On 27/01/2023 10:34, Oliver Mihatsch wrote:
Hello OpenSSL users,
I'm currently searching for the reverse operation of
EC_GROUP_new_from_params() which should create an EC_GROUP from an
OSSL_PARAM array in the public API.
I need to convert an EC_GROUP back to an OSSL_PARAM array to modify it
(in this case shift the generator/base point of the group).
A suitable function is available in 'include/crypto/ec.h' called
ossl_ec_group_todata() but I couldn't find a way to access it via
public API.
Is there something I've overlooked or is the counterpart function of
EC_GROUP_new_from_params() missing in the public API?
AFAIK it is missing.
If this the case,
would you accept a pull request to add a function like
EC_GROUP_to_params() which internally calls ossl_ec_group_todata()?
It seems like a reasonable feature request. I can't promise it would be
accepted but it would be looked at. Any such PR would need to target the
master branch (it would not be acceptable for 3.1/3.0/1.1.1) and ensure
it included appropriate documentation and tests.
Matt
Thanks a lot,
Oliver
------
(/include/openssl/ec.h)
EC_GROUP *EC_GROUP_new_from_params(const OSSL_PARAM params[],
OSSL_LIB_CTX *libctx, const char *propq);
(include/crypto/ec.h)
int ossl_ec_group_todata(const EC_GROUP *group, OSSL_PARAM_BLD *tmpl,
OSSL_PARAM params[], OSSL_LIB_CTX *libctx,
const char *propq,
BN_CTX *bnctx, unsigned char **genbuf);
int ossl_ec_group_fromdata(EC_KEY *ec, const OSSL_PARAM params[]);
