The recent changes to SPNEGO removed support for GSS_C_PEER_HAS_UPDATED_SPNEGO,
through which the Kerberos mechanism could indicate to SPNEGO that the peer did
not suffer from SPNEGO conformance bugs present in some versions of Windows.*
This patch restores this workaround, documented in [MS-SPNG] Appendix A <7>
Section 3.1.5.1. Whilst improving interoperability with these admittedly now
unsupported versions of Windows, it does introduce a risk that Kerberos with
pre-AES ciphers could be negotiated in lieu of a stronger and more preferred
mechanism.
Note: this patch inverts the mechanism interface from
GSS_C_PEER_HAS_UPDATED_SPNEGO to GSS_C_INQ_PEER_HAS_BUGGY_SPNEGO, so that new
mechanisms (which did not ship with these older versions of Windows) are not
required to implement it.
* Windows 2000, Windows 2003, and Windows XP
NTLM erroneously requires a mechListMIC at the SPNEGO layer if an internal MIC
in the NTLM protocol was used. Add a private interface between SPNEGO and the
Samba NTLM mechanism to allow the mechanism to signal that a mechListMIC is
required even if it otherwise would not be.
This interface is the same as that supported by MIT.
Note that only the Samba NTLM mechanism currently implements this feature, it
is not implemented by the Heimdal NTLM mechanism (which does not support NTLM
authenticate message MICs).
An implementation of draft-zhu-negoex-04 for MIT Kerberos was developed in
2011. This has been recently integrated, with many fixes from Greg Hudson. This
commit ports it to Heimdal. The implementation has been interoperability tested
with MIT Kerberos and Windows, using the GSS EAP mechanism developed as part of
the Moonshot project.
The SPNEGO code was also updated to import the state machine from Apple which
improves mechListMIC processing and avoids discarding initial context tokens
generated during mechanism probing, that can be used for optimistic tokens.
Finally, to aid in testing, the GSS-API mechanism glue configuration file can
be changed using the environment variable GSS_MECH_CONFIG. This environment
variable name, along with the format of the configuration file, is compatible
with MIT (although it would be difficult for a single mechanism binary to
support both implementations).
Implement the GSS-API credential store API extensions defined by MIT here:
https://k5wiki.kerberos.org/wiki/Projects/Credential_Store_extensions
Note: we kill off gss_acquire_cred_ext() here. This was never a public API,
although mechanisms could have implemented it and I briefly used it in my
BrowserID prototype mechanism. gss_acquire_cred_ext_from() occupies the place
in the dispatch table where gss_acquire_cred_ext() used to, but this structure
was never visible outside Heimdal (i.e. it is only used by internal
mechanisms);
(Mechanisms that need to accept arbitrary key/value dictionaries from
applications should now implement gss_acquire_cred_from().)
restore correct OID for GSS_C_PEER_HAS_UPDATED_SPNEGO, this should have no
ABI implications, it's for internal use only. The current OID was incorrectly
copied in commit dbeeb18a, it should belong to 1.3.6.1.4.1.5322.19 which is
... enterprise(1) padl(5322) gssKrb5Extensions(19). The OID we were camping
on belongs to another party.
This is generated from lib/gssapi/oid.txt using lib/gssapi/gen-oid.pl,
which sorts the entries to ensure minimal diff churn when an oid is
added or changed.
The lack of effective changes can be seen by sorting both versions, a
bit like this:
$ git show HEAD~~:lib/gssapi/mech/gss_oid.c | sort > /tmp/gss_oid.c-OLD
$ cat lib/gssapi/mech/gss_oid.c | sort > /tmp/gss_oid.c-NEW
$ diff -u /tmp/gss_oid.c*
$ #Nothing to see!
This is of course not a reliable check in general, but works for this
simple file in concert with ordinary inspection.
Signed-off-by: Douglas Bagnall <douglas.bagnall@catalyst.net.nz>
These missed out on the rk_UNCONST()ification by virtue of being added
in a parallel branch. In the diagram below, they got added in 02cf28e,
while the rk_UNCONSTs were added in f5f9014.
* cc47c8f Turn on -Wextra -Wno-sign-compare -Wno-unused-paramter and fix issues.
* 3069d80 Merge branch 'master' into lukeh/acquire-cred-ex
|\
| * f5f9014 Warning fixes from Christos Zoulas
* | 02cf28e implement gss_acquire_cred_ex with password support
|/
* 2170219 add more oids
rk_UNCONST amounts to a cast to (void *), removing const.
Signed-off-by: Douglas Bagnall <douglas.bagnall@catalyst.net.nz>
We turn on a few extra warnings and fix the fallout that occurs
when building with --enable-developer. Note that we get different
warnings on different machines and so this will be a work in
progress. So far, we have built on NetBSD/amd64 5.99.64 (which
uses gcc 4.5.3) and Ubuntu 10.04.3 LTS (which uses gcc 4.4.3).
Notably, we fixed
1. a lot of missing structure initialisers,
2. unchecked return values for functions that glibc
marks as __attribute__((warn-unused-result)),
3. made minor modifications to slc and asn1_compile
which can generate code which generates warnings,
and
4. a few stragglers here and there.
We turned off the extended warnings for many programs in appl/ as
they are nearing the end of their useful lifetime, e.g. rsh, rcp,
popper, ftp and telnet.
Interestingly, glibc's strncmp() macro needed to be worked around
whereas the function calls did not.
We have not yet tried this on 32 bit platforms, so there will be
a few more warnings when we do.
