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
