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, )