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samba-mirror/python/samba/netcmd/delegation.py
Joseph Sutton 0bd4bc40f4 samba-tool: Check specified domain and realm against our own
Signed-off-by: Joseph Sutton <josephsutton@catalyst.net.nz>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>

Autobuild-User(master): Andrew Bartlett <abartlet@samba.org>
Autobuild-Date(master): Mon Mar 28 03:11:51 UTC 2022 on sn-devel-184
2022-03-28 03:11:51 +00:00

690 lines
26 KiB
Python

# delegation management
#
# Copyright Matthieu Patou mat@samba.org 2010
# Copyright Stefan Metzmacher metze@samba.org 2011
# Copyright Bjoern Baumbach bb@sernet.de 2011
#
# 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 samba.getopt as options
import ldb
from samba import provision
from samba import dsdb
from samba.samdb import SamDB
from samba.auth import system_session
from samba.dcerpc import security
from samba.ndr import ndr_pack, ndr_unpack
from samba.netcmd.common import _get_user_realm_domain
from samba.netcmd import (
Command,
CommandError,
SuperCommand,
Option
)
class cmd_delegation_show(Command):
"""Show the delegation setting of an account."""
synopsis = "%prog <accountname> [options]"
takes_optiongroups = {
"sambaopts": options.SambaOptions,
"credopts": options.CredentialsOptions,
"versionopts": options.VersionOptions,
}
takes_options = [
Option("-H", "--URL", help="LDB URL for database or target server", type=str,
metavar="URL", dest="H"),
]
takes_args = ["accountname"]
def show_security_descriptor(self, sam, security_descriptor):
dacl = security_descriptor.dacl
desc_type = security_descriptor.type
warning_info = ('Security Descriptor of attribute '
'msDS-AllowedToActOnBehalfOfOtherIdentity')
if dacl is None or not desc_type & security.SEC_DESC_DACL_PRESENT:
self.errf.write(f'Warning: DACL not present in {warning_info}!\n')
return
if not desc_type & security.SEC_DESC_SELF_RELATIVE:
self.errf.write(f'Warning: DACL in {warning_info} lacks '
f'SELF_RELATIVE flag!\n')
return
first = True
for ace in dacl.aces:
trustee = ace.trustee
# Convert the trustee SID into a DN if we can.
try:
res = sam.search(f'<SID={trustee}>',
scope=ldb.SCOPE_BASE)
except ldb.LdbError as err:
num, _ = err.args
if num != ldb.ERR_NO_SUCH_OBJECT:
raise
else:
if len(res) == 1:
trustee = res[0].dn
ignore = False
if (ace.type == security.SEC_ACE_TYPE_ACCESS_DENIED
or ace.type == security.SEC_ACE_TYPE_ACCESS_DENIED_OBJECT):
self.errf.write(f'Warning: ACE in {warning_info} denies '
f'access for trustee {trustee}!\n')
# Ignore the ACE if it denies access
ignore = True
elif (ace.type != security.SEC_ACE_TYPE_ACCESS_ALLOWED
and ace.type != security.SEC_ACE_TYPE_ACCESS_ALLOWED_OBJECT):
# Ignore the ACE if it doesn't explicitly allow access
ignore = True
inherit_only = ace.flags & security.SEC_ACE_FLAG_INHERIT_ONLY
object_inherit = ace.flags & security.SEC_ACE_FLAG_OBJECT_INHERIT
container_inherit = (
ace.flags & security.SEC_ACE_FLAG_CONTAINER_INHERIT)
inherited_ace = ace.flags & security.SEC_ACE_FLAG_INHERITED_ACE
if inherit_only and not object_inherit and not container_inherit:
