When the master's log has all entries from version 1 to now, and no
uber entry (legacy master), then new slaves will not pull version 1,
because their uber record has version 1.
The fix is to force the uber version to 0 always, and avoid adding a
truncate nop when doing a full prop. The uber record now records the
database version even in the absence of any other log entries so that
we know what to pull going forward.
This adds a new backend for libhcrypto: the OpenSSL backend.
Now libhcrypto has these backends:
- hcrypto itself (i.e., the algorithms coded in lib/hcrypto)
- Common Crypto (OS X)
- PKCS#11 (specifically for Solaris, but not Solaris-specific)
- Windows CNG (Windows)
- OpenSSL (generic)
The ./configure --with-openssl=... option no longer disables the use of
hcrypto. Instead it enables the use of OpenSSL as a (and the default)
backend in libhcrypto. The libhcrypto framework is now always used.
OpenSSL should no longer be used directly within Heimdal, except in the
OpenSSL hcrypto backend itself, and files where elliptic curve (EC)
crypto is needed.
Because libhcrypto's EC support is incomplete, we can only use OpenSSL
for EC. Currently that means separating all EC-using code so that it
does not use hcrypto, thus the libhx509/hxtool and PKINIT EC code has
been moved out of the files it used to be in.
CVE-2016-2400
kadmind(8) was not checking for 'add' permission to aliases added via
kadm5_modify_principal(). This is a security vulnerability. The impact
of this vulnerability is mostly minor because most sites that use
kadmind(8) generally grant roughly the same level of permissions to all
administrators. However, the impact will be higher for sites that grant
modify privileges to large numbers of less-privileged users.
From what we know of existing deployments of Heimdal, it seems very
likely that the impact of this vulnerability will be minor for most
sites.
We used to update the iprop log and HDB in different orders depending on
the kadm5 operation, which then led to various race conditions.
The iprop log now functions as a two-phase commit (with roll forward)
log for HDB changes. The log is auto-truncated, keeping the latest
entries that fit in a configurable maximum number of bytes (defaults to
50MB). See the log-max-size parameter description in krb5.conf(5).
The iprop log format and the protocol remain backwards-compatible with
earlier versions of Heimdal. This is NOT a flag-day; there is NO need
to update all the slaves at once with the master, though it is advisable
in general. Rolling upgrades and downgrades should work.
The sequence of updates is now (with HDB and log open and locked):
a) check that the HDB operation will succeed if attempted,
b) append to iprop log and fsync() it,
c) write to HDB (which should fsync()),
d) mark last log record committed (no fsync in this case).
Every kadm5 write operation recover transactions not yet confirmed as
committed, thus there can be at most one unconfirmed commit on a master
KDC.
Reads via kadm5_get_principal() also attempt to lock the log, and if
successful, recover unconfirmed transactions; readers must have write
access and must win any race to lock the iprop log.
The ipropd-master daemon also attempts to recover unconfirmed
transactions when idle.
The log now starts with a nop record whose payload records the offset of
the logical end of the log: the end of the last confirmed committed
transaction. This is kown as the "uber record". Its purpose is
two-fold: act as the confirmation of committed transactions, and provide
an O(1) method of finding the end of the log (i.e., without having to
traverse the entire log front to back).
Two-phase commit makes all kadm5 writes single-operation atomic
transactions (though some kadm5 operations, such as renames of
principals, and changes to principals' aliases, use multiple low-level
HDB write operations, but still all in one transaction). One can still
hold a lock on the HDB across many operations (e.g., by using the lock
command in a kadmin -l or calling kadm5_lock()) in order to push
multiple transactions in sequence, but this sequence will not be atomic
if the process or host crashes in the middle.
As before, HDB writes which do not go through the kadm5 API are excluded
from all of this, but there should be no such writes.
Lastly, the iprop-log(1) command is enhanced as follows:
- The dump, last-version, truncate, and replay sub-commands now have an
option to not lock the log. This is useful for inspecting a running
system's log file, especially on slave KDCs.
- The dump, last-version, truncate, and replay sub-commands now take an
optional iprop log file positional argument, so that they may be used
to inspect log files other than the running system's
configured/default log file.
Extensive code review and some re-writing for clarity by Viktor Dukhovni.
Tests that start daemons have to "wait" for them to start.
This commit makes Heimdal daemons prep to detach (when requested) by
forking early, then having the child signal readiness to the parent when
the child really is ready. The parent exits only which the child is
ready. This means that tests will no longer need to wait for daemons.
However, tests will still need a pidfile or such so they can stop the
daemons.
Note that the --detach options should not be used on OS X from launchd,
only from tests.
The Heimdal kadmind sends bogus keys when the client has 'get'
but not 'get-keys' permission. For some kadmin commands this is
dangerous. For example, ext_keytab could happily write bogus
keys to a keytab when real keys are expected, causing eventual
breakage. Sending bogus keys is important for the kadmin get
command: so it can list the keysets that a principal has.
