I haven’t done exactly what you are trying, but something similar. See EVP_PKEY_set_params:
https://www.openssl.org/docs/man3.0/man3/EVP_PKEY_set_params.html <https://www.openssl.org/docs/man3.0/man3/EVP_PKEY_set_params.html> The specific parm to set the group could be set like this: OSSL_PARAM_BLD_push_utf8_string(param_bld, "group", curve, 0; Please note that that I have not tested the above code as my code uses key-from-data. But I think it should work. > On Oct 24, 2022, at 2:31 PM, Martin via openssl-users > <openssl-users@openssl.org> wrote: > > Hi, > > How can I set a GROUP to an existing EC type EVP_PKEY in OpenSSL 3? > > In 1.0.2 I was using this code having the EC_KEY: > > EC_KEY_set_group(eckey, EC_GROUP_new_by_curve_name(nid)); > > In OpenSSL 3 still EC_GROUP_new_by_curve_name(nid) can be used, but I don’t > know how to go from that to set it on the existing key. > > > Thanks, > > Martin
