BIO_s_socket(3ssl)

BIO_s_socket3ssl

Socket bio

Usage

 #include <openssl/bio.h>
 const BIO_METHOD *BIO_s_socket(void);
 BIO *BIO_new_socket(int sock, int close_flag);

Overview

BIO_s_socket() returns the socket BIO method. This is a wrapper round the platform's socket routines.

BIO_read_ex() and BIO_write_ex() read or write the underlying socket. BIO_puts() is supported but BIO_gets() is not.

If the close flag is set then the socket is shut down and closed when the BIO is freed.

BIO_new_socket() returns a socket BIO using sock and close_flag.

Notes

Socket BIOs also support any relevant functionality of file descriptor BIOs.

The reason for having separate file descriptor and socket BIOs is that on some platforms sockets are not file descriptors and use distinct I/O routines, Windows is one such platform. Any code mixing the two will not work on all platforms.

Return values

BIO_s_socket() returns the socket BIO method.

BIO_new_socket() returns the newly allocated BIO or NULL is an error occurred.

Releases

13 releases since Debian 3.0 (Woody); the text changed 12 times.

  1. 3.0
  2. 3.1
  3. 4.0
  4. 5.0
  5. 6.0
  6. 7
  7. 8
  8. 9
  9. 10
  10. 11
  11. 12
  12. 13
  13. Arch

From openssl 3.6.5-1 in Arch Linux 2026-11-01. Parsed by carta from the page's man source.