laywerrobot/lib/python3.6/site-packages/wheel/install.py
2020-08-27 21:55:39 +02:00

512 lines
18 KiB
Python

"""
Operations on existing wheel files, including basic installation.
"""
# XXX see patched pip to install
from __future__ import print_function
import csv
import hashlib
import os.path
import re
import shutil
import sys
import warnings
import zipfile
from . import signatures
from .paths import get_install_paths
from .pep425tags import get_supported
from .pkginfo import read_pkg_info_bytes
from .util import (
urlsafe_b64encode, from_json, urlsafe_b64decode, native, binary, HashingFile, open_for_csv)
try:
_big_number = sys.maxsize
except NameError:
_big_number = sys.maxint
# The next major version after this version of the 'wheel' tool:
VERSION_TOO_HIGH = (1, 0)
# Non-greedy matching of an optional build number may be too clever (more
# invalid wheel filenames will match). Separate regex for .dist-info?
WHEEL_INFO_RE = re.compile(
r"""^(?P<namever>(?P<name>.+?)-(?P<ver>\d.*?))(-(?P<build>\d.*?))?
-(?P<pyver>[a-z].+?)-(?P<abi>.+?)-(?P<plat>.+?)(\.whl|\.dist-info)$""",
re.VERBOSE).match
def parse_version(version):
"""Use parse_version from pkg_resources or distutils as available."""
global parse_version
try:
from pkg_resources import parse_version
except ImportError:
from distutils.version import LooseVersion as parse_version
return parse_version(version)
class reify(object):
"""Put the result of a method which uses this (non-data)
descriptor decorator in the instance dict after the first call,
effectively replacing the decorator with an instance variable.
"""
def __init__(self, wrapped):
self.wrapped = wrapped
self.__doc__ = wrapped.__doc__
def __get__(self, inst, objtype=None):
if inst is None:
return self
val = self.wrapped(inst)
setattr(inst, self.wrapped.__name__, val)
return val
class BadWheelFile(ValueError):
pass
class WheelFile(object):
"""Parse wheel-specific attributes from a wheel (.whl) file and offer
basic installation and verification support.
WheelFile can be used to simply parse a wheel filename by avoiding the
methods that require the actual file contents."""
WHEEL_INFO = "WHEEL"
RECORD = "RECORD"
def __init__(self,
filename,
fp=None,
append=False,
context=get_supported):
"""
:param fp: A seekable file-like object or None to open(filename).
:param append: Open archive in append mode.
:param context: Function returning list of supported tags. Wheels
must have the same context to be sortable.
"""
self.filename = filename
self.fp = fp
self.append = append
self.context = context
basename = os.path.basename(filename)
self.parsed_filename = WHEEL_INFO_RE(basename)
if not basename.endswith('.whl') or self.parsed_filename is None:
raise BadWheelFile("Bad filename '%s'" % filename)
def __repr__(self):
return self.filename
@property
def distinfo_name(self):
return "%s.dist-info" % self.parsed_filename.group('namever')
@property
def datadir_name(self):
return "%s.data" % self.parsed_filename.group('namever')
@property
def record_name(self):
return "%s/%s" % (self.distinfo_name, self.RECORD)
@property
def wheelinfo_name(self):
return "%s/%s" % (self.distinfo_name, self.WHEEL_INFO)
@property
def tags(self):
"""A wheel file is compatible with the Cartesian product of the
period-delimited tags in its filename.
To choose a wheel file among several candidates having the same
distribution version 'ver', an installer ranks each triple of
(pyver, abi, plat) that its Python installation can run, sorting
the wheels by the best-ranked tag it supports and then by their
arity which is just len(list(compatibility_tags)).
"""
tags = self.parsed_filename.groupdict()
for pyver in tags['pyver'].split('.'):
for abi in tags['abi'].split('.'):
for plat in tags['plat'].split('.'):
yield (pyver, abi, plat)
compatibility_tags = tags
@property
def arity(self):
"""The number of compatibility tags the wheel declares."""
return len(list(self.compatibility_tags))
@property
def rank(self):
"""
Lowest index of any of this wheel's tags in self.context(), and the
arity e.g. (0, 1)
"""
return self.compatibility_rank(self.context())
@property
def compatible(self):
return self.rank[0] != _big_number # bad API!
# deprecated:
def compatibility_rank(self, supported):
"""Rank the wheel against the supported tags. Smaller ranks are more
compatible!
:param supported: A list of compatibility tags that the current
Python implemenation can run.
