:created_on: Created on Nov 17, 2010

    :author: marcink

    :copyright: (C) 2009-2011 Marcin Kuzminski <marcin@python-works.com>

    :license: GPLv3, see COPYING for more details.

"""

# This program is free software: you can redistribute it and/or modify

# it under the terms of the GNU General Public License as published by

# the Free Software Foundation, either version 3 of the License, or

# (at your option) any later version.

#

# This program is distributed in the hope that it will be useful,

# but WITHOUT ANY WARRANTY; without even the implied warranty of

# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

# GNU General Public License for more details.

#

# You should have received a copy of the GNU General Public License

# along with this program.  If not, see <http://www.gnu.org/licenses/>.

import logging

from rhodecode.lib.exceptions import LdapConnectionError, LdapUsernameError, \

    LdapPasswordError

log = logging.getLogger(__name__)

try:

    import ldap

except ImportError:

    # means that python-ldap is not installed

    pass

class AuthLdap(object):

    def __init__(self, server, base_dn, port=389, bind_dn='', bind_pass='',

                 tls_kind='PLAIN', tls_reqcert='DEMAND', ldap_version=3,

                 ldap_filter='(&(objectClass=user)(!(objectClass=computer)))',

                 search_scope='SUBTREE',

                 attr_login='uid'):

        self.ldap_version = ldap_version

        ldap_server_type = 'ldap'

        self.TLS_KIND = tls_kind

        if self.TLS_KIND == 'LDAPS':

            port = port or 689

            ldap_server_type = ldap_server_type + 's'

        self.LDAP_SERVER_ADDRESS = server

        self.LDAP_SERVER_PORT = port

        #USE FOR READ ONLY BIND TO LDAP SERVER

        self.LDAP_BIND_DN = bind_dn

        self.LDAP_BIND_PASS = bind_pass

        self.LDAP_SERVER = "%s://%s:%s" % (ldap_server_type,

        self.BASE_DN = base_dn

        self.LDAP_FILTER = ldap_filter

        self.attr_login = attr_login

    def authenticate_ldap(self, username, password):

        """Authenticate a user via LDAP and return his/her LDAP properties.

        Raises AuthenticationError if the credentials are rejected, or

        EnvironmentError if the LDAP server can't be reached.

        :param username: username

        :param password: password

        """

        from rhodecode.lib.helpers import chop_at

        uid = chop_at(username, "@%s" % self.LDAP_SERVER_ADDRESS)

        if "," in username:

            raise LdapUsernameError("invalid character in username: ,")

        try:

            ldap.set_option(ldap.OPT_REFERRALS, ldap.OPT_OFF)

            ldap.set_option(ldap.OPT_RESTART, ldap.OPT_ON)

            ldap.set_option(ldap.OPT_TIMEOUT, 20)

            ldap.set_option(ldap.OPT_NETWORK_TIMEOUT, 10)

            ldap.set_option(ldap.OPT_TIMELIMIT, 15)

            if self.TLS_KIND != 'PLAIN':

                ldap.set_option(ldap.OPT_X_TLS_REQUIRE_CERT, self.TLS_REQCERT)

            server = ldap.initialize(self.LDAP_SERVER)

            if self.ldap_version == 2:

                server.protocol = ldap.VERSION2

            else:

                server.protocol = ldap.VERSION3

            if self.TLS_KIND == 'START_TLS':

                server.start_tls_s()

            if self.LDAP_BIND_DN and self.LDAP_BIND_PASS:

                server.simple_bind_s(self.LDAP_BIND_DN, self.LDAP_BIND_PASS)

            filt = '(&%s(%s=%s))' % (self.LDAP_FILTER, self.attr_login,

                                     username)

            log.debug("Authenticating %r filt %s at %s", self.BASE_DN,

                      filt, self.LDAP_SERVER)

            lobjects = server.search_ext_s(self.BASE_DN, self.SEARCH_SCOPE,

                                           filt)

            if not lobjects:

                raise ldap.NO_SUCH_OBJECT()

            for (dn, _attrs) in lobjects:

                if dn is None:

                    continue

                try:

                    server.simple_bind_s(dn, password)

                    attrs = server.search_ext_s(dn, ldap.SCOPE_BASE,

                                                '(objectClass=*)')[0][1]

                    break

                except ldap.INVALID_CREDENTIALS, e:

                    log.debug("LDAP rejected password for user '%s' (%s): %s",

                              uid, username, dn)

            else:

                log.debug("No matching LDAP objects for authentication "

                          "of '%s' (%s)", uid, username)

                raise LdapPasswordError()