templates: add filter to reverse list
The filter supports only lists because for lists, it’s straightforward to
implement. Reversing text doesn’t seem very useful and is hard to implement.
Reversing the bytes would break multi-bytes encodings. Reversing the code
points would break characters consisting of multiple code points. Reversing
graphemes is non-trivial without using a library not included in the standard
library.
import base64
import hashlib
from mercurial.hgweb import common
from mercurial import node
def parse_keqv_list(req, l):
"""Parse list of key=value strings where keys are not duplicated."""
parsed = {}
for elt in l:
k, v = elt.split(b'=', 1)
if v[0:1] == b'"' and v[-1:] == b'"':
v = v[1:-1]
parsed[k] = v
return parsed
class digestauthserver:
def __init__(self):
self._user_hashes = {}
def gethashers(self):
def _md5sum(x):
m = hashlib.md5()
m.update(x)
return node.hex(m.digest())
h = _md5sum
kd = lambda s, d, h=h: h(b"%s:%s" % (s, d))
return h, kd
def adduser(self, user, password, realm):
h, kd = self.gethashers()
a1 = h(b'%s:%s:%s' % (user, realm, password))
self._user_hashes[(user, realm)] = a1
def makechallenge(self, realm):
# We aren't testing the protocol here, just that the bytes make the
# proper round trip. So hardcoded seems fine.
nonce = b'064af982c5b571cea6450d8eda91c20d'
return b'realm="%s", nonce="%s", algorithm=MD5, qop="auth"' % (
realm,
nonce,
)
def checkauth(self, req, header):
log = req.rawenv[b'wsgi.errors']
h, kd = self.gethashers()
resp = parse_keqv_list(req, header.split(b', '))
if resp.get(b'algorithm', b'MD5').upper() != b'MD5':
log.write(b'Unsupported algorithm: %s' % resp.get(b'algorithm'))
raise common.ErrorResponse(
common.HTTP_FORBIDDEN, b"unknown algorithm"
)
user = resp[b'username']
realm = resp[b'realm']
nonce = resp[b'nonce']
ha1 = self._user_hashes.get((user, realm))
if not ha1:
log.write(b'No hash found for user/realm "%s/%s"' % (user, realm))
raise common.ErrorResponse(common.HTTP_FORBIDDEN, b"bad user")
qop = resp.get(b'qop', b'auth')
if qop != b'auth':
log.write(b"Unsupported qop: %s" % qop)
raise common.ErrorResponse(common.HTTP_FORBIDDEN, b"bad qop")
cnonce, ncvalue = resp.get(b'cnonce'), resp.get(b'nc')
if not cnonce or not ncvalue:
log.write(b'No cnonce (%s) or ncvalue (%s)' % (cnonce, ncvalue))
raise common.ErrorResponse(common.HTTP_FORBIDDEN, b"no cnonce")
a2 = b'%s:%s' % (req.method, resp[b'uri'])
noncebit = b"%s:%s:%s:%s:%s" % (nonce, ncvalue, cnonce, qop, h(a2))
respdig = kd(ha1, noncebit)
if respdig != resp[b'response']:
log.write(
b'User/realm "%s/%s" gave %s, but expected %s'
% (user, realm, resp[b'response'], respdig)
)
return False
return True
digest = digestauthserver()
def perform_authentication(hgweb, req, op):
auth = req.headers.get(b'Authorization')
if req.headers.get(b'X-HgTest-AuthType') == b'Digest':
if not auth:
challenge = digest.makechallenge(b'mercurial')
raise common.ErrorResponse(
common.HTTP_UNAUTHORIZED,
b'who',
[(b'WWW-Authenticate', b'Digest %s' % challenge)],
)
if not digest.checkauth(req, auth[7:]):
raise common.ErrorResponse(common.HTTP_FORBIDDEN, b'no')
return
if not auth:
raise common.ErrorResponse(
common.HTTP_UNAUTHORIZED,
b'who',
[(b'WWW-Authenticate', b'Basic Realm="mercurial"')],
)
if base64.b64decode(auth.split()[1]).split(b':', 1) != [b'user', b'pass']:
raise common.ErrorResponse(common.HTTP_FORBIDDEN, b'no')
def extsetup(ui):
common.permhooks.insert(0, perform_authentication)
digest.adduser(b'user', b'pass', b'mercurial')