This patch implements a heuristic detection of kadmin get vs.
ext_keytab, add_enctype, del_enctype, and check commands. If the
client principal lacks 'get-keys' permission, then the server
will fail requests that appear to be from those kadmin commands,
but will continue to serve bogus keys to kadmin get commands.
Thanks to Nico Williams for the idea behind this implementation.
When performing a permission check for a GET operation the
KADM5_PRIV_GET_KEYS privilege should not be assumed to be a pure
superset of KADM5_PRIV_GET. If the "get" permission is denied the
user cannot get an entry with or without key data.
If any of the keys returned by kadmin are the magic bogus key
generate a warning to the user that they are missing the git-keys
privilege.
Change-Id: I235b87eeb2f81e8fd8c8481154d613e92a7e11e2
If kadmind returned bogus keys it means that the user lacks the
get-keys permission. Generate a warning and exit.
Change-Id: Ib76dd86b65bd84a00f3e27c245b9cfc0173fff56
If kadmind returned bogus keys it means that the user lacks the
get-keys permission. Generate a warning and exit.
Also use calloc() to allocate the new_key_data.
Change-Id: I21b697e2ff5adf753b1cfe698877b3f593bbea9e
When running as a service under systemd, kadmin cannot successfully use
setpgid(). The call fails with EPERM. Do not treat this as a fatal
error; instead, allow kadmind to continue starting up.
When we added the get-keys privilege we lost the ability to setup
keytabs with the kadmin ext command. The fix is to note that we got
bogus key data and randkey (as we used to).
On Windows a file descriptor is an int value allocated by the
local module instance of the C Run Time Library. A socket handle is a
SOCKET value allocated by a Winsock Provider for the requested family and
protocol. These two values cannot be mixed and there is no mechanism for
converting between the two. The _get_osfhandle() and _open_osfhandle()
functions can work with a standard HANDLE (file, pipe, etc) but cannot be
used for a SOCKET.
The Heimdal krb5_storage_from_fd() routine counted on the osf conversion
functions working on SOCKET values. Since they do not any attempt to call
krb5_storage_from_fd() on a socket resulted in an assertion being thrown
by the C RTL.
Another problem is SOCKET value truncation when storing a 64-bit value
into a 32-bit int.
To address these problems a new krb5_storage_from_socket() routine is
introduced. This routine setups a krb5_storage that stores a socket value
as a rk_socket_t and provides a set of helper routines that always use
network ready functions.
The krb5_storage_from_fd() routines no longer use net_read() and
net_write() but provide helpers that follow their logic so that pipes can
be processed.
All call sites that allocate a socket now store the socket as rk_socket_t
and call krb5_storage_from_socket().
All locations that previously called the bare close() on a socket value
now call rk_closesocket().
Change-Id: I045f775b2a5dbf5cf803751409490bc27fffe597
Before this change Heimdal could read KDBs. Now it can write to
them too.
Heimdal can now also dump HDBs (including KDBs) in MIT format, which
can then be imported with kdb5_util load.
This is intended to help in migrations from MIT to Heimdal by
allowing migrations from Heimdal to MIT so that it is possible
to rollback from Heimdal to MIT should there be any issues. The
idea is to allow a) running Heimdal kdc/kadmind with a KDB, or
b) running Heimdal with an HDB converted from a KDB and then
rollback by dumping the HDB and loading a KDB.
Note that not all TL data types are supported, only two: last
password change and modify-by. This is the minimum necessary.
PKINIT users may need to add support for KRB5_TL_USER_CERTIFICATE,
and for databases with K/M history we may need to add KRB5_TL_MKVNO
support.
Support for additional TL data types can be added in
lib/hdb/hdb-mitdb.c:_hdb_mdb_value2entry() and
lib/hdb/print.c:entry2mit_string_int().
We turn on a few extra warnings and fix the fallout that occurs
when building with --enable-developer. Note that we get different
warnings on different machines and so this will be a work in
progress. So far, we have built on NetBSD/amd64 5.99.64 (which
uses gcc 4.5.3) and Ubuntu 10.04.3 LTS (which uses gcc 4.4.3).
Notably, we fixed
1. a lot of missing structure initialisers,
2. unchecked return values for functions that glibc
marks as __attribute__((warn-unused-result)),
3. made minor modifications to slc and asn1_compile
which can generate code which generates warnings,
and
4. a few stragglers here and there.
We turned off the extended warnings for many programs in appl/ as
they are nearing the end of their useful lifetime, e.g. rsh, rcp,
popper, ftp and telnet.
Interestingly, glibc's strncmp() macro needed to be worked around
whereas the function calls did not.
We have not yet tried this on 32 bit platforms, so there will be
a few more warnings when we do.
