[PATCH] Early request for comments: U2F authentication

[Klaus Keppler]

> If I do that, EVP_VerifyFinal() will result in EVP_R_WRONG_PUBLIC_KEY_TYPE.

This is strange... I don't get any error here, though I use the (same?) 
ECDSA public key from the attestation certificate (using OpenSSL 1.0.1i, 
but that shouldn't matter).

> Looking at the OpenSSL source, I can see that in crypto/evp/m_sha1.c, the
> sha* digests are defined with EVP_PKEY_RSA_method, which requires an RSA
> publickey, but we have an ECDSA publickey. The only digest working with
> ECDSA publickeys is crypto/evp/m_ecdsa.c AFAICT.

Both EVP_PKEY_RSA_method and EVP_PKEY_ECDSA_method are #defined there as 
"EVP_PKEY_NULL_method". (don't ask me why... I don't understand most of 
that macro mess...)

> Unfortunately not. Could you share the code that you have please? Or is it
> not yet working?

Voila: https://github.com/keppler/fido-u2f/blob/master/fido-example.c
It uses the example messages from the official specs, so should be easy 
to reproduce.

If I'm wrong at any point there, please let me know.

Best regards

    -Klaus