Rename ALLOW_NON_CBC_CIPHERS to ENABLE_OFB_CFB_MODE, and add to configure.

Makes OFB/CFB compile time configurable, and fixes output of --show-ciphers
to also show OFB/CFB ciphers along the way (becasue crypto.h was not
included from crypto_openssl.c).

Signed-off-by: Steffan Karger <steffan@karger.me>
Acked-by: Arne Schwabe <arne@rfc2549.org>
Message-Id: <1402244175-31462-2-git-send-email-steffan@karger.me>
URL: http://article.gmane.org/gmane.network.openvpn.devel/8781
Signed-off-by: Gert Doering <gert@greenie.muc.de>
Add proper check for crypto modes (CBC or OFB/CFB)

OpenSSL has added AEAD-CBC mode ciphers like AES-128-CBC-HMAC-SHA1, which
have mode EVP_CIPH_CBC_MODE, but require a different API (the AEAD API).
So, add extra checks to filter out those AEAD-mode ciphers.

Adding these made the crypto library agnostic function cfb_ofb_mode()
superfuous, so removed that on the go.

Also update all cipher mode checks to use the new cipher_kt_mode_*()
functions for consistency.

Signed-off-by: Steffan Karger <steffan@karger.me>
Acked-by: Arne Schwabe <arne@rfc2549.org>
Message-Id: <1402244175-31462-3-git-send-email-steffan@karger.me>
URL: http://article.gmane.org/gmane.network.openvpn.devel/8779
Signed-off-by: Gert Doering <gert@greenie.muc.de>
Improve --show-ciphers to show if a cipher can be used in static key mode

Also remove the bulky warning from init_key_type() and add the information
to the --show-ciphers output.

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: <53BAEF65.2070509@karger.me>
URL: http://article.gmane.org/gmane.network.openvpn.devel/8852
Signed-off-by: Gert Doering <gert@greenie.muc.de>
Extend t_lpback tests to test all ciphers reported by --show-ciphers

... instead of just BF-CBC. Should catch more mistakes.

Signed-off-by: Steffan Karger <steffan@karger.me>
Acked-by: Arne Schwabe <arne@rfc2549.org>
Message-Id: <1402244175-31462-5-git-send-email-steffan@karger.me>
URL: http://article.gmane.org/gmane.network.openvpn.devel/8777
Signed-off-by: Gert Doering <gert@greenie.muc.de>