Hi Max,
at last I took some time to evaluate you SSPI bridge. This is part one.
Interaction evaluation will follow in a second email.
Assumptions:
* All methods, objects behave the same as with JGSS
* AcceptSecurityContext is not implemented so should everything
associated with it fail (GSSException)
* Code analysis happens based on
https://github.com/AdoptOpenJDK/openjdk-jdk13u/blob/master/src/java.security.jgss/windows/native/libsspi_bridge/sspi.cpp
and zulu13.29.9-ca-jdk13.0.2-win_x64
Findings C:
* sspi.cpp: Would it make sense to replace "__declspec(dllexport)" with
JNIEXPORT?
* GSSManager#createCredential(): I'd expect an exception when *not*
GSSCredential.INITIATE_ONLY is requested/passed
* sspi.cpp#L67-L68: Feels a bit awkward to permit SSPI_BRIDGE_TRACE="".
Why not have "if (trace && *trace)"?
* sspi.cpp#L233: The function name says "show_oid", but I see no OID
printed. Simply symbolic names.
* sspi.cpp#L290: Empty string check? like (realm && *realm)
* Usage of %p: If you don't know that %p is used it is hard to tell why
this output is there. May turn to "at 0x%p" in general?
* sspi.cpp#L359: -2!= reads awkward. Reformat?
* sspi.cpp#L482-L483: This is highly questionable. While it is true for
Windows, it does not stick to gss_compare_name behavior. Don't know what
the correct approach would be here.
* sspi.cpp#L595: That's weird. A string leads to a length? Should it
read: PP("Name found: %ls -> %s [%d]", names, buffer, len)
* sspi.cpp#L618: You are resetting cred_usage passed with the function.
This looks like a bug to me.
* sspi.cpp#L619: Reads very bad, maybe turn into
"PP("AcquireCredentialsHandle with usage: %d, creds: 0x%p", cred_usage,
desired_mechs)"
* sspi.cpp#L627-L633: Trace message could be more expressive, e.g.,
"Requesting Kerberos mech"
* sspi.cpp#L657-L658 and sspi.cpp#L687-L688: They look wrong and do not
correspond to GSSCredentialImpl.java#L628-L640. default value should be
INITIATE_AND_ACCEPT.
Same as in GSS-API:
$ sudo python3
> Python 3.7.7 (default, Mar 19 2020, 21:26:00)
> [Clang 9.0.1 (g...@github.com:llvm/llvm-project.git
c1a0a213378a458fbea1a5c77b31 on freebsd12
> Type "help", "copyright", "credits" or "license" for more information.
> >>> import gssapi
> >>> cred = gssapi.Credentials(usage='nonsense')
> >>> cred.usage
> 'both'
This also may be a bug in py-gssapi/MIT Kerberos
* sspi.cpp#L149
** Can you apply a better output like ISO 8601? In strftime(3) that
would be "%FT%T, ..."
** "%uld" does not seem to work here: 4294967295ld. Shouldn't that read
"%"PRIu32" seconds" or "%lu seconds"?
* sspi.cpp#L744: "Comparison result: %d". You are not comparing the
result, but print comparsion result.
* sspi.cpp#L841: man 3 gss_import_sec_context says: GSS_S_UNAVAILABLE
* sspi.cpp#L977-L979: Not helpful when the SEC_E_* not mapped to
major/minor. This likely applies to most mapping functions.
* sspi.cpp#L1012: Maybe: "Names: client: %s, server: %s"?
* sspi.cpp#L1046: Maybe like gss_export_sec_context?
* sspi.cpp#L1169: Remove word "IMPLEMENTED"
* sspi.cpp#L1169: Maybe like gss_export_sec_context?
* sspi.cpp#L1480: Includes a trailing, redundant newline
* sspi.cpp#L729-L748: Why do you do this? The documentation for
parameter 1 says: If the process that requests the handle does not have
access to the credentials, the function returns an error. I have
verified this with py-win32: win32security.AcquireCredentialsHandle().
