1*2175Sjp161948=pod 2*2175Sjp161948 3*2175Sjp161948=head1 NAME 4*2175Sjp161948 5*2175Sjp161948SSL_connect - initiate the TLS/SSL handshake with an TLS/SSL server 6*2175Sjp161948 7*2175Sjp161948=head1 SYNOPSIS 8*2175Sjp161948 9*2175Sjp161948 #include <openssl/ssl.h> 10*2175Sjp161948 11*2175Sjp161948 int SSL_connect(SSL *ssl); 12*2175Sjp161948 13*2175Sjp161948=head1 DESCRIPTION 14*2175Sjp161948 15*2175Sjp161948SSL_connect() initiates the TLS/SSL handshake with a server. The communication 16*2175Sjp161948channel must already have been set and assigned to the B<ssl> by setting an 17*2175Sjp161948underlying B<BIO>. 18*2175Sjp161948 19*2175Sjp161948=head1 NOTES 20*2175Sjp161948 21*2175Sjp161948The behaviour of SSL_connect() depends on the underlying BIO. 22*2175Sjp161948 23*2175Sjp161948If the underlying BIO is B<blocking>, SSL_connect() will only return once the 24*2175Sjp161948handshake has been finished or an error occurred. 25*2175Sjp161948 26*2175Sjp161948If the underlying BIO is B<non-blocking>, SSL_connect() will also return 27*2175Sjp161948when the underlying BIO could not satisfy the needs of SSL_connect() 28*2175Sjp161948to continue the handshake, indicating the problem by the return value -1. 29*2175Sjp161948In this case a call to SSL_get_error() with the 30*2175Sjp161948return value of SSL_connect() will yield B<SSL_ERROR_WANT_READ> or 31*2175Sjp161948B<SSL_ERROR_WANT_WRITE>. The calling process then must repeat the call after 32*2175Sjp161948taking appropriate action to satisfy the needs of SSL_connect(). 33*2175Sjp161948The action depends on the underlying BIO. When using a non-blocking socket, 34*2175Sjp161948nothing is to be done, but select() can be used to check for the required 35*2175Sjp161948condition. When using a buffering BIO, like a BIO pair, data must be written 36*2175Sjp161948into or retrieved out of the BIO before being able to continue. 37*2175Sjp161948 38*2175Sjp161948=head1 RETURN VALUES 39*2175Sjp161948 40*2175Sjp161948The following return values can occur: 41*2175Sjp161948 42*2175Sjp161948=over 4 43*2175Sjp161948 44*2175Sjp161948=item 1 45*2175Sjp161948 46*2175Sjp161948The TLS/SSL handshake was successfully completed, a TLS/SSL connection has been 47*2175Sjp161948established. 48*2175Sjp161948 49*2175Sjp161948=item 0 50*2175Sjp161948 51*2175Sjp161948The TLS/SSL handshake was not successful but was shut down controlled and 52*2175Sjp161948by the specifications of the TLS/SSL protocol. Call SSL_get_error() with the 53*2175Sjp161948return value B<ret> to find out the reason. 54*2175Sjp161948 55*2175Sjp161948=item E<lt>0 56*2175Sjp161948 57*2175Sjp161948The TLS/SSL handshake was not successful, because a fatal error occurred either 58*2175Sjp161948at the protocol level or a connection failure occurred. The shutdown was 59*2175Sjp161948not clean. It can also occur of action is need to continue the operation 60*2175Sjp161948for non-blocking BIOs. Call SSL_get_error() with the return value B<ret> 61*2175Sjp161948to find out the reason. 62*2175Sjp161948 63*2175Sjp161948=back 64*2175Sjp161948 65*2175Sjp161948=head1 SEE ALSO 66*2175Sjp161948 67*2175Sjp161948L<SSL_get_error(3)|SSL_get_error(3)>, L<SSL_accept(3)|SSL_accept(3)>, 68*2175Sjp161948L<SSL_shutdown(3)|SSL_shutdown(3)>, L<ssl(3)|ssl(3)>, L<bio(3)|bio(3)>, 69*2175Sjp161948L<SSL_set_connect_state(3)|SSL_set_connect_state(3)>, 70*2175Sjp161948L<SSL_do_handshake(3)|SSL_do_handshake(3)>, 71*2175Sjp161948L<SSL_CTX_new(3)|SSL_CTX_new(3)> 72*2175Sjp161948 73*2175Sjp161948=cut 74