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.
- Replace external -DOPENSSL/-DPKCS11CRYPTO with properly AC_DEFINEd
HAVE_OPENSSL/HAVE_PKCS11
- Don't enforce the crypto provider from platform.h, just from dst_api.c
and configure scripts
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
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]
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]
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]
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]
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]
4503. [cleanup] "make uninstall" now removes file installed by
BIND. (This currently excludes Python files
due to lack of support in setup.py.) [RT #42912]