# Ignore the ACE if it is propagated only to child objects, but
# neither of the object and container inherit flags are set.
ignore = True
else:
if container_inherit:
self.errf.write(f'Warning: ACE for trustee {trustee} has '
f'unexpected CONTAINER_INHERIT flag set in '
f'{warning_info}!\n')
ignore = True
if inherited_ace:
self.errf.write(f'Warning: ACE for trustee {trustee} has '
f'unexpected INHERITED_ACE flag set in '
f'{warning_info}!\n')
ignore = True
if not ace.access_mask:
# Ignore the ACE if it doesn't grant any permissions.
ignore = True
if not ignore:
if first:
self.outf.write(f' Principals that may delegate to this '
f'account:\n')
first = False
self.outf.write(f'msDS-AllowedToActOnBehalfOfOtherIdentity: '
f'{trustee}\n')
def run(self, accountname, H=None, credopts=None, sambaopts=None, versionopts=None):
lp = sambaopts.get_loadparm()
creds = credopts.get_credentials(lp)
paths = provision.provision_paths_from_lp(lp, lp.get("realm"))
if H is None:
path = paths.samdb
else:
path = H
sam = SamDB(path, session_info=system_session(),
credentials=creds, lp=lp)
# TODO once I understand how, use the domain info to naildown
# to the correct domain
(cleanedaccount, realm, domain) = _get_user_realm_domain(accountname,
sam)
res = sam.search(expression="sAMAccountName=%s" %
ldb.binary_encode(cleanedaccount),
scope=ldb.SCOPE_SUBTREE,
attrs=["userAccountControl", "msDS-AllowedToDelegateTo",
"msDS-AllowedToActOnBehalfOfOtherIdentity"])
if len(res) == 0:
raise CommandError("Unable to find account name '%s'" % accountname)
assert(len(res) == 1)
uac = int(res[0].get("userAccountControl")[0])
allowed = res[0].get("msDS-AllowedToDelegateTo")
allowed_from = res[0].get("msDS-AllowedToActOnBehalfOfOtherIdentity", idx=0)
self.outf.write("Account-DN: %s\n" % str(res[0].dn))
self.outf.write("UF_TRUSTED_FOR_DELEGATION: %s\n"
% bool(uac & dsdb.UF_TRUSTED_FOR_DELEGATION))
self.outf.write("UF_TRUSTED_TO_AUTHENTICATE_FOR_DELEGATION: %s\n" %
bool(uac & dsdb.UF_TRUSTED_TO_AUTHENTICATE_FOR_DELEGATION))
if allowed:
self.outf.write(" Services this account may delegate to:\n")
for a in allowed:
self.outf.write("msDS-AllowedToDelegateTo: %s\n" % a)
if allowed_from is not None:
try:
security_descriptor = ndr_unpack(security.descriptor, allowed_from)
except RuntimeError:
self.errf.write("Warning: Security Descriptor of attribute "
"msDS-AllowedToActOnBehalfOfOtherIdentity "
"could not be unmarshalled!\n")
else:
self.show_security_descriptor(sam, security_descriptor)
class cmd_delegation_for_any_service(Command):
"""Set/unset UF_TRUSTED_FOR_DELEGATION for an account."""
synopsis = "%prog <accountname> [(on|off)] [options]"
takes_optiongroups = {
"sambaopts": options.SambaOptions,
"credopts": options.CredentialsOptions,
"versionopts": options.VersionOptions,
}
takes_options = [
Option("-H", "--URL", help="LDB URL for database or target server", type=str,
metavar="URL", dest="H"),
]
takes_args = ["accountname", "onoff"]
def run(self, accountname, onoff, H=None, credopts=None, sambaopts=None,
versionopts=None):
on = False
if onoff == "on":
on = True
elif onoff == "off":
on = False
else:
raise CommandError("invalid argument: '%s' (choose from 'on', 'off')" % onoff)
lp = sambaopts.get_loadparm()
creds = credopts.get_credentials(lp)
paths = provision.provision_paths_from_lp(lp, lp.get("realm"))
if H is None:
path = paths.samdb
else:
path = H
sam = SamDB(path, session_info=system_session(),
credentials=creds, lp=lp)
# TODO once I understand how, use the domain info to naildown
# to the correct domain
(cleanedaccount, realm, domain) = _get_user_realm_domain(accountname,
sam)
search_filter = "sAMAccountName=%s" % ldb.binary_encode(cleanedaccount)
flag = dsdb.UF_TRUSTED_FOR_DELEGATION
try:
sam.toggle_userAccountFlags(search_filter, flag,
flags_str="Trusted-for-Delegation",
on=on, strict=True)
except Exception as err:
raise CommandError(err)
class cmd_delegation_for_any_protocol(Command):
"""Set/unset UF_TRUSTED_TO_AUTHENTICATE_FOR_DELEGATION (S4U2Proxy) for an account."""
