168651Skris=pod
268651Skris
368651Skris=head1 NAME
468651Skris
568651SkrisSSL_accept - wait for a TLS/SSL client to initiate a TLS/SSL handshake
668651Skris
768651Skris=head1 SYNOPSIS
868651Skris
968651Skris #include <openssl/ssl.h>
1068651Skris
1168651Skris int SSL_accept(SSL *ssl);
1268651Skris
1368651Skris=head1 DESCRIPTION
1468651Skris
1568651SkrisSSL_accept() waits for a TLS/SSL client to initiate the TLS/SSL handshake.
1668651SkrisThe communication channel must already have been set and assigned to the
1768651SkrisB<ssl> by setting an underlying B<BIO>.
1868651Skris
1968651Skris=head1 NOTES
2068651Skris
2168651SkrisThe behaviour of SSL_accept() depends on the underlying BIO. 
2268651Skris
2368651SkrisIf the underlying BIO is B<blocking>, SSL_accept() will only return once the
2468651Skrishandshake has been finished or an error occurred, except for SGC (Server
2568651SkrisGated Cryptography). For SGC, SSL_accept() may return with -1, but
2668651SkrisSSL_get_error() will yield B<SSL_ERROR_WANT_READ/WRITE> and SSL_accept()
2768651Skrisshould be called again.
2868651Skris
2968651SkrisIf the underlying BIO is B<non-blocking>, SSL_accept() will also return
3068651Skriswhen the underlying BIO could not satisfy the needs of SSL_accept()
31120631Snectarto continue the handshake, indicating the problem by the return value -1.
32120631SnectarIn this case a call to SSL_get_error() with the
3368651Skrisreturn value of SSL_accept() will yield B<SSL_ERROR_WANT_READ> or
3468651SkrisB<SSL_ERROR_WANT_WRITE>. The calling process then must repeat the call after
3568651Skristaking appropriate action to satisfy the needs of SSL_accept().
3668651SkrisThe action depends on the underlying BIO. When using a non-blocking socket,
3768651Skrisnothing is to be done, but select() can be used to check for the required
3868651Skriscondition. When using a buffering BIO, like a BIO pair, data must be written
3968651Skrisinto or retrieved out of the BIO before being able to continue.
4068651Skris
4168651Skris=head1 RETURN VALUES
4268651Skris
4368651SkrisThe following return values can occur:
4468651Skris
4568651Skris=over 4
4668651Skris
47264331Sjkim=item Z<>0
4868651Skris
4968651SkrisThe TLS/SSL handshake was not successful but was shut down controlled and
5068651Skrisby the specifications of the TLS/SSL protocol. Call SSL_get_error() with the
5168651Skrisreturn value B<ret> to find out the reason.
5268651Skris
53264331Sjkim=item Z<>1
54264331Sjkim
55264331SjkimThe TLS/SSL handshake was successfully completed, a TLS/SSL connection has been
56264331Sjkimestablished.
57264331Sjkim
5872613Skris=item E<lt>0
5968651Skris
6068651SkrisThe TLS/SSL handshake was not successful because a fatal error occurred either
6168651Skrisat the protocol level or a connection failure occurred. The shutdown was
6268651Skrisnot clean. It can also occur of action is need to continue the operation
6368651Skrisfor non-blocking BIOs. Call SSL_get_error() with the return value B<ret>
6468651Skristo find out the reason.
6568651Skris
6668651Skris=back
6768651Skris
6868651Skris=head1 SEE ALSO
6968651Skris
7068651SkrisL<SSL_get_error(3)|SSL_get_error(3)>, L<SSL_connect(3)|SSL_connect(3)>,
7176866SkrisL<SSL_shutdown(3)|SSL_shutdown(3)>, L<ssl(3)|ssl(3)>, L<bio(3)|bio(3)>,
7276866SkrisL<SSL_set_connect_state(3)|SSL_set_connect_state(3)>,
73100936SnectarL<SSL_do_handshake(3)|SSL_do_handshake(3)>,
7476866SkrisL<SSL_CTX_new(3)|SSL_CTX_new(3)>
7568651Skris
7668651Skris=cut
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