cryptocheck: Don't treat OpenSSL errors as fatal

[jhb]

Summary

Abort the current test but keep running additional tests if OpenSSL
reports an error during a test. This matches the behavior for other
tests such as an error from OCF.

[markj]

Why would openssl return an error?

These errors don't get propagated up so cryptocheck may still exit with status 0 after an error. Is that reasonable?

[jhb]

In D45279#1033131, @markj wrote:

Why would openssl return an error?

When OpenSSL 3.0 removes support for IV sizes for chacha20 for example. :(

These errors don't get propagated up so cryptocheck may still exit with status 0 after an error. Is that reasonable?

That is true of non-OpenSSL errors today, so is at least consistent. If we wanted to propagate errors we could perhaps add a global boolean that determines the return value from main. Some errors we might want to ignore though which is the hard part. OCF doesn't implement AES-XTS with small payload sizes for example, and I think two of the small tests (single byte payload) when doing -a all -z have identical cipher and plain text because the first byte of the keystream is 0x00. I generally redirect stdout/stderr to a file and use diff or a side-by-side tool like kompare.