synopsis = "%prog <accountname> [(on|off)] [options]"
takes_optiongroups = {
"sambaopts": options.SambaOptions,
"credopts": options.CredentialsOptions,
"versionopts": options.VersionOptions,
}
takes_options = [
Option("-H", "--URL", help="LDB URL for database or target server", type=str,
metavar="URL", dest="H"),
]
takes_args = ["accountname", "onoff"]
def run(self, accountname, onoff, H=None, credopts=None, sambaopts=None,
versionopts=None):
on = False
if onoff == "on":
on = True
elif onoff == "off":
on = False
else:
raise CommandError("invalid argument: '%s' (choose from 'on', 'off')" % onoff)
lp = sambaopts.get_loadparm()
creds = credopts.get_credentials(lp, fallback_machine=True)
paths = provision.provision_paths_from_lp(lp, lp.get("realm"))
if H is None:
path = paths.samdb
else:
path = H
sam = SamDB(path, session_info=system_session(),
credentials=creds, lp=lp)
# TODO once I understand how, use the domain info to naildown
# to the correct domain
(cleanedaccount, realm, domain) = _get_user_realm_domain(accountname,
sam)
search_filter = "sAMAccountName=%s" % ldb.binary_encode(cleanedaccount)
flag = dsdb.UF_TRUSTED_TO_AUTHENTICATE_FOR_DELEGATION
try:
sam.toggle_userAccountFlags(search_filter, flag,
flags_str="Trusted-to-Authenticate-for-Delegation",
on=on, strict=True)
except Exception as err:
raise CommandError(err)
class cmd_delegation_add_service(Command):
"""Add a service principal to msDS-AllowedToDelegateTo so that an account may delegate to it."""
synopsis = "%prog <accountname> <principal> [options]"
takes_optiongroups = {
"sambaopts": options.SambaOptions,
"credopts": options.CredentialsOptions,
"versionopts": options.VersionOptions,
}
takes_options = [
Option("-H", "--URL", help="LDB URL for database or target server", type=str,
metavar="URL", dest="H"),
]
takes_args = ["accountname", "principal"]
def run(self, accountname, principal, H=None, credopts=None, sambaopts=None,
versionopts=None):
lp = sambaopts.get_loadparm()
creds = credopts.get_credentials(lp)
paths = provision.provision_paths_from_lp(lp, lp.get("realm"))
if H is None:
path = paths.samdb
else:
path = H
sam = SamDB(path, session_info=system_session(),
credentials=creds, lp=lp)
# TODO once I understand how, use the domain info to naildown
# to the correct domain
(cleanedaccount, realm, domain) = _get_user_realm_domain(accountname,
sam)
res = sam.search(expression="sAMAccountName=%s" %
ldb.binary_encode(cleanedaccount),
scope=ldb.SCOPE_SUBTREE,
attrs=["msDS-AllowedToDelegateTo"])
if len(res) == 0:
raise CommandError("Unable to find account name '%s'" % accountname)
assert(len(res) == 1)
msg = ldb.Message()
msg.dn = res[0].dn
msg["msDS-AllowedToDelegateTo"] = ldb.MessageElement([principal],
ldb.FLAG_MOD_ADD,
"msDS-AllowedToDelegateTo")
try:
sam.modify(msg)
except Exception as err:
raise CommandError(err)
class cmd_delegation_del_service(Command):
"""Delete a service principal from msDS-AllowedToDelegateTo so that an account may no longer delegate to it."""
