Allow underscore characters in FQDNs and pointers.
authorMichael Orlitzky <michael@orlitzky.com>
Thu, 5 Dec 2019 15:34:54 +0000 (10:34 -0500)
committerMichael Orlitzky <michael@orlitzky.com>
Thu, 5 Dec 2019 15:45:34 +0000 (10:45 -0500)
commit7c5df8ad5c18a9f8b9440dbd1ae4faacf55b452a
treeef055d8b30dbb38cc4d9f8e2a1edf7f0c3666a64
parent422cc33cf0da52d10c271a75cda271d5963da4eb
Allow underscore characters in FQDNs and pointers.

Modern DNS records can contain underscores for a number of reasons. In
particular, DKIM records involve a "_domainkey" part,

  https://tools.ietf.org/html/rfc6376

that is rejected by the current "fqdn" and "p" validation routines.
Moreover, any SRV records will have a service name prefixed with an
underscore:

  https://tools.ietf.org/html/rfc2782

To recognize these tokens as valid, this commit expands the "fqdn" and
"p" regular expressions to allow underscores as the first character in
each component of an FQDN.
valtz