70 lines
2.3 KiB
Text
70 lines
2.3 KiB
Text
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=pod
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=head1 NAME
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SSL_accept - Wait for a TLS client to initiate a TLS handshake
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=head1 SYNOPSIS
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#include <openssl/ssl.h>
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int SSL_accept(SSL *ssl);
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=head1 DESCRIPTION
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SSL_accept() waits for a TLS client to initiate the TLS handshake.
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The communication channel must already have been set and assigned to the
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B<ssl> by setting an underlying B<BIO>. The behaviour of SSL_accept() depends
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on the underlying BIO.
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If the underlying BIO is B<blocking>, SSL_accept() will only return, once the
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handshake has been finished or an error occured, except for SGC (Server
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Gated Cryptography). For SGC SSL_accept() may return with -1 but
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SSL_get_error() will yield SSL_ERROR_WANT_READ/WRITE and SSL_accept()
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should be called again.
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If the underlying BIO is B<non-blocking>, SSL_accept() will also return,
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when the underlying BIO could not satisfy the needs of SSL_accept()
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to continue the handshake. In this case a call to SSL_get_error() with the
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return value of SSL_accept() will yield SSL_ERROR_WANT_READ or
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SSL_ERROR_WANT_WRITE. The calling process then must repeat the call after
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taking appropriate action to satisfy the needs of SSL_accept().
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The action depends on the underlying BIO. When using a non-blocking socket,
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nothing is to be done, but select() can be used to check for the required
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condition. When using a buffering BIO, like a BIO pair, data must be written
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into or retrieved out of the BIO before being able to continue.
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=head1 RETURN VALUES
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The following return values can occur:
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=over 4
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=item 1
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The TLS handshake was successfully completed, a TLS connection has been
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established.
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=item 0
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The TLS handshake was not successfull but was shut down controlled and
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by the specifications of the TLS protocol. Call SSL_get_error() with the
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return value B<ret> to find out the reason.
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=item -1
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The TLS handshake was not successfull, because a fatal error occured either
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at the protocol level or a connection failure occured. The shutdown was
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not clean. It can also occure of action is need to continue the operation
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for non-blocking BIOs. Call SSL_get_error() with the return value B<ret>
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to find out the reason.
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=back
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=head1 SEE ALSO
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L<SSL_get_error(3)|SSL_get_error(3)>, L<SSL_connect(3)|SSL_connect(3)>,
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L<SSL_shutdown(3)|SSL_shutdown(3)>, L<ssl(3)|ssl(3)>, L<bio(3)|bio(3)>
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=cut
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