narrow_widen_acl: enforce narrowacl in narrow_widen (SEC)
Reviewer note: this was sent by the author as a simple bugfix, but can be
considered a security patch, since it allows users to access things outside
of the ACL, hence the (SEC) prefix.
However, this affects the `narrow` extention which is still marked as
experimental and has relatively few users aside from large companies with
their own security layers on top from what we can gather.
We feel (Alphare: or at least, I feel) like pinging the packaging list is
enough in this case.
# base85.py: pure python base85 codec
#
# Copyright (C) 2009 Brendan Cully <brendan@kublai.com>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.
from __future__ import absolute_import
import struct
from .. import pycompat
_b85chars = pycompat.bytestr(
b"0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdef"
b"ghijklmnopqrstuvwxyz!#$%&()*+-;<=>?@^_`{|}~"
)
_b85chars2 = [(a + b) for a in _b85chars for b in _b85chars]
_b85dec = {}
def _mkb85dec():
for i, c in enumerate(_b85chars):
_b85dec[c] = i
def b85encode(text, pad=False):
"""encode text in base85 format"""
l = len(text)
r = l % 4
if r:
text += b'\0' * (4 - r)
longs = len(text) >> 2
words = struct.unpack(b'>%dL' % longs, text)
out = b''.join(
_b85chars[(word // 52200625) % 85]
+ _b85chars2[(word // 7225) % 7225]
+ _b85chars2[word % 7225]
for word in words
)
if pad:
return out
# Trim padding
olen = l % 4
if olen:
olen += 1
olen += l // 4 * 5
return out[:olen]
def b85decode(text):
"""decode base85-encoded text"""
if not _b85dec:
_mkb85dec()
l = len(text)
out = []
for i in range(0, len(text), 5):
chunk = text[i : i + 5]
chunk = pycompat.bytestr(chunk)
acc = 0
for j, c in enumerate(chunk):
try:
acc = acc * 85 + _b85dec[c]
except KeyError:
raise ValueError(
'bad base85 character at position %d' % (i + j)
)
if acc > 4294967295:
raise ValueError('Base85 overflow in hunk starting at byte %d' % i)
out.append(acc)
# Pad final chunk if necessary
cl = l % 5
if cl:
acc *= 85 ** (5 - cl)
if cl > 1:
acc += 0xFFFFFF >> (cl - 2) * 8
out[-1] = acc
out = struct.pack(b'>%dL' % (len(out)), *out)
if cl:
out = out[: -(5 - cl)]
return out