tests/httpserverauth.py

nodemap: only use persistent nodemap for non-inlined revlog

Revlog are inlined while they are small (to avoid having too many file to deal
with). The persistent nodemap will only provides a significant boost for large
enough revlog index. So it does not make sens to add an extra file to store
nodemap for small revlog.

We could consider inclining the nodemap data inside the revlog itself, but the
benefit is unclear so let it be an adventure for another time.

Differential Revision: https://phab.mercurial-scm.org/D7837

from __future__ import absolute_import

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(object):
    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')