SSL_accept.pod revision 264331 
1=pod
2
3=head1 NAME
4
5SSL_accept - wait for a TLS/SSL client to initiate a TLS/SSL handshake
6
7=head1 SYNOPSIS
8
9 #include <openssl/ssl.h>
10
11 int SSL_accept(SSL *ssl);
12
13=head1 DESCRIPTION
14
15SSL_accept() waits for a TLS/SSL client to initiate the TLS/SSL handshake.
16The communication channel must already have been set and assigned to the
17B<ssl> by setting an underlying B<BIO>.
18
19=head1 NOTES
20
21The behaviour of SSL_accept() depends on the underlying BIO. 
22
23If the underlying BIO is B<blocking>, SSL_accept() will only return once the
24handshake has been finished or an error occurred, except for SGC (Server
25Gated Cryptography). For SGC, SSL_accept() may return with -1, but
26SSL_get_error() will yield B<SSL_ERROR_WANT_READ/WRITE> and SSL_accept()
27should be called again.
28
29If the underlying BIO is B<non-blocking>, SSL_accept() will also return
30when the underlying BIO could not satisfy the needs of SSL_accept()
31to continue the handshake, indicating the problem by the return value -1.
32In this case a call to SSL_get_error() with the
33return value of SSL_accept() will yield B<SSL_ERROR_WANT_READ> or
34B<SSL_ERROR_WANT_WRITE>. The calling process then must repeat the call after
35taking appropriate action to satisfy the needs of SSL_accept().
36The action depends on the underlying BIO. When using a non-blocking socket,
37nothing is to be done, but select() can be used to check for the required
38condition. When using a buffering BIO, like a BIO pair, data must be written
39into or retrieved out of the BIO before being able to continue.
40
41=head1 RETURN VALUES
42
43The following return values can occur:
44
45=over 4
46
47=item Z<>0
48
49The TLS/SSL handshake was not successful but was shut down controlled and
50by the specifications of the TLS/SSL protocol. Call SSL_get_error() with the
51return value B<ret> to find out the reason.
52
53=item Z<>1
54
55The TLS/SSL handshake was successfully completed, a TLS/SSL connection has been
56established.
57
58=item E<lt>0
59
60The TLS/SSL handshake was not successful because a fatal error occurred either
61at the protocol level or a connection failure occurred. The shutdown was
62not clean. It can also occur of action is need to continue the operation
63for non-blocking BIOs. Call SSL_get_error() with the return value B<ret>
64to find out the reason.
65
66=back
67
68=head1 SEE ALSO
69
70L<SSL_get_error(3)|SSL_get_error(3)>, L<SSL_connect(3)|SSL_connect(3)>,
71L<SSL_shutdown(3)|SSL_shutdown(3)>, L<ssl(3)|ssl(3)>, L<bio(3)|bio(3)>,
72L<SSL_set_connect_state(3)|SSL_set_connect_state(3)>,
73L<SSL_do_handshake(3)|SSL_do_handshake(3)>,
74L<SSL_CTX_new(3)|SSL_CTX_new(3)>
75
76=cut
77