ssl_connect(3) - Linux man page

Name

SSL_connect - initiate the TLS/SSL handshake with an TLS/SSL server

Synopsis

#include <openssl/ssl.h>

int SSL_connect(SSL *ssl);

Description

SSL_connect() initiates the TLS/SSL handshake with a server. The communication channel must already have been set and assigned to the ssl by setting an underlying BIO .

Notes

The behaviour of SSL_connect() depends on the underlying BIO .

If the underlying BIO is blocking, SSL_connect() will only return once the handshake has been finished or an error occurred.

If the underlying BIO is non-blocking, SSL_connect() will also return when the underlying BIO could not satisfy the needs of SSL_connect() to continue the handshake, indicating the problem by the return value -1. In this case a call to SSL_get_error() with the return value of SSL_connect() will yield SSL_ERROR_WANT_READ or SSL_ERROR_WANT_WRITE . The calling process then must repeat the call after taking appropriate action to satisfy the needs of SSL_connect(). The action depends on the underlying BIO . When using a non-blocking socket, nothing is to be done, but select() can be used to check for the required condition. When using a buffering BIO , like a BIO pair, data must be written into or retrieved out of the BIO before being able to continue.

Return Values

The following return values can occur:

1.

The TLS/SSL handshake was successfully completed, a TLS/SSL connection has been established.

2.

The TLS/SSL handshake was not successful but was shut down controlled and by the specifications of the TLS/SSL protocol. Call SSL_get_error() with the return value ret to find out the reason.

3.

<0

The TLS/SSL handshake was not successful, because a fatal error occurred either at the protocol level or a connection failure occurred. The shutdown was not clean. It can also occur of action is need to continue the operation for non-blocking BIOs. Call SSL_get_error() with the return value ret to find out the reason.

See Also

ssl_get_error(3), ssl_accept(3), ssl_shutdown(3), ssl(3), bio(3), ssl_set_connect_state(3), ssl_do_handshake(3), ssl_ctx_new(3)

Pod Errors

Hey! The above document had some coding errors, which are explained below:

Around line 49:
You have '=item 0' instead of the expected '=item 2'
Around line 55:
Expected '=item 3'

Referenced By

ssl_read(3), ssl_set_bio(3), ssl_set_fd(3), ssl_write(3)