I had this problem before and I forgot the solution
Using OpenVPN with OpenSSL and the Cryptodev engine always fails the OpenVPN crypto test at byte 560 with a RAND_bytes() fail assertion. This is regardless of any hardware crypto driver loaded.
I had this working before I did full clean install of the build environment so it must be some selection I missed.
- select the hardware acceleration in the OpenSSL lib.
- have some (p)rng show up under /proc/crypto
- check dmesg log that the CRNG is initialized.
Low entropy could be a reason, but if I run the test again immediately it runs until the same 560. I have the same problem on different SoC / builds so it must be a selection / module I’m missing.