For users who has no OTP tokens defined (yet), a missing token should
not be seen as a failure. This is needed to allow a basic password
change.
The logic around enforcement of OTP over LDAP bind is the following:
----------------------------------------------------------------------
- when LDAP OTP control is requested by the LDAP client, OTP is
explicitly required
- when EnforceLDAPOTP is set in the IPA configuration, OTP is implicitly
required, regardless of the state of LDAP client
In either case, only users with 'user-auth-type: otp' are allowed to
authenticate.
If these users have no OTP token associated yet, they will be allowed to
authenticate with their password. This is to allow initial password
change and adding an OTP token.
----------------------------------------------------------------------
Implement test that simulates lifecycle for new user who get to change
their password before adding an OTP token.
Related: https://pagure.io/freeipa/issue/5169
Signed-off-by: Alexander Bokovoy <abokovoy@redhat.com>
Reviewed-By: Florence Blanc-Renaud <frenaud@redhat.com>
Reviewed-By: Rob Crittenden <rcritten@redhat.com>
find_sid_for_ldap_entry could fail in several ways if a Posix ID can not
be converted to an unused SID. This could happen for example for ducplicate
IDs or user/group out of range.
This change enables ipa_sidgen_task to continue in the error case to try
to convert the entries without errors. The error messages have been
extended to additionally show the DN string for the bad entries.
Fixes: https://pagure.io/freeipa/issue/9618
Signed-off-by: Thomas Woerner <twoerner@redhat.com>
Reviewed-By: Alexander Bokovoy <abokovoy@redhat.com>
The initial design for ticket flags was implementing this logic:
* If a ticket policy is defined for the principal entry, use flags from
this policy if they are set. Otherwise, use default ticket flags.
* If no ticket policy is defined for the principal entry, but there is a
global one, use flags from the global ticket policy if they are set.
Otherwise, use default ticket flags.
* If no policy (principal nor global) is defined, use default ticket
flags.
However, this logic was broken by a1165ffb which introduced creation of
a principal-level ticket policy in case the ticket flag set is modified.
This was typically the case for the -allow_tix flag, which was set
virtually by the KDB driver when a user was locked until they initialize
their password on first kinit pre-authentication.
This was causing multiple issues, which are mitigated by the new
approach:
Now flags from each level are combined together. There flags like
+requires_preauth which are set systematically by the KDB diver, as
well as -allow_tix which is set based on the value of "nsAccountLock".
This commit also adds the implicit -allow_svr ticket flag for user
principals to protect users against Kerberoast-type attacks. None of
these flags are stored in the LDAP database, they are hard-coded in the
KDB driver.
In addition to these "virtual" ticket flags, flags from both global and
principal ticket policies are applied (if these policies exist).
Principal ticket policies are not supported for hosts and services, but
this is only an HTTP API limitation. The "krbTicketPolicyAux" object
class is supported for all account types. This is required for ticket
flags like +ok_to_auth_as_delegate. Such flags can be set using "ipa
host-mod" and "ipa serivce-mod", or using kadmin's "modprinc".
It is possible to ignore flags from the global ticket policy or default
flags like -allow_svr for a user principal by setting the
"final_user_tkt_flags" string attribute to "true" in kadmin. In this
case, any ticket flag can be configured in the principal ticket policy,
except requires_preauth and allow_tix.
When in IPA setup mode (using the "ipa-setup-override-restrictions" KDB
argument), all the system described above is disabled and ticket flags
are written in the principal ticket policy as they are provided. This is
required to initialize the Kerberos LDAP container during IPA server
installation.
This fixes CVE-2024-3183
Signed-off-by: Julien Rische <jrische@redhat.com>
The initial implementation of MS-SFU by MIT Kerberos was missing a
condition for granting the "forwardable" flag on S4U2Self tickets.
Fixing this mistake required adding special case for the
check_allowed_to_delegate() function: if the target service argument is
NULL, then it means the KDC is probing for general constrained
delegation rules, not actually checking a specific S4U2Proxy request.
In commit e86807b5, the behavior of ipadb_match_acl() was modified to
match the changes from upstream MIT Kerberos a441fbe3. However, a
mistake resulted in this mechanism to apply in cases where target
service argument is set AND unset. This results in S4U2Proxy requests to
be accepted regardless of the fact there is a matching service
delegation rule or not.
This vulnerability does not affect services having RBCD (resource-based
constrained delegation) rules.