synopsis = "%prog <accountname> <principal> [options]"
takes_optiongroups = {
"sambaopts": options.SambaOptions,
"credopts": options.CredentialsOptions,
"versionopts": options.VersionOptions,
}
takes_options = [
Option("-H", "--URL", help="LDB URL for database or target server", type=str,
metavar="URL", dest="H"),
]
takes_args = ["accountname", "principal"]
def run(self, accountname, principal, H=None, credopts=None, sambaopts=None,
versionopts=None):
lp = sambaopts.get_loadparm()
creds = credopts.get_credentials(lp)
paths = provision.provision_paths_from_lp(lp, lp.get("realm"))
if H is None:
path = paths.samdb
else:
path = H
sam = SamDB(path, session_info=system_session(),
credentials=creds, lp=lp)
# TODO once I understand how, use the domain info to naildown
# to the correct domain
(cleanedaccount, realm, domain) = _get_user_realm_domain(accountname,
sam)
res = sam.search(expression="sAMAccountName=%s" %
ldb.binary_encode(cleanedaccount),
scope=ldb.SCOPE_SUBTREE,
attrs=["msDS-AllowedToDelegateTo"])
if len(res) == 0:
raise CommandError("Unable to find account name '%s'" % accountname)
assert(len(res) == 1)
msg = ldb.Message()
msg.dn = res[0].dn
msg["msDS-AllowedToDelegateTo"] = ldb.MessageElement([principal],
ldb.FLAG_MOD_DELETE,
"msDS-AllowedToDelegateTo")
try:
sam.modify(msg)
except Exception as err:
raise CommandError(err)
class cmd_delegation_add_principal(Command):
"""Add a principal to msDS-AllowedToActOnBehalfOfOtherIdentity that may delegate to an account."""
synopsis = "%prog <accountname> <principal> [options]"
takes_optiongroups = {
"sambaopts": options.SambaOptions,
"credopts": options.CredentialsOptions,
"versionopts": options.VersionOptions,
}
takes_options = [
Option("-H", "--URL", help="LDB URL for database or target server",
type=str, metavar="URL", dest="H"),
]
takes_args = ["accountname", "principal"]
def run(self, accountname, principal, H=None, credopts=None, sambaopts=None,
versionopts=None):
lp = sambaopts.get_loadparm()
creds = credopts.get_credentials(lp)
paths = provision.provision_paths_from_lp(lp, lp.get("realm"))
if H is None:
path = paths.samdb
else:
path = H
sam = SamDB(path, session_info=system_session(),
credentials=creds, lp=lp)
# TODO once I understand how, use the domain info to naildown
# to the correct domain
cleanedaccount, _, _ = _get_user_realm_domain(accountname, sam)
account_res = sam.search(
expression="sAMAccountName=%s" %
ldb.binary_encode(cleanedaccount),
scope=ldb.SCOPE_SUBTREE,
attrs=["msDS-AllowedToActOnBehalfOfOtherIdentity"])
if len(account_res) == 0:
raise CommandError(f"Unable to find account name '{accountname}'")
assert(len(account_res) == 1)
data = account_res[0].get(
"msDS-AllowedToActOnBehalfOfOtherIdentity", idx=0)
if data is None:
# Create the security descriptor if it is not present.
owner_sid = security.dom_sid(security.SID_BUILTIN_ADMINISTRATORS)
security_desc = security.descriptor()
security_desc.revision = security.SD_REVISION
security_desc.type = (security.SEC_DESC_DACL_PRESENT |
security.SEC_DESC_SELF_RELATIVE)
security_desc.owner_sid = owner_sid
dacl = None
else:
try:
security_desc = ndr_unpack(security.descriptor, data)
except RuntimeError:
raise CommandError(f"Security Descriptor of attribute "
f"msDS-AllowedToActOnBehalfOfOtherIdentity "
f"for account '{accountname}' could not be "
f"unmarshalled!")
