Previously, when invalid DNS message is received over TCP we throw the
garbage DNS message away and continued looking for valid DNS message
that would match our outgoing queries. This logic makes sense for UDP,
because anyone can send DNS message over UDP.
Change the logic that the TCP connection is closed when we receive
garbage, because the other side is acting malicious.
When outgoing TCP connection was prematurely terminated (f.e. with
connection reset), the dispatch code would not cleanup the resources
used by such connection leading to dangling dns_dispentry_t entries.
This commit adds support for client-side TLS parameters to XoT.
Prior to this commit all client-side TLS contexts were using default
parameters only, ignoring the options from the BIND's configuration
file.
Currently, the following 'tls' parameters are supported:
- protocols;
- ciphers;
- prefer-server-ciphers.
This commit completes the integration of the new, extended ACL syntax
featuring 'port' and 'transport' options.
The runtime presentation and ACL loading code are extended to allow
the syntax to be used beyond the 'allow-transfer' option (e.g. in
'acl' definitions and other 'allow-*' options) and can be used to
ultimately extend the ACL support with transport-only
ACLs (e.g. 'transport-acl tls-acl port 853 transport tls'). But, due
to fundamental nature of such a change, it has not been completed as a
part of 9.17.X release series due to it being close to 9.18 stable
release status. That means that we do not have enough time to fully
test it.
The complete integration is planned as a part of 9.19.X release
series.
The code was manually verified to work as expected by temporarily
enabling the extended syntax for 'acl' statements and 'allow-query'
options, including ACL merging, negated ACLs.
The parsing loop needs to process ISC_R_NOSPACE to properly
size the buffer. If result is still ISC_R_NOSPACE at the end
of the parsing loop set result to DNS_R_SERVFAIL.
In file included from rdata.c:602:
In file included from ./code.h:88:
./rdata/in_1/svcb_64.c:259:9: warning: array subscript is of type 'char' [-Wchar-subscripts]
if (!isdigit(*region->base)) {
^~~~~~~~~~~~~~~~~~~~~~
/usr/include/sys/ctype_inline.h:51:44: note: expanded from macro 'isdigit'
#define isdigit(c) ((int)((_ctype_tab_ + 1)[(c)] & _CTYPE_D))
^~~~
When a UDP dispatch receives a mismatched response, it checks whether
there is still enough time to wait for the correct one to arrive before
the timeout fires. If there is not, the result code is set to
ISC_R_TIMEDOUT, but it is not subsequently used anywhere as 'response'
is set to NULL a few lines earlier. This results in the higher-level
read callback (resquery_response() in case of resolver code) not being
called. However, shortly afterwards, a few levels up the call chain,
isc__nm_udp_read_cb() calls isc__nmsocket_timer_stop() on the dispatch
socket, effectively disabling read timeout handling for that socket.
Combined with the fact that reading is not restarted in such a case
(e.g. by calling dispatch_getnext() from udp_recv()), this leads to the
higher-level query structure remaining referenced indefinitely because
the dispatch socket it uses will neither be read from nor closed due to
a timeout. This in turn causes fetch contexts to linger around
indefinitely, which in turn i.a. prevents certain cache nodes (those
containing rdatasets used by fetch contexts, like fctx->nameservers)
from being cleaned.
Fix by making sure the higher-level callback does get invoked with the
ISC_R_TIMEDOUT result code when udp_recv() determines there is no more
time left to receive the correct UDP response before the timeout fires.
This allows the higher-level callback to clean things up, preventing the
reference leak described above.
The following scenario triggers a "named" crash:
1. Configure a catalog zone.
2. Start "named".
3. Comment out the "catalog-zone" clause.
4. Run `rndc reconfig`.
5. Uncomment the "catalog-zone" clause.
6. Run `rndc reconfig` again.
Implement the required cleanup of the in-memory catalog zone during
the first `rndc reconfig`, so that the second `rndc reconfig` could
find it in an expected state.
opensslecdsa_fromdns() already rejects too short ECDSA public keys.
