extern BIO *bio_err;
BIO *dup_bio_in(int format);
BIO *dup_bio_out(int format);
+BIO *dup_bio_err(int format);
BIO *bio_open_owner(const char *filename, int format, int private);
BIO *bio_open_default(const char *filename, char mode, int format);
BIO *bio_open_default_quiet(const char *filename, char mode, int format);