SSL_SET_CONNECT_STATE(3) | Library Functions Manual | SSL_SET_CONNECT_STATE(3)

# NAME

`SSL_set_connect_state`, `SSL_set_accept_state`, `SSL_is_server` — prepare SSL object to work in client or server mode

# SYNOPSIS

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

void
`SSL_set_connect_state`(SSL *ssl);

void
`SSL_set_accept_state`(SSL *ssl);

int
`SSL_is_server`(const SSL *ssl);

# DESCRIPTION

`SSL_set_connect_state`() sets ssl to work in client mode.

`SSL_set_accept_state`() sets ssl to work in server mode.

`SSL_is_server`() checks whether ssl is set to server mode.

When the SSL_CTX object was created with SSL_CTX_new(3), it was either assigned a dedicated client method, a dedicated server method, or a generic method, that can be used for both client and server connections. (The method might have been changed with SSL_CTX_set_ssl_version(3) or SSL_set_ssl_method(3).)

When beginning a new handshake, the SSL engine must know whether it must call the connect (client) or accept (server) routines. Even though it may be clear from the method chosen whether client or server mode was requested, the handshake routines must be explicitly set.

When using the SSL_connect(3) or SSL_accept(3) routines, the correct handshake routines are automatically set. When performing a transparent negotiation using SSL_write(3) or SSL_read(3), the handshake routines must be explicitly set in advance using either `SSL_set_connect_state`() or `SSL_set_accept_state`().

If `SSL_is_server`() is called before `SSL_set_connect_state`() or `SSL_set_accept_state`() was called either automatically or explicitly, the result depends on what method was used when the SSL_CTX was created. If a generic method or a dedicated server method was passed to SSL_CTX_new(3), `SSL_is_server`() returns 1; otherwise, it returns 0.

# RETURN VALUES

`SSL_is_server`() returns 1 if ssl is set to server mode or 0 if it is set to client mode.

# SEE ALSO

ssl(3), SSL_accept(3), SSL_connect(3), SSL_CTX_new(3), SSL_CTX_set_ssl_version(3), SSL_do_handshake(3), SSL_new(3), SSL_read(3), SSL_write(3)

# HISTORY

`SSL_set_connect_state`() and `SSL_set_accept_state`() first appeared in SSLeay 0.6.0 and have been available since OpenBSD 2.4.

`SSL_is_server`() first appeared in OpenSSL 1.0.2 and has been available since OpenBSD 6.3.

June 8, 2025 | Debian