Implementation of SHA1 in OpenSSL library is much faster and optimized
for all available CPU architectures and instruction sets.  OVS should
use it instead of internal implementation if possible.

Depending on compiler options OpenSSL's version finishes our sha1
unit tests from 3 to 12 times faster.  Performance of OpenSSL's
version is constant, but OVS's implementation highly depends on
compiler.  Interestingly, default build with  '-g -O2' works faster
than optimized '-march=native -Ofast'.

Tests with ovsdb-server on big databases shows ~5-10% improvement of
the time needed for database compaction (sha1 is only a part of this
operation), depending on compiler options.

We still need internal implementation, because OpenSSL can be not
available on some platforms.  Tests enhanced to check both versions
of API.

Reviewed-by: Dumitru Ceara <dceara@redhat.com>
Signed-off-by: Ilya Maximets <i.maximets@ovn.org>

This is a unit test for the overflow detection issue fixed by commit
a1d2c5f5d9ed ("sha1: Fix algorithm for data bigger than 512 megabytes.")

Signed-off-by: Ilya Maximets <i.maximets@ovn.org>
Acked-by: Paolo Valerio <pvalerio@redhat.com>
Tested-by: Paolo Valerio <pvalerio@redhat.com>

./configure accepts --enable-ndebug option.  Make ovs_assert() honor
it, and make sure all test programs disable it.

The order of include files in test programs is also made uniform:

1. #include <config.h>
2. #undef NDEBUG
3. Include file of the test subject (to make sure it itself has
   sufficient include directives).
4. System includes in alphapetical order.
5. OVS includes in aplhapetical order.

Suggested-by: Ben Pfaff <blp@nicira.com>
Signed-off-by: Jarno Rajahalme <jrajahalme@nicira.com>
Acked-by: Ben Pfaff <blp@nicira.com>

Improve link speed by linking 29 test programs into ovstest.

On my machine, running the following command against a fully
built tree:

  $ touch lib/random.c; time make

Improve the overall build time from 7 seconds to 3.5 seconds.

Signed-off-by: Andy Zhou <azhou@nicira.com>
Acked-by: Ben Pfaff <blp@nicira.com>

Signed-off-by: Ben Pfaff <blp@nicira.com>

Replaced all instances of Nicira Networks(, Inc) to Nicira, Inc.

Feature #10593
Signed-off-by: Raju Subramanian <rsubramanian@nicira.com>
Signed-off-by: Ben Pfaff <blp@nicira.com>

Otherwise sparse warns: warning: memset with byte count of 1000000

The SHA-1 library that we used until now was taken from RFC 3174.  That
library has no clearly free license statement, only a license on the text
of the RFC.  This commit replaces this library with a modified version of
the code from the Apache Portable Runtime library from apr.apache.org,
which is licensed under the Apache 2.0 license, the same as the rest of
Open vSwitch.