Added DRBG_HMAC & DRBG_HASH + Added defaults for setting DRBG for master/public/priva...

[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 f1050b0c5a005e46a3c9e89a4884f137538c8e49..b3ab50568731593058ba39a81168d5da09240a1f 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.


@@ -122,6 +142,9 @@ 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.
 
 The OpenSSL error queue may contain more information on the error.
 For socket I/O on Unix systems, consult B<errno> for details.
 

+This value can also be returned for other errors, check the error queue for
+details.
+

 =item SSL_ERROR_SSL
 
 A failure in the SSL library occurred, usually a protocol error.  The
 =item SSL_ERROR_SSL
 
 A failure in the SSL library occurred, usually a protocol error.  The