RPKI-To-Router (RTR) sessions seem to be similar security-sensitivity as
IBGP sessions. BIRD already offered a choice of either "plain TCP" (meh)
or "SSH" (secure, albeit a bit more hassle to set up than TCP-MD5).
The patch adds TCP-MD5 as another option. TCP-MD5 for RTR is specified
through RFC 6810 section 7.3 and RFC 8210 section 9.3.
Minor changes by committer.
Allow to explicitly configure the source IP address for RPKI-To-Router
sessions. Predictable source addresses are useful for minimizing the
holes to be poked in ACLs.
Changed from 'source address' to 'local address' by committer.
Add 'ignore max length' option to RPKI protocol, which ignores received
max length in ROA records and instead uses max value (32 or 128). This
may be useful for implementing loose RPKI check for blackholes.