Remove third_party/twisted_8_1

third_party/twisted_8_1/twisted/cred/strcred.py

-# -*- test-case-name: twisted.test.test_strcred -*-
-#
-# Copyright (c) 2007-2008 Twisted Matrix Laboratories.
-# See LICENSE for details.
-#
-
-"""
-Support for resolving command-line strings that represent different
-checkers available to cred.
-
-Examples:
- - passwd:/etc/passwd
- - memory:admin:asdf:user:lkj
- - unix
-"""
-
-import sys
-
-from zope.interface import Interface, Attribute
-
-from twisted.plugin import getPlugins
-from twisted.python import usage
-
-
-
-class ICheckerFactory(Interface):
-    """
-    A factory for objects which provide
-    L{twisted.cred.checkers.ICredentialsChecker}.
-
-    It's implemented by twistd plugins creating checkers.
-    """
-
-    authType = Attribute(
-        'A tag that identifies the authentication method.')
-
-
-    authHelp = Attribute(
-        'A detailed (potentially multi-line) description of precisely '
-        'what functionality this CheckerFactory provides.')
-
-
-    argStringFormat = Attribute(
-        'A short (one-line) description of the argument string format.')
-
-
-    credentialInterfaces = Attribute(
-        'A list of credentials interfaces that this factory will support.')
-
-
-    def generateChecker(argstring):
-        """
-        Return an L{ICredentialChecker} provider using the supplied
-        argument string.
-        """
-
-
-
-class StrcredException(Exception):
-    """
-    Base exception class for strcred.
-    """
-
-
-
-class InvalidAuthType(StrcredException):
-    """
-    Raised when a user provides an invalid identifier for the
-    authentication plugin (known as the authType).
-    """
-
-
-
-class InvalidAuthArgumentString(StrcredException):
-    """
-    Raised by an authentication plugin when the argument string
-    provided is formatted incorrectly.
-    """
-
-
-
-class UnsupportedInterfaces(StrcredException):
-    """
-    Raised when an application is given a checker to use that does not
-    provide any of the application's supported credentials interfaces.
-    """
-
-
-
-# This will be used to warn the users whenever they view help for an
-# authType that is not supported by the application.
-notSupportedWarning = ("WARNING: This authType is not supported by "
-                       "this application.")
-
-
-
-def findCheckerFactories():
-    """
-    Find all objects that implement L{ICheckerFactory}.
-    """
-    return getPlugins(ICheckerFactory)
-
-
-
-def findCheckerFactory(authType):
-    """
-    Find the first checker factory that supports the given authType.
-    """
-    for factory in findCheckerFactories():
-        if factory.authType == authType:
-            return factory
-    raise InvalidAuthType(authType)
-
-
-
-def makeChecker(description):
-    """
-    Returns an L{twisted.cred.checkers.ICredentialsChecker} based on the
-    contents of a descriptive string. Similar to
-    L{twisted.application.strports}.
-    """
-    if ':' in description:
-        authType, argstring = description.split(':', 1)
-    else:
-        authType = description
-        argstring = ''
-    return findCheckerFactory(authType).generateChecker(argstring)
-
-
-
-class AuthOptionMixin:
-    """
-    Defines helper methods that can be added on to any
-    L{usage.Options} subclass that needs authentication.
-
-    This mixin implements three new options methods:
-
-    The opt_auth method (--auth) will write two new values to the
-    'self' dictionary: C{credInterfaces} (a dict of lists) and
-    C{credCheckers} (a list).
-
-    The opt_help_auth method (--help-auth) will search for all
-    available checker plugins and list them for the user; it will exit
-    when finished.
-
-    The opt_help_auth_type method (--help-auth-type) will display
-    detailed help for a particular checker plugin.
-
-    @cvar supportedInterfaces: An iterable object that returns
-       credential interfaces which this application is able to support.
-
-    @cvar authOutput: A writeable object to which this options class
-        will send all help-related output. Default: L{sys.stdout}
-    """
-
-    supportedInterfaces = None
-    authOutput = sys.stdout
-
-
-    def supportsInterface(self, interface):
-        """
-        Returns whether a particular credentials interface is supported.