This fixes CVE-2024-2698
Signed-off-by: Julien Rische <jrische@redhat.com>
The function slapi_pblock_set_flag_operation_notes(); is defined in
ldap/servers/slapd/pblock.c in 389-ds but is only available through
slapi-private.h header, not through slapi-plugin.h public API.
It was introduced in ~1.4.1.7 (~2019) via https://pagure.io/389-ds-base/issue/50349.
Since we only use it with an MFA note, all versions of the 389-ds that
will support MFA note will have this function.
Fixes: https://pagure.io/freeipa/issue/9554
Signed-off-by: Alexander Bokovoy <abokovoy@redhat.com>
Reviewed-By: Florence Blanc-Renaud <flo@redhat.com>
In case there is a successful OTP authentication attempt, register it as
an operation note on the BIND operation in LDAP. 389-ds then will print
a multi-factor authentication note in both access and security logs
according to https://www.port389.org/docs/389ds/design/mfa-operation-note-design.html
Fixes: https://pagure.io/freeipa/issue/5169
Signed-off-by: Alexander Bokovoy <abokovoy@redhat.com>
Reviewed-By: Florence Blanc-Renaud <flo@redhat.com>
When authentication indicators were introduced in 2016, ipa-pwd-extop
plugin gained ability to reject LDAP BIND when an LDAP client insists
the authentication must use an OTP token. This is used by ipa-otpd to
ensure Kerberos authentication using OTP method is done with at least
two factors (the token and the password).
This enfrocement is only possible when an LDAP client sends the LDAP
control. There are cases when LDAP clients cannot be configured to send
a custom LDAP control during BIND operation. For these clients an LDAP
BIND against an account that only has password and no valid token would
succeed even if admins intend it to fail.
Ability to do LDAP BIND without a token was added to allow users to add
their own OTP tokens securely. If administrators require full
enforcement over LDAP BIND, it is cannot be achieved with LDAP without
sending the LDAP control to do so.
Add IPA configuration string, EnforceLDAPOTP, to allow administrators to
prevent LDAP BIND with a password only if user is required to have OTP
tokens. With this configuration enabled, it will be not possible for
users to add OTP token if one is missing, thus ensuring no user can
authenticate without OTP and admins will have to add initial OTP tokens
to users explicitly.
Fixes: https://pagure.io/freeipa/issue/5169
Signed-off-by: Alexander Bokovoy <abokovoy@redhat.com>
Reviewed-By: Florence Blanc-Renaud <flo@redhat.com>
Modify ipadb_reinit_mspac() to allocate and initialize ipactx->mspac
only if all its attributes can be set. If not, ipactx->mspac is set to
NULL. This makes easier to determine if the KDC is able to generate PACs
or not.
Also ipadb_reinit_mspac() is now able to return a status message
explaining why initialization of the PAC generator failed. This message
is printed in KDC logs.
Fixes: https://pagure.io/freeipa/issue/9535
Signed-off-by: Julien Rische <jrische@redhat.com>
Reviewed-By: Alexander Bokovoy <abbra@users.noreply.github.com>
Samba 4.20 will change name extension of the private libraries from
'samba4' to 'private-samba'. Detect private extension through configure
step and make sure to use the right library name in Makefile.
Signed-off-by: Alexander Bokovoy <abokovoy@redhat.com>
Reviewed-By: Florence Blanc-Renaud <flo@redhat.com>
krbCanonicalName is mandatory for services but IPA services created
before commit e6ff83e (FreeIPA 4.4.0, ~2016) had no normalization done
to set krbCanonicalName; services created after that version were
upgraded to do have krbCanonicalName.
Accept krbPrincipalName alone since they have no alias either */
Fixes: https://pagure.io/freeipa/issue/9465
Signed-off-by: Alexander Bokovoy <abokovoy@redhat.com>
Reviewed-By: Florence Blanc-Renaud <flo@redhat.com>
Reviewed-By: Thierry Bordaz <tbordaz@redhat.com>
Staged users have
uidNumber: -1
gidNumber: -1
ipaUniqueID: autogenerate
We cannot generate ipaSecurityIdentifier based on those UID/GID numbers.
However, '-1' value will trigger an error
find_sid_for_ldap_entry - [file ipa_sidgen_common.c, line 483]: ID value too large.
And that, in turn, will cause stopping SID generation for all users.
Detect 'ipaUniqueID: autogenerate' situation and ignore these entries.
