Current File : //usr/lib/python3/dist-packages/pathod/language/base.py
import operator
import os
import abc
import functools
import pyparsing as pp
from mitmproxy.utils import strutils
from mitmproxy.utils import human
import typing # noqa
from . import generators
from . import exceptions
class Settings:
def __init__(
self,
is_client=False,
staticdir=None,
unconstrained_file_access=False,
request_host=None,
websocket_key=None,
protocol=None,
):
self.is_client = is_client
self.staticdir = staticdir
self.unconstrained_file_access = unconstrained_file_access
self.request_host = request_host
self.websocket_key = websocket_key # TODO: refactor this into the protocol
self.protocol = protocol
Sep = pp.Optional(pp.Literal(":")).suppress()
v_integer = pp.Word(pp.nums)\
.setName("integer")\
.setParseAction(lambda toks: int(toks[0]))
v_literal = pp.MatchFirst(
[
pp.QuotedString(
"\"",
unquoteResults=True,
multiline=True
),
pp.QuotedString(
"'",
unquoteResults=True,
multiline=True
),
]
)
v_naked_literal = pp.MatchFirst(
[
v_literal,
pp.Word("".join(i for i in pp.printables if i not in ",:\n@\'\""))
]
)
class Token:
"""
A token in the specification language. Tokens are immutable. The token
classes have no meaning in and of themselves, and are combined into
Components and Actions to build the language.
"""
__metaclass__ = abc.ABCMeta
@classmethod
def expr(cls): # pragma: no cover
"""
A parse expression.
"""
return None
@abc.abstractmethod
def spec(self): # pragma: no cover
"""
A parseable specification for this token.
"""
return None
@property
def unique_name(self) -> typing.Optional[str]:
"""
Controls uniqueness constraints for tokens. No two tokens with the
same name will be allowed. If no uniquness should be applied, this
should be None.
"""
return self.__class__.__name__.lower()
def resolve(self, settings_, msg_):
"""
Resolves this token to ready it for transmission. This means that
the calculated offsets of actions are fixed.
settings: a language.Settings instance
msg: The containing message
"""
return self
def __repr__(self):
return self.spec()
class _TokValueLiteral(Token):
def __init__(self, val):
self.val = strutils.escaped_str_to_bytes(val)
def get_generator(self, settings_):
return self.val
def freeze(self, settings_):
return self
class TokValueLiteral(_TokValueLiteral):
"""
A literal with Python-style string escaping
"""
@classmethod
def expr(cls):
e = v_literal.copy()
return e.setParseAction(cls.parseAction)
@classmethod
def parseAction(cls, x):
v = cls(*x)
return v
def spec(self):
inner = strutils.bytes_to_escaped_str(self.val)
inner = inner.replace(r"'", r"\x27")
return "'" + inner + "'"
class TokValueNakedLiteral(_TokValueLiteral):
@classmethod
def expr(cls):
e = v_naked_literal.copy()
return e.setParseAction(lambda x: cls(*x))
def spec(self):
return strutils.bytes_to_escaped_str(self.val, escape_single_quotes=True)
class TokValueGenerate(Token):
def __init__(self, usize, unit, datatype):
if not unit:
unit = "b"
self.usize, self.unit, self.datatype = usize, unit, datatype
def bytes(self):
return self.usize * human.SIZE_UNITS[self.unit]
def get_generator(self, settings_):
return generators.RandomGenerator(self.datatype, self.bytes())
def freeze(self, settings):
g = self.get_generator(settings)
return TokValueLiteral(strutils.bytes_to_escaped_str(g[:], escape_single_quotes=True))
@classmethod
def expr(cls):
e = pp.Literal("@").suppress() + v_integer
u = functools.reduce(
operator.or_,
[pp.Literal(i) for i in human.SIZE_UNITS.keys()]
).leaveWhitespace()
e = e + pp.Optional(u, default=None)
s = pp.Literal(",").suppress()
s += functools.reduce(
operator.or_,
[pp.Literal(i) for i in generators.DATATYPES.keys()]
)
e += pp.Optional(s, default="bytes")
return e.setParseAction(lambda x: cls(*x))
def spec(self):
s = "@%s" % self.usize
if self.unit != "b":
s += self.unit
if self.datatype != "bytes":
s += ",%s" % self.datatype
return s
class TokValueFile(Token):
def __init__(self, path):
self.path = str(path)
@classmethod
def expr(cls):
e = pp.Literal("<").suppress()
e = e + v_naked_literal
return e.setParseAction(lambda x: cls(*x))
def freeze(self, settings_):
return self
def get_generator(self, settings):
if not settings.staticdir:
raise exceptions.FileAccessDenied("File access disabled.")
