xref: /onnv-gate/usr/src/common/openssl/doc/ssl/SSL_accept.pod (revision 2175:b0b2f052a486)
1*2175Sjp161948=pod
2*2175Sjp161948
3*2175Sjp161948=head1 NAME
4*2175Sjp161948
5*2175Sjp161948SSL_accept - wait for a TLS/SSL client to initiate a TLS/SSL handshake
6*2175Sjp161948
7*2175Sjp161948=head1 SYNOPSIS
8*2175Sjp161948
9*2175Sjp161948 #include <openssl/ssl.h>
10*2175Sjp161948
11*2175Sjp161948 int SSL_accept(SSL *ssl);
12*2175Sjp161948
13*2175Sjp161948=head1 DESCRIPTION
14*2175Sjp161948
15*2175Sjp161948SSL_accept() waits for a TLS/SSL client to initiate the TLS/SSL handshake.
16*2175Sjp161948The communication channel must already have been set and assigned to the
17*2175Sjp161948B<ssl> by setting an underlying B<BIO>.
18*2175Sjp161948
19*2175Sjp161948=head1 NOTES
20*2175Sjp161948
21*2175Sjp161948The behaviour of SSL_accept() depends on the underlying BIO.
22*2175Sjp161948
23*2175Sjp161948If the underlying BIO is B<blocking>, SSL_accept() will only return once the
24*2175Sjp161948handshake has been finished or an error occurred, except for SGC (Server
25*2175Sjp161948Gated Cryptography). For SGC, SSL_accept() may return with -1, but
26*2175Sjp161948SSL_get_error() will yield B<SSL_ERROR_WANT_READ/WRITE> and SSL_accept()
27*2175Sjp161948should be called again.
28*2175Sjp161948
29*2175Sjp161948If the underlying BIO is B<non-blocking>, SSL_accept() will also return
30*2175Sjp161948when the underlying BIO could not satisfy the needs of SSL_accept()
31*2175Sjp161948to continue the handshake, indicating the problem by the return value -1.
32*2175Sjp161948In this case a call to SSL_get_error() with the
33*2175Sjp161948return value of SSL_accept() will yield B<SSL_ERROR_WANT_READ> or
34*2175Sjp161948B<SSL_ERROR_WANT_WRITE>. The calling process then must repeat the call after
35*2175Sjp161948taking appropriate action to satisfy the needs of SSL_accept().
36*2175Sjp161948The action depends on the underlying BIO. When using a non-blocking socket,
37*2175Sjp161948nothing is to be done, but select() can be used to check for the required
38*2175Sjp161948condition. When using a buffering BIO, like a BIO pair, data must be written
39*2175Sjp161948into or retrieved out of the BIO before being able to continue.
40*2175Sjp161948
41*2175Sjp161948=head1 RETURN VALUES
42*2175Sjp161948
43*2175Sjp161948The following return values can occur:
44*2175Sjp161948
45*2175Sjp161948=over 4
46*2175Sjp161948
47*2175Sjp161948=item 1
48*2175Sjp161948
49*2175Sjp161948The TLS/SSL handshake was successfully completed, a TLS/SSL connection has been
50*2175Sjp161948established.
51*2175Sjp161948
52*2175Sjp161948=item 0
53*2175Sjp161948
54*2175Sjp161948The TLS/SSL handshake was not successful but was shut down controlled and
55*2175Sjp161948by the specifications of the TLS/SSL protocol. Call SSL_get_error() with the
56*2175Sjp161948return value B<ret> to find out the reason.
57*2175Sjp161948
58*2175Sjp161948=item E<lt>0
59*2175Sjp161948
60*2175Sjp161948The TLS/SSL handshake was not successful because a fatal error occurred either
61*2175Sjp161948at the protocol level or a connection failure occurred. The shutdown was
62*2175Sjp161948not clean. It can also occur of action is need to continue the operation
63*2175Sjp161948for non-blocking BIOs. Call SSL_get_error() with the return value B<ret>
64*2175Sjp161948to find out the reason.
65*2175Sjp161948
66*2175Sjp161948=back
67*2175Sjp161948
68*2175Sjp161948=head1 SEE ALSO
69*2175Sjp161948
70*2175Sjp161948L<SSL_get_error(3)|SSL_get_error(3)>, L<SSL_connect(3)|SSL_connect(3)>,
71*2175Sjp161948L<SSL_shutdown(3)|SSL_shutdown(3)>, L<ssl(3)|ssl(3)>, L<bio(3)|bio(3)>,
72*2175Sjp161948L<SSL_set_connect_state(3)|SSL_set_connect_state(3)>,
73*2175Sjp161948L<SSL_do_handshake(3)|SSL_do_handshake(3)>,
74*2175Sjp161948L<SSL_CTX_new(3)|SSL_CTX_new(3)>
75*2175Sjp161948
76*2175Sjp161948=cut
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