This reverts commit 6f81e4c93b.
This patch may have originated in Samba from before force_canonicalize was
supported. Because the server_principal argument to tgs_make_reply() is
canonicalized prior to calling (if the server entry has force_canonicalize
set), honoring it again in tgs_make_reply() is superfluous.
Initialize the tgs_req buffer in init_tgs_req() so pointers are valid when
freed. Fixes regression introduced when Apple TGS-REQ FAST code was imported in
PR #805.
Look up the client name of the armor TGT in the database, and check that
the PAC is valid.
Signed-off-by: Joseph Sutton <josephsutton@catalyst.net.nz>
Closes: #891
This allows Samba to have a behaviour where
even if canonicalize flag is not set, the canonical realm
is returned, allowing a HDB module to require behaviour
that is the same as Windows.
Regression (for a HDB module wanting AD behaviour) was
introduced by commit:
378f34b4be
Signed-off-by: Isaac Boukris <iboukris@gmail.com>
[abartlet@samba.org Similar to Samba commit a9e6119ca0c2a78ef314c3162122539ee834aa04
but made conditional on server->entry.flags.force_canonicalize to
allow upstream submission]
If the pre-authentication mechanism replaced the reply key, then the kvno in
the KDC-REP should be zero, as the reply is not encrypted in the client's
(versioned) long-term key.
Closes: #899
We now pass on the original client name and the client address to allow
consistent audit logging in Samba across multiple protocols.
We also log the authentication duration.
This is not a general purpose profiling solution, but in Smaba
these JSON logs are already being generated and stored, so this
is worth adding.
Some administrators are very keen to know how long authentication
takes, particularly due to long replication transactions in other
Samba processes.
We use config->db[0] to find the first database to record incorrect
users.
Signed-off-by: Andrew Bartlett <abartlet@samba.org>
(Similar to Samba commit f498ba77df2313e78863e5f2706840c43e232a96 and
bb2a1c6b3eaccf114ac3f3b5b51f57828a04996)
[metze@samba.org: improved for heimdal upstream]
Signed-off-by: Stefan Metzmacher <metze@samba.org>
[abartlet@samba.org: improved again for Heimdal based on feedback]
AES256 and AES128 are newer enctypes because they are officially
specified in RFC4120 and RFC8009, while enctypes not officially
specified since RFC4120 are considered older. This function differs from
older_enctype() in that it does not report unknown or non-existent
enctypes as being 'newer'.
Signed-off-by: Joseph Sutton <josephsutton@catalyst.net.nz>
Assists Samba to address CVE-2020-25719
It is critical to ensure that the name in the U2U TGT is still associated with
the account was issued to, so we must check the PAC to verify the SID.
Otherwise the SPN check via the S4U2Self hook might be mislead.
Samba BUG: https://bugzilla.samba.org/show_bug.cgi?id=14873
Signed-off-by: Joseph Sutton <josephsutton@catalyst.net.nz>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>
(Similar to Samba commit 49a13f0fc942d1cfb767d5b6bf49d62241d52046)
Assists Samba to address CVE-2020-25719
Again, this may be contary to RFC4120 3.3.3
https://datatracker.ietf.org/doc/html/rfc4120/#section-3.3.3
(clearer at the GSS spec here:
https://datatracker.ietf.org/doc/html/draft-swift-win2k-krb-user2user-03 )
as server-name is decribed as optional, however Windows AD and Samba
both require that the server-name exist and be a valid SPN matching
the provided TGT.
The lookup of SPN -> entry ensures that the SPN the client thought it
was connecting to was held by the target server. it could be the
typical user principal, or a service principal, but needs to be checked
for the client not to be fooled into connecting to the wrong service.
The check is the same as needed for S4U2Self so the same HDB hook is re-used.
Samba BUG: https://bugzilla.samba.org/show_bug.cgi?id=14873
(Similar to Samba commit f08e6ac86226dcd939fd0e40b6f7dc80c5c00e79)
Assists Samba to address CVE-2020-25719
This may be contary to RFC4120 3.3.3 at
https://datatracker.ietf.org/doc/html/rfc4120/#section-3.3.3
(clearer in the GSS mechanism here:
https://datatracker.ietf.org/doc/html/draft-swift-win2k-krb-user2user-03 )
as server-name is decribed as optional, however Windows AD and Samba
both require that the server-name exist and be a valid SPN matching
the provided TGT.