s = os.path.expanduser(self.path)
s = os.path.normpath(
os.path.abspath(os.path.join(settings.staticdir, s))
)
uf = settings.unconstrained_file_access
if not uf and not s.startswith(os.path.normpath(settings.staticdir)):
raise exceptions.FileAccessDenied(
"File access outside of configured directory"
)
if not os.path.isfile(s):
raise exceptions.FileAccessDenied("File not readable")
return generators.FileGenerator(s)
def spec(self):
return "<'%s'" % self.path
TokValue = pp.MatchFirst(
[
TokValueGenerate.expr(),
TokValueFile.expr(),
TokValueLiteral.expr()
]
)
TokNakedValue = pp.MatchFirst(
[
TokValueGenerate.expr(),
TokValueFile.expr(),
TokValueLiteral.expr(),
TokValueNakedLiteral.expr(),
]
)
TokOffset = pp.MatchFirst(
[
v_integer,
pp.Literal("r"),
pp.Literal("a")
]
)
class _Component(Token):
"""
A value component of the primary specification of an message.
Components produce byte values describing the bytes of the message.
"""
def values(self, settings): # pragma: no cover
"""
A sequence of values, which can either be strings or generators.
"""
pass
def string(self, settings=None):
"""
A bytestring representation of the object.
"""
return b"".join(i[:] for i in self.values(settings or {}))
class KeyValue(_Component):
"""
A key/value pair.
cls.preamble: leader
"""
def __init__(self, key, value):
self.key, self.value = key, value
@classmethod
def expr(cls):
e = pp.Literal(cls.preamble).suppress()
e += TokValue
e += pp.Literal("=").suppress()
e += TokValue
return e.setParseAction(lambda x: cls(*x))
def spec(self):
return f"{self.preamble}{self.key.spec()}={self.value.spec()}"
def freeze(self, settings):
return self.__class__(
self.key.freeze(settings), self.value.freeze(settings)
)
class CaselessLiteral(_Component):
"""
A caseless token that can take only one value.
"""
def __init__(self, value):
self.value = value
@classmethod
def expr(cls):
spec = pp.CaselessLiteral(cls.TOK)
spec = spec.setParseAction(lambda x: cls(*x))
return spec
def values(self, settings):
return self.TOK
def spec(self):
return self.TOK
def freeze(self, settings_):
return self
class OptionsOrValue(_Component):
"""
Can be any of a specified set of options, or a value specifier.
"""
preamble = ""
options: typing.List[str] = []
def __init__(self, value):