"""
preferences = []
for tag in self.compatibility_tags:
try:
preferences.append(supported.index(tag))
# Tag not present
except ValueError:
pass
if len(preferences):
return (min(preferences), self.arity)
return (_big_number, 0)
# deprecated
def supports_current_python(self, x):
assert self.context == x, 'context mismatch'
return self.compatible
# Comparability.
# Wheels are equal if they refer to the same file.
# If two wheels are not equal, compare based on (in this order):
# 1. Name
# 2. Version
# 3. Compatibility rank
# 4. Filename (as a tiebreaker)
@property
def _sort_key(self):
return (self.parsed_filename.group('name'),
parse_version(self.parsed_filename.group('ver')),
tuple(-x for x in self.rank),
self.filename)
def __eq__(self, other):
return self.filename == other.filename
def __ne__(self, other):
return self.filename != other.filename
def __lt__(self, other):
if self.context != other.context:
raise TypeError("{0}.context != {1}.context".format(self, other))
return self._sort_key < other._sort_key
# XXX prune
sn = self.parsed_filename.group('name')
on = other.parsed_filename.group('name')
if sn != on:
return sn < on
sv = parse_version(self.parsed_filename.group('ver'))
ov = parse_version(other.parsed_filename.group('ver'))
if sv != ov:
return sv < ov
# Compatibility
if self.context != other.context:
raise TypeError("{0}.context != {1}.context".format(self, other))
sc = self.rank
oc = other.rank
if sc is not None and oc is not None and sc != oc:
# Smaller compatibility ranks are "better" than larger ones,
# so we have to reverse the sense of the comparison here!
return sc > oc
elif sc is None and oc is not None:
return False
return self.filename < other.filename
def __gt__(self, other):
return other < self
def __le__(self, other):
return self == other or self < other
def __ge__(self, other):
return self == other or other < self
#
# Methods using the file's contents:
#
@reify
def zipfile(self):
mode = "r"
if self.append:
mode = "a"
vzf = VerifyingZipFile(self.fp if self.fp else self.filename, mode)
if not self.append:
self.verify(vzf)
return vzf
@reify
def parsed_wheel_info(self):
"""Parse wheel metadata (the .data/WHEEL file)"""
return read_pkg_info_bytes(self.zipfile.read(self.wheelinfo_name))
def check_version(self):
version = self.parsed_wheel_info['Wheel-Version']
if tuple(map(int, version.split('.'))) >= VERSION_TOO_HIGH:
raise ValueError("Wheel version is too high")
@reify
def install_paths(self):
"""
Consult distutils to get the install paths for our dist. A dict with
('purelib', 'platlib', 'headers', 'scripts', 'data').
We use the name from our filename as the dist name, which means headers
could be installed in the wrong place if the filesystem-escaped name
is different than the Name. Who cares?
"""
name = self.parsed_filename.group('name')
return get_install_paths(name)
def install(self, force=False, overrides={}):
"""
Install the wheel into site-packages.
"""
# Utility to get the target directory for a particular key
def get_path(key):
return overrides.get(key) or self.install_paths[key]
# The base target location is either purelib or platlib
if self.parsed_wheel_info['Root-Is-Purelib'] == 'true':
root = get_path('purelib')
else:
root = get_path('platlib')
# Parse all the names in the archive
name_trans = {}
for info in self.zipfile.infolist():
name = info.filename
# Zip files can contain entries representing directories.
# These end in a '/'.
# We ignore these, as we create directories on demand.
if name.endswith('/'):
continue
# Pathnames in a zipfile namelist are always /-separated.
# In theory, paths could start with ./ or have other oddities
# but this won't happen in practical cases of well-formed wheels.
# We'll cover the simple case of an initial './' as it's both easy
# to do and more common than most other oddities.
if name.startswith('./'):
name = name[2:]
# Split off the base directory to identify files that are to be
# installed in non-root locations
basedir, sep, filename = name.partition('/')
if sep and basedir == self.datadir_name:
# Data file. Target destination is elsewhere
key, sep, filename = filename.partition('/')
if not sep:
raise ValueError("Invalid filename in wheel: {0}".format(name))
target = get_path(key)
else:
# Normal file. Target destination is root
key = ''
target = root
filename = name
# Map the actual filename from the zipfile to its intended target
# directory and the pathname relative to that directory.
dest = os.path.normpath(os.path.join(target, filename))
name_trans[info] = (key, target, filename, dest)
# We're now ready to start processing the actual install. The process
# is as follows:
# 1. Prechecks - is the wheel valid, is its declared architecture
# OK, etc. [[Responsibility of the caller]]
# 2. Overwrite check - do any of the files to be installed already
# exist?
# 3. Actual install - put the files in their target locations.
# 4. Update RECORD - write a suitably modified RECORD file to
# reflect the actual installed paths.
if not force:
for info, v in name_trans.items():
k = info.filename
key, target, filename, dest = v
if os.path.exists(dest):
raise ValueError(
"Wheel file {0} would overwrite {1}. Use force if this is intended".format(
k, dest))
# Get the name of our executable, for use when replacing script
# wrapper hashbang lines.
# We encode it using getfilesystemencoding, as that is "the name of
# the encoding used to convert Unicode filenames into system file
# names".
exename = sys.executable.encode(sys.getfilesystemencoding())
record_data = []
record_name = self.distinfo_name + '/RECORD'
for info, (key, target, filename, dest) in name_trans.items():
name = info.filename
source = self.zipfile.open(info)
# Skip the RECORD file
if name == record_name:
continue
ddir = os.path.dirname(dest)
if not os.path.isdir(ddir):
os.makedirs(ddir)
temp_filename = dest + '.part'
try:
with HashingFile(temp_filename, 'wb') as destination:
if key == 'scripts':
hashbang = source.readline()
if hashbang.startswith(b'#!python'):
hashbang = b'#!' + exename + binary(os.linesep)
destination.write(hashbang)
shutil.copyfileobj(source, destination)
except BaseException:
if os.path.exists(temp_filename):
os.unlink(temp_filename)
raise
os.rename(temp_filename, dest)
reldest = os.path.relpath(dest, root)
reldest.replace(os.sep, '/')
record_data.append((reldest, destination.digest(), destination.length))
destination.close()
source.close()
# preserve attributes (especially +x bit for scripts)
attrs = info.external_attr >> 16
if attrs: # tends to be 0 if Windows.