dacl = security_desc.dacl
if dacl is None:
# Create the DACL if it is not present.
dacl = security.acl()
dacl.revision = security.SECURITY_ACL_REVISION_ADS
dacl.num_aces = 0
# TODO once I understand how, use the domain info to naildown
# to the correct domain
cleanedprinc, _, _ = _get_user_realm_domain(principal, sam)
princ_res = sam.search(expression="sAMAccountName=%s" %
ldb.binary_encode(cleanedprinc),
scope=ldb.SCOPE_SUBTREE,
attrs=["objectSid"])
if len(princ_res) == 0:
raise CommandError(f"Unable to find principal name '{principal}'")
assert(len(princ_res) == 1)
princ_sid = security.dom_sid(
sam.schema_format_value(
"objectSID",
princ_res[0].get("objectSID", idx=0)).decode("utf-8"))
aces = dacl.aces
# Check that there is no existing ACE for this principal.
if any(ace.trustee == princ_sid for ace in aces):
raise CommandError(
f"ACE for principal '{principal}' already present in Security "
f"Descriptor of attribute "
f"msDS-AllowedToActOnBehalfOfOtherIdentity for account "
f"'{accountname}'.")
# Create the new ACE.
ace = security.ace()
ace.type = security.SEC_ACE_TYPE_ACCESS_ALLOWED
ace.flags = 0
ace.access_mask = security.SEC_ADS_GENERIC_ALL
ace.trustee = princ_sid
aces.append(ace)
dacl.aces = aces
dacl.num_aces += 1
security_desc.dacl = dacl
new_data = ndr_pack(security_desc)
# Set the new security descriptor. First, delete the original value to
# detect a race condition if someone else updates the attribute at the
# same time.
msg = ldb.Message()
msg.dn = account_res[0].dn
if data is not None:
msg["0"] = ldb.MessageElement(
data, ldb.FLAG_MOD_DELETE,
"msDS-AllowedToActOnBehalfOfOtherIdentity")
msg["1"] = ldb.MessageElement(
new_data, ldb.FLAG_MOD_ADD,
"msDS-AllowedToActOnBehalfOfOtherIdentity")
try:
sam.modify(msg)
except ldb.LdbError as err:
num, _ = err.args
if num == ldb.ERR_NO_SUCH_ATTRIBUTE:
raise CommandError(
f"Refused to update attribute "
f"msDS-AllowedToActOnBehalfOfOtherIdentity for account "
f"'{accountname}': a conflicting attribute update "
f"occurred simultaneously.")
else:
raise CommandError(err)
class cmd_delegation_del_principal(Command):
"""Delete a principal from msDS-AllowedToActOnBehalfOfOtherIdentity that may no longer delegate to an account."""
synopsis = "%prog <accountname> <principal> [options]"
takes_optiongroups = {
"sambaopts": options.SambaOptions,
"credopts": options.CredentialsOptions,
"versionopts": options.VersionOptions,
}
takes_options = [
Option("-H", "--URL", help="LDB URL for database or target server",
type=str, metavar="URL", dest="H"),
]
takes_args = ["accountname", "principal"]
def run(self, accountname, principal, H=None, credopts=None, sambaopts=None,
versionopts=None):
lp = sambaopts.get_loadparm()
creds = credopts.get_credentials(lp)
paths = provision.provision_paths_from_lp(lp, lp.get("realm"))
if H is None:
path = paths.samdb
else:
path = H
sam = SamDB(path, session_info=system_session(),
credentials=creds, lp=lp)
# TODO once I understand how, use the domain info to naildown
# to the correct domain
cleanedaccount, _, _ = _get_user_realm_domain(accountname, sam)
account_res = sam.search(
expression="sAMAccountName=%s" %
ldb.binary_encode(cleanedaccount),
scope=ldb.SCOPE_SUBTREE,
attrs=["msDS-AllowedToActOnBehalfOfOtherIdentity"])
if len(account_res) == 0:
raise CommandError("Unable to find account name '%s'" % accountname)
assert(len(account_res) == 1)
data = account_res[0].get(
"msDS-AllowedToActOnBehalfOfOtherIdentity", idx=0)
if data is None:
raise CommandError(f"Attribute "
f"msDS-AllowedToActOnBehalfOfOtherIdentity for "
f"account '{accountname}' not present!")
