SSL_get_fd.3ossl - Man Page

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.

See Also

SSL_set_fd(3), ssl(7) , bio(7)

Info

2026-09-29 3.5.9 OpenSSL