Update IPv6 related readme files

Acked-by: Gert Doering <gert@greenie.muc.de>
Message-Id: <1388760580-7548-1-git-send-email-arne@rfc2549.org>
URL: http://article.gmane.org/gmane.network.openvpn.devel/8167

Signed-off-by: Gert Doering <gert@greenie.muc.de>
Make tls_ctx_restrict_ciphers accept NULL as char *cipher_list.

This adds some ifs to check for NULL in tls_ctx_restrict_ciphers() to
prepare
for disabling export ciphers by default in OpenVPN 2.4+.

Also let tls_ctx_restrict_ciphers always be called, also when *cipher_list
is
NULL.

Signed-off-by: Steffan Karger <steffan@karger.me>
Acked-by: Gert Doering <gert@greenie.muc.de>
Message-Id: <52C8922E.3030607@karger.me>
URL: http://article.gmane.org/gmane.network.openvpn.devel/8173
Signed-off-by: Gert Doering <gert@greenie.muc.de>
Disable export ciphers by default for OpenSSL builds.

Export ciphers are deliberately weak ciphers, and not fully supported by
OpenVPN since ephemeral RSA support has been removed a few commits ago.
This commit removes them from the default cipher list to avoid confusion.

PolarSSL does not support export ciphers, so no action required there.

Signed-off-by: Steffan Karger <steffan@karger.me>
Acked-by: Arne Schwabe <arne@rfc2549.org>
Acked-by: Gert Doering <gert@greenie.muc.de>
Message-Id: <1388607026-12297-7-git-send-email-steffan@karger.me>
URL: http://article.gmane.org/gmane.network.openvpn.devel/8146
Signed-off-by: Gert Doering <gert@greenie.muc.de>