-        """
-        return (self.supportedInterfaces is None
-                or interface in self.supportedInterfaces)
-
-
-    def supportsCheckerFactory(self, factory):
-        """
-        Returns whether a checker factory will provide at least one of
-        the credentials interfaces that we care about.
-        """
-        for interface in factory.credentialInterfaces:
-            if self.supportsInterface(interface):
-                return True
-        return False
-
-
-    def addChecker(self, checker):
-        """
-        Supply a supplied credentials checker to the Options class.
-        """
-        # First figure out which interfaces we're willing to support.
-        supported = []
-        if self.supportedInterfaces is None:
-            supported = checker.credentialInterfaces
-        else:
-            for interface in checker.credentialInterfaces:
-                if self.supportsInterface(interface):
-                    supported.append(interface)
-        if not supported:
-            raise UnsupportedInterfaces(checker.credentialInterfaces)
-        # If we get this far, then we know we can use this checker.
-        if 'credInterfaces' not in self:
-            self['credInterfaces'] = {}
-        if 'credCheckers' not in self:
-            self['credCheckers'] = []
-        self['credCheckers'].append(checker)
-        for interface in supported:
-            self['credInterfaces'].setdefault(interface, []).append(checker)
-
-
-    def opt_auth(self, description):
-        """
-        Specify an authentication method for the server.
-        """
-        try:
-            self.addChecker(makeChecker(description))
-        except UnsupportedInterfaces, e:
-            raise usage.UsageError(
-                'Auth plugin not supported: %s' % e.args[0])
-        except InvalidAuthType, e:
-            raise usage.UsageError(
-                'Auth plugin not recognized: %s' % e.args[0])
-        except Exception, e:
-            raise usage.UsageError('Unexpected error: %s' % e)
-
-
-    def _checkerFactoriesForOptHelpAuth(self):
-        """
-        Return a list of which authTypes will be displayed by --help-auth.
-        This makes it a lot easier to test this module.
-        """
-        for factory in findCheckerFactories():
-            for interface in factory.credentialInterfaces:
-                if self.supportsInterface(interface):
-                    yield factory
-                    break
-
-
-    def opt_help_auth(self):
-        """
-        Show all authentication methods available.
-        """
-        self.authOutput.write("Usage: --auth AuthType[:ArgString]\n")
-        self.authOutput.write("For detailed help: --help-auth-type AuthType\n")
-        self.authOutput.write('\n')
-        # Figure out the right width for our columns
-        firstLength = 0
-        for factory in self._checkerFactoriesForOptHelpAuth():
-            if len(factory.authType) > firstLength:
-                firstLength = len(factory.authType)
-        formatString = '  %%-%is\t%%s\n' % firstLength
-        self.authOutput.write(formatString % ('AuthType', 'ArgString format'))
-        self.authOutput.write(formatString % ('========', '================'))
-        for factory in self._checkerFactoriesForOptHelpAuth():
-            self.authOutput.write(
-                formatString % (factory.authType, factory.argStringFormat))
-        self.authOutput.write('\n')
-        raise SystemExit(0)
-
-
-    def opt_help_auth_type(self, authType):
-        """
-        Show help for a particular authentication type.
-        """
-        try:
-            cf = findCheckerFactory(authType)
-        except InvalidAuthType:
-            raise usage.UsageError("Invalid auth type: %s" % authType)
-        self.authOutput.write("Usage: --auth %s[:ArgString]\n" % authType)
-        self.authOutput.write("ArgString format: %s\n" % cf.argStringFormat)
-        self.authOutput.write('\n')
-        for line in cf.authHelp.strip().splitlines():
-            self.authOutput.write('  %s\n' % line.rstrip())
-        self.authOutput.write('\n')
-        if not self.supportsCheckerFactory(cf):
-            self.authOutput.write('  %s\n' % notSupportedWarning)
-            self.authOutput.write('\n')
-        raise SystemExit(0)