int i2d_PKCS8PrivateKeyInfo_fp(FILE *fp, EVP_PKEY *key);
int i2d_PrivateKey_fp(FILE *fp, EVP_PKEY *pkey);
EVP_PKEY *d2i_PrivateKey_fp(FILE *fp, EVP_PKEY **a);
int i2d_PKCS8PrivateKeyInfo_fp(FILE *fp, EVP_PKEY *key);
int i2d_PrivateKey_fp(FILE *fp, EVP_PKEY *pkey);
EVP_PKEY *d2i_PrivateKey_fp(FILE *fp, EVP_PKEY **a);