Problem with ECC signature verification on STM32L071xx using STM32 crypto library

[Maxim Zhmak]

I have a problem with ECC signature verifiacation using STM32 crypto library example projects.

I'm using ECC based on P-256.

What I do:

1. Start a firmware crypto example project - ECC/KeyGen_Sign_Verif - generate public and private keys, sign simple message
2. Copy public key and signature and paste it into ECC/Sign_Verif example project and try to verify public key and signature.
3. Public key is verified but ignature verification fails.

I've checked byte-to-byte of MessageDigest, Message,Signature and Public key to avoid errors on coping. Also __CRC_CLK_ENABLE() - is done.

What I'm doing wrong - why can signature verification can fail on same curve, public key, message digest?

And in general - is it possible to export public key and signature to use them into with openssl on other platforms?