diff options
| -rwxr-xr-x | wsgitools/digest.py | 134 |
1 files changed, 134 insertions, 0 deletions
diff --git a/wsgitools/digest.py b/wsgitools/digest.py index 52cdcee..d0039e0 100755 --- a/wsgitools/digest.py +++ b/wsgitools/digest.py @@ -293,6 +293,140 @@ class MemoryNonceStore(NonceStoreBase): self.nonces[lower] = (nt, nv, uses+1) return True +__all__.append("LazyDBAPI2Opener") +class LazyDBAPI2Opener: + """ + Connects to database on first request. Otherwise it behaves like a dbapi2 + connection. + """ + def __init__(self, function, *args, **kwargs): + """ + The database will be connected on the first method call. This is done + by calling the given function with the remaining parameters. + @param function: is the function that connects to the database + """ + self._function = function + self._args = args + self._kwargs = kwargs + self._dbhandle = None + def _getdbhandle(self): + """Returns an open database connection. Open if necessary.""" + if self._dbhandle is None: + self._dbhandle = self._function(*self._args, **self._kwargs) + self._function = self._args = self._kwargs = None + return self._dbhandle + def cursor(self): + """dbapi2""" + return self._getdbhandle().cursor() + def commit(self): + """dbapi2""" + return self._getdbhandle().commit() + def rollback(self): + """dbapi2""" + return self._getdbhandle().rollback() + def close(self): + """dbapi2""" + return self._getdbhandle().close() + +__all__.append("DBAPI2NonceStore") +class DBAPI2NonceStore(NonceStoreBase): + """ + A dbapi2-backed nonce store implementation suitable for usage with forking + wsgi servers such as scgi.forkpool. + """ + def __init__(self, dbhandle, maxage=300, maxuses=5, table="nonces"): + """ + @type filename: str + @param filename: the path to the bsddb file that is used as backingstore + @type maxage: int + @param maxage: is the number of seconds a nonce may be valid. Choosing a + large value may result in more memory usage whereas a smaller + value results in more requests. Defaults to 5 minutes. + @type maxuses: int + @param maxuses: is the number of times a nonce may be used (with + different nc values). A value of 1 makes nonces usable exactly + once resulting in more requests. Defaults to 5. + """ + NonceStoreBase.__init__(self) + self.dbhandle = dbhandle + self.maxage = maxage + self.maxuses = maxuses + self.table = table + self.server_secret = gen_rand_str() + + def _cleanup(self, cur): + """internal methods cleaning list of valid nonces""" + old = format_time(time.time() - self.maxage) + cur.execute("DELETE FROM %s WHERE key < '%s:';" % (self.table, old)) + + def newnonce(self, ident=None): + """ + Generates a new nonce string. + @rtype: str + """ + nonce_time = format_time(time.time()) + nonce_value = gen_rand_str() + dbkey = "%s:%s" % (nonce_time, nonce_value) + cur = self.dbhandle.cursor() + self._cleanup(cur) # avoid growing database + cur.execute("INSERT INTO %s VALUES ('%s', '1');" % (self.table, dbkey)) + self.dbhandle.commit() + token = "%s:%s" % (dbkey, self.server_secret) + if ident is not None: + token = "%s:%s" % (token, ident) + token = md5(token).hexdigest() + return "%s:%s:%s" % (nonce_time, nonce_value, token) + + def checknonce(self, nonce, count=1, ident=None): + """ + Do a check for whether the provided string is a nonce and increase usage + count on returning True. + @type nonce: str + @type count: int + @rtype: bool + """ + try: + nonce_time, nonce_value, nonce_hash = nonce.split(':') + except ValueError: + return False + if not nonce_time.isalnum() or not nonce_value.replace("+", ""). \ + replace("/", "").replace("=", "").isalnum(): + return False + token = "%s:%s:%s" % (nonce_time, nonce_value, self.server_secret) + if ident is not None: + token = "%s:%s" % (token, ident) + token = md5(token).hexdigest() + if token != nonce_hash: + return False + + if nonce_time < format_time(time.time() - self.maxage): + return False + + cur = self.dbhandle.cursor() + #self._cleanup(cur) # avoid growing database + + dbkey = "%s:%s" % (nonce_time, nonce_value) + cur.execute("SELECT value FROM %s WHERE key = '%s';" % + (self.table, dbkey)) + uses = cur.fetchone() + if uses is None: + self.dbhandle.commit() + return False + uses = int(uses[0]) + if count != uses: + cur.execute("DELETE FROM %s WHERE key = '%s';" % + (self.table, dbkey)) + self.dbhandle.commit() + return False + if uses >= self.maxuses: + cur.execute("DELETE FROM %s WHERE key = '%s';" % + (self.table, dbkey)) + else: + cur.execute("UPDATE %s SET value = '%d' WHERE key = '%s';" % + (self.table, uses + 1, dbkey)) + self.dbhandle.commit() + return True + __all__.append("AuthDigestMiddleware") class AuthDigestMiddleware: """Middleware partly implementing RFC2617. (md5-sess was omited)""" |