Add libkdc wrappers for heimbase object accessors so plugins can use audit and
request attribute APIs without consuming libheimbase. Exposed API surface is
minimal and is limited to reading array collections, and reading/creating base
and custom types.
Build the entry to write to the log file in memory, the write it with
O_APPEND. This should make writes to the request log file safer in
multi-process KDC configurations.
Also, check results of krb5_store_*() functions (coverity alerted to
this).
We will use the kdc_ rather than krb5_kdc_ prefix for new public APIs exported
from libkdc. Amend the recently introduced
request_{get,set,copy,delete}_attribute APIs to conform.
Annotate libkdc APIs with KDC_LIB_{CALL,FUNCTION} to ensure correct calling
convention and optimized DLL importing on Windows.
Ensure Windows and libtool export tables are consistent.
Now heim_audit_addkv() correctly supports multiple values, the other functions
that (by design) replace existing values with a single value should use the
heim_audit_setkv prefix.
A subsequent commit could add variants that support multiple values for
non-string types.
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.
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.
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
- Don't log "Request from wrong address (ignoring)".
- Add "wrongaddr=yes" kv to final log message.
- Add request and ticket addresses (up to 3) to final log message.
Now we'll put the "reason=..." last in the log lines and we won't escape
spaces -- just newlines and other control characters. This makes
reading log lines much easier without complicating parsing of log lines
because interior key=value pairs do get whitespace escaped or removed.
We refactor the code a bit to extend kdc_request_t which until now
was only used for the AS. We make the structure extensible and
start using it for the TGS as well. We leave digest and kx509
alone for the time being.
We also define the concept of kv-pairs in our audit trail which
allows us to define a rigorous but extensible format:
type error from-addr client server key1=val1 key2=val2 ...
This commit adds support for kx509 in libkrb5, and revamps the KDC's
kx509 service (fixing bugs, adding features).
Of note is that kx509 is attempted optimistically by the client, with
the certificate and private key stored in the ccache, and optionally in
an external PEM or DER file.
NOTE: We do not optimistically use kx509 in krb5_cc_store_cred() if the
ccache is a MEMORY ccache so we don't generate a key when
accepting a GSS context with a delegated credential.
kx509 protocol issues to be fixed in an upcoming commit:
- no proof of possession (this is mostly not too bad, but we'll want to
fix it by using CSRs)
- no algorithm agility (only plain RSA is supported)
- very limited (no way to request any options in regards to the
requested cert)
- error codes are not very useful
Things we're adding in this commit:
- libkrb5 kx509 client
- automatic kx509 usage hooked in via krb5_cc_store_cred() of start TGT
- per-realm templates on the KDC side
- per-realm issuer certificates
- send error messages on the KDC side
(this is essential to avoid client-side timeouts on error)
- authenticate as many error messages
- add a protocol probe feature so we can avoid generating a
keypair if the service is not enabled
(once we add support for ECC algorithms we won't need this
anymore; the issue is that RSA keygen is slow)
- support for different types of client principals, not just username:
- host-based service and domain-based service, each with its own
template set per-{realm, service} or per-service
(the idea is to support issuance of server certificates too, not
just client/user certs)
- more complete support for SAN types
- tests (including that PKINIT->kx509->PKINIT works, which makes it
possible to have "delegation" of PKIX credentials by just delegating
Kerberos credentials)
- document the protocol in lib/krb5/kx509.c
Future work:
- add option for longer-ticket-lifetime service certs
- add support for ECDSA, and some day for ed25519 and ed448
- reuse private key when running kinit
(this will require rethinking how we trigger optimistic kx509
usage)
- HDB lookup for:
- optional revocation check (not strictly necessary)
- adding to certificates those SANs listed in HDB
- hostname aliases (dNSName SANs)
- rfc822Name (email)
- XMPP SANs
- id-pkinit-san (a user could have aliases too)
- support username wild-card A RRs, ala OSKT/krb5_admin
i.e., if a host/f.q.d.n principal asks for a certificate for
some service at some-label.f.q.d.n, then issue it
(this is not needed at OSKT sites because OSKT already
supports keying such service principals, which means kx509
will issue certificates for them, however, it would be nice
to be able to have this independent of OSKT)
(a better way to do this would be to integrate more of OSKT
into Heimdal proper)
- a kx509 command, or heimtools kx509 subcommand for explicitly
attempting use of the kx509 protocol (as opposed to implicit, as is
done in kinit via krb5_cc_store_cred() magic right now)
Issues:
- optimistically trying kx509 on start realm TGT store -> timeout issues!
- newer KDCs will return errors because of this commit; older ones
will not, which causes timouts
- need a separate timeout setting for kx509 for optimistic case
- need a [realm] config item and DNS SRV RR lookup for whether a
realm is expected to support kx509 service
