view tests/httpserverauth.py @ 51326:178e50edb4f8

changelog: stop useless enforcing split at the end of transaction

Changelogs are no longer created inline, and existing changelogs are
automatically split. Since we now enforce splitting at the start of any write,
we don't need to enforce splitting at the end of the transaction.

This has the nice side effect of killing the only user of "side_write".

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')