diff options
Diffstat (limited to 'crypto/openssl/doc/ssl/SSL_read.pod')
| -rw-r--r-- | crypto/openssl/doc/ssl/SSL_read.pod | 25 |
1 files changed, 18 insertions, 7 deletions
diff --git a/crypto/openssl/doc/ssl/SSL_read.pod b/crypto/openssl/doc/ssl/SSL_read.pod index cc7aa1a..f6c37f7 100644 --- a/crypto/openssl/doc/ssl/SSL_read.pod +++ b/crypto/openssl/doc/ssl/SSL_read.pod @@ -25,11 +25,10 @@ the SSL_read() operation. The behaviour of SSL_read() depends on the underlying BIO. For the transparent negotiation to succeed, the B<ssl> must have been -initialized to client or server mode. This is not the case if a generic -method is being used (see L<SSL_CTX_new(3)|SSL_CTX_new(3)>, so that +initialized to client or server mode. This is being done by calling L<SSL_set_connect_state(3)|SSL_set_connect_state(3)> or SSL_set_accept_state() -must be used before the first call to an SSL_read() or -L<SSL_write(3)|SSL_write(3)> function). +before the first call to an SSL_read() or L<SSL_write(3)|SSL_write(3)> +function. SSL_read() works based on the SSL/TLS records. The data are received in records (with a maximum record size of 16kB for SSLv3/TLSv1). Only when a @@ -84,9 +83,20 @@ bytes actually read from the TLS/SSL connection. =item 0 -The read operation was not successful, probably because no data was -available. Call SSL_get_error() with the return value B<ret> to find out, -whether an error occurred. +The read operation was not successful. The reason may either be a clean +shutdown due to a "close notify" alert sent by the peer (in which case +the SSL_RECEIVED_SHUTDOWN flag in the ssl shutdown state is set +(see L<SSL_shutdown(3)|SSL_shutdown(3)>, +L<SSL_set_shutdown(3)|SSL_set_shutdown(3)>). It is also possible, that +the peer simply shut down the underlying transport and the shutdown is +incomplete. Call SSL_get_error() with the return value B<ret> to find out, +whether an error occurred or the connection was shut down cleanly +(SSL_ERROR_ZERO_RETURN). + +SSLv2 (deprecated) does not support a shutdown alert protocol, so it can +only be detected, whether the underlying connection was closed. It cannot +be checked, whether the closure was initiated by the peer or by something +else. =item E<lt>0 @@ -102,6 +112,7 @@ L<SSL_get_error(3)|SSL_get_error(3)>, L<SSL_write(3)|SSL_write(3)>, L<SSL_CTX_set_mode(3)|SSL_CTX_set_mode(3)>, L<SSL_CTX_new(3)|SSL_CTX_new(3)>, L<SSL_connect(3)|SSL_connect(3)>, L<SSL_accept(3)|SSL_accept(3)> L<SSL_set_connect_state(3)|SSL_set_connect_state(3)>, +L<SSL_shutdown(3)|SSL_shutdown(3)>, L<SSL_set_shutdown(3)|SSL_set_shutdown(3)>, L<ssl(3)|ssl(3)>, L<bio(3)|bio(3)> =cut |