The lookup of SPN -> entry ensures that the SPN the client thought it
was connecting to was held by the target server. it could be the
typical user principal, or a service principal, but needs to be checked
for the client not to be fooled into connecting to the wrong service.
Samba BUG: https://bugzilla.samba.org/show_bug.cgi?id=14873
Signed-off-by: Joseph Sutton <josephsutton@catalyst.net.nz>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>
(Similar to Samba commit fd50fecbe99ae4fc63843c796d0a516731a1fe6a)
Assists Samba to address CVE-2020-25719
Passing in target_server as a string principal means that for
an alias we must looking up the DB twice.
This is subject to a race and is a poor use of resources,
so instead just pass in the record we
already got when trying to confirm that the server in
S4U2Self is the same as the requesting client.
We also avoid doing a name comparison if the HDB plugin provides
a validation hook, this allows the HDB layer more freedom
to choose how to handle things.
In Samba AD the client record has already been bound to the the
original client by the SID check in the PAC, so the record is
known to match the ticket.
Likewise by looking up server only once we ensure that the
keys looked up originally (to decrypt) are in the record
we confirm the SID for here.
Samba BUG: https://bugzilla.samba.org/show_bug.cgi?id=14686
Signed-off-by: Andrew Bartlett <abartlet@samba.org>
(Based on Samba commit 05898cfb139ae0674c8251acc9d64c4c3d4c8376)
Instead of always advertising PADATA-ENCRYPTED-CHALLENGE, we only
advertise it if FAST is in use.
We also check configuration options to only advertise
PADATA-ENC-TIMESTAMP if it will be accepted based on whether FAST is
currently in use. This permits the non-RFC behaviour required to avoid
breaking earlier Heimdal clients.
This incorporates changes from Apple Heimdal-597.140.2.
Signed-off-by: Joseph Sutton <josephsutton@catalyst.net.nz>
Normally when FAST is used with a TGS-REQ, the armor key is implicitly
derived from the TGT rather than armor being explicitly present, as for
AS-REQs. However, Windows allows a TGS-REQ to be explicitly armored with
a computer's TGT, so that the armor key also depends on the ticket
session key.
This is used for compound identity, where the computer's group
membership and claims are added to the PAC of the resulting ticket.
Signed-off-by: Joseph Sutton <josephsutton@catalyst.net.nz>
Samba includes the user's long-term credentials (encrypted in the AS reply key)
to allow legacy authentication protocols such as NTLM to work even if the
pre-authentication mechanism replaced the reply key (as PKINIT does).
Samba also needs to know whether the client explicitly requested a PAC be
included (or excluded), in order to defer PAC exclusion until a service ticket
is issued (thereby avoiding a name binding attack if the user is renamed
between TGT and service ticket issuance).
References:
https://bugzilla.samba.org/show_bug.cgi?id=11441https://bugzilla.samba.org/show_bug.cgi?id=14561Closes: #864
Original authors:
- Joseph Sutton <josephsutton@catalyst.net.nz>
- Andrew Bartlett <abartlet@samba.org>
- Stefan Metzmacher <metze@samba.org>
This lets us call it from Samba.
Signed-off-by: Joseph Sutton <josephsutton@catalyst.net.nz>
[abartlet@samba.org Similar to Samba commit 3bdce12789af1e7a7aba56691f184625a432410d
but also fixed for caller in Heimdal windc plugin tests]
Previously, if left==right==A1_HEADER_LEN(tos), this would read past the
end of the template array. Now we treat [left, right) as a half-open
interval and no longer try to read from 'right'.
Signed-off-by: Joseph Sutton <josephsutton@catalyst.net.nz>
Always require a strengthen key to be used if GSS pre-authentication is used
within FAST. TRhis avoids a MITM attack that could result in unintended
privilege escalation, should a KDC add additional positive authorization data
from the armor ticket to the issued ticket.
An upcoming revision of the draft will reflect this.
