Inconsistency with key identifier size
Per https://tools.ietf.org/html/rfc5905, the key identifier is a 32-bit integer.
https://chrony.tuxfamily.org/doc/3.1/chrony.conf.html#keyfile says:
The ID can be any unsigned integer in the range 1 through 2^32-1.
docs/authentic.txt, docs/includes/assoc-options.txt, docs/includes/auth-commands.txt, docs/ntpkeygen.txt, and ntpd/ntp.keys-man.txt say there are 65,534 possible keys.
docs/includes/ntpkeygen-body.txt and include/ntp.h say there are 65,535 possible keys.
We also use keyid_t and uint32_t in the code. We should pick one form, for consistency.
Also, #define KEYID_T_MAX (0xffffffff)
and #define NTP_MAXKEY 65535
. Is one form an autokey holdover?