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author | Wojtek Kosior <wk@koszkonutek-tmp.pl.eu.org> | 2021-04-30 00:33:56 +0200 |
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committer | Wojtek Kosior <wk@koszkonutek-tmp.pl.eu.org> | 2021-04-30 00:33:56 +0200 |
commit | aa4d426b4d3527d7e166df1a05058c9a4a0f6683 (patch) | |
tree | 4ff17ce8b89a2321b9d0ed4bcfc37c447bcb6820 /openssl-1.1.0h/doc/ssl/SSL_pending.pod | |
download | smtps-and-pop3s-console-program-master.tar.gz smtps-and-pop3s-console-program-master.zip |
Diffstat (limited to 'openssl-1.1.0h/doc/ssl/SSL_pending.pod')
-rw-r--r-- | openssl-1.1.0h/doc/ssl/SSL_pending.pod | 68 |
1 files changed, 68 insertions, 0 deletions
diff --git a/openssl-1.1.0h/doc/ssl/SSL_pending.pod b/openssl-1.1.0h/doc/ssl/SSL_pending.pod new file mode 100644 index 0000000..f6ed565 --- /dev/null +++ b/openssl-1.1.0h/doc/ssl/SSL_pending.pod @@ -0,0 +1,68 @@ +=pod + +=head1 NAME + +SSL_pending, SSL_has_pending - check for readable bytes buffered in an +SSL object + +=head1 SYNOPSIS + + #include <openssl/ssl.h> + + int SSL_pending(const SSL *ssl); + int SSL_has_pending(const SSL *s); + +=head1 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 L<SSL_read(3)>. + +SSL_pending() returns the number of bytes which have been processed, buffered +and are available inside B<ssl> for immediate read. + +If the B<SSL> object's I<read_ahead> flag is set (see +L<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 L<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 B<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() 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() +call because the buffered and unprocessed data is not yet processable (e.g. +because OpenSSL has only received a partial record so far). + +=head1 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. + +=head1 SEE ALSO + +L<SSL_read(3)>, L<SSL_CTX_set_read_ahead(3)>, +L<SSL_CTX_set_split_send_fragment(3)>, L<ssl(3)> + +=head1 HISTORY + +The SSL_has_pending() function was added in OpenSSL 1.1.0. + +=head1 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 +L<https://www.openssl.org/source/license.html>. + +=cut |