Samba is starting to protect against bi-di attacks and the starting point
is to require that input files be fully UTF-8. In 2021 this is a reasonable
starting point anyway.
Signed-off-by: Andrew Bartlett <abartlet@samba.org>
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
The TGS will issue referrals based on [domain_realm] mappings.
With this change the TGS will also issue referrals based on HDB entry
aliases.
The TGS needed no changes for this, only support in lib/hdb was missing.
All we had to do was return HDB_ERR_WRONG_REALM from hdb_fetch_kvno()
when the given principal is an alias and its canonical name's realm is
different from the alias'.
This feature is important because the KDC currently does not re-read
krb5.conf and must be restarted for changes to e.g., [domain_realm]
mappings to take effect. As well, making krb5.conf changes to all the
KDCs for a realm would need to be arranged. But with aliases in the
HDB, these problems go away.
Relatedly, we should really have an option to store the KDC's entire
configuration in the HDB...
Futures:
- Add support for aliasing of entire namespaces via HDB aliases with
WELLKNOWN namespace name forms. This will round out domain-to-realm
mapping configuration support via HDB.
Deleting an alias causes the HDB_entry_alias entry value encoding to be
written to the iprop log, which later cannot be decoded as an HDB_entry.
Meanwhile, the alias is removed from the HDB but not from the list of
aliases in the canonical principal's HDB entry.
This commit makes deletion of alias names an error.
For Samba the fast key is not stored in the replicated DB, so
this helps Samba find it in the Samba hdb module.
Signed-off-by: Andrew Bartlett <abartlet@samba.org>
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>
If a DB does not already exist, ipropd-slave will use the compiled
default, which is not necessarily what is desired or configured in
`[kdc]`.
This change makes `hdb_default_db()` return the first dbanme in the
`[kdc]` configuration, falling back on `HDB_DEFAULT_DB`.
Also, this adds a `--database` option to `ipropd-slave`.
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!
Checking the error code of decoding a blob as an hdb_entry or
hdb_entry_alias to determine which of those the blob is depends on a
detail of the Heimdal ASN.1 compiler and library that shouldn't be
depended on. Using a CHOICE adds no octets to the encoding:
HDB-EntryOrAlias ::= CHOICE {
entry hdb_entry,
alias hdb_entry_alias
}
since we're adding no additional tags and the two arms of the CHOICE
already differ in tag (hdb_entry's tag is a [UNIVERSAL Sequence] tag,
while hdb_entry_alias's is an [APPLICATION 0] tag).
Test that we can dump an HDB w/o blocking write transactions.
This currently works for different processes (both backends), but not
for threads (for either backend), and it's not yet clear why.
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.
The new [hdb] new_service_key_delay parameter should not apply to
principal entries when used as clients. Otherwise new passwords would
not take effect immediately, and that would be very confusing.
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
Older databases may lack explicitly stored salts where the salt is the default
one. When fetching a client entry for an AS-REQ, add default salts to keys that
lack one.
Whilst Windows does not canonicalize enterprise principal names if the
canonicalize flag is unset, the original specification in
draft-ietf-krb-wg-kerberos-referrals-03.txt says we should. Non-Windows
deployments of Heimdals are unlikely to understand enterprise principal names
in tickets, and are also unlikely to set the canonicalize flag, so this makes
sense. (It was also the behavior prior to moving the name canonicalization
logic into the KDC.)
This reverts commit 1b7e196e66.
It turns out that, contrary to the referrals draft, Windows does not
canonicalize enterprise principal names if the canonicalize KDC option is
unset.
Enterprise principal client names in AS-REQs should always be canonicalized
irrespective of the setting the canonicalize KDC option. Perform this check in
the KDC rather than HDB.
Do not set the HDB_F_GET_KRBTGT flag unless the client actually requested a TGS
principal.
Mirroring the logic recently introduced in the TGS, this patch modifies the KDC
to perform client and server canonicalization itself rather than relying on the
backend to do so. Per RFC 6806, the behavior is slightly different for the AS
in that the setting of the canonicalize flag in the AS-REQ does impact the
returned names in the ticket. In order to support realm canonicalization or
other custom behavior, we allow the backend to force the KDC to canonicalize by
setting the force-canonicalize flag in the returned client or server entries.
e11abf41 added support in libhdb for always dereferencing principal aliases
during an AS-REQ (where dereferencing refers to enabling alias lookups, and
rewriting the returned entry with the alias name unless canonicalization was
enabled).
Due to the KDC setting HDB_F_FOR_AS_REQ for all lookups from the AS, this
allowed aliases on the TGS itself to be dereferenced during an AS-REQ; however,
on presenting the TGT, the TGS would fail to resolve. Creating an explicit TGS
principal for the aliased realm would work (at least prior to c555ed6a), but
this could be confusing to deploy.
This commit changes enables alias dereferencing when HDB_F_GET_ANY is set,
which essentially means dereference whenever the request is coming from the KDC
(as opposed to, say, kadmin).
We also backout c555ed6a, which changed the TGS to always canonicalize the
server realm, as this breaks serving multiple realms from a single KDC, where
server principals in different realms share a single canonical entry.
HDB_F_CANON is now passed to the backend as a hint only, and per RFC 6806 the
principal name is never changed in TGS replies. (However, for Samba interop,
backends can override this by setting the force-canonicalize HDB flag.)
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).
Adds support for "hard" aliases when initially authenticating, that is,
allowing a client or server principal to be known by many names without
requiring that the client support name canonicalization.
In order to avoid changing the behavior for other backends such as Samba, this
is implemented in the HDB backend rather than the KDC.
To use, add an alias for both the client and TGS ("krbtgt") principals using
kadmin. This behavior is unchanged if name canonicalization is enabled.
Heimdal will refuse to create new entries when an entry already exists even
if said entry has no kerberos info and is a new entry.
This patch fixes this issue by allowing object modifications even if the
flags disallow them when we are inserting a new principal on the database.
Signed-off-by: Francisco Blas Izquierdo Riera (klondike) <klondike@gentoo.org>
