SSL_GET_FINISHED(3)

🎀 NAME 🎀

okay so this is the Library Functions Manual entry for SSL_GET_FINISHED(3), and it covers SSL_get_finished and SSL_get_peer_finished — aka the besties that get the last sent or last expected finished message. 💅✨

🌸 SYNOPSIS 🌸

#include <openssl/ssl.h>

size_t
SSL_get_finished(const SSL *ssl, void *buf, size_t count);

size_t
SSL_get_peer_finished(const SSL *ssl, void *buf, size_t count);

🦋 DESCRIPTION 🦋

okay bestie, here's the vibe: SSL_get_finished() and SSL_get_peer_finished() copy count bytes from the last finished message sent to the peer or expected from the peer into the caller-provided buffer buf. no cap, that's literally the whole move. 💖

the finished message is computed from a checksum of the handshake records exchanged with the peer. its length depends on the ciphersuite in use and is at most EVP_MAX_MD_SIZE, i.e., 64 bytes. so yes, it's giving “small but iconic.” 🔥

⭐ RETURN VALUES ⭐

SSL_get_finished() and SSL_get_peer_finished() return the number of bytes copied into buf. the return value is zero if the handshake has not reached the finished message. 🫶

lowkey important: if the handshake hasn't gotten to the finished message yet, you get 0 back — no finished message to copy, bestie. 😭

🌈 SEE ALSO 🌈

• ssl(3)
• SSL_get_session(3)
• SSL_set_session(3)

👑 STANDARDS 👑

• RFC 8446: The Transport Layer Security (TLS) Protocol Version 1.3, section 4.4.4: Finished.
• RFC 5246: The Transport Layer Security (TLS) Protocol Version 1.2, section 7.4.9: Finished.

💜 HISTORY 💜

SSL_get_finished() and SSL_get_peer_finished() first appeared in SSLeay 0.9.5 and have been available since OpenBSD 2.7. periodt. 💀✨

mwah 💋 this lil rewrite is serving the SSL_GET_FINISHED(3) page as packaged by Debian, dated January 30, 2021 — bye bestie 🫶🎀