This is part of the fix to #173. MSFT RODCs insist on the name type for
krbtgt principals be set to KRB5_NT_SRV_INST.
Commentary from Jeffrey Altman <jaltman@secure-endpoints.com>
As reported by David Mulder of Dell's Quest, Active Directory will
return a BAD_INTEGRITY error when a request for a krbtgt service
ticket is received with principal type NT-PRINCIPAL instead of NT-SRV-INST
as required by RFC 4120.
[Nico: RFC4120 does not require this. See the description of the
name-type field of PrincipalName on page 55.]
ERROR: VAS_ERR_KRB5: Failed to obtain credentials.
Client: SLED10-32$@F.QAS,
Service: SLED10-32$@F.QAS, Server: ad2-f.f.qas
Caused by: KRB5KRB_AP_ERR_BAD_INTEGRITY (-1765328353): Decrypt integrity check failed
Microsoft began enforcing principal type checking for RODCs in 2008R2.
Microsoft does state that ALL krgtgt/REALM tickets SHOULD be sent using
principal name type of KRB5_NT_SRV_INST instead of KRB5_NT_PRINCIPAL.
From Microsoft:
"I believe we discovered the problem. There isn't a bug in Windows.
There's been a code change to address another issue which puts in additional
checks for Kerberos tickets. The problem is with the Unix clients when the
client request a TGT. The Unix clients are using Name-type Principal
[KRB_NT_PRINCIPAL (1)] instead of using Name-type Service and Instance
[KRB_NT_SRV_INST (2)]...."
This change assigns the NT-SRV-INST principal type each time a krbtgt
service principal is created. Unlike Microsoft, the Heimdal mostly does
not care about the name-type of any principals, with the exception of
referrals, where the name type is needed to decide how to find a
next-hop realm.
Bugs exposed by 61720a0:
- test_context --client-name=... --mech-type=ntlm ... fails;
- gss_acquire_cred() with desired_mech=NTLM and
desired_name==GSS_C_NO_NAME fails;
- gss_init_sec_context() with non-default cred handle calls the
mechanism even when the given cred handle has no element for the
requencet mechanism.
tests/gss/check-ntlm works by accident: gss_acquire_cred() with
desired_mechs==GSS_C_NO_OID_SET succeeds mostly because there are
Kerberos credentials available, and then the subsequent
gss_init_sec_context() call works because of the third bug described
above.
Put kdc last in tests/Makefile.am. There's two tests in tests/kdc
that have been failing for a long time, and that causes the
remaining tests to not be run. By putting kdc last those tests do
run.
Works for krb5 and SPNEGO mechanisms. Kerberos credentials are passed as
credential cache names, or if there are memory based credentials, inband in the protocol. This means that the credentials buffers must be keep secret.
As documented by IBM (they have the wrong prototype though)
and GGF (GSS-API Extensions) back in 2001
