provide consistent environement to test SSL libraries with 3rd party tool

the idea is to have a script (set of scripts) which build and install
environement such we can evaluate SSL performance of different
SSL implementations.

The initial version supports httpd from apache. The idea is to build
desired SSL library and install it to custom location (INSTALL ROOT).
Then we build apache and siege client and install it to INSTALL ROOT.

The proposed approach uses shell script as it is very lightweight
and portable between various *NIX flavours.

Reviewed-by: Neil Horman <[email protected]>
(Merged from #49)

Author: Sashan

bench-scripts/README.md

@@ -0,0 +1,90 @@
+# https performance tests with apache (or nginx)
+
+The scripts here install and configure desired server with OpenSSL [1],
+WolfSSL[2], LibreSSL [3], BoringSSL [4] and aws-lc [5]. Script builds
+and installs the library to dedicated directory. Each library is built
+with its default options which enable/disable features. The script then
+uses siege [6] to measure https performance for each library. There are
+no command line options everything is controlled using env. variables:
+    -  `BENCH_INSTALL_ROOT` sets the directory under which the SSL libraries
+	and tools are installed (`/tmp/branch.binaries` by default)
+    -  `BENCH_WORKSPACE_ROOT` sets the workspace directory where libraries and
+	tools are compiled.
+    -  `BENCH_MAKE_OPTS` command line options for make(1) command
+    -  `BENCH_RESULTS` directory where to save results
+	(`$BENCH_INSTALL_ROOT/results` by default)
+    -  `BENCH_HTTPS_PORT` port where https test server should listen to
+	(4430 by default).
+    -  `BENCH_HTTP_PORT` port where http test server should listen to
+	(8080 by default)
+    -  `BENCH_TEST_TIME` time to run performance test. default value is
+	5 minutes (5M). See option `-t` in siege manual [7] for details.
+    -  `BENCH_HOST` hostname/ip address where server is listening to
+	(127.0.0.1 by default)
+    -  `BENCH_CERT_SUBJ` set to `/CN=localhost` by default
+    -  `BENCH_CERT_ALT_SUBJ`  set to `subjectAltName=DNS:localhost,IP:127.0.0.1`
+	by default
+The siege client runs in benchmark mode (with option `-b`). It is told to fetch
+16 files until `BENCH_TEST_TIME` elapses. The file sizes are 64B, 128B,
+256B, ... 4MB.
+
+The libraries the benchmark tests are as follows:
+    - OpenSSL 3.0, 3.1, ... 3.6, master
+    - WolfSSL 5.8.2
+    - BorinSSL master version
+    - LibreSSL 4.1.0
+    - aws-lc master version
+
+## Apache
+
+All tests use version 2.4.65 (except wolfssl which must use 2.4.51, however the
+apache still does not work with WolfSSL, issue is still being investigated).
+The apache server configuration is identical for all SSL libraries. The apache
+server is built with mpm worker, event and pre-fork loadable modules. The test
+iterates over three server configurations which each uses particular mpm
+module. The modules run with their configuration supplied by apache.
+
+The configuration for apache server (httpd.conf) is saved along the results
+together with configuration for mod\_ssl. The script does not change any
+parameters except adjustments of file paths. Everything runs with
+default settings which come with apache installation.
+
+## nginx
+
+All tests use nginx 1.28 (except WolfSSL which uses 1.24). The
+`worker_processes` configuration option is st to auto.
+Apart from adjusting paths in nginx.conf the script also sets
+option `work_process` to auto. Nginx server configuration is
+saved along the results for each test.
+
+## Build requirements
+
+Requirements for ubuntu are the following:
+    - ksh
+    - gnuplot
+    - git
+    - ninja-build
+    - cmake
+    - wget
+    - autoconf
+    - bzip2
+    - libpcre2-dev
+    - libexpat-dev
+    - golang-go
+    - zlib1g-dev
+    - libtool
+    - g++
+
+[1]: https://www.openssl.org/
+
+[2]: https://www.wolfssl.com/
+
+[3]: https://www.libressl.org/
+
+[4]: https://www.chromium.org/Home/chromium-security/boringssl/
+
+[5]: https://aws.amazon.com/security/opensource/cryptography/
+
+[6]: https://www.joedog.org/siege-home/
+
+[7]: https://www.joedog.org/siege-manual/