New feature: --auth-gen-token

This is an updated patch-set of the --auth-gen-token feature. A couple of patches have already been sent to the previous mail thread [1], but I thought it would be easier to do the final ACK round when everything was collected into the same thread.

As the previous PATCH 1/5 got ACKed and is already applied to the master branch, this patch is excluded from this updated thread.

[1] <https://www.mail-archive.com/[email protected]/msg12701.html>

Quick recap
===========

This patch-set adds a new --auth-gen-token option with an optional lifetime argument. This allows existing authentication modules to let clients store a temporary authentication token for the session instead of caching passwords locally. This also have the benefit of allowing Two Factor Authentication (2FA) implementations to work properly with the --reneg-* options enabled without any further modifications. This feature can be used against any OpenVPN v2.3.0 client and newer.

What has changed since the first patche-set
===========================================

- Changes.rst have been updated
- man page have been improved
- Ensuring the feature has a consistent naming scheme in the code
- Ensuring the code don't exceed 80 chars line length
- Various improvements to comments

David Sommerseth (4):
auth-gen-token: Add --auth-gen-token option
auth-gen-token: Generate an auth-token per client
auth-gen-token: Push generated auth-tokens to the client
auth-gen-token: Authenticate generated auth-tokens when client
re-authenticates

 Changes.rst              | 15 ++++++++
 doc/openvpn.8            | 22 +++++++++++
 src/openvpn/init.c       |  2 +
 src/openvpn/misc.c       |  9 +++++
 src/openvpn/options.c    | 16 ++++++++
 src/openvpn/options.h    |  2 +
 src/openvpn/push.c       | 12 +++++-
 src/openvpn/ssl.c        |  6 +++
 src/openvpn/ssl_common.h | 13 +++++++
 src/openvpn/ssl_verify.c | 97 ++++++++++++++++++++++++++++++++++++++++++++++++
 10 files changed, 193 insertions(+), 1 deletion(-)

1.8.3.1