This commit reverts the previous change to use system provided
entropy, as (SYS_)getrandom is very slow on Linux because it is
a syscall.
The change introduced in this commit adds a new call isc_nonce_buf
that uses CSPRNG from cryptographic library provider to generate
secure data that can be and must be used for generating nonces.
Example usage would be DNS cookies.
The isc_random() API has been changed to use fast PRNG that is not
cryptographically secure, but runs entirely in user space. Two
contestants have been considered xoroshiro family of the functions
by Villa&Blackman and PCG by O'Neill. After a consideration the
xoshiro128starstar function has been used as uint32_t random number
provider because it is very fast and has good enough properties
for our usage pattern.
The other change introduced in the commit is the more extensive usage
of isc_random_uniform in places where the usage pattern was
isc_random() % n to prevent modulo bias. For usage patterns where
only 16 or 8 bits are needed (DNS Message ID), the isc_random()
functions has been renamed to isc_random32(), and isc_random16() and
isc_random8() functions have been introduced by &-ing the
isc_random32() output with 0xffff and 0xff. Please note that the
functions that uses stripped down bit count doesn't pass our
NIST SP 800-22 based random test.
- added a 1-second floor to max-stale-ttl similar to stale-answer-ttl;
if set to 0, it will be silently updated to 1.
- fixed the ARM entry on max-stale-ttl, which incorrectly suggested that
the default was 0 instead of 1 week.
- clarified rndc serve-stale documentation.
- mark the 'geoip-use-ecs' option obsolete; warn when it is used
in named.conf
- prohibit 'ecs' ACL tags in named.conf; note that this is a fatal error
since simply ignoring the tags could make ACLs behave unpredictably
- re-simplify the radix and iptable code
- clean up dns_acl_match(), dns_aclelement_match(), dns_acl_allowed()
and dns_geoip_match() so they no longer take ecs options
- remove the ECS-specific unit and system test cases
- remove references to ECS from the ARM
The three functions has been modeled after the arc4random family of
functions, and they will always return random bytes.
The isc_random family of functions internally use these CSPRNG (if available):
1. getrandom() libc call (might be available on Linux and Solaris)
2. SYS_getrandom syscall (might be available on Linux, detected at runtime)
3. arc4random(), arc4random_buf() and arc4random_uniform() (available on BSDs and Mac OS X)
4. crypto library function:
4a. RAND_bytes in case OpenSSL
4b. pkcs_C_GenerateRandom() in case PKCS#11 library
Replace dns_fixedname_init() calls followed by dns_fixedname_name()
calls with calls to dns_fixedname_initname() where it is possible
without affecting current behavior and/or performance.
This patch was mostly prepared using Coccinelle and the following
semantic patch:
@@
expression fixedname, name;
@@
- dns_fixedname_init(&fixedname);
...
- name = dns_fixedname_name(&fixedname);
+ name = dns_fixedname_initname(&fixedname);
The resulting set of changes was then manually reviewed to exclude false
positives and apply minor tweaks.
It is likely that more occurrences of this pattern can be refactored in
an identical way. This commit only takes care of the low-hanging fruit.
Instead of relying on the caller to set up task-exclusive mode, make
dns_dt_reopen() enforce task-exclusive mode itself, using the task
specified at dnstap environment creation time.
4867. [cleanup] Normalize rndc on/off commands (validation,
querylog, serve-stale) so they all accept the
same synonyms for on/off (yes/no, true/false,
enable/disable). Thanks to Tony Finch. [RT #47022]
4836. [bug] Zones created using "rndc addzone" could
temporarily fail to inherit an "allow-transfer"
ACL that had been configured in the options
statement. [RT #46603]
4807. [cleanup] isc_rng_randombytes() returns a specified number of
bytes from the PRNG; this is now used instead of
calling isc_rng_random() multiple times. [RT #46230]
4798. [func] Keys specified in "managed-keys" statements
are tagged as "initializing" until they have been
updated by a key refresh query. If initialization
fails it will be visible from "rndc secroots".
[RT #46267]
This reverts commit 560d8b833e.
This change created a potential race between key refresh queries and
root zone priming queries which could leave the root name servers in
the bad-server cache.
4773. [bug] Keys specified in "managed-keys" statements
can now only be used when validating key refresh
queries during initialization of RFC 5011 key
maintenance. If initialization fails, DNSSEC
validation of normal queries will also fail.
Previously, validation of normal queries could
succeed using the initializing key, potentially
masking problems with managed-keys. [RT #46077]
4750. [func] "rndc managed-keys destroy" shuts down RFC 5011 key
maintenance and deletes the managed-keys database.
If followed by "rndc reconfig" or a server restart,
key maintenance is reinitialized from scratch.
This is primarily intended for testing. [RT #32456]
4749. [func] The ISC DLV service has been shut down, and all
DLV records have been removed from dlv.isc.org.
