SSL_get_fd(3) get file descriptor linked to an SSL object


#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);


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.


The following return values can occur:
The operation failed, because the underlying BIO is not of the correct type (suitable for file descriptors).
The file descriptor linked to ssl.