Infact, it accepts any principal and always returns the default one. I
found these:
** https://github.com/twosigma/gsskrb5/blob/master/krb5/krb5cred.c#L127-L132
** https://github.com/twosigma/gsskrb5/blob/master/krb5/krb5cred.c#L127-L132
> >>> cred, time =
win32security.AcquireCredentialsHandle("administra...@oracle.com",
"Kerberos", win32security.SECPKG_CRED_OUTBOUND, None, None)
> >>> cred.QueryCredentialsAttributes(1)
> 'osipo...@ad001.siemens.net'
Findings Java:
* GssManager#createCredential() with ACCEPT_ONLY or INITIATE_AND_ACCEPT
gives me weird credentials with partial null nembers. I'd expect an
exception here.
* This is one fails, but shall work:
> GSSManager manager = GSSManager.getInstance();
> GSSName userName = manager.createName("osipovmi", GSSName.NT_USER_NAME);
> GSSCredential cred = manager.createCredential(userName,
GSSCredential.DEFAULT_LIFETIME, krb5Oid, GSSCredential.INITIATE_ONLY);
> [SSPI:1627] >>>> Calling gss_create_empty_oid_set...
> [SSPI:1542] >>>> Calling gss_add_oid_set_member...
> [SSPI:612] >>>> Calling gss_acquire_cred...
> [SSPI:619] AcquireCredentialsHandle with 0 00000257FFB199B0
> [SSPI:262] gss_OID_set.count is 1
> [SSPI:237] Kerberos mech
> [SSPI:628] reqKerberos
> [SSPI:152] cred expiration: 09/13/30828 04:48 4294967295ld
> [SSPI:732] Acquiring cred with a name. Check if it's me.
> [SSPI:791] >>>> Calling gss_inquire_cred...
> [SSPI:811] Allocate new name at 00000257FFB2BC40
> [SSPI:428] >>>> Calling gss_compare_name...
> [SSPI:437] Comparing osipo...@ad001.siemens.net and osipovmi
> [SSPI:325] >>>> Calling gss_release_name 00000257FFB17830...
> [SSPI:744] Comparing result: 0
> [SSPI:767] >>>> Calling gss_release_cred...
> [SSPI:1641] >>>> Calling gss_release_oid_set...
> Exception in thread "main" GSSException: Failure unspecified at
GSS-API level
> at
java.security.jgss/sun.security.jgss.wrapper.GSSLibStub.acquireCred(Native
Method)
The problem is that I provide a local name and expect the default realm
to be used. It seems like #createCredential() does not take that into
account. It also has no avail when the canonicalized form is used. See
sspi.cpp#L729-L748.
* GssManager#createContext(GSSCredential) still works although this
should be a acceptor context. I expect an expception. Does not fail with
JGSS either. MIT Kerberos with py-gssapi properly fails:
> >>> cred = gssapi.Credentials(usage='accept')
>>> cred
> <gssapi.creds.Credentials object at 0x80164bbb0>
> >>> context = gssapi.SecurityContext(usage='initiate', creds=cred,
name=canon_name, mech=gssapi.MechType.kerberos)
> >>> context.step(None)
> Traceback (most recent call last):
> File "<stdin>", line 1, in <module>
> File "<decorator-gen-15>", line 2, in step
> File "/usr/local/lib/python3.7/site-packages/gssapi/_utils.py",
line 167, in check_last_err
> return func(self, *args, **kwargs)
> File "<decorator-gen-5>", line 2, in step
> File "/usr/local/lib/python3.7/site-packages/gssapi/_utils.py",
line 127, in catch_and_return_token
> return func(self, *args, **kwargs)
> File
"/usr/local/lib/python3.7/site-packages/gssapi/sec_contexts.py", line
521, in step
> return self._initiator_step(token=token)
> File
"/usr/local/lib/python3.7/site-packages/gssapi/sec_contexts.py", line
542, in _initiator_step
> token)
> File "gssapi/raw/sec_contexts.pyx", line 245, in
gssapi.raw.sec_contexts.init_sec_context
> gssapi.raw.exceptions.MissingCredentialsError: Major (458752): Es
wurden keine Anmeldedaten übergeben oder die Anmeldedaten waren nicht
verfügbar bzw. ein Zugriff darauf nicht möglich., Minor (100001):
Unknown code 0
That's it for now.
Michael
