and heuristic function refreshes a server
response for replay.
- It adjusts date, expires and last-modified headers.
- It adjusts cookie expiration.
"""
if not now:
now = time.time()
delta = now - self.timestamp_start
refresh_headers = [
"date",
"expires",
"last-modified",
]
for i in refresh_headers:
if i in self.headers:
d = parsedate_tz(self.headers[i][0])
if d:
new = mktime_tz(d) + delta
self.headers[i] = [formatdate(new)]
c = []
for i in self.headers["set-cookie"]:
c.append(self._refresh_cookie(i, delta))
if c:
self.headers["set-cookie"] = c