try:
security_desc = ndr_unpack(security.descriptor, data)
except RuntimeError:
raise CommandError(f"Security Descriptor of attribute "
f"msDS-AllowedToActOnBehalfOfOtherIdentity for "
f"account '{accountname}' could not be "
f"unmarshalled!")
dacl = security_desc.dacl
if dacl is None:
raise CommandError(f"DACL not present on Security Descriptor of "
f"attribute "
f"msDS-AllowedToActOnBehalfOfOtherIdentity for "
f"account '{accountname}'!")
# TODO once I understand how, use the domain info to naildown
# to the correct domain
cleanedprinc, _, _ = _get_user_realm_domain(principal, sam)
princ_res = sam.search(expression="sAMAccountName=%s" %
ldb.binary_encode(cleanedprinc),
scope=ldb.SCOPE_SUBTREE,
attrs=["objectSid"])
if len(princ_res) == 0:
raise CommandError(f"Unable to find principal name '{principal}'")
assert(len(princ_res) == 1)
princ_sid = security.dom_sid(
sam.schema_format_value(
"objectSID",
princ_res[0].get("objectSID", idx=0)).decode("utf-8"))
old_aces = dacl.aces
# Remove any ACEs relating to the specified principal.
aces = [ace for ace in old_aces if ace.trustee != princ_sid]
# Raise an error if we didn't find any.
if len(aces) == len(old_aces):
raise CommandError(f"Unable to find ACE for principal "
f"'{principal}' in Security Descriptor of "
f"attribute "
f"msDS-AllowedToActOnBehalfOfOtherIdentity for "
f"account '{accountname}'.")
dacl.num_aces = len(aces)
dacl.aces = aces
security_desc.dacl = dacl
new_data = ndr_pack(security_desc)
# Set the new security descriptor. First, delete the original value to
# detect a race condition if someone else updates the attribute at the
# same time.
msg = ldb.Message()
msg.dn = account_res[0].dn
msg["0"] = ldb.MessageElement(
data, ldb.FLAG_MOD_DELETE,
"msDS-AllowedToActOnBehalfOfOtherIdentity")
msg["1"] = ldb.MessageElement(
new_data, ldb.FLAG_MOD_ADD,
"msDS-AllowedToActOnBehalfOfOtherIdentity")
try:
sam.modify(msg)
except ldb.LdbError as err:
num, _ = err.args
if num == ldb.ERR_NO_SUCH_ATTRIBUTE:
raise CommandError(
f"Refused to update attribute "
f"msDS-AllowedToActOnBehalfOfOtherIdentity for account "
f"'{accountname}': a conflicting attribute update "
f"occurred simultaneously.")
else:
raise CommandError(err)
class cmd_delegation(SuperCommand):
"""Delegation management."""
subcommands = {}
subcommands["show"] = cmd_delegation_show()
subcommands["for-any-service"] = cmd_delegation_for_any_service()
subcommands["for-any-protocol"] = cmd_delegation_for_any_protocol()
subcommands["add-service"] = cmd_delegation_add_service()
subcommands["del-service"] = cmd_delegation_del_service()
subcommands["add-principal"] = cmd_delegation_add_principal()
subcommands["del-principal"] = cmd_delegation_del_principal()