mitmproxy/netlib/utils.py
Maximilian Hils 693cdfc6d7 python3++
2015-09-20 19:40:09 +02:00

343 lines
8.9 KiB
Python

from __future__ import absolute_import, print_function, division
import os.path
import re
import string
import unicodedata
import six
from six.moves import urllib
def isascii(bytes):
try:
bytes.decode("ascii")
except ValueError:
return False
return True
def clean_bin(s, keep_spacing=True):
"""
Cleans binary data to make it safe to display.
Args:
keep_spacing: If False, tabs and newlines will also be replaced.
"""
if isinstance(s, six.text_type):
if keep_spacing:
keep = u" \n\r\t"
else:
keep = u" "
return u"".join(
ch if (unicodedata.category(ch)[0] not in "CZ" or ch in keep) else u"."
for ch in s
)
else:
if keep_spacing:
keep = (9, 10, 13) # \t, \n, \r,
else:
keep = ()
return b"".join(
six.int2byte(ch) if (31 < ch < 127 or ch in keep) else b"."
for ch in six.iterbytes(s)
)
def hexdump(s):
"""
Returns:
A generator of (offset, hex, str) tuples
"""
for i in range(0, len(s), 16):
offset = b"%.10x" % i
part = s[i:i + 16]
x = b" ".join(b"%.2x" % i for i in six.iterbytes(part))
x = x.ljust(47) # 16*2 + 15
yield (offset, x, clean_bin(part, False))
def setbit(byte, offset, value):
"""
Set a bit in a byte to 1 if value is truthy, 0 if not.
"""
if value:
return byte | (1 << offset)
else:
return byte & ~(1 << offset)
def getbit(byte, offset):
mask = 1 << offset
return bool(byte & mask)
class BiDi(object):
"""
A wee utility class for keeping bi-directional mappings, like field
constants in protocols. Names are attributes on the object, dict-like
access maps values to names:
CONST = BiDi(a=1, b=2)
assert CONST.a == 1
assert CONST.get_name(1) == "a"
"""
def __init__(self, **kwargs):
self.names = kwargs
self.values = {}
for k, v in kwargs.items():
self.values[v] = k
if len(self.names) != len(self.values):
raise ValueError("Duplicate values not allowed.")
def __getattr__(self, k):
if k in self.names:
return self.names[k]
raise AttributeError("No such attribute: %s", k)
def get_name(self, n, default=None):
return self.values.get(n, default)
def pretty_size(size):
suffixes = [
("B", 2 ** 10),
("kB", 2 ** 20),
("MB", 2 ** 30),
]
for suf, lim in suffixes:
if size >= lim:
continue
else:
x = round(size / float(lim / 2 ** 10), 2)
if x == int(x):
x = int(x)
return str(x) + suf
class Data(object):
def __init__(self, name):
m = __import__(name)
dirname, _ = os.path.split(m.__file__)
self.dirname = os.path.abspath(dirname)
def path(self, path):
"""
Returns a path to the package data housed at 'path' under this
module.Path can be a path to a file, or to a directory.
This function will raise ValueError if the path does not exist.
"""
fullpath = os.path.join(self.dirname, '../test/', path)
if not os.path.exists(fullpath):
raise ValueError("dataPath: %s does not exist." % fullpath)
return fullpath
_label_valid = re.compile(b"(?!-)[A-Z\d-]{1,63}(?<!-)$", re.IGNORECASE)
def is_valid_host(host):
"""
Checks if a hostname is valid.
Args:
host (bytes): The hostname
"""
try:
host.decode("idna")
except ValueError:
return False
if len(host) > 255:
return False
if host[-1] == b".":
host = host[:-1]
return all(_label_valid.match(x) for x in host.split(b"."))
def is_valid_port(port):
return 0 <= port <= 65535
# PY2 workaround
def decode_parse_result(result, enc):
if hasattr(result, "decode"):
return result.decode(enc)
else:
return urllib.parse.ParseResult(*[x.decode(enc) for x in result])
# PY2 workaround
def encode_parse_result(result, enc):
if hasattr(result, "encode"):
return result.encode(enc)
else:
return urllib.parse.ParseResult(*[x.encode(enc) for x in result])
def parse_url(url):
"""
URL-parsing function that checks that
- port is an integer 0-65535
- host is a valid IDNA-encoded hostname with no null-bytes
- path is valid ASCII
Args:
A URL (as bytes or as unicode)
Returns:
A (scheme, host, port, path) tuple
Raises:
ValueError, if the URL is not properly formatted.
