Nginx OCSP processing module designed for response caching
C
Latest commit 8e978ef Mar 24, 2014 Eldar Zaitov correctly handle different datetime formats

README.md

Description

nginx_ocsp_proxy-module - module for OCSP request and response processing designed to allow response caching using srcache-nginx-module and memc-nginx-module. If you want to use standart caching mechanisms module could help you rewrite POST OCSP requests to GET.

Status

Working alpha

Note

If you're not an CA owner with a lot of legacy clients - forget about this module and use OCSP stapling instead.

Directives

ocsp_proxy

syntax: ocsp_proxy (on|off);

default: off

context: http, server, location, if

on - Enable module and GET/POST request processing

off - Disable module

ocsp_cache_timeout

syntax: ocsp_cache_timeout 1h;

default: 24 hrs

context: http, server, location, if

Maximum cache time for OCSP response.

Variables

ocsp_request

Base64 encoded OCSP request body. Can be used for POST to GET rewrite.

ocsp_serial

Certificate serial

ocsp_skip_cache

If set on request:

1 - no cached response should be sent

Will be set to 1 in case of:

* Nonce found in reqest

If set on response:

0 - response can be cached

1 - response can not be cached

Will be set to 1 in case of:

* Nonce found in response

* Service Locator extension found in request

ocsp_response_cache_time

Cache time for specific response.

Can't be more than ocsp_cache_timeout.

Will be set to 0 if ocsp_skip_cache set to 1. 0 means FOREVER in memcached, so don't forget to configure store_skip correctly!

Example configuration

upstream my_memcached {
    server 127.0.0.1:11211;
}

server {
    listen       80;
    server_name  localhost;
    client_max_body_size 256k;

    location /memc {
        internal;

        set $memc_key $arg_key;
        set $memc_exptime $arg_exptime;

        memc_pass my_memcached;
        memc_ignore_client_abort on;
    }

    location / { 
        ocsp_proxy on;
        set $key $ocsp_serial;

        srcache_methods GET POST;

        srcache_fetch GET /memc key=$key;
        srcache_fetch_skip $ocsp_skip_cache;

        srcache_store PUT /memc key=$key&exptime=$ocsp_response_cache_time;
        srcache_store_statuses 200;
        srcache_store_skip $ocsp_skip_cache;
        srcache_store_hide_header Date;

        proxy_pass http://ocsp.someca.com;
        proxy_ignore_client_abort on;
    }
}

Example configuration 2

server {
    ...

    location / {
        ocsp_proxy on;

        if ($request_method = "POST") {
            rewrite ^(.*)$ $1$ocsp_request break;
        }

        proxy_method GET;
        proxy_pass_request_body off;

        proxy_set_header Content-Length "";
        proxy_set_header Content-Type "";

        proxy_cache_key "$proxy_host$ocsp_serial$request_uri";

        ...

        proxy_pass http://ocsp.someca.com;
        proxy_ignore_client_abort on;
    }
}

Installation

Grab the nginx source code from nginx.org, for example, the version 1.5.8 (see nginx compatibility). Grab srcache-nginx-module and memc-nginx-module. Build the source with this module:

wget 'http://nginx.org/download/nginx-1.5.8.tar.gz'
tar -xzvf nginx-1.5.8.tar.gz
cd nginx-1.5.8/
./configure --with-debug --add-module=/path/to/srcache-nginx-module \
                    --add-module=/path/to/memc-nginx-module \
                    --add-module=/path/to/nginx_ocsp_proxy-module

make
make install

Modules order does matter!

Compatibility

Module was tested with nginx 1.5+, but should work with 1.4+.

Sources

Available on github at /kyprizel/nginx_ocsp_proxy-module. Most POST processing code was borrowed from form-input-nginx-module.

Analytics

TODO

  • Code review
  • Testing
  • Load testing
  • OCSP Response validation with CA cert

Bugs

Feel free to report bugs and send patches to eldar@kyprizel.net or using github's issue tracker.

Copyright & License

Copyright (c) 2013-2014, Eldar Zaitov All rights reserved.

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:

  • Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.

  • Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.

  • Neither the name of the {organization} nor the names of its contributors may be used to endorse or promote products derived from this software without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.