The generate-keys command now generates both an RSA and an ECDSA keypair,
but one can generate-rsa-keys or generate-ecdsa-keys to just generate one type.
It is modelled after the pseudorandom function from RFC4346 (TLS 1.1), the only
significant change is the use of SHA512 and Whirlpool instead of MD5 and SHA1.
REQ_KEY requests have an extra field indicating key exchange version.
If it is present and > 0, the sender supports ECDH. If the receiver also
does, then it will generate a new keypair and sends the public key in a
ANS_KEY request with "ECDH:" prefixed. The ans_key_h() function will
compute the shared secret, which, at the moment,is used as is to set the
cipher and HMAC keys. However, this must be changed to use a proper KDF.
In the future, the ECDH key exchange must also be signed.
The pid is now written first, so that a version 1.0.x tincd can be used to stop
a running version 1.1 tincd. Getsockname() is used to determine the address of
the first listening socket, so that tincctl can connect to the local tincd even
if AddressFamily = ipv6, or if BindToAddress or BindToInterface is used.
Instead of UNIX time, the log messages now start with the time in RFC3339
format, which human-readable and still easy for the computer to parse and sort.
The HUP signal will also cause the log file to be closed and reopened, which is
useful when log rotation is used. If there is an error while opening the log
file, this is logged to stderr.
But we do ignore SIGPIPE, and tinc 1.0.x signals that are no longer used
(SIGUSR1 and SIGUSR2), since the default handler of these signals is to
terminate tincd immediately.
Although we use qsort(), which is not guaranteed to be stable, resorting the
previously sorted array is more stable than recreating and resorting the array
each time.
We live in the 21st century, and we require C99 semantics, so we do not need to
work around buggy libcs. The xmalloc() and related functions are now static
inline functions.
We don't override any signal handlers anymore except those for SIGPIPE and
SIGCHLD. Fatal signals (SIGSEGV, SIGBUS etc.) will terminate tincd and
optionally dump core. The previous behaviour was to terminate gracefully and
try to restart, but that usually failed and made any core dump useless.