Fixes: https://pagure.io/freeipa/issue/9517
Signed-off-by: Alexander Bokovoy <abokovoy@redhat.com>
Reviewed-By: Florence Blanc-Renaud <flo@redhat.com>
Reviewed-By: Thierry Bordaz <tbordaz@redhat.com>
Commit 0022bd70d9 introduced a memory leak
during the copy of some PAC buffers, because of an unfreed memory
allocation context.
Fixes: https://pagure.io/freeipa/issue/9520
Signed-off-by: Julien Rische <jrische@redhat.com>
Reviewed-By: Alexander Bokovoy <abokovoy@redhat.com>
For the trusted domain object for remote realm, we have to use
krbtgt/REMOTE-FLAT-NAME@OUR-REALM as a canonical name.
Fixes: https://pagure.io/freeipa/issue/9471
Signed-off-by: Alexander Bokovoy <abokovoy@redhat.com>
Reviewed-By: Francisco Trivino <ftrivino@redhat.com>
Related: https://pagure.io/freeipa/issue/9485
Signed-off-by: Alexander Bokovoy <abokovoy@redhat.com>
Reviewed-By: Francisco Trivino <ftrivino@redhat.com>
PKINIT differs from other pre-authentication methods by the fact that it
can be matched indepedently of the user authentication types via certmap
plugin in KDC.
Since PKINIT is a strong authentication method, allow its authentication
indicator and only apply the ticket policy.
Fixes: https://pagure.io/freeipa/issue/9485
Signed-off-by: Alexander Bokovoy <abokovoy@redhat.com>
Reviewed-By: Francisco Trivino <ftrivino@redhat.com>
If default user authentication type is set to a list that does not
include a password or a hardened credential, the resulting configuration
might be incorrect for special service principals, including a krbtgt/..
one.
Add detection of special principals to avoid these situations and always
allow password or hardened for services.
Special handling is needed for the following principals:
- krbtgt/.. -- TGT service principals
- K/M -- master key principal
- kadmin/changepw -- service for changing passwords
- kadmin/kadmin -- kadmin service principal
- kadmin/history -- key used to encrypt history
Additionally, implicitly allow password or hardened credential use for
IPA services and IPA hosts since applications typically use keytabs for
that purpose.
Fixes: https://pagure.io/freeipa/issue/9485
Signed-off-by: Alexander Bokovoy <abokovoy@redhat.com>
Reviewed-By: Francisco Trivino <ftrivino@redhat.com>
Covscan detected an unused value in ipa_kdb_principals.c
and a use-after-free in ipa-print-pac.c.
Fixes: https://pagure.io/freeipa/issue/9431
Signed-off-by: Florence Blanc-Renaud <flo@redhat.com>
Reviewed-By: Alexander Bokovoy <abokovoy@redhat.com>
Adding proper error handling to the is_master_host() function to allow
it to make the difference between the absence of a master host object
and a connection failure. This will keep the krb5kdc daemon from
continuing to run with a NULL LDAP context.
Fixes: https://pagure.io/freeipa/issue/9422
Signed-off-by: Julien Rische <jrische@redhat.com>
Reviewed-By: Alexander Bokovoy <abokovoy@redhat.com>
Three memory leaks are addressed:
1. String values retrieved from the pblock need to be manually
freed.
2. The list of objectclasses retreived from the pblock need to be
freed.
3. Internal search results need to be freed.
Fixes: https://pagure.io/freeipa/issue/9403
Signed-off-by: Rob Crittenden <rcritten@redhat.com>
Reviewed-By: Rafael Guterres Jeffman <rjeffman@redhat.com>
Reviewed-By: Alexander Bokovoy <abokovoy@redhat.com>
When 389-ds process an OTP authentication, the ipa-pwd-extop
plugin reads a buffer to extract the authentication type.
The type is stored in an int but the data is a ber_tag_t.
On big endian machines the type cast does not cause any issue
but on s390x the buffer that should return 128 is seen as 0.
As a consequence, the plugin considers that the method is not
LDAP_AUTH_SIMPLE and exits early, without processing the OTP.
The fix is simple and consists in using the right type
(ber_tag_t is an unsigned long).
Fixes: https://pagure.io/freeipa/issue/9402
Signed-off-by: Florence Blanc-Renaud <flo@redhat.com>
Reviewed-By: Rob Crittenden <rcritten@redhat.com>
MIT Kerberos KDC code will do verification of the PAC full checksum
buffers, we don't need to process them. This change only applies to
newer MIT Kerberos version which have this buffer type defined, hence
using #ifdef to protect the use of the define.
