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SSL_PENDING(3)			    OpenSSL			SSL_PENDING(3)

NAME
       SSL_pending, SSL_has_pending - check for	readable bytes buffered	in an
       SSL object

SYNOPSIS
	#include <openssl/ssl.h>

	int SSL_pending(const SSL *ssl);
	int SSL_has_pending(const SSL *s);

DESCRIPTION
       Data is received	in whole blocks	known as records from the peer.	A
       whole record is processed (e.g. decrypted) in one go and	is buffered by
       OpenSSL until it	is read	by the application via a call to
       SSL_read_ex(3) or SSL_read(3).

       SSL_pending() returns the number	of bytes which have been processed,
       buffered	and are	available inside ssl for immediate read.

       If the SSL object's read_ahead flag is set (see
       SSL_CTX_set_read_ahead(3)), additional protocol bytes (beyond the
       current record) may have	been read containing more TLS/SSL records.
       This also applies to DTLS and pipelining	(see
       SSL_CTX_set_split_send_fragment(3)). These additional bytes will	be
       buffered	by OpenSSL but will remain unprocessed until they are needed.
       As these	bytes are still	in an unprocessed state	SSL_pending() will
       ignore them. Therefore it is possible for no more bytes to be readable
       from the	underlying BIO (because	OpenSSL	has already read them) and for
       SSL_pending() to	return 0, even though readable application data	bytes
       are available (because the data is in unprocessed buffered records).

       SSL_has_pending() returns 1 if s	has buffered data (whether processed
       or unprocessed) and 0 otherwise.	Note that it is	possible for
       SSL_has_pending() to return 1, and then a subsequent call to
       SSL_read_ex() or	SSL_read() to return no	data because the unprocessed
       buffered	data when processed yielded no application data	(for example
       this can	happen during renegotiation). It is also possible in this
       scenario	for SSL_has_pending() to continue to return 1 even after an
       SSL_read_ex() or	SSL_read() call	because	the buffered and unprocessed
       data is not yet processable (e.g. because OpenSSL has only received a
       partial record so far).

RETURN VALUES
       SSL_pending() returns the number	of buffered and	processed application
       data bytes that are pending and are available for immediate read.
       SSL_has_pending() returns 1 if there is buffered	record data in the SSL
       object and 0 otherwise.

SEE ALSO
       SSL_read_ex(3), SSL_read(3), SSL_CTX_set_read_ahead(3),
       SSL_CTX_set_split_send_fragment(3), ssl(7)

HISTORY
       The SSL_has_pending() function was added	in OpenSSL 1.1.0.

COPYRIGHT
       Copyright 2000-2016 The OpenSSL Project Authors.	All Rights Reserved.

       Licensed	under the OpenSSL license (the "License").  You	may not	use
       this file except	in compliance with the License.	 You can obtain	a copy
       in the file LICENSE in the source distribution or at
       <https://www.openssl.org/source/license.html>.

1.1.1d				  2019-09-10			SSL_PENDING(3)

NAME | SYNOPSIS | DESCRIPTION | RETURN VALUES | SEE ALSO | HISTORY | COPYRIGHT

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