Since some OpenSSL binaries, namely Gentoo’s, don’t support bracketed
IPv6 addresses but unbracketed ones, specified as the -connect option,
the UNBRACKETED_IPV6 environment variable can be set to true for
disabling the automatic addition of brackets around IPv6 addresses on
such platforms.
While standard OpenSSL requires the literal IPv6 address enclosed
in [brackets], standard DNS lookup tools don’t support the additional
characters. Before making reverse PTR lookups, these brackets have to
be removed from the IPv6 addresses.
CBC cipher selection is not so easy using the openssl tool alone. Selecting the cipher based on the string CBC occuring in it would be right if it’s
about the RFC name of the cipher but not so with the openssl naming. Since CBC ciphers are not going to be continued anyway, I think it’s safe to take
a static list. However, it’s easy to extract it from the cipher list in openssl-rfc.mapping.html, but we certainly don’t want to require that file to
be shipped all the time.
typingArtist