x/crypto/ssh: add 3des-cbc as a non-default cipher

3des-cbc is an insecure cipher. As such, you must explictly add it to
Config in order to use it.

Change-Id: Ifd15cde46a9908eefef1c75bae7e97b05767361d
Reviewed-on: https://go-review.googlesource.com/22770
Reviewed-by: Han-Wen Nienhuys <hanwen@google.com>
Run-TryBot: Han-Wen Nienhuys <hanwen@google.com>
3 files changed