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import random
import string
import mitmproxy.net.websockets
from mitmproxy.utils import strutils
import pyparsing as pp
from . import base, generators, actions, message
NESTED_LEADER = b"pathod!"
class WF(base.CaselessLiteral):
TOK = "wf"
class OpCode(base.IntField):
names = {
"continue": mitmproxy.net.websockets.OPCODE.CONTINUE,
"text": mitmproxy.net.websockets.OPCODE.TEXT,
"binary": mitmproxy.net.websockets.OPCODE.BINARY,
"close": mitmproxy.net.websockets.OPCODE.CLOSE,
"ping": mitmproxy.net.websockets.OPCODE.PING,
"pong": mitmproxy.net.websockets.OPCODE.PONG,
}
max = 15
preamble = "c"
class Body(base.Value):
preamble = "b"
class RawBody(base.Value):
unique_name = "body"
preamble = "r"
class Fin(base.Boolean):
name = "fin"
class RSV1(base.Boolean):
name = "rsv1"
class RSV2(base.Boolean):
name = "rsv2"
class RSV3(base.Boolean):
name = "rsv3"
class Mask(base.Boolean):
name = "mask"
class Key(base.FixedLengthValue):
preamble = "k"
length = 4
class KeyNone(base.CaselessLiteral):
unique_name = "key"
TOK = "knone"
class Length(base.Integer):
bounds = (0, 1 << 64)
preamble = "l"
class Times(base.Integer):
preamble = "x"
COMPONENTS = (
OpCode,
Length,
# Bit flags
Fin,
RSV1,
RSV2,
RSV3,
Mask,
actions.PauseAt,
actions.DisconnectAt,
actions.InjectAt,
KeyNone,
Key,
Times,
Body,
RawBody,
)
class WebsocketFrame(message.Message):
components = COMPONENTS
logattrs = ["body"]
# Used for nested frames
unique_name = "body"
@property
def actions(self):
return self.toks(actions._Action)
@property
def body(self):
return self.tok(Body)
@property
def rawbody(self):
return self.tok(RawBody)
@property
def opcode(self):
return self.tok(OpCode)
@property
def fin(self):
return self.tok(Fin)
@property
def rsv1(self):
return self.tok(RSV1)
@property
def rsv2(self):
return self.tok(RSV2)
@property
def rsv3(self):
return self.tok(RSV3)
@property
def mask(self):
return self.tok(Mask)
@property
def key(self):
return self.tok(Key)
@property
def knone(self):
return self.tok(KeyNone)
@property
def times(self):
return self.tok(Times)
@property
def toklength(self):
return self.tok(Length)
@classmethod
def expr(cls):
parts = [i.expr() for i in cls.components]
atom = pp.MatchFirst(parts)
resp = pp.And(
[
WF.expr(),
base.Sep,
pp.ZeroOrMore(base.Sep + atom)
]
)
resp = resp.setParseAction(cls)
return resp
@property
def nested_frame(self):
return self.tok(NestedFrame)
def resolve(self, settings, msg=None):
tokens = self.tokens[:]
if not self.mask and settings.is_client:
tokens.append(
Mask(True)
)
if not self.knone and self.mask and self.mask.value and not self.key:
allowed_chars = string.ascii_letters + string.digits
k = ''.join([allowed_chars[random.randrange(0, len(allowed_chars))] for i in range(4)])
tokens.append(
Key(base.TokValueLiteral(k))
)
return self.__class__(
[i.resolve(settings, self) for i in tokens]
)
def values(self, settings):
if self.body:
bodygen = self.body.value.get_generator(settings)
length = len(self.body.value.get_generator(settings))
elif self.rawbody:
bodygen = self.rawbody.value.get_generator(settings)
length = len(self.rawbody.value.get_generator(settings))
elif self.nested_frame:
bodygen = NESTED_LEADER + strutils.always_bytes(self.nested_frame.parsed.spec())
length = len(bodygen)
else:
bodygen = None
length = 0
if self.toklength:
length = int(self.toklength.value)
frameparts = dict(
payload_length=length
)
if self.mask and self.mask.value:
frameparts["mask"] = True
if self.knone:
frameparts["masking_key"] = None
elif self.key:
key = self.key.values(settings)[0][:]
frameparts["masking_key"] = key
for i in ["opcode", "fin", "rsv1", "rsv2", "rsv3", "mask"]:
v = getattr(self, i, None)
if v is not None:
frameparts[i] = v.value
frame = mitmproxy.net.websockets.FrameHeader(**frameparts)
vals = [bytes(frame)]
if bodygen:
if frame.masking_key and not self.rawbody:
masker = mitmproxy.net.websockets.Masker(frame.masking_key)
vals.append(
generators.TransformGenerator(
bodygen,
masker.mask
)
)
else:
vals.append(bodygen)
return vals
def spec(self):
return ":".join([i.spec() for i in self.tokens])
class NestedFrame(base.NestedMessage):
preamble = "f"
nest_type = WebsocketFrame
class WebsocketClientFrame(WebsocketFrame):
components = COMPONENTS + (
NestedFrame,
)
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