161 lines
4.9 KiB
Python
161 lines
4.9 KiB
Python
import hashlib
|
|
|
|
from pip._internal.exceptions import HashMismatch, HashMissing, InstallationError
|
|
from pip._internal.utils.misc import read_chunks
|
|
from pip._internal.utils.typing import MYPY_CHECK_RUNNING
|
|
|
|
if MYPY_CHECK_RUNNING:
|
|
from hashlib import _Hash
|
|
from typing import BinaryIO, Dict, Iterator, List, NoReturn
|
|
|
|
|
|
# The recommended hash algo of the moment. Change this whenever the state of
|
|
# the art changes; it won't hurt backward compatibility.
|
|
FAVORITE_HASH = 'sha256'
|
|
|
|
|
|
# Names of hashlib algorithms allowed by the --hash option and ``pip hash``
|
|
# Currently, those are the ones at least as collision-resistant as sha256.
|
|
STRONG_HASHES = ['sha256', 'sha384', 'sha512']
|
|
|
|
|
|
class Hashes:
|
|
"""A wrapper that builds multiple hashes at once and checks them against
|
|
known-good values
|
|
|
|
"""
|
|
def __init__(self, hashes=None):
|
|
# type: (Dict[str, List[str]]) -> None
|
|
"""
|
|
:param hashes: A dict of algorithm names pointing to lists of allowed
|
|
hex digests
|
|
"""
|
|
allowed = {}
|
|
if hashes is not None:
|
|
for alg, keys in hashes.items():
|
|
# Make sure values are always sorted (to ease equality checks)
|
|
allowed[alg] = sorted(keys)
|
|
self._allowed = allowed
|
|
|
|
def __and__(self, other):
|
|
# type: (Hashes) -> Hashes
|
|
if not isinstance(other, Hashes):
|
|
return NotImplemented
|
|
|
|
# If either of the Hashes object is entirely empty (i.e. no hash
|
|
# specified at all), all hashes from the other object are allowed.
|
|
if not other:
|
|
return self
|
|
if not self:
|
|
return other
|
|
|
|
# Otherwise only hashes that present in both objects are allowed.
|
|
new = {}
|
|
for alg, values in other._allowed.items():
|
|
if alg not in self._allowed:
|
|
continue
|
|
new[alg] = [v for v in values if v in self._allowed[alg]]
|
|
return Hashes(new)
|
|
|
|
@property
|
|
def digest_count(self):
|
|
# type: () -> int
|
|
return sum(len(digests) for digests in self._allowed.values())
|
|
|
|
def is_hash_allowed(
|
|
self,
|
|
hash_name, # type: str
|
|
hex_digest, # type: str
|
|
):
|
|
# type: (...) -> bool
|
|
"""Return whether the given hex digest is allowed."""
|
|
return hex_digest in self._allowed.get(hash_name, [])
|
|
|
|
def check_against_chunks(self, chunks):
|
|
# type: (Iterator[bytes]) -> None
|
|
"""Check good hashes against ones built from iterable of chunks of
|
|
data.
|
|
|
|
Raise HashMismatch if none match.
|
|
|
|
"""
|
|
gots = {}
|
|
for hash_name in self._allowed.keys():
|
|
try:
|
|
gots[hash_name] = hashlib.new(hash_name)
|
|
except (ValueError, TypeError):
|
|
raise InstallationError(
|
|
f'Unknown hash name: {hash_name}'
|
|
)
|
|
|
|
for chunk in chunks:
|
|
for hash in gots.values():
|
|
hash.update(chunk)
|
|
|
|
for hash_name, got in gots.items():
|
|
if got.hexdigest() in self._allowed[hash_name]:
|
|
return
|
|
self._raise(gots)
|
|
|
|
def _raise(self, gots):
|
|
# type: (Dict[str, _Hash]) -> NoReturn
|
|
raise HashMismatch(self._allowed, gots)
|
|
|
|
def check_against_file(self, file):
|
|
# type: (BinaryIO) -> None
|
|
"""Check good hashes against a file-like object
|
|
|
|
Raise HashMismatch if none match.
|
|
|
|
"""
|
|
return self.check_against_chunks(read_chunks(file))
|
|
|
|
def check_against_path(self, path):
|
|
# type: (str) -> None
|
|
with open(path, 'rb') as file:
|
|
return self.check_against_file(file)
|
|
|
|
def __nonzero__(self):
|
|
# type: () -> bool
|
|
"""Return whether I know any known-good hashes."""
|
|
return bool(self._allowed)
|
|
|
|
def __bool__(self):
|
|
# type: () -> bool
|
|
return self.__nonzero__()
|
|
|
|
def __eq__(self, other):
|
|
# type: (object) -> bool
|
|
if not isinstance(other, Hashes):
|
|
return NotImplemented
|
|
return self._allowed == other._allowed
|
|
|
|
def __hash__(self):
|
|
# type: () -> int
|
|
return hash(
|
|
",".join(sorted(
|
|
":".join((alg, digest))
|
|
for alg, digest_list in self._allowed.items()
|
|
for digest in digest_list
|
|
))
|
|
)
|
|
|
|
|
|
class MissingHashes(Hashes):
|
|
"""A workalike for Hashes used when we're missing a hash for a requirement
|
|
|
|
It computes the actual hash of the requirement and raises a HashMissing
|
|
exception showing it to the user.
|
|
|
|
"""
|
|
def __init__(self):
|
|
# type: () -> None
|
|
"""Don't offer the ``hashes`` kwarg."""
|
|
# Pass our favorite hash in to generate a "gotten hash". With the
|
|
# empty list, it will never match, so an error will always raise.
|
|
super().__init__(hashes={FAVORITE_HASH: []})
|
|
|
|
def _raise(self, gots):
|
|
# type: (Dict[str, _Hash]) -> NoReturn
|
|
raise HashMissing(gots[FAVORITE_HASH].hexdigest())
|