Fixes the test suites to consistently use mbedtls_fprintf to output to
stdout or stderr.
Also redirects output from the tests to /dev/null to avoid confusing
output if the test suite code or library outputs anything to stdout.
Minor fixes following review including:
* formatting changes including indentation and code style
* corrections
* removal of debug code
* clarification of code through variable renaming
* memory leak
* compiler warnings
Changes to allow the entropy tests to work for configurations without an
entropy seed file (MBEDTLS_ENTROPY_NV_SEED), and with no entropy sources
configured (MBEDTLS_TEST_NULL_ENTROPY).
Instead of polling the hardware entropy source a single time and
comparing the output with itself, the source is polled at least twice
and make sure that the separate outputs are different.
The self test is a quick way to check at startup whether the entropy
sources are functioning correctly. The self test only polls 8 bytes
from the default entropy source and performs the following checks:
- The bytes are not all 0x00 or 0xFF.
- The hardware does not return an error when polled.
- The entropy does not provide data in a patter. Only check pattern
at byte, word and long word sizes.
A standard 'test' that writes a seed file is added so that regular tests
still can succeed. This is in lieu of a 'SUITE_PRE_CODE' kind of
arrangement where a suite can run code before (and after) all other code
runs.
A test is added that checks if we can read and write the standard NV
seed file
A test is added that actually checks if the entropy and seed file values
that are the result of just using the NV seed are the same as the manual
calculation.
For a start, they don't even compile with Visual Studio due to strcasecmp
being missing. Secondly, on Windows Perl scripts aren't executable and have
to be run using the Perl interpreter directly; thankfully CMake is able to
find cygwin Perl straight away without problems.
