SSL_CTX_SET_KEYLOG_CALLBACK(3) | Library Functions Manual | SSL_CTX_SET_KEYLOG_CALLBACK(3)

# NAME

`SSL_CTX_set_keylog_callback`, `SSL_CTX_get_keylog_callback` — set and get the unused key logging callback

# SYNOPSIS

library “libssl” libcrypto
`#include <openssl/ssl.h>`

typedef void
`(*SSL_CTX_keylog_cb_func)`(const SSL *ssl, const char *line);

void
`SSL_CTX_set_keylog_callback`(SSL_CTX *ctx, SSL_CTX_keylog_cb_func cb);

SSL_CTX_keylog_cb_func
`SSL_CTX_get_keylog_callback`(const SSL_CTX *ctx);

# DESCRIPTION

`SSL_CTX_set_keylog_callback`() sets the TLS key logging callback. This callback is never called in LibreSSL.

`SSL_CTX_get_keylog_callback`() retrieves the previously set TLS key logging callback.

These functions are provided only for compatibility with OpenSSL.

# RETURN VALUES

`SSL_CTX_get_keylog_callback`() returns the previously set TLS key logging callback, or `NULL` if no callback has been set.

# SEE ALSO

ssl(3), SSL_CTX_new(3)

# HISTORY

These function first appeared in OpenSSL 1.1.1 and have been available since OpenBSD 7.1.

June 8, 2025 | Debian