Re: Refactring FIPS_escda_sign() for OpenSSL 3.0.0

[Matt Caswell]

On 28/10/2021 22:46, Kory Hamzeh wrote:
Hi Matt,

I am making the changes that you suggested, I think I can get the X and Y by 
using

EVP_PKEY_get_bn_param() with  OSSL_PKEY_PARAM_EC_PUB_X and _PUB_Y.

Yes. Correct.

What I cannot figure out is how to get R and S. If I had an ECDSA_SIG, I would 
call ECDSA_SIG_get0_r() and _s().

Are there EVP_PKEY params for R and S?


An ECDSA signature is just a DER encoded ECDSA_SIG structure. Therefore 
take the resulting signature and call d2i_ECDSA_SIG. This will enable 
you to access r and s.

Matt



Thanks,
Kory



On Oct 27, 2021, at 11:04 AM, Kory Hamzeh <k...@avatarci.com> wrote:


Hi,

I am upgrading some 3RD party code which performs FIPS ECDSA AVS testing for 
FIPS 140-2 certification. The code uses FIPS_escda_sign(), which in 
Openssl-fips-2.0.5 is define as:

ECDSA_SIG * FIPS_ecdsa_sign(EC_KEY *key,
                        const unsigned char *msg, size_t msglen
,                       const EVP_MD *mhash)


The full code is here:

https://github.com/majek/openssl/blob/master/fips/ecdsa/fips_ecdsavs.c

I have read through all of the ECDSA sign man pages, and I cannot find a 
functions that is close to accepting some of the same parameter. I could use 
some help please. I have very little experience with ECDSA.

Thanks,
Kory