- Removed references to ISC DLV in documentation
- Removed DLV key from bind.keys
- No longer use ISC DLV by default in delv
[RT #46155]
4724. [func] By default, BIND now uses the random number
functions provided by the crypto library (i.e.,
OpenSSL or a PKCS#11 provider) as a source of
randomness rather than /dev/random. This is
suitable for virtual machine environments
which have limited entropy pools and lack
hardware random number generators.
This can be overridden by specifying another
entropy source via the "random-device" option
in named.conf, or via the -r command line option;
however, for functions requiring full cryptographic
strength, such as DNSSEC key generation, this
cannot be overridden. In particular, the -r
command line option no longer has any effect on
dnssec-keygen.
This can be disabled by building with
"configure --disable-crypto-rand".
[RT #31459] [RT #46047]
4727. [bug] Retransferring an inline-signed slave using NSEC3
around the time its NSEC3 salt was changed could result
in an infinite signing loop. [RT #45080]
4713. [func] Added support for the DNS Response Policy Service
(DNSRPS) API, which allows named to use an external
response policy daemon when built with
"configure --enable-dnsrps". Thanks to Vernon
Schryver and Farsight Security. [RT #43376]
4708. [cleanup] Legacy Windows builds (i.e. for XP and earlier)
are no longer supported. [RT #45186]
4707. [func] The lightweight resolver daemon and library (lwresd
and liblwres) have been removed. [RT #45186]
4706. [func] Code implementing name server query processing has
been moved from bin/named to a new library "libns".
Functions remaining in bin/named are now prefixed
with "named_" rather than "ns_". This will make it
easier to write unit tests for name server code, or
link name server functionality into new tools.
[RT #45186]
allows named to provide stale cached answers when
the authoritative server is under attack.
See max-stale-ttl, stale-answer-enable,
stale-answer-ttl. [RT #44790]
4664. [func] Add a "glue-cache" option to enable or disable the
glue cache. The default is "no" to reduce memory
usage, but enabling this option will improve
performance in delegation-heavy zones. [RT #45125]
4610. [func] The "new-zones-directory" option specifies the
location of NZF or NZD files for storing
configuration of zones added by "rndc addzone".
Thanks to Petr Menšík. [RT #44853]
4579. [func] Logging channels and dnstap output files can now
be configured with a "suffix" option, set to
either "increment" or "timestamp", indicating
whether to use incrementing numbers or timestamps
as the file suffix when rolling over a log file.
[RT #42838]
4572. [func] The "dnstap-output" option can now take "size" and
"versions" parameters to indicate the maximum size
a dnstap log file can grow before rolling to a new
file, and how many old files to retain. [RT #44502]
4549. [func] Added support for the EDNS TCP Keepalive option
(RFC 7828). [RT #42126]
4548. [func] Added support for the EDNS Padding option (RFC 7830).
[RT #42094]
no-auth and no-auth-recursive which suppress
adding the NS records to the authority section
as well as the associated address records for the
nameservers. [RT #42005]
to provide feedback to the trust-anchor administrators
about how key rollovers are progressing as per
draft-ietf-dnsop-edns-key-tag-02. This can be
disabled using 'trust-anchor-telemetry no;'.
[RT #40583]
4421. [func] When built with LMDB (Lightning Memory-mapped
Database), named will now use a database to store
the configuration for zones added by "rndc addzone"
instead of using a flat NZF file. This improves
performance of "rndc delzone" and "rndc modzone"
significantly. Existing NZF files will
automatically by converted to NZD databases.
To view the contents of an NZD or to roll back to
NZF format, use "named-nzd2nzf". To disable
this feature, use "configure --without-lmdb".
[RT #39837]
4411. [func] "rndc dnstap -roll" automatically rolls the
dnstap output file; the previous version is
saved with ".0" suffix, and earlier versions
with ".1" and so on. An optional numeric argument
indicates how many prior files to save. [RT #42830]
4380. [experimental] Added a "zone-directory" option to "catalog-zones"
syntax, allowing local masterfiles for slaves
that are provisioned by catalog zones to be stored
in a directory other than the server's working
directory. [RT #42527]
provisioning secondary servers in which a list of
zones to be served is stored in a DNS zone and can
be propagated to slaves via AXFR/IXFR. [RT #41581]
4375. [func] Add support for automatic reallocation of isc_buffer
to isc_buffer_put* functions. [RT #42394]
4371. [func] New "minimal-any" option reduces the size of UDP
responses for qtype ANY by returning a single
arbitrarily selected RRset instead of all RRsets.
Thanks to Tony Finch. [RT #41615]
4352. [cleanup] The ISC DNSSEC Lookaside Validation (DLV) service
is scheduled to be disabled in 2017. A warning is
now logged when named is configured to use it,
either explicitly or via "dnssec-lookaside auto;"
[RT #42207]
