The advantage is that is the name is mispellt, cpp will warn us.
$ git grep -Ee "conf.set\('(HAVE|ENABLE)_" -l|xargs sed -r -i "s/conf.set\('(HAVE|ENABLE)_/conf.set10('\1_/"
$ git grep -Ee '#ifn?def (HAVE|ENABLE)' -l|xargs sed -r -i 's/#ifdef (HAVE|ENABLE)/#if \1/; s/#ifndef (HAVE|ENABLE)/#if ! \1/;'
$ git grep -Ee 'if.*defined\(HAVE' -l|xargs sed -i -r 's/defined\((HAVE_[A-Z0-9_]*)\)/\1/g'
$ git grep -Ee 'if.*defined\(ENABLE' -l|xargs sed -i -r 's/defined\((ENABLE_[A-Z0-9_]*)\)/\1/g'
+ manual changes to meson.build
squash! build-sys: use #if Y instead of #ifdef Y everywhere
v2:
- fix incorrect setting of HAVE_LIBIDN2
For the wildcard NSEC check we need to generate an "asterisk" domain, by
prepend the common ancestor with "*.". So far we did that with a simple
strappenda() which is fine for most domains, but doesn't work if the
common ancestor is the root domain as we usually write that as "." in
normalized form, and "*." joined with "." is "*.." and not "*." as it
should be.
Hence, use the clean way out, let's just use dns_name_concat() which
only exists precisely for this reason, to properly concatenate labels.
There's a good chance this actually fixes#5029, as this NSEC proof is
triggered by lookups in the TLD "example", which doesn't exist in the
Internet.
It's annoying to have the exact same function in three places.
It's stored in src/shared, but it's not added to the library to
avoid the dependency on libgcrypt.
This gets rid of the private DNSSEC TODO and moves it in the main TODO dump site, as the DNSSEC implementation is
pretty complete now, and the remaining bits are low-priority.
In some cases we get NSEC3 RRs that have not been authenticated (because the chain of trust to the root is somewhere
broken). We can use these for checking negative replies, as long as we don't claim they were ultimately authenticated.
This means we need to be able to deal with NSEC3 RRs that lack RRSIG metadata.
If we are looking for a DS RR we need to check the NSEC3 bitmap of the parent zone's NSEC3 RR, not the one from the
child. For any other RR we need to look at the child's however, hence enforce this with the bitmaps.
Note that not coverign checks only the lower zone's NSEC3 bitmaps matter, hence the existing check is fine.
Move IDNA logic out of the normal domain name processing, and into the bus frontend calls. Previously whenever
comparing two domain names we'd implicitly do IDNA conversion so that "pöttering.de" and "xn--pttering-n4a.de" would be
considered equal. This is problematic not only for DNSSEC, but actually also against he IDNA specs.
Moreover it creates problems when encoding DNS-SD services in classic DNS. There, the specification suggests using
UTF8 encoding for the actual service name, but apply IDNA encoding to the domain suffix.
With this change IDNA conversion is done only:
- When the user passes a non-ASCII hostname when resolving a host name using ResolveHostname()
- When the user passes a non-ASCII domain suffix when resolving a service using ResolveService()
No IDNA encoding is done anymore:
- When the user does raw ResolveRecord() RR resolving
- On the service part of a DNS-SD service name
Previously, IDNA encoding was done when serializing names into packets, at a point where information whether something
is a label that needs IDNA encoding or not was not available, but at a point whether it was known whether to generate a
classic DNS packet (where IDNA applies), or an mDNS/LLMNR packet (where IDNA does not apply, and UTF8 is used instead
for all host names). With this change each DnsQuery object will now maintain two copies of the DnsQuestion to ask: one
encoded in IDNA for use with classic DNS, and one encoded in UTF8 for use with LLMNR and MulticastDNS.
This fills in the last few gaps:
- When checking if a domain is non-existing, also check that no wildcard for it exists
- Ensure we don't base "covering" tests on NSEC RRs from a parent zone
- Refuse to accept expanded wildcard NSEC RRs for absence proofs.
empty non-terminals generally lack NSEC RRs, which means we can deduce their existance only from the fact that there
are other RRs that contain them in their suffix. Specifically, the NSEC proof for NODATA on ENTs works by sending the
NSEC whose next name is a suffix of the queried name to the client. Use this information properly.
Having this information available is useful when we need to check whether various RRs are suitable for proofs. This
information is stored in the RRs as number of labels to skip from the beginning of the owner name to reach the
synthesizing source/signer. Simple accessor calls are then added to retrieve the signer/source from the RR using this
information.
This also moves validation of a a number of RRSIG parameters into a new call dnssec_rrsig_prepare() that as side-effect
initializes the two numeric values.
When proving NODATA DS lookups we need to insist on looking at the parent zone's NSEC RR, not the child zone's.
When proving any other NODATA lookups we need to insist on looking at the child zone's NSEC RR, not the parent's.
Properly handle RRs that begin with an asterisk label. These are the unexpanded forms of wildcard domains and appear in
NSEC RRs for example. We need to make sure we handle the signatures of these RRs properly, since they mostly are
considered normal RRs, except that the RRSIG labels counter is one off for them, as the asterisk label is always
excluded of the signature.
This implements RFC 5155, Section 8.8 and RFC 4035, Section 5.3.4:
When we receive a response with an RRset generated from a wildcard we
need to look for one NSEC/NSEC3 RR that proves that there's no explicit RR
around before we accept the wildcard RRset as response.
This patch does a couple of things: the validation calls will now
identify wildcard signatures for us, and let us know the RRSIG used (so
that the RRSIG's signer field let's us know what the wildcard was that
generate the entry). Moreover, when iterating trough the RRsets of a
response we now employ three phases instead of just two.
a) in the first phase we only look for DNSKEYs RRs
b) in the second phase we only look for NSEC RRs
c) in the third phase we look for all kinds of RRs
Phase a) is necessary, since DNSKEYs "unlock" more signatures for us,
hence we shouldn't assume a key is missing until all DNSKEY RRs have
been processed.
Phase b) is necessary since NSECs need to be validated before we can
validate wildcard RRs due to the logic explained above.
Phase c) validates everything else. This phase also handles RRsets that
cannot be fully validated and removes them or lets the transaction fail.
There's now nsec3_hashed_domain_format() and nsec3_hashed_domain_make().
The former takes a hash value and formats it as domain, the latter takes
a domain name, hashes it and then invokes nsec3_hashed_domain_format().
This way we can reuse more code, as the formatting logic can be unified
between this call and another place.
The domain name for this NSEC3 RR was originally stored in a variable
called "suffix", which was then renamed to "zone" in
d1511b3338. Hence also rename the
RR variable accordingly.
When storing negative responses, clamp the SOA minimum TTL (as suggested
by RFC2308) to the TTL of the NSEC/NSEC3 RRs we used to prove
non-existance, if it there is any.
This is necessary since otherwise an attacker might put together a faked
negative response for one of our question including a high-ttl SOA RR
for any parent zone, and we'd use trust the TTL.
Zbigniew Jędrzejewski-Szmek