SSL_GET_FD(3)

💖 NAME 💖

okay so bestie, welcome to SSL_GET_FD(3) from the Library Functions Manual — this is the page for SSL_get_fd, SSL_get_rfd, and SSL_get_wfd, aka the little functions that get you the file descriptor linked to an SSL object. slay. 💅

✨ SYNOPSIS ✨

the synopsis is giving library-and-header energy, and it goes exactly like this:

library “libssl” libcrypto #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 🦋

so SSL_get_fd() returns the file descriptor which is linked to ssl. iconic.

SSL_get_rfd() and SSL_get_wfd() return the file descriptors for the read or the write channel, which can be different. no cap.

if the read and the write channel are different, SSL_get_fd() will return the file descriptor of the read channel. periodt. 🎀

🎀 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). oof. 💀
• ≥0 — the file descriptor linked to ssl. yay. 🌸

🌈 SEE ALSO 🌈

• BIO_new(3)
• ssl(3)
• SSL_set_fd(3)

👑 HISTORY 👑

SSL_get_fd() appeared in SSLeay 0.4 or earlier and has been available since OpenBSD 2.4. fr fr. 🫶

SSL_get_rfd() and SSL_get_wfd() first appeared in OpenSSL 0.9.6c and have been available since OpenBSD 3.2. 💫

and that's the whole vibe, bestie 💖 — this page is from Debian, dated June 8, 2025, under the SSL_GET_FD(3) name. byeee 🦋