"""
parsed = urllib.parse.urlparse(url)
if not parsed.hostname:
raise ValueError("No hostname given")
if isinstance(url, six.binary_type):
host = parsed.hostname
# this should not raise a ValueError
decode_parse_result(parsed, "ascii")
else:
host = parsed.hostname.encode("idna")
parsed = encode_parse_result(parsed, "ascii")
port = parsed.port
if not port:
port = 443 if parsed.scheme == b"https" else 80
full_path = urllib.parse.urlunparse(
(b"", b"", parsed.path, parsed.params, parsed.query, parsed.fragment)
)
if not full_path.startswith(b"/"):
full_path = b"/" + full_path
if not is_valid_host(host):
raise ValueError("Invalid Host")
if not is_valid_port(port):
raise ValueError("Invalid Port")
return parsed.scheme, host, port, full_path
def get_header_tokens(headers, key):
"""
Retrieve all tokens for a header key. A number of different headers
follow a pattern where each header line can containe comma-separated
tokens, and headers can be set multiple times.
"""
if key not in headers:
return []
tokens = headers[key].split(b",")
return [token.strip() for token in tokens]
def hostport(scheme, host, port):
"""
Returns the host component, with a port specifcation if needed.
"""
if (port, scheme) in [(80, b"http"), (443, b"https")]:
return host
else:
return b"%s:%d" % (host, port)
def unparse_url(scheme, host, port, path=""):
"""
Returns a URL string, constructed from the specified compnents.
"""
return b"%s://%s%s" % (scheme, hostport(scheme, host, port), path)
def urlencode(s):
"""
Takes a list of (key, value) tuples and returns a urlencoded string.
"""
s = [tuple(i) for i in s]
return urllib.parse.urlencode(s, False)
def urldecode(s):
"""
Takes a urlencoded string and returns a list of (key, value) tuples.
"""
return urllib.parse.parse_qsl(s, keep_blank_values=True)
def parse_content_type(c):
"""
A simple parser for content-type values. Returns a (type, subtype,
parameters) tuple, where type and subtype are strings, and parameters
is a dict. If the string could not be parsed, return None.
E.g. the following string:
text/html; charset=UTF-8
Returns:
("text", "html", {"charset": "UTF-8"})
"""
parts = c.split(b";", 1)
ts = parts[0].split(b"/", 1)
if len(ts) != 2:
return None
d = {}
if len(parts) == 2:
for i in parts[1].split(b";"):
clause = i.split(b"=", 1)
if len(clause) == 2:
d[clause[0].strip()] = clause[1].strip()
return ts[0].lower(), ts[1].lower(), d
def multipartdecode(headers, content):
"""
Takes a multipart boundary encoded string and returns list of (key, value) tuples.
"""
v = headers.get(b"Content-Type")
if v:
v = parse_content_type(v)
if not v:
return []
boundary = v[2].get(b"boundary")
if not boundary:
return []
rx = re.compile(br'\bname="([^"]+)"')
r = []
for i in content.split(b"--" + boundary):
parts = i.splitlines()
if len(parts) > 1 and parts[0][0:2] != b"--":
match = rx.search(parts[1])
if match:
key = match.group(1)
value = b"".join(parts[3 + parts[2:].index(b""):])
r.append((key, value))
return r
return []
def always_bytes(unicode_or_bytes, *encode_args):
if isinstance(unicode_or_bytes, six.text_type):
return unicode_or_bytes.encode(*encode_args)
return unicode_or_bytes
def always_byte_args(*encode_args):
"""Decorator that transparently encodes all arguments passed as unicode"""
def decorator(fun):
def _fun(*args, **kwargs):
args = [always_bytes(arg, *encode_args) for arg in args]
kwargs = {k: always_bytes(v, *encode_args) for k, v in six.iteritems(kwargs)}
return fun(*args, **kwargs)
return _fun
return decorator