SSL_connect.pod revision 72613 
1=pod
2
3=head1 NAME
4
5SSL_connect - initiate the TLS/SSL handshake with an TLS/SSL server
6
7=head1 SYNOPSIS
8
9 #include <openssl/ssl.h>
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11 int SSL_connect(SSL *ssl);
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13=head1 DESCRIPTION
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15SSL_connect() initiates the TLS/SSL handshake with a server. The communication
16channel must already have been set and assigned to the B<ssl> by setting an
17underlying B<BIO>.
18
19=head1 NOTES
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21The behaviour of SSL_connect() depends on the underlying BIO. 
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23If the underlying BIO is B<blocking>, SSL_connect() will only return once the
24handshake has been finished or an error occurred.
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26If the underlying BIO is B<non-blocking>, SSL_connect() will also return
27when the underlying BIO could not satisfy the needs of SSL_connect()
28to continue the handshake. In this case a call to SSL_get_error() with the
29return value of SSL_connect() will yield B<SSL_ERROR_WANT_READ> or
30B<SSL_ERROR_WANT_WRITE>. The calling process then must repeat the call after
31taking appropriate action to satisfy the needs of SSL_connect().
32The action depends on the underlying BIO. When using a non-blocking socket,
33nothing is to be done, but select() can be used to check for the required
34condition. When using a buffering BIO, like a BIO pair, data must be written
35into or retrieved out of the BIO before being able to continue.
36
37=head1 RETURN VALUES
38
39The following return values can occur:
40
41=over 4
42
43=item 1
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45The TLS/SSL handshake was successfully completed, a TLS/SSL connection has been
46established.
47
48=item 0
49
50The TLS/SSL handshake was not successful but was shut down controlled and
51by the specifications of the TLS/SSL protocol. Call SSL_get_error() with the
52return value B<ret> to find out the reason.
53
54=item E<lt>0
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56The TLS/SSL handshake was not successful, because a fatal error occurred either
57at the protocol level or a connection failure occurred. The shutdown was
58not clean. It can also occur of action is need to continue the operation
59for non-blocking BIOs. Call SSL_get_error() with the return value B<ret>
60to find out the reason.
61
62=back
63
64=head1 SEE ALSO
65
66L<SSL_get_error(3)|SSL_get_error(3)>, L<SSL_accept(3)|SSL_accept(3)>,
67L<SSL_shutdown(3)|SSL_shutdown(3)>, L<ssl(3)|ssl(3)>, L<bio(3)|bio(3)>
68
69=cut
70