X-Git-Url: https://git.openssl.org/?p=openssl.git;a=blobdiff_plain;f=doc%2Fssl%2FSSL_read.pod;h=e0a9bd47bceeb29bf4aab93d962ac79063024099;hp=8ca0ce5058da0e5f1299e16d559067e5983737d8;hb=87d9cafa332bd006086b56dc645c03fe7cfed654;hpb=c8919dde09d56f03615a52031964bc9a77b26e90 diff --git a/doc/ssl/SSL_read.pod b/doc/ssl/SSL_read.pod index 8ca0ce5058..e0a9bd47bc 100644 --- a/doc/ssl/SSL_read.pod +++ b/doc/ssl/SSL_read.pod @@ -18,16 +18,16 @@ buffer B. =head1 NOTES If necessary, SSL_read() will negotiate a TLS/SSL session, if -not already explicitly performed by L or -L. If the +not already explicitly performed by L or +L. If the peer requests a re-negotiation, it will be performed transparently during the SSL_read() operation. The behaviour of SSL_read() depends on the underlying BIO. For the transparent negotiation to succeed, the B must have been initialized to client or server mode. This is being done by calling -L or SSL_set_accept_state() -before the first call to an SSL_read() or L +L or SSL_set_accept_state() +before the first call to an SSL_read() or L function. SSL_read() works based on the SSL/TLS records. The data are received in @@ -49,12 +49,12 @@ If the underlying BIO is B, SSL_read() will only return, once the read operation has been finished or an error occurred, except when a renegotiation take place, in which case a SSL_ERROR_WANT_READ may occur. This behaviour can be controlled with the SSL_MODE_AUTO_RETRY flag of the -L call. +L call. If the underlying BIO is B, SSL_read() will also return when the underlying BIO could not satisfy the needs of SSL_read() to continue the operation. In this case a call to -L with the +L with the return value of SSL_read() will yield B or B. As at any time a re-negotiation is possible, a call to SSL_read() can also cause write operations! The calling process @@ -64,7 +64,7 @@ non-blocking socket, nothing is to be done, but select() can be used to check for the required condition. When using a buffering BIO, like a BIO pair, data must be written into or retrieved out of the BIO before being able to continue. -L can be used to find out whether there +L can be used to find out whether there are buffered bytes available for immediate retrieval. In this case SSL_read() can be called without blocking or actually receiving new data from the underlying socket. @@ -91,18 +91,13 @@ bytes actually read from the TLS/SSL connection. 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, -L). It is also possible, that +(see L, +L). 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 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 E0 The read operation was not successful, because either an error occurred @@ -113,12 +108,12 @@ return value B to find out the reason. =head1 SEE ALSO -L, L, -L, L, -L, L -L, -L, -L, L, -L, L +L, L, +L, L, +L, L +L, +L, +L, L, +L, L =cut