This should have no functional difference.
Related: https://pagure.io/freeipa/issue/9371
Signed-off-by: Alexander Bokovoy <abokovoy@redhat.com>
Reviewed-By: Julien Rische <jrische@redhat.com>
Kerberos principal aliases lookup had a long-standing TODO item to
support server referrals for host-based aliases. This commit implements
server referrals for hosts belonging to trusted domains. The use-case is
a part of S4U processing in a two-way trust when an IPA service requests
a ticket to a host in a trusted domain (e.g. service on AD DC). In such
situation, the server principal in TGS request will be a normal principal
in our domain and KDC needs to respond with a server referral. This
referral can be issued by a KDB driver or by the KDC itself, using
'domain_realms' section of krb5.conf. Since KDB knows all suffixes
associated with the trusted domains, implement the logic there.
Fixes: https://pagure.io/freeipa/issue/9164
Signed-off-by: Alexander Bokovoy <abokovoy@redhat.com>
Reviewed-By: Julien Rische <jrische@redhat.com>
Postpone ticket checksum configuration after KDB module was initialized.
This, in practice, should now happen when a master key is retrieved.
Signed-off-by: Alexander Bokovoy <abokovoy@redhat.com>
Reviewed-By: Julien Rische <jrische@redhat.com>
Early in startup LDAP server might not respond well yet and
should_support_pac_tkt_sign() will bail out with
KRB5_KDB_SERVER_INTERNAL_ERR. We should postpone this call but for time
being we should prevent a crash.
Crash happens because init_module() returns with an error and KDC then
calls fini_module() which will free the DB context which is already
corrupted for some reason.
Do not call any free() call because the whole context is corrupted as
tests do show.
Signed-off-by: Alexander Bokovoy <abokovoy@redhat.com>
Reviewed-By: Julien Rische <jrische@redhat.com>
From https://krbdev.mit.edu/rt/Ticket/Display.html?id=9089
--------
The KDC uses the first local TGT key for the privsvr and full PAC
checksums. If this key is of an aes-sha2 enctype in a cross-realm
TGT, a Microsoft KDC in the target realm may reject the ticket because
it has an unexpectedly large privsvr checksum buffer. This behavior
is unnecessarily picky as the target realm KDC cannot and does not
need to very the privsvr checksum, but [MS-PAC] 2.8.2 does limit the
checksum key to three specific enctypes.
--------
Use MIT Kerberos 1.21+ facility to hint about proper enctype for
cross-realm TGT.
Fixes: https://pagure.io/freeipa/issue/9124
Signed-off-by: Alexander Bokovoy <abokovoy@redhat.com>
Reviewed-By: Julien Rische <jrische@redhat.com>
By setting passkey_child_debug_level in default.conf the debug level for
the passkey_child helper utility can be set.
Reviewed-By: Alexander Bokovoy <abokovoy@redhat.com>
- added passkey detection based on the presence of ipaPassKey attribute
in the LDAP entry of the principal
- added 'passkey' authentication indicator
- added support for enforcing KDC policy based on the 'passkey'
indicator
Fixes: https://pagure.io/freeipa/issue/9263
Signed-off-by: Alexander Bokovoy <abokovoy@redhat.com>
Reviewed-By: Alexander Bokovoy <abokovoy@redhat.com>
Commit f78dc0b163 was missing an exception for the constrained
delegation ACL TL data type during the principal entry update operation.
This ACL is not meant to be stored as encoded data in krbExtraData.
Signed-off-by: Julien Rische <jrische@redhat.com>
Reviewed-By: Rob Crittenden <rcritten@redhat.com>
Reviewed-By: Alexander Bokovoy <abokovoy@redhat.com>
Since November 2020, Active Directory KDC generates a new type of
signature as part of the PAC. It is called "ticket signature", and is
generated based on the encrypted part of the ticket. The presence of
this signature is not mandatory in order for the PAC to be accepted for
S4U requests.
However, the behavior is different for MIT krb5. Support was added as
part of the 1.20 release, and this signature is required in order to
process S4U requests. Contrary to the PAC extended KDC signature, the
code generating this signature cannot be isolated and backported to
older krb5 versions because this version of the KDB API does not allow
passing the content of the ticket's encrypted part to IPA.
This is an issue in gradual upgrade scenarios where some IPA servers
rely on 1.19 and older versions of MIT krb5, while others use version
1.20 or newer. A service ticket that was provided by 1.19- IPA KDC will
be rejected when used by a service against a 1.20+ IPA KDC for S4U
requests.
