tests/httpserverauth.py

tests: add tests of pathcopies()

I'm working on support for storing copy metadata in the changeset
instead of in the filelog. When storing it in the changeset, it will
obviously be efficient to get the copy metadata for all files in a
single changeset, but it will be more expensive to get the copy
metadata all revisions of a single file. Some algorithms will then
need to be optimized differently. The first method I'm going to
rewrite is pathcopies().

This commit adds many tests for pathcopies(), so we can run the tests
with both old and new versions of the code, as well as with metadata
stored in filelog or in changeset (later). They use the
debugpathcopies command I recently added (with no tests when it was
added). They show a few bugs and few cases of slightly weird
behavior. I'll fix the bugs in the next few commits.

Differential Revision: https://phab.mercurial-scm.org/D5986

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')