Thanks Matt, i just assumed the BIGNUMs were the coordinates without any projection - obviously that assumption was wrong - mislead by the funtions name. However, we're operating on brainpool curves, so the latter function should do the job. I'll lookup the parameters and try tomorrow. MfG -- Chris Am 08.01.2015 um 22:43 schrieb Matt Caswell <matt at openssl.org>: > > > On 08/01/15 17:16, Christian Weber wrote: >> Dear OpenSSL-Users, >> >> recently i found a pitfall using EC_KEY_get0_public_key(key->pkey.ec). >> The function just returns a copy to a pointer to key->pub_key which is a >> EC_POINT pointer. >> The key itself is taken from a certificate using EVP_PKEY *key = >> X509_get_pubkey(cert); >> >> Fine, i assumed, these must be coordinates of the publich key in the >> elements X and Y! >> Both are BIGNUMS as expected. > > How are you accessing the elements X and Y? The internal representation > could be transformed and you should make sure you are using the correct > functions to access them, i.e. one of: > > EC_POINT_get_affine_coordinates_GFp > or > EC_POINT_get_affine_coordinates_GF2m > > Which one to use depends on whether you are using a prime or binary curve. > > Matt > _______________________________________________ > openssl-users mailing list > openssl-users at openssl.org > https://mta.openssl.org/mailman/listinfo/openssl-users