Make it also reject too long ones. Remove an assignment made redundant
by this change.
raw_key_to_ossl() assumes fixed ECDSA private key sizes (32 bytes for
ECDSAP256SHA256, 48 bytes for ECDSAP384SHA384). Meanwhile, in rare
cases, ECDSAP256SHA256 private keys are representable in 31 bytes or
less (similarly for ECDSAP384SHA384) and that is how they are then
stored in the "PrivateKey" field of the key file. Nevertheless,
raw_key_to_ossl() always calls BN_bin2bn() with a fixed length argument,
which in the cases mentioned above leads to erroneously interpreting
uninitialized memory as a part of the private key. This results in the
latter being malformed and broken signatures being generated. Address
by using the key length provided by the caller rather than a fixed one.
Apply the same change to public key parsing code for consistency, adding
an INSIST() to prevent buffer overruns.
when processing a mismatched response, we call dns_dispatch_getnext().
If that fails, for example because of a timeout, fctx_done() is called,
which cancels all queries. This triggers a crash afterward when
fctx_cancelquery() is called, and is unnecessary since fctx_done()
would have been called later anyway.
When dns_adb is shutting down, first the adb->shutting_down flag is set
and then task is created that runs shutdown_stage2() that sets the
shutdown flag on names and entries. However, when dns_adb_createfind()
is called, only the individual shutdown flags are being checked, and the
global adb->shutting_down flag was not checked. Because of that it was
possible for a different thread to slip in and create new find between
the dns_adb_shutdown() and dns_adb_detach(), but before the
shutdown_stage2() task is complete. This was detected by
ThreadSanitizer as data race because the zonetable might have been
already detached by dns_view shutdown process and simultaneously
accessed by dns_adb_createfind().
This commit converts the adb->shutting_down to atomic_bool to prevent
the global adb lock when creating the find.
Add a new parameter to 'ns_client_t' to store potential extended DNS
error. Reset when the client request ends, or is put back.
Add defines for all well-known info-codes.
Update the number of DNS_EDNSOPTIONS that we are willing to set.
Create a new function to set the extended error for a client reply.
This commit makes BIND set the "max-age" value of the "Cache-Control"
HTTP header to the minimal TTL from the Answer section for positive
answers, as RFC 8484 advises in section 5.1.
We calculate the minimal TTL as a side effect of rendering the
response DNS message, so it does not change the code flow much, nor
should it have any measurable negative impact on the performance.
For negative answers, the "max-age" value is set using the TTL and
SOA-minimum values from an SOA record in the Authority section.
1) if 'key->external' is set we just need to call
dst__privstruct_writefile
2) the cleanup of 'bufs' was incorrect as 'i' doesn't reflect the
the current index into 'bufs'. Use a simple for loop.
This review was triggered by Coverity reporting a buffer overrun
on 'bufs'.
'dh' was being assigned to key->keydata.dh too soon which could
result in a memory leak on error. Moved the assignement of
key->keydata.dh until after dh was correct.
Coverity was reporting dead code on the error path cleaning up 'dh'
which triggered this review.
'make dist' omits lib/dns/tests/comparekeys/ (added in
7101afa23cfc7cd005aeeb00802481094a0b9cf5) from release tarball it
creates which makes the unit:gcc:tarball CI job permanently fail in the
dst unit test.
Previously, when lame cache would be disabled by setting lame-ttl to 0,
it would also disable lame answer detection. In this commit, we enable
the lame response detection even when the lame cache is disabled. This
enables stopping answer processing early rather than going through the
whole answer processing flow.
OpenSSL 3 deprecates most of the DH* family and associated APIs.
Reimplement the existing functionality using a newer set of APIs
which will be used when compiling/linking with OpenSSL 3.0.0 or newer
versions.
OpenSSL 3 deprecates most of the RSA* family and associated APIs.
Reimplement the existing functionality using a newer set of APIs
which will be used when compiling/linking with OpenSSL 3.0.0 or newer
versions.
