rsa_st
struct rsa_st *rsa; /* RSA */
struct rsa_st;
struct rsa_st *EVP_PKEY_get0_RSA(EVP_PKEY *pkey);
struct rsa_st *EVP_PKEY_get1_RSA(EVP_PKEY *pkey);
int EVP_PKEY_set1_RSA(EVP_PKEY *pkey, struct rsa_st *key);
typedef struct rsa_st RSA;