def generate_api_key(str_, salt=None):

    """

    Generates API KEY from given string

    :param str_:

    :param salt:

    """

    if salt is None:

        salt = _RandomNameSequence().next()

    return hashlib.sha1(str_ + salt).hexdigest()

def authfunc(environ, username, password):

    """

    Dummy authentication wrapper function used in Mercurial and Git for

    access control.

    :param environ: needed only for using in Basic auth

    """

    return authenticate(username, password)

def authenticate(username, password):

    """

    Authentication function used for access control,

    firstly checks for db authentication then if ldap is enabled for ldap

    authentication, also creates ldap user if not in database

    :param username: username

    :param password: password

    """

    user_model = UserModel()

    user = User.get_by_username(username)

    log.debug('Authenticating user using RhodeCode account')

    if user is not None and not user.ldap_dn:

        if user.active:

            if user.username == 'default' and user.active:

                log.info('user %s authenticated correctly as anonymous user',

                         username)

                return True

            elif user.username == username and check_password(password,

                                                              user.password):

                log.info('user %s authenticated correctly' % username)

                return True

        else:

            log.warning('user %s is disabled' % username)

    else:

        log.debug('Regular authentication failed')

        user_obj = User.get_by_username(username, case_insensitive=True)

        if user_obj is not None and not user_obj.ldap_dn:

            log.debug('this user already exists as non ldap')

            return False

        ldap_settings = RhodeCodeSetting.get_ldap_settings()

        #======================================================================

        # FALLBACK TO LDAP AUTH IF ENABLE

        #======================================================================

        if str2bool(ldap_settings.get('ldap_active')):

            log.debug("Authenticating user using ldap")

            kwargs = {

                  'server': ldap_settings.get('ldap_host', ''),

                  'base_dn': ldap_settings.get('ldap_base_dn', ''),

                  'port': ldap_settings.get('ldap_port'),

                  'bind_dn': ldap_settings.get('ldap_dn_user'),

                  'bind_pass': ldap_settings.get('ldap_dn_pass'),

                  'tls_kind': ldap_settings.get('ldap_tls_kind'),

                  'tls_reqcert': ldap_settings.get('ldap_tls_reqcert'),

                  'ldap_filter': ldap_settings.get('ldap_filter'),

                  'search_scope': ldap_settings.get('ldap_search_scope'),

                  'attr_login': ldap_settings.get('ldap_attr_login'),

                  'ldap_version': 3,

                  }

            log.debug('Checking for ldap authentication')

            try:

                aldap = AuthLdap(**kwargs)

                (user_dn, ldap_attrs) = aldap.authenticate_ldap(username,

                                                                password)

                log.debug('Got ldap DN response %s' % user_dn)

                get_ldap_attr = lambda k: ldap_attrs.get(ldap_settings\

                                                           .get(k), [''])[0]

                user_attrs = {

                 'name': safe_unicode(get_ldap_attr('ldap_attr_firstname')),

                 'lastname': safe_unicode(get_ldap_attr('ldap_attr_lastname')),

                 'email': get_ldap_attr('ldap_attr_email'),

                }

                                          user_attrs):

                    log.info('created new ldap user %s' % username)

                Session.commit()

                return True

            except (LdapUsernameError, LdapPasswordError,):

                pass

            except (Exception,):

                log.error(traceback.format_exc())

                pass

    return False

def login_container_auth(username):

    user = User.get_by_username(username)

    if user is None:

        user_attrs = {

            'name': username,

            'lastname': None,

            'email': None,

        }

        user = UserModel().create_for_container_auth(username, user_attrs)

        if not user:

            return None

        log.info('User %s was created by container authentication' % username)

    if not user.active:

        return None

    user.update_lastlogin()

    Session.commit()

    log.debug('User %s is now logged in by container authentication',

              user.username)

    return user

def get_container_username(environ, config):

    username = None

    if str2bool(config.get('container_auth_enabled', False)):

        from paste.httpheaders import REMOTE_USER

        username = REMOTE_USER(environ)

    if not username and str2bool(config.get('proxypass_auth_enabled', False)):

        username = environ.get('HTTP_X_FORWARDED_USER')

    if username:

        # Removing realm and domain from username

        username = username.partition('@')[0]

        username = username.rpartition('\\')[2]

        log.debug('Received username %s from container' % username)

    return username

class  AuthUser(object):

    """

    A simple object that handles all attributes of user in RhodeCode

    It does lookup based on API key,given user, or user present in session

    Then it fills all required information for such user. It also checks if

    anonymous access is enabled and if so, it returns default user as logged

    in

    """

    def __init__(self, user_id=None, api_key=None, username=None):

        self.user_id = user_id

        self.api_key = None

        self.username = username

        self.name = ''

        self.lastname = ''

        self.email = ''

        self.is_authenticated = False

        self.admin = False

        self.permissions = {}

        self._api_key = api_key

        self.propagate_data()

        self._instance = None

    def propagate_data(self):

        user_model = UserModel()

        self.anonymous_user = User.get_by_username('default', cache=True)

        is_user_loaded = False

        # try go get user by api key

        if self._api_key and self._api_key != self.anonymous_user.api_key:

            log.debug('Auth User lookup by API KEY %s' % self._api_key)

            is_user_loaded = user_model.fill_data(self, api_key=self._api_key)

        # lookup by userid

        elif (self.user_id is not None and

              self.user_id != self.anonymous_user.user_id):

            log.debug('Auth User lookup by USER ID %s' % self.user_id)

            is_user_loaded = user_model.fill_data(self, user_id=self.user_id)