On Fedora, CentOS 9 Stream, and RHEL 9, when the krb5 version is 1.20 or
newer, it will include a downstream-only update adding the
"optional_pac_tkt_chksum" KDB string attribute allowing to tolerate the
absence of PAC ticket signatures, if necessary.
This commit adds an extra step during the installation and update
processes where it adds a "pacTktSignSupported" ipaConfigString
attribute in "cn=KDC,cn=[server],cn=masters,cn=ipa,cn=etc,[basedn]" if
the MIT krb5 version IPA what built with was 1.20 or newer.
This commit also set "optional_pac_tkt_chksum" as a virtual KDB entry
attribute. This means the value of the attribute is not actually stored
in the database (to avoid race conditions), but its value is determined
at the KDC starting time by search the "pacTktSignSupported"
ipaConfigString in the server list. If this value is missing for at
least of them is missing, enforcement of the PAC ticket signature is
disabled by setting "optional_pac_tkt_chksum" to true for the local
realm TGS KDB entry.
For foreign realm TGS KDB entries, the "optional_pac_tkt_chksum" virtual
string attribute is set to true systematically, because, at least for
now, trusted AD domains can still have PAC ticket signature support
disabled.
Given the fact the "pacTktSignSupported" ipaConfigString for a single
server is added when this server is updated, and that the value of
"optional_pac_tkt_chksum" is determined at KDC starting time based on
the ipaConfigString attributes of all the KDCs in the domain, this
requires to restart all the KDCs in the domain after all IPA servers
were updated in order for PAC ticket signature enforcement to actually
take effect.
Fixes: https://pagure.io/freeipa/issue/9371
Signed-off-by: Julien Rische <jrische@redhat.com>
Reviewed-By: Rob Crittenden <rcritten@redhat.com>
Reviewed-By: Alexander Bokovoy <abokovoy@redhat.com>
In November 2022, Microsoft introduced a new PAC signature type called
"extended KDC signature" (or "full PAC checksum"). This new PAC
signature will be required by default by Active Directory in July 2023
for S4U requests, and opt-out will no longer be possible after October
2023.
Support for this new signature type was added to MIT krb5, but it relies
on the new KDB API introduced in krb5 1.20. For older MIT krb5 versions,
the code generating extended KDC signatures cannot be backported as it
is without backporting the full new KDB API code too. This would have
too much impact to be done.
As a consequence, krb5 packages for Fedora 37, CentOS 8 Stream, and RHEL
8 will include a downstream-only update adding the
krb5_pac_full_sign_compat() function, which can be used in combination
with the prior to 1.20 KDB API to generate PAC extended KDC signatures.
Fixes: https://pagure.io/freeipa/issue/9373
Signed-off-by: Julien Rische <jrische@redhat.com>
Reviewed-By: Rob Crittenden <rcritten@redhat.com>
Reviewed-By: Alexander Bokovoy <abokovoy@redhat.com>
Fix Covscan-discovered DEADCODE block when searching for PAC info,
caused by a wrong condition being evaluated when entry is a trusted
domain object.
Fixes: https://pagure.io/freeipa/issue/9368
Signed-off-by: Rafael Guterres Jeffman <rjeffman@redhat.com>
Reviewed-By: Rob Crittenden <rcritten@redhat.com>
Reviewed-By: Alexander Bokovoy <abokovoy@redhat.com>
Resource-based constrained delegation (RBCD) is implemented with a new
callback used by the KDC. This callback is called when a server asks for
S4U2Proxy TGS request and passes a ticket that contains RBCD PAC
options.
The callback is supposed to take a client and a server principals, a PAC and a target
service database entry. Using the target service database entry it then
needs to decide whether a server principal is allowed to delegate the
client credentials to the target service.
The callback can also cross-check whether the client principal can be
limited in delegating own tickets but this is not implemented in the
current version.
Fixes: https://pagure.io/freeipa/issue/9354
Signed-off-by: Alexander Bokovoy <abokovoy@redhat.com>
Reviewed-By: Rob Crittenden <rcritten@redhat.com>
Confine search for S4U2Proxy access control lists to the subtree where
they created. This will allow to use a similar method to describe RBCD
access controls.
Related: https://pagure.io/freeipa/issue/5444
Signed-off-by: Alexander Bokovoy <abokovoy@redhat.com>
Reviewed-By: Rob Crittenden <rcritten@redhat.com>
