Heimdal's HDB plugin interface, and hence Samba's KDC that depends upon
it, doesn't work on 32-bit builds due to structure fields being arranged
in the wrong order. This problem presents itself in the form of
segmentation faults on 32-bit systems, but goes unnoticed on 64-bit
builds thanks to extra structure padding absorbing the errant fields.
This commit reorders the HDB plugin structure fields to prevent crashes
and introduces a common macro to ensure every plugin presents a
consistent interface.
Samba BUG: https://bugzilla.samba.org/show_bug.cgi?id=15110
Signed-off-by: Joseph Sutton <josephsutton@catalyst.net.nz>
instead of testing both cb_ctx.h and cb_ctx.h->prefix
for non-NULL, ensure that cb_ctx.h is NULL after each
failed for() loop. This also ensures that cb_ctx.h
is never left pointing to an invalid non-NULL value.
Change-Id: I3264577b0fbf1d620b00f87d251e8c43b81e0f29
Remove hdb_entry_ex and revert to the original design of hdb_entry (except with
an additional context member in hdb_entry which is managed by the free_entry
method in HDB).
Decorate HDB_entry with context and move free_entry callback into HDB structure
itself. Requires updating hdb_free_entry() signature to include HDB parameter.
A follow-up commit will consolidate hdb_entry_ex (which has a single hdb_entry
member) into hdb_entry.
On Ubuntu 20.04 with gcc version 9.3.0 during a strict
Samba build with -Werror=maybe-uninitialized we get:
../../source4/heimdal/lib/hdb/hdb.c: In function ‘hdb_create’:
../../source4/heimdal/lib/hdb/hdb.c:831:13: error: ‘ret’ may be used uninitialized in this function [-Werror=maybe-uninitialized]
831 | if (*db && ret == 0)
| ~~~~^~~~~~~~~~~
cc1: all warnings being treated as errors
Signed-off-by: Andrew Bartlett <abartlet@samba.org>
Status:
- And it works!
- We have an extensive test based on decoding a rich EK certficate.
This test exercises all of:
- decoding
- encoding with and without decoded open types
- copying of decoded values with decoded open types
- freeing of decoded values with decoded open types
Valgrind finds no memory errors.
- Added a manual page for the compiler.
- rfc2459.asn1 now has all three primary PKIX types that we care about
defined as in RFC5912, with IOS constraints and parameterization:
- `Extension` (embeds open type in an `OCTET STRING`)
- `OtherName` (embeds open type in an `ANY`-like type)
- `SingleAttribute` (embeds open type in an `ANY`-like type)
- `AttributeSet` (embeds open type in a `SET OF ANY`-like type)
All of these use OIDs as the open type type ID field, but integer
open type type ID fields are also supported (and needed, for
Kerberos).
That will cover every typed hole pattern in all our ASN.1 modules.
With this we'll be able to automatically and recursively decode
through all subject DN attributes even when the subject DN is a
directoryName SAN, and subjectDirectoryAttributes, and all
extensions, and all SANs, and all authorization-data elements, and
PA-data, and...
We're not really using `SingleAttribute` and `AttributeSet` yet
because various changes are needed in `lib/hx509` for that.
- `asn1_compile` builds and recognizes the subset of X.681/682/683 that
we need for, and now use in, rfc2459.asn1. It builds the necessary
AST, generates the correct C types, and generates templating for
object sets and open types!
- See READMEs for details.
- Codegen backend not tested; I won't make it implement automatic open
type handling, but it should at least not crash by substituting
`heim_any` for open types not embedded in `OCTET STRING`.
- We're _really_ starting to have problems with the ITU-T ASN.1
grammar and our version of it...
Type names have to start with upper-case, value names with
lower-case, but it's not enough to disambiguate.
The fact the we've allowed value and type names to violate their
respective start-with case rules is causing us trouble now that we're
adding grammar from X.681/682/683, and we're going to have to undo
that.
In preparation for that I'm capitalizing the `heim_any` and
`heim_any_set` types, and doing some additional cleanup, which
requires changes to other parts of Heimdal (all in this same commit
for now).
Problems we have because of this:
- We cannot IMPORT values into modules because we have no idea if a
symbol being imported refers to a value or a type because the only
clue we would have is the symbol's name, so we assume IMPORTed
symbols are for types.
This means we can't import OIDs, for example, which is super
annoying.
One thing we might be able to do here is mark imported symbols as
being of an undetermined-but-not-undefined type, then coerce the
symbol's type the first time it's used in a context where its type
is inferred as type, value, object, object set, or class. (Though
since we don't generate C symbols for objects or classes, we won't
be able to import them, especially since we need to know them at
compile time and cannot defer their handling to link- or
run-time.)
- The `NULL` type name, and the `NULL` value name now cause two
reduce/reduce conflicts via the `FieldSetting` production.
- Various shift/reduce conflicts involving `NULL` values in
non-top-level contexts (in constraints, for example).
- Currently I have a bug where to disambiguate the grammar I have a
CLASS_IDENTIFIER token that is all caps, while TYPE_IDENTIFIER must
start with a capital but not be all caps, but this breaks Kerberos
since all its types are all capitalized -- oof!
To fix this I made it so class names have to be all caps and
start with an underscore (ick).
