minor todo.org updates
[test suite] added --enable-openssl-checks

Added --enable-openssl-checks to send all SPA packets encrypted via libfko
through the OpenSSL library to ensure that the libfko usage of AES is always
compatible with OpenSSL.  This ensures that the fwknop usage of AES is properly
implemented as verified by the OpenSSL library, which is a frequently audited
high profile crypto engine.  If a vulnerability is discovered in OpenSSL and a
change is made, then the --enable-openssl-checks mode will allow the test suite
to discover this in a automated fashion for fwknop.
minor typo spelling fix
memset() AES buffers to zero
openssl tests to use '-pass file:' method for setting passphrase
Maintain backwards compatibility with old "zero padding" code

[libfko] Added the ability to maintain backwards compatibility with the
now deprecated "zero padding" strategy in AES mode that was a hold over
from the old perl fwknop implementation.  This enables the backwards
compatiblity tests to continue to pass in the test suite.
ensure test/conf/ files are included
added encryption_mode() support to perl FKO module
added legacy IV tests for perl FKO client -> C server
added fuzzing test counters with summary output
more legacy IV mode tests with the perl FKO module
Merge remote-tracking branch 'fjoncourt/hmac_support' into hmac_support

Applied fix from Franck Joncourt for the 'warning: dereferencing type-punned
pointer will break strict-aliasing rules [-Wstrict-aliasing]' error in the
MD5 digest code.
[test suite] bug fix for 'set_legacy_iv' mode in perl_fko_module_complete_cycle()
Merge pull request #19 from fjoncourt/hmac_support

Fixed gcc warning for the md5 driver.
minor spacing fix
make sure test message strings are unique across all tests
bug fix for iptables duplicate rules test to account for rules that may have a different time stamp
Make valgrind test fail for new flagged functions

In --enable-valgrind mode, this commit adds the ability to compare current test
result output with any previous test suite execution.  Whenever valgrind flags
a new function or if an existing flagged function has a greater number of
calls, then the final valgrind test will fail.  This allows a greater level of
valgrind validation to take place for new code in an automated fashion.  For
example, if a change to a piece of code introduces a memory handling problem of
the sort that valgrind can detect, then the final test will fail like so:

 # ./test-fwknop.pl --include "complete cycle.*HMAC" --enable-valgrind --test-limit 1

 [+] Starting the fwknop test suite...

     args: --include complete cycle.*HMAC --enable-valgrind --test-limit 1

     Saved results from previous run to: output.last/

 [Rijndael SPA] [client+server] complete cycle + HMAC (tcp/22 ssh)...pass (1)
 [valgrind output] [flagged functions] ..............................fail (2)

 [+] 1/1/2 tests passed/failed/executed

The newly flagged functions will be written to the corresponding test file:

 # cat output/2.test

 [+] TEST: [valgrind output] [flagged functions]~
 [-] 1.test (client) '[+] TEST: [Rijndael SPA] [client+server] complete cycle + HMAC (tcp/22 ssh)' --> NEW valgrind flagged function: main
 [-] 1.test (client) '[+] TEST: [Rijndael SPA] [client+server] complete cycle + HMAC (tcp/22 ssh)' --> NEW valgrind flagged function: fko_spa_data_final
 [-] 1.test (client) '[+] TEST: [Rijndael SPA] [client+server] complete cycle + HMAC (tcp/22 ssh)' --> NEW valgrind flagged function: strdup
 [-] 1.test (client) '[+] TEST: [Rijndael SPA] [client+server] complete cycle + HMAC (tcp/22 ssh)' --> NEW valgrind flagged function: fko_new
 [-] 1.test (client) '[+] TEST: [Rijndael SPA] [client+server] complete cycle + HMAC (tcp/22 ssh)' --> NEW valgrind flagged function: fko_encrypt_spa_data
 [-] 1.test (client) '[+] TEST: [Rijndael SPA] [client+server] complete cycle + HMAC (tcp/22 ssh)' --> NEW valgrind flagged function: fko_encode_spa_data
 [-] 1.test (client) '[+] TEST: [Rijndael SPA] [client+server] complete cycle + HMAC (tcp/22 ssh)' --> NEW valgrind flagged function: fko_calculate_hmac
 [-] 1.test (client) '[+] TEST: [Rijndael SPA] [client+server] complete cycle + HMAC (tcp/22 ssh)' --> NEW valgrind flagged function: fko_set_username
 [-] 1.test (client) '[+] TEST: [Rijndael SPA] [client+server] complete cycle + HMAC (tcp/22 ssh)' --> NEW valgrind flagged function: fko_set_rand_value
 [-] 1.test (client) '[+] TEST: [Rijndael SPA] [client+server] complete cycle + HMAC (tcp/22 ssh)' --> NEW valgrind flagged function: fko_set_spa_message
 [-] 1.test (client) '[+] TEST: [Rijndael SPA] [client+server] complete cycle + HMAC (tcp/22 ssh)' --> NEW valgrind flagged function: set_digest
 [-] 1.test New and/or greater number of valgrind flagged function calls
ensure matching test file comparison for valgrind test
Minor memory leak bug fix in --rotate-digest-cache mode

This commit fixes a minor memory leak for the digest cache file path in
--rotate-digest-cache mode in the replay_cache_init() function.  The leak was
caught by valgrind, and a new test was added to the test suite for it.  Here
is the valgrind warning:

==29021== 21 bytes in 1 blocks are definitely lost in loss record 2 of 2
==29021==    at 0x4C2B3F8: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==29021==    by 0x1103AA: replay_cache_init (replay_cache.c:96)
==29021==    by 0x10BB8C: main (fwknopd.c:254)