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>
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]
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.
Import KDC FAST from Apple's Heimdal-597.121.1, adding support for:
- PA-ENC-CHALLENGE
- reply key strengthening
- FAST authentication in TGS
kuser: Apple sync (squash)
krb5_init_creds_store_config/krb5_init_creds_warn_user in kinit
Sync with most changes in AS/TGS client from Apple's Heimdal-597.121.1
(opensource.apple.com).
Changes include:
- FAST support in TGS client
- Refactored pre-auth client to be more easily extensible
- Pin KDC host and AD site name in API calls
Note the completely refactored TGS client loop is not imported as that was
considered too intrusive.
This reverts commit 24a7a82e82.
After further discussion in #863, the alignment (which differs according to
info buffer type) should be handled by the caller.
The reply structure was not being zero-initialised in all cases, leading
to crashes or possible heap corruption on error paths when we later
freed it.
Signed-off-by: Joseph Sutton <josephsutton@catalyst.net.nz>
Setting `dns_lookup_realm = false` in `[libdefaults]` and setting name
canon rules that force the empty realm causes destination-TGT delegation
to break because the client doesn't know the service's realm.
Because MIT and Heimdal check that the (unauthenticated plaintext)
sname/realm of the Ticket in the KDC reply matches the sname/srealm in
the enc-part of the KDC reply, we know we can trust the realm of the
ticket found in the ccache. So use that.
SQLite3 defaults to 0644 unless overridden, relying on the process'
umask to make that tighter.
Our in-tree SQLite3 uses 0600 as the permissions for DB files it
creates.
Out-of-tree builds of SQLite3 probably get the 0644 default.
We can't change the umask in libraries -- it's not thread-safe.
So this commit changes the SCC ccache type's default ccname to include
an intermediate directory which is created with `mkdir(2)` with
permissions set to 0700, then it chmods the DB file to 0644.
Samba is starting to protect against bi-di attacks and the starting point
is to require that input files be fully UTF-8. In 2021 this is a reasonable
starting point anyway.
Signed-off-by: Andrew Bartlett <abartlet@samba.org>
Although not required to address bad code generation in
some versions of gcc 9 and 10, a coding style that requires
explicit comparison of the result to zero before use is
both clearer and would have avoided the generation of bad
code.
This change converts all use of cmp function usage from
```
if (strcmp(a, b) || !strcmp(c, d)) ...
```
to
```
if (strcmp(a, b) != 0 || strcmp(c, d)) == 0
```
for all C library cmp functions and related:
- strcmp(), strncmp()
- strcasecmp(), strncasecmp()
- stricmp(), strnicmp()
- memcmp()
Change-Id: Ic60c15e1e3a07e4faaf10648eefe3adae2543188
The plugin interfaces were originally implemented for use on
Unix where KRB5_CALLCONV, HEIM_CALLCONV and similar are defined
as nothing. However, on 32-bit Windows the calling convention
matters and executing a __stdcall function through a __cdecl
function pointer will result in failures.
This change updates the krb5plugin_windc, krb5plugin_service_locate,
krb5plugin_send_to_kdc plugins to specify the KRB5_CALLCONV for
functions. This brings the plugins into compliance with the
heim_plugin_common interface requirement that init() and fini()
use the platform specified HEIM_CALLCONV.
The krb5-plugin(7) man page is updated and the lib/krb5/test_plugin
test is also fixed.
With this change all tests pass on 32-bit Windows.
Change-Id: Ic9d2e1285c9c179e3898dc9d071ed092bcddc406
Make keyed checksums mandatory when generating and verifying checksums, with
the following exceptions:
* the checksum is being generated or verified as part of encrypting data for
a legacy (DES) encryption type
* the KRB5_CRYPTO_FLAG_ALLOW_UNKEYED_CHECKSUM flag was set on the crypto
context, used to allow unkeyed checksums in krb5 authenticators
By making unkeyed checksums opt-in, we eliminate a class of potential
vulnerabilities where callers could pass unkeyed checksums.
Any code that uses the mandatory checksum type for a given non-legacy
encryption type should not be affected by this change. It could potentially
break, say, a client trying to do FAST with DES keys but, that should not be
supported (because FAST KDCs also support AES).
Closes: #835
Split Windows PAC signing and verification logic, as the signing has to be when
the ticket is ready.
Create sign and verify the PAC KDC signature if the plugin did not, allowing
for S4U2Proxy to work, instead of KRB5SignedPath.
Use the header key to verify PAC server signature, as the same key used to
encrypt/decrypt the ticket should be used for PAC server signature, like U2U
tickets are signed witht the tgt session-key and not with the longterm key,
and so krbtgt should be no different and the header key should be used.
Lookup the delegated client in DB instead of passing the delegator DB entry.
Add PAC ticket-signatures and related functions.
Note: due to the change from KRB5SignedPath to PAC, S4U2Proxy requests
against new KDC will not work if the evidence ticket was acquired from
an old KDC, and vide versa.
Closes: #767
krb5_enomem() was lacking a calling convention decoration, breaking Windows
consumers if __cdecl was not the default calling convention. Add KRB5_LIB_CALL
to make it consistent with other library functions.
Closes: #834
Add a new krbhst type, KRB5_KRBHST_TKTBRIDGEAP to krb5_krbhst_init_flags(),
that looks for the DNS SRV record kerberos-tkt-bridge. This is to support a new
PADL project.
Add unkeyed checksum types for SHA-256, SHA-384 and SHA-512, for future
internal use. They are assigned private (negative) checksum types and must
never appear in cleartext on the wire.
This reverts commit 34b374b5e4.
We are revising the GSS-API pre-authentication draft to include the nonce from
the first request in the GSS channel bindings, to avoid re-encoding issues that
may surface with Kerberos implementations that do not correctly implement DER.
Zero nonce before encoding KDC-REQ-BODY to be used as channel binding
application data in GSS-API pre-authentication. This is because the nonce may
change between AS-REQs and the channel binding data should be invariant between
calls to GSS_Init_sec_context().
Add support for GSS-API pre-authentication to the KDC, using a simplified
variation of draft-perez-krb-wg-gss-preauth-02 that encodes GSS-API context
tokens directly in PADATA, and uses FX-COOKIE for state management.
More information on the protocol and implementation may be found in
lib/gssapi/preauth/README.md.
Fix merge issue introduced in ef1d63a9 which did not update the call
site after updating the _krb5_make_fast_ap_fxarmor() prototype to take
the realm (used in the anonymous PKINIT case).
