SSL_connect - initiate the TLS/SSL handshake with an TLS/SSL server
#include <openssl/ssl.h> int SSL_connect(SSL *ssl);
SSL_connect(3openssl) OpenSSL SSL_connect(3openssl) 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. ATTRIBUTES See attributes(7) for descriptions of the following attributes: +---------------+--------------------------+ |ATTRIBUTE TYPE | ATTRIBUTE VALUE | +---------------+--------------------------+ |Availability | library/security/openssl | +---------------+--------------------------+ |Stability | Pass-through uncommitted | +---------------+--------------------------+ 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. Source code for open source software components in Oracle Solaris can be found at https://www.oracle.com/downloads/opensource/solaris-source- code-downloads.html. This software was built from source available at https://github.com/oracle/solaris-userland. The original community source was downloaded from https://www.openssl.org/source/openssl-1.0.2ze.tar.gz. Further information about this software can be found on the open source community website at https://www.openssl.org/. RETURN VALUES The following return values can occur: 0 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. 1 The TLS/SSL handshake was successfully completed, a TLS/SSL connection has been established. <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) 1.0.2ze 2022-05-03 SSL_connect(3openssl)