man SSL_get_fd () - get file descriptor linked to an SSL object
NAME
SSL_get_fd - get file descriptor linked to an SSL object
SYNOPSIS
#include <openssl/ssl.h>
int SSL_get_fd(const SSL *ssl); int SSL_get_rfd(const SSL *ssl); int SSL_get_wfd(const SSL *ssl);
DESCRIPTION
SSL_get_fd() returns the file descriptor which is linked to ssl. SSL_get_rfd() and SSL_get_wfd() return the file descriptors for the read or the write channel, which can be different. If the read and the write channel are different, SSL_get_fd() will return the file descriptor of the read channel.
RETURN VALUES
The following return values can occur:
- -1
- The operation failed, because the underlying BIO is not of the correct type (suitable for file descriptors).
- >=0
- The file descriptor linked to ssl.