# If it's a string, we were passed one of the options, so we lower-case
# it to be canonical. The user can specify a different case by using a
# string value literal.
self.option_used = False
if isinstance(value, str):
for i in self.options:
# Find the exact option value in a case-insensitive way
if i.lower() == value.lower():
self.option_used = True
value = TokValueLiteral(i)
break
self.value = value
@classmethod
def expr(cls):
parts = [pp.CaselessLiteral(i) for i in cls.options]
m = pp.MatchFirst(parts)
spec = m | TokValue.copy()
spec = spec.setParseAction(lambda x: cls(*x))
if cls.preamble:
spec = pp.Literal(cls.preamble).suppress() + spec
return spec
def values(self, settings):
return [
self.value.get_generator(settings)
]
def spec(self):
s = self.value.spec()
if s[1:-1].lower() in self.options:
s = s[1:-1].lower()
return f"{self.preamble}{s}"
def freeze(self, settings):
return self.__class__(self.value.freeze(settings))
class Integer(_Component):
bounds: typing.Tuple[typing.Optional[int], typing.Optional[int]] = (None, None)
preamble = ""
def __init__(self, value):
v = int(value)
outofbounds = any([
self.bounds[0] is not None and v < self.bounds[0],
self.bounds[1] is not None and v > self.bounds[1]
])
if outofbounds:
raise exceptions.ParseException(
"Integer value must be between %s and %s." % self.bounds,
0, 0
)
self.value = str(value).encode()
@classmethod
def expr(cls):
e = v_integer.copy()
if cls.preamble:
e = pp.Literal(cls.preamble).suppress() + e
return e.setParseAction(lambda x: cls(*x))
def values(self, settings):
return [self.value]
def spec(self):
return f"{self.preamble}{self.value.decode()}"
def freeze(self, settings_):
return self
class Value(_Component):
"""
A value component lead by an optional preamble.
"""
preamble = ""
def __init__(self, value):
self.value = value
@classmethod
def expr(cls):
e = (TokValue | TokNakedValue)
if cls.preamble:
e = pp.Literal(cls.preamble).suppress() + e
return e.setParseAction(lambda x: cls(*x))
def values(self, settings):
return [self.value.get_generator(settings)]
def spec(self):
return f"{self.preamble}{self.value.spec()}"
def freeze(self, settings):
return self.__class__(self.value.freeze(settings))
class FixedLengthValue(Value):
"""
A value component lead by an optional preamble.
"""
preamble = ""
length: typing.Optional[int] = None
def __init__(self, value):
Value.__init__(self, value)
lenguess = None
try:
lenguess = len(value.get_generator(Settings()))
except exceptions.RenderError:
pass
# This check will fail if we know the length upfront
if lenguess is not None and lenguess != self.length:
raise exceptions.RenderError(
"Invalid value length: '{}' is {} bytes, should be {}.".format(
self.spec(),
lenguess,
self.length
)
)
def values(self, settings):
ret = Value.values(self, settings)
l = sum(len(i) for i in ret)
# This check will fail if we don't know the length upfront - i.e. for
# file inputs
if l != self.length:
raise exceptions.RenderError(
"Invalid value length: '{}' is {} bytes, should be {}.".format(
self.spec(),
l,
self.length
)
)
return ret
class Boolean(_Component):
"""
A boolean flag.
name = true
-name = false
"""
name = ""
def __init__(self, value):
self.value = value
@classmethod
def expr(cls):
e = pp.Optional(pp.Literal("-"), default=True)
e += pp.Literal(cls.name).suppress()
def parse(s_, loc_, toks):
val = True
if toks[0] == "-":
val = False
return cls(val)
return e.setParseAction(parse)
def spec(self):
return "{}{}".format("-" if not self.value else "", self.name)
class IntField(_Component):
"""
An integer field, where values can optionally specified by name.
"""
names: typing.Dict[str, int] = {}
max = 16
preamble = ""
def __init__(self, value):
self.origvalue = value
self.value = self.names.get(value, value)
if self.value > self.max:
raise exceptions.ParseException(
"Value can't exceed %s" % self.max, 0, 0
)
@classmethod
def expr(cls):
parts = [pp.CaselessLiteral(i) for i in cls.names.keys()]
m = pp.MatchFirst(parts)
spec = m | v_integer.copy()
spec = spec.setParseAction(lambda x: cls(*x))
if cls.preamble:
spec = pp.Literal(cls.preamble).suppress() + spec
return spec
def values(self, settings):
return [str(self.value)]
def spec(self):
return f"{self.preamble}{self.origvalue}"
Mini Shell