TBD:
- Check all the XXX comments and address them
- Apply this treatment to Kerberos! Automatic handling of authz-data
sounds useful :)
- Apply this treatment to PKCS#10 (CSRs) and other ASN.1 modules too.
- Replace various bits of code in `lib/hx509/` with uses of this
feature.
- Add JER.
- Enhance `hxtool` and `asn1_print`.
Getting there!
Do not allow a change in build configuration time default HDB backend
selection cause existing default HDBs to not be possible to open.
Otherwise such a change will cause a KDC configured to use the default
HDB (i.e., without setting it in the "database" stanza in the "[kdc]"
section of krb5.conf) to not start.
This is a large commit that adds several features:
- Revamps and moves virtual host-based service principal functionality
from kdc/ to lib/hdb/ so that it may be automatically visible to
lib/kadm5/, as well as kadmin(1)/kadmind(8) and ktutil(1).
The changes are backwards-incompatible.
- Completes support for documenting a service principal's supported
enctypes in its HDB entry independently of its long-term keys. This
will reduce HDB bloat by not requiring that service principals have
more long-term keys than they need just to document the service's
supported enctypes.
- Adds support for storing krb5.conf content in principals' HDB
entries. This may eventually be used for causing Heimdal KDC
services to reconfigure primary/secondary roles automatically by
discovering the configured primary in an HDB entry for the realm.
For now this will be used to help reduce the amount of configuration
needed by clients of an upcoming HTTP binding of the kadmin service.
This is the second of two commits in a series that must be picked together.
This series of two commits moves parts of lib/krb5/ infrastructure
functionality to lib/base/, leaving behind wrappers.
Some parts of libkrb5 are entirely generic or easily made so, and could
be useful in various parts of Heimdal that are not specific to the krb5
API, such as:
- lib/gssapi/ (especially since the integration of NegoEx)
- lib/hx509/
- bx509d (which should really move out of kdc/)
For the above we need to move these bits of lib/krb5/:
- lib/krb5/config_file.c (all of it, leaving forwardings behind)
- lib/krb5/config_reg.c (all of it)
- lib/krb5/plugin.c (all of it, leaving forwardings behind)
- lib/krb5/log.c (all of it, ditto)
- lib/krb5/heim_err.et (all of it)
And because of those two, these too must also move:
- lib/krb5/expand_path.c (all of it, leaving forwardings behind)
- lib/krb5/warn.c (just the warning functions, ditto)
The changes to the moved files are mostly quite straightforward and are
best reviewed with --word-diff=color.
We're also creating a heim_context and a heim API to go with it. But
it's as thin as possible, with as little state as necessary to enable
this move. Functions for dealing with error messages use callbacks.
Moving plugin.c does have one knock-on effect on all users of the old
krb5 plugin API (which remains), which is that a global search and
replace of struct krb5_plugin_data to struct heim_plugin_data was
needed, though the layout and size of that structure doesn't change, so
the ABI doesn't either.
As well, we now build lib/vers/ and lib/com_err/ before lib/base/ so as
to be able to move lib/krb5/heim_err.et to lib/base/ so that we can make
use of HEIM_ERR_* in lib/base/, specifically in the files that moved.
Once this is all done we'll be able to use config files and plugins in
lib/hx509/, we'll be able to move bx509d out of kdc/, and so on.
Most if not all of the new functions in lib/base/ are Heimdal-private,
thus calling conventions for them are not declared.
Status:
- builds and passes CIs (Travis, Appveyor)
- ran make check-valgrind and no new leaks or other memory errors
- ready for review
HOW TO REVIEW:
$ # Review file moves:
$ git log --stat -n1 HEAD^
$
$ # Review changes to moved files using --word-diff=color
$ git log -p -b -w --word-diff=color HEAD^..HEAD \
lib/base/config_file.c \
lib/base/config_reg.c \
lib/base/expand_path.c \
lib/base/warn.c \
lib/krb5/config_file.c \
lib/krb5/config_reg.c \
lib/krb5/expand_path.c \
lib/krb5/warn.c
$
$ # Review the whole thing, possibly adding -b and/or -w, and
$ # maybe --word-diff=color:
$ git log -p origin/master..HEAD
$ git log -p -b -w origin/master..HEAD
$ git log -p -b -w --word-diff=color origin/master..HEAD
TBD (future commits):
- make lib/gssapi use the new heimbase functions
- move kx509/bx509d common code to lib/hx509/ or other approp. location
- move bx509d out of kdc/
On 32-bit Windows Intel builds the __cdecl and __stdcall calling
conventions are different so labeling the functions that are
exported or assigned to function pointers matters.
Change-Id: I03b6f34baeb9ffb2e683fd979f12f27a5078a4da
Refactor plugin framework to use a single list of loaded plugins; add a new
plugin API where DSOs export a load function that can declare dependencies and
export multiple plugins; refactor kadm5 hook API to use krb5 plugin framework.
More information in krb5-plugin(7).
This fixes the following problems from #210:
- hdb_ldap doesn't load even when installed correctly
- loadable hdb backends not listed by kdc --builtin-hdb
Not fixed:
- hdb_ldap.so not installed in plugin dir
AD issues x-realm TGTs with kvno 0. On key x-realm trust key change
we need to be able to try current and previous keys for trust, else
we will have some failures.
