The auth event details audit key (formerly, parameter to auth_status)
contained, variously, an encryption type name; a PKINIT client certificate
name; or, a GSS initiator name. Audit these instead using individual keys that
reflect the values' contents.
Preserve integer/boolean audit values as their native types; convert to strings
when logging only. This commit goes some way towards unifying the two auditing
APIs.
Make Samba-specific HDB auth status API a wrapper on the existing auditing API,
with a view towards unifying the two APIs in a future commit.
The term "auth status" is replaced with "auth event", and the HDB auth_status
method is replaced with a more general purpose audit method which has access to
the entire request structure.
Return KRB5KDC_ERR_C_PRINCIPAL_UNKNOWN, not HDB_ERR_NOENTRY, if a client
principal could not be found during pre-authentication.
This fixes a regression introduced with synthetic principals in 00358252d3.
We're logging SUCCESS even when the KDC sends error replies. That's
because we're returning success to process_request() even when we send
errors to clients. The error we want to send to the client, and that we
succeed or fail to send it, are different statuses.
Also, further move things into `r` and out of function arguments.
Remove the outpadata field from astgs_request_t, because it's not something we
wish to expose publically (yet it is something that Samba needs in the
client_access plugin API, to add Windows error information).
Instead, allocate rep->padata at the start of AS/TGS request handling, and
ensure it is valid for the lifetime of the request until it is encoded (at
which point it will be freed and set to NULL if zero length, to avoid sending a
zero length METHOD-DATA to the client).
(The previous approach of setting rep->padata to point to &r->outpadata was
fragile, because it required clearing the pointer before freeing the KDC-REP.)
Make client_access plugin API take a single argument, astgs_request_t. Note: in
order to avoid making r->outpadata public (it's an internal buffer), but allow
Samba to modify the reply pa data, some pointer magic is required.
Add a helper function that returns TRUE if a PAC should be included in ticket
authorization data, that can be called from both AS and TGS paths.
Per [MS-KILE] 3.3.5.3, PACs are always included for TGTs; for service
tickets, policy is governed by whether the client explicitly requested
a PAC be omitted when requesting a TGT, or if the no-auth-data-reqd
flag is set on the service principal entry.
Remove the unwieldy pac_attributes_present field from the request structure.
Instead, if PAC attributes are not present in the TGT, the default is to assume
they were set to KRB5_PAC_WAS_GIVEN_IMPLICITLY.
Distinguish pre-authentication mechanisms that replace the reply key from those
that use the client's long-term key. In the general case, one is the inverse of
the other, however KRB5_PADATA_ENCRYPTED_CHALLENGE replaces the reply-key with
one derived from the long-term key.
PA_REPLACE_REPLY_KEY indicates that the kvno should be set to zero in the
reply; the absence of PA_USES_LONG_TERM_KEY indicates that the client's
long-term key may be included in the PAC (PAC_CREDENTIAL_INFO with Samba only).
Corrects e8984871.
Distinguish pre-authentication mechanisms that replace the reply key from those
that use the client's long-term key. In the general case, one is the inverse of
the other, however KRB5_PADATA_ENCRYPTED_CHALLENGE replaces the reply-key with
one derived from the long-term key.
PA_REPLACE_REPLY_KEY indicates that the kvno should be set to zero in the
reply; the absence of PA_USES_LONG_TERM_KEY indicates that the client's
long-term key may be included in the PAC (PAC_CREDENTIAL_INFO with Samba only).
PACs are included when issuing TGTs, if there is no PAC_ATTRIBUTES buffer
(legacy behavior) or if the attributes buffer indicates the AS client requested
one.
Only include the PAC_ATTRIBUTES PAC info buffer if we are issuing a TGT, as its
contents are not relevant to application services. (The buffer contains a bit
indicating whether the client explicitly or implicitly requested a PAC.)
In the altsecid GSS pre-authentication authorizer plugin, don't add the
REQUESTOR_SID PAC info buffer unless the client requested a TGT. It is not
relevant to application services.
Update the sample GSS pre-authentication authorizer plugin to allow the PAC to
be pinned to the authenticating user's SID.
There is still a race condition between the time the user authenticates and the
time the SID is looked up via LDAP, but it should be sufficient as an example;
if more security is required, then users should be enrolled with their SIDs.
Note the selected pre-authentication mechanism, and add a callback to allow the
pre-authentication mechanism to update the PAC immediately prior to signing.
Add PAC_ATTRIBUTES_INFO to the PAC. This info buffer indicates whether the user
explicitly requested a PAC be present or absent.
Note: this changes the windc plugin ABI.
Use the UPN_DNS_INFO buffer of the PAC to include the canonical principal name.
Arguably we should use AD-LOGIN-ALIAS as defined in RFC6806, but we may not
always know all the principal's aliases, and this approach allows us to share
application service logic with Windows.
r->client_princ and r->server_princ are only set in the AS-REQ case, but
we perform the PAC check in the TGS-REQ case, so calling
krb5_unparse_name() will dereference a NULL pointer. Instead, use
r->cname and r->sname.
Signed-off-by: Joseph Sutton <josephsutton@catalyst.net.nz>
08e0305b introduced a patch to validate armor ticket PACs, but required that
the armor client principal was in the local realm (as it did not allow
_kdc_db_fetch() to fail).
Allow cross-realm FAST armor clients by using the same logic to look up the
client principal as the TGS itself does, i.e. use db_fetch_client() which
handles the case where the client is not local to the KDC.
Note: the armor PAC is only required to be validated when issuing a final,
non-referral service ticket, as this is the only point upon which device claims
should be inserted (according to my understanding).
Closes: #901
Add a new authorization data type to indicate a synthetic principal was used,
to allow synthetic clients acquired outside of PKINIT (e.g. with GSS-API
pre-authentication) to use the TGS.
Note: we continue to honor KRB5_AUTHDATA_INITIAL_VERIFIED_CAS to indicate that
it is OK for the client to be synthetic, even though it is only an indication
that the client *may* have been synthetic.