os.chmod(dest, info.external_attr >> 16)
record_name = os.path.join(root, self.record_name)
with open_for_csv(record_name, 'w+') as record_file:
writer = csv.writer(record_file)
for reldest, digest, length in sorted(record_data):
writer.writerow((reldest, digest, length))
writer.writerow((self.record_name, '', ''))
def verify(self, zipfile=None):
"""Configure the VerifyingZipFile `zipfile` by verifying its signature
and setting expected hashes for every hash in RECORD.
Caller must complete the verification process by completely reading
every file in the archive (e.g. with extractall)."""
sig = None
if zipfile is None:
zipfile = self.zipfile
zipfile.strict = True
record_name = '/'.join((self.distinfo_name, 'RECORD'))
sig_name = '/'.join((self.distinfo_name, 'RECORD.jws'))
# tolerate s/mime signatures:
smime_sig_name = '/'.join((self.distinfo_name, 'RECORD.p7s'))
zipfile.set_expected_hash(record_name, None)
zipfile.set_expected_hash(sig_name, None)
zipfile.set_expected_hash(smime_sig_name, None)
record = zipfile.read(record_name)
record_digest = urlsafe_b64encode(hashlib.sha256(record).digest())
try:
sig = from_json(native(zipfile.read(sig_name)))
except KeyError: # no signature
pass
if sig:
headers, payload = signatures.verify(sig)
if payload['hash'] != "sha256=" + native(record_digest):
msg = "RECORD.jws claimed RECORD hash {} != computed hash {}."
raise BadWheelFile(msg.format(payload['hash'],
native(record_digest)))
reader = csv.reader((native(r, 'utf-8') for r in record.splitlines()))
for row in reader:
filename = row[0]
hash = row[1]
if not hash:
if filename not in (record_name, sig_name):
print("%s has no hash!" % filename, file=sys.stderr)
continue
algo, data = row[1].split('=', 1)
assert algo == "sha256", "Unsupported hash algorithm"
zipfile.set_expected_hash(filename, urlsafe_b64decode(binary(data)))
class VerifyingZipFile(zipfile.ZipFile):
"""ZipFile that can assert that each of its extracted contents matches
an expected sha256 hash. Note that each file must be completely read in
order for its hash to be checked."""
def __init__(self, file, mode="r",
compression=zipfile.ZIP_STORED,
allowZip64=True):
super(VerifyingZipFile, self).__init__(file, mode, compression, allowZip64)
self.strict = False
self._expected_hashes = {}
self._hash_algorithm = hashlib.sha256
def set_expected_hash(self, name, hash):
"""
:param name: name of zip entry
:param hash: bytes of hash (or None for "don't care")
"""
self._expected_hashes[name] = hash
def open(self, name_or_info, mode="r", pwd=None):
"""Return file-like object for 'name'."""
# A non-monkey-patched version would contain most of zipfile.py
ef = super(VerifyingZipFile, self).open(name_or_info, mode, pwd)
if isinstance(name_or_info, zipfile.ZipInfo):
name = name_or_info.filename
else:
name = name_or_info
if name in self._expected_hashes and self._expected_hashes[name] is not None:
expected_hash = self._expected_hashes[name]
try:
_update_crc_orig = ef._update_crc
except AttributeError:
warnings.warn('Need ZipExtFile._update_crc to implement '
'file hash verification (in Python >= 2.7)')
return ef
running_hash = self._hash_algorithm()
if hasattr(ef, '_eof'): # py33
def _update_crc(data):
_update_crc_orig(data)
running_hash.update(data)
if ef._eof and running_hash.digest() != expected_hash:
raise BadWheelFile("Bad hash for file %r" % ef.name)
else:
def _update_crc(data, eof=None):
_update_crc_orig(data, eof=eof)
running_hash.update(data)
if eof and running_hash.digest() != expected_hash:
raise BadWheelFile("Bad hash for file %r" % ef.name)
ef._update_crc = _update_crc
elif self.strict and name not in self._expected_hashes:
raise BadWheelFile("No expected hash for file %r" % ef.name)
return ef
def pop(self):
"""Truncate the last file off this zipfile.
Assumes infolist() is in the same order as the files (true for
ordinary zip files created by Python)"""
if not self.fp:
raise RuntimeError(
"Attempt to pop from ZIP archive that was already closed")
last = self.infolist().pop()
del self.NameToInfo[last.filename]
self.fp.seek(last.header_offset, os.SEEK_SET)
self.fp.truncate()
self._didModify = True