This commit converts the license handling to adhere to the REUSE
specification. It specifically:
1. Adds used licnses to LICENSES/ directory
2. Add "isc" template for adding the copyright boilerplate
3. Changes all source files to include copyright and SPDX license
header, this includes all the C sources, documentation, zone files,
configuration files. There are notes in the doc/dev/copyrights file
on how to add correct headers to the new files.
4. Handle the rest that can't be modified via .reuse/dep5 file. The
binary (or otherwise unmodifiable) files could have license places
next to them in <foo>.license file, but this would lead to cluttered
repository and most of the files handled in the .reuse/dep5 file are
system test files.
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.
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
3705. [func] "configure --enable-native-pkcs11" enables BIND
to use the PKCS#11 API for all cryptographic
functions, so that it can drive a hardware service
module directly without the need to use a modified
OpenSSL as intermediary (so long as the HSM's vendor
provides a complete-enough implementation of the
PKCS#11 interface). This has been tested successfully
with the Thales nShield HSM and with SoftHSMv2 from
the OpenDNSSEC project. [RT #29031]
Change isc_entropy_usebestsource() to have saner semantics:
- If an invalid file is specified, an error will be returned instead of the
keyboard being used.
- If no file is specified but a random device is present, the keyboard will
be used if there is an error opening the random device.
- ISC_ENTROPY_KEYBOARDYES indicates that the keyboard should be the
only device used. Otherwise, passing '-r keyboard' is meaningless
on a machine with a random device, since the keyboard will not be used.
Change the callers in the dnssec tools and rndc-confgen to check for the
special file "keyboard" and call isc_entropy_usebestsource() with the right set
of parameters.
'magic' was not being declared consistantly.
some #include <isc/magic.h> were missing from other include files.
NS_SERVER_VALID was not using ISC_MAGIC_VALID.
