=head1 NAME
-SSL_accept - Wait for a TLS client to initiate a TLS handshake
+SSL_accept - wait for a TLS/SSL client to initiate a TLS/SSL handshake
=head1 SYNOPSIS
=head1 DESCRIPTION
-SSL_accept() waits for a TLS client to initiate the TLS handshake.
+SSL_accept() waits for a TLS/SSL client to initiate the TLS/SSL handshake.
The communication channel must already have been set and assigned to the
-B<ssl> by setting an underlying B<BIO>. The behaviour of SSL_accept() depends
-on the underlying BIO.
+B<ssl> by setting an underlying B<BIO>.
-If the underlying BIO is B<blocking>, SSL_accept() will only return, once the
-handshake has been finished or an error occured, except for SGC (Server
-Gated Cryptography). For SGC SSL_accept() may return with -1 but
-SSL_get_error() will yield SSL_ERROR_WANT_READ/WRITE and SSL_accept()
+=head1 NOTES
+
+The behaviour of SSL_accept() depends on the underlying BIO.
+
+If the underlying BIO is B<blocking>, SSL_accept() will only return once the
+handshake has been finished or an error occurred, except for SGC (Server
+Gated Cryptography). For SGC, SSL_accept() may return with -1, but
+SSL_get_error() will yield B<SSL_ERROR_WANT_READ/WRITE> and SSL_accept()
should be called again.
-If the underlying BIO is B<non-blocking>, SSL_accept() will also return,
+If the underlying BIO is B<non-blocking>, SSL_accept() will also return
when the underlying BIO could not satisfy the needs of SSL_accept()
to continue the handshake. In this case a call to SSL_get_error() with the
-return value of SSL_accept() will yield SSL_ERROR_WANT_READ or
-SSL_ERROR_WANT_WRITE. The calling process then must repeat the call after
+return value of SSL_accept() will yield B<SSL_ERROR_WANT_READ> or
+B<SSL_ERROR_WANT_WRITE>. The calling process then must repeat the call after
taking appropriate action to satisfy the needs of SSL_accept().
The action depends on the underlying BIO. When using a non-blocking socket,
nothing is to be done, but select() can be used to check for the required
condition. When using a buffering BIO, like a BIO pair, data must be written
into or retrieved out of the BIO before being able to continue.
+When using a generic method (see L<SSL_CTX_new(3)|SSL_CTX_new(3)>), it
+is necessary to call SSL_set_accept_state()
+before calling SSL_accept() to explicitly switch the B<ssl> to server
+mode.
+
=head1 RETURN VALUES
The following return values can occur:
=item 1
-The TLS handshake was successfully completed, a TLS connection has been
+The TLS/SSL handshake was successfully completed, a TLS/SSL connection has been
established.
=item 0
-The TLS handshake was not successfull but was shut down controlled and
-by the specifications of the TLS protocol. Call SSL_get_error() with the
+The TLS/SSL handshake was not successful but was shut down controlled and
+by the specifications of the TLS/SSL protocol. Call SSL_get_error() with the
return value B<ret> to find out the reason.
-=item -1
+=item E<lt>0
-The TLS handshake was not successfull, because a fatal error occured either
-at the protocol level or a connection failure occured. The shutdown was
-not clean. It can also occure of action is need to continue the operation
+The TLS/SSL handshake was not successful because a fatal error occurred either
+at the protocol level or a connection failure occurred. The shutdown was
+not clean. It can also occur of action is need to continue the operation
for non-blocking BIOs. Call SSL_get_error() with the return value B<ret>
to find out the reason.
=head1 SEE ALSO
L<SSL_get_error(3)|SSL_get_error(3)>, L<SSL_connect(3)|SSL_connect(3)>,
-L<SSL_shutdown(3)|SSL_shutdown(3)>, L<ssl(3)|ssl(3)>, L<bio(3)|bio(3)>
+L<SSL_shutdown(3)|SSL_shutdown(3)>, L<ssl(3)|ssl(3)>, L<bio(3)|bio(3)>,
+L<SSL_set_connect_state(3)|SSL_set_connect_state(3)>,
+L<SSL_CTX_new(3)|SSL_CTX_new(3)>
=cut
projects / openssl.git / blobdiff