trace: add PROVIDER_CONF trace category

[openssl.git] / doc / man3 / SSL_get_error.pod

diff --git a/doc/man3/SSL_get_error.pod b/doc/man3/SSL_get_error.pod
index 688f772afac672e54c1b3b808397963eb2bc7551..150dd50f702a5c6617110ba534310a50e0dd9730 100644 (file)
--- a/doc/man3/SSL_get_error.pod
+++ b/doc/man3/SSL_get_error.pod
@@ -39,32 +39,52 @@ if and only if B<ret E<gt> 0>.
 =item SSL_ERROR_ZERO_RETURN
 
 The TLS/SSL peer has closed the connection for writing by sending the
 =item SSL_ERROR_ZERO_RETURN
 
 The TLS/SSL peer has closed the connection for writing by sending the

-"close notify" alert.
+close_notify alert.

 No more data can be read.
 Note that B<SSL_ERROR_ZERO_RETURN> does not necessarily
 indicate that the underlying transport has been closed.
 
 =item SSL_ERROR_WANT_READ, SSL_ERROR_WANT_WRITE
 
 No more data can be read.
 Note that B<SSL_ERROR_ZERO_RETURN> does not necessarily
 indicate that the underlying transport has been closed.
 
 =item SSL_ERROR_WANT_READ, SSL_ERROR_WANT_WRITE
 

-The operation did not complete; the same TLS/SSL I/O function should be
-called again later.  If, by then, the underlying B<BIO> has data
-available for reading (if the result code is B<SSL_ERROR_WANT_READ>)
-or allows writing data (B<SSL_ERROR_WANT_WRITE>), then some TLS/SSL
-protocol progress will take place, i.e. at least part of an TLS/SSL
-record will be read or written.  Note that the retry may again lead to
-a B<SSL_ERROR_WANT_READ> or B<SSL_ERROR_WANT_WRITE> condition.
+The operation did not complete and can be retried later.
+
+B<SSL_ERROR_WANT_READ> is returned when the last operation was a read
+operation from a non-blocking B<BIO>.
+It means that not enough data was available at this time to complete the
+operation.
+If at a later time the underlying B<BIO> has data available for reading the same
+function can be called again.
+
+SSL_read() and SSL_read_ex() can also set B<SSL_ERROR_WANT_READ> when there is
+still unprocessed data available at either the B<SSL> or the B<BIO> layer, even
+for a blocking B<BIO>.
+See L<SSL_read(3)> for more information.
+
+B<SSL_ERROR_WANT_WRITE> is returned when the last operation was a write
+to a non-blocking B<BIO> and it was unable to sent all data to the B<BIO>.
+When the B<BIO> is writeable again, the same function can be called again.
+
+Note that the retry may again lead to an B<SSL_ERROR_WANT_READ> or
+B<SSL_ERROR_WANT_WRITE> condition.

 There is no fixed upper limit for the number of iterations that
 may be necessary until progress becomes visible at application
 protocol level.
 
 There is no fixed upper limit for the number of iterations that
 may be necessary until progress becomes visible at application
 protocol level.
 

+It is safe to call SSL_read() or SSL_read_ex() when more data is available
+even when the call that set this error was an SSL_write() or SSL_write_ex().
+However if the call was an SSL_write() or SSL_write_ex(), it should be called
+again to continue sending the application data.
+

 For socket B<BIO>s (e.g. when SSL_set_fd() was used), select() or
 poll() on the underlying socket can be used to find out when the
 TLS/SSL I/O function should be retried.
 
 Caveat: Any TLS/SSL I/O function can lead to either of
 For socket B<BIO>s (e.g. when SSL_set_fd() was used), select() or
 poll() on the underlying socket can be used to find out when the
 TLS/SSL I/O function should be retried.
 
 Caveat: Any TLS/SSL I/O function can lead to either of

-B<SSL_ERROR_WANT_READ> and B<SSL_ERROR_WANT_WRITE>.  In particular,
+B<SSL_ERROR_WANT_READ> and B<SSL_ERROR_WANT_WRITE>.
+In particular,

 SSL_read_ex(), SSL_read(), SSL_peek_ex(), or SSL_peek() may want to write data
 SSL_read_ex(), SSL_read(), SSL_peek_ex(), or SSL_peek() may want to write data

-and SSL_write() or SSL_write_ex() may want to read data.  This is mainly because
+and SSL_write() or SSL_write_ex() may want to read data.
+This is mainly because

 TLS/SSL handshakes may occur at any time during the protocol (initiated by
 either the client or the server); SSL_read_ex(), SSL_read(), SSL_peek_ex(),
 SSL_peek(), SSL_write_ex(), and SSL_write() will handle any pending handshakes.
 TLS/SSL handshakes may occur at any time during the protocol (initiated by
 either the client or the server); SSL_read_ex(), SSL_read(), SSL_peek_ex(),
 SSL_peek(), SSL_write_ex(), and SSL_write() will handle any pending handshakes.


@@ -118,14 +138,20 @@ Details depend on the application.
 
 =item SSL_ERROR_SYSCALL
 
 
 =item SSL_ERROR_SYSCALL
 

-Some non-recoverable I/O error occurred.
-The OpenSSL error queue may contain more information on the error.
-For socket I/O on Unix systems, consult B<errno> for details.
+Some non-recoverable, fatal I/O error occurred. The OpenSSL error queue may
+contain more information on the error. For socket I/O on Unix systems, consult
+B<errno> for details. If this error occurs then no further I/O operations should
+be performed on the connection and SSL_shutdown() must not be called.
+
+This value can also be returned for other errors, check the error queue for
+details.

 
 =item SSL_ERROR_SSL
 
 
 =item SSL_ERROR_SSL
 

-A failure in the SSL library occurred, usually a protocol error.  The
-OpenSSL error queue contains more information on the error.
+A non-recoverable, fatal error in the SSL library occurred, usually a protocol
+error.  The OpenSSL error queue contains more information on the error. If this
+error occurs then no further I/O operations should be performed on the
+connection and SSL_shutdown() must not be called.

 
 =back
 
 
 =back
 


@@ -135,14 +161,14 @@ L<ssl(7)>
 
 =head1 HISTORY
 
 
 =head1 HISTORY
 

-SSL_ERROR_WANT_ASYNC was added in OpenSSL 1.1.0.
-SSL_ERROR_WANT_CLIENT_HELLO_CB was added in OpenSSL 1.1.1.
+The SSL_ERROR_WANT_ASYNC error code was added in OpenSSL 1.1.0.
+The SSL_ERROR_WANT_CLIENT_HELLO_CB error code was added in OpenSSL 1.1.1.

 
 =head1 COPYRIGHT
 
 
 =head1 COPYRIGHT
 

-Copyright 2000-2017 The OpenSSL Project Authors. All Rights Reserved.
+Copyright 2000-2018 The OpenSSL Project Authors. All Rights Reserved.

 
 

-Licensed under the OpenSSL license (the "License").  You may not use
+Licensed under the Apache License 2.0 (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>.
 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>.