Decodes a EC_POINT from a octet string
\param group underlying EC_GROUP object
\param p EC_POINT object
\param buf memory buffer with the encoded ec point
\param len length of the encoded ec point
\param ctx BN_CTX object (optional)
\return 1 on success and 0 if an error occured
Decodes a EC_POINT from a octet string \param group underlying EC_GROUP object \param p EC_POINT object \param buf memory buffer with the encoded ec point \param len length of the encoded ec point \param ctx BN_CTX object (optional) \return 1 on success and 0 if an error occured