SSL_CTX_CTRL(3) | Library Functions Manual | SSL_CTX_CTRL(3)

# NAME

`SSL_CTX_ctrl`, `SSL_CTX_callback_ctrl`, `SSL_ctrl`, `SSL_callback_ctrl` — internal handling functions for SSL_CTX and SSL objects

# SYNOPSIS

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

long
`SSL_CTX_ctrl`(SSL_CTX *ctx, int cmd, long larg, void *parg);

long
`SSL_CTX_callback_ctrl`(SSL_CTX *, int cmd, void (*fp)());

long
`SSL_ctrl`(SSL *ssl, int cmd, long larg, void *parg);

long
`SSL_callback_ctrl`(SSL *, int cmd, void (*fp)());

# DESCRIPTION

The `SSL_*_ctrl`() family of functions is used to manipulate settings of the SSL_CTX and SSL objects. Depending on the command cmd the arguments larg, parg, or fp are evaluated. These functions should never be called directly. All functionalities needed are made available via other functions or macros.

# RETURN VALUES

The return values of the `SSL*_ctrl`() functions depend on the command supplied via the `cmd`() parameter.

# SEE ALSO

ssl(3), SSL_CTX_add_extra_chain_cert(3), SSL_CTX_sess_number(3), SSL_CTX_sess_set_cache_size(3), SSL_CTX_set_max_cert_list(3), SSL_CTX_set_mode(3), SSL_CTX_set_options(3), SSL_CTX_set_session_cache_mode(3), SSL_CTX_set_tlsext_servername_callback(3), SSL_CTX_set_tlsext_status_cb(3), SSL_CTX_set_tlsext_ticket_key_cb(3), SSL_get_server_tmp_key(3), SSL_num_renegotiations(3), SSL_session_reused(3), SSL_set_max_send_fragment(3)

# HISTORY

`SSL_CTX_ctrl`() and `SSL_ctrl`() first appeared in SSLeay 0.8.0 and have been available since OpenBSD 2.4.

`SSL_CTX_callback_ctrl`() and `SSL_callback_ctrl`() first appeared in OpenSSL 0.9.5 and have been available since OpenBSD 2.7.

June 8, 2025 | Debian