Encodes a EC_POINT object to a octet string
\param group underlying EC_GROUP object
\param p EC_POINT object
\param form point conversion form
\param buf memory buffer for the result. If NULL the function returns
required buffer size.
\param len length of the memory buffer
\param ctx BN_CTX object (optional)
\return the length of the encoded octet string or 0 if an error occurred
Encodes a EC_POINT object to a octet string \param group underlying EC_GROUP object \param p EC_POINT object \param form point conversion form \param buf memory buffer for the result. If NULL the function returns required buffer size. \param len length of the memory buffer \param ctx BN_CTX object (optional) \return the length of the encoded octet string or 0 if an error occurred