OpenSSL 3 deprecates most of the EC* family and associated APIs.
Reimplement the existing functionality using a newer set of APIs
which will be used when compiling/linking with OpenSSL 3.0.0 or newer
versions.
EVP_PKEY_eq() is the replacement with a smaller result range (0, 1)
instead of (-1, 0, 1). EVP_PKEY_cmp() is mapped to EVP_PKEY_eq() when
building with older versions of OpenSSL.
OpenSSL 3.0.0 deprecates the ERR_get_error_line_data() function.
Use ERR_get_error_all() instead of ERR_get_error_line_data() and create
a shim to use the old variant for the older OpenSSL versions which don't
have the newer ERR_get_error_all().
The dst_key_pubcompare() and dst_key_compare() didn't have a unit test,
add the unit tests which test comparing the same keys, different keys,
and, where possible, similar keys with a manually altered parameter.
dst_key_pubcompare() internally uses the *_todns() functions of the
lib/dns/openssl*_link.c modules.
dst_key_compare() internally uses the *_compare() functions of the
lib/dns/openssl*_link.c modules.
It was found, that the original commit adding the setmodtime() was
incompletely squashed and there was double check for
DNS_ZONEFLG_NEEDDUMP instead of check for DNS_ZONEFLG_NEEDDUMP and
DNS_ZONEFLG_DUMPING.
Change the duplicate check to DNS_ZONEFLG_DUMPING.
If an ADB find is started on behalf of a resolver fetch, and fails to
find any addresses but has a pending resolver fetch associated with it,
then we need to check whether the fetch it's waiting on is the one
that created it. If so, it can never finish and needs to be terminated.
The NAME_FETCH_A and NAME_FETCH_AAAA macros were meant to be
boolean, indicating whether the pointers were set or not, while
the NAME_FETCH_V4 and NAME_FETCH_V6 macros were meant to return
the pointer values. The latter were only used as booleans, so
they've been removed in favor of the former.
Also did some style cleanup and removed an unreachable code block.
there was a race possible in which a dispatch was put into
the 'connected' state before it had a TCP handle attached,
which could cause an assertion failure in dns_dispatch_gettcp().
The fctxbucket_t properly attaches to the fetchctx_t, so it can safely
use its memory context. Save a little bit of memory by removing own
memory context from fctxbucket_t.
Using proper attach/detach functions for the fetch context
instead of fctx_increference() and _decreference() makes
it easier to debug reference counting errors in the resolver.
Fixed several such errors that were found as a result.
After receiving a new version of a catalog zone it is required
to merge it with the old version.
The algorithm walks through the new version's hash table and applies
the following logic:
1. If an entry from the new version does not exist in the old
version, then it's a new entry, add the entry to the `toadd` hash
table.
2. If the zone does not exist in the set of configured zones, because
it was deleted via rndc delzone or it was removed from another
catalog zone instance, then add into to the `toadd` hash table to
be reinstantiated.
3. If an entry from the new version also exists in the old version,
but is modified, then add the entry to the `tomod` hash table, then
remove it from the old version's hash table.
4. If an entry from the new version also exists in the old version and
is the same (unmodified) then just remove it from the old version's
hash table.
The algorithm then deletes all the remaining zones which still exist
in the old version's hash table (because only the ones that don't
exist in the new version should now remain there), then adds the ones
that were added to the `toadd`, and modifies the ones that were added
to the `tomod`, completing the merge.
During a recent refactoring, the part when the entry should be
removed from the old version's hash table on condition (4.) above
was accidentally omitted, so the unmodified zones were remaining
in the old version's hash table and consequently being deleted.
The new rules compare the target name in PTR and SRV records against
the machine name embedded in the kerberos principal. This can be
used to further restrict what PTR and SRV records can be added or
deleted via dynamic updates if desired.
The librpz.h defined LIRPZ_LIKELY() and LIBRPZ_UNLIKELY() macros that
were actually unused in the code. Remove the macros and the autoconf
check for __builtin_expect().
