Finish first round of session cache documentation.

[openssl.git] / doc / ssl / SSL_write.pod

diff --git a/doc/ssl/SSL_write.pod b/doc/ssl/SSL_write.pod
index b086258e82e4388c5e04c94cf14fa794d97b29cd..f95907981d6fd097e05dc2d0bee34ccdbc5bb45d 100644 (file)
--- a/doc/ssl/SSL_write.pod
+++ b/doc/ssl/SSL_write.pod
@@ -2,7 +2,7 @@
 
 =head1 NAME
 
-SSL_read - write bytes to a TLS/SSL connection.
+SSL_write - write bytes to a TLS/SSL connection.
 
 =head1 SYNOPSIS
 
@@ -13,27 +13,40 @@ SSL_read - write bytes to a TLS/SSL connection.
 =head1 DESCRIPTION
 
 SSL_write() writes B<num> bytes from the buffer B<buf> into the specified
-B<ssl>. If necessary, SSL_write() will negotiate a TLS/SSL session, if
+B<ssl> connection.
+
+=head1 NOTES
+
+If necessary, SSL_write() will negotiate a TLS/SSL session, if
 not already explicitly performed by SSL_connect() or SSL_accept(). If the
 peer requests a re-negotiation, it will be performed transparently during
 the SSL_write() operation. The behaviour of SSL_write() depends on the
 underlying BIO. 
 
 If the underlying BIO is B<blocking>, SSL_write() will only return, once the
-write operation has been finished or an error occurred.
+write 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<SSL_CTX_set_mode(3)|SSL_CTX_set_mode(3)> call.
 
 If the underlying BIO is B<non-blocking>, SSL_write() will also return,
 when the underlying BIO could not satisfy the needs of SSL_write()
 to continue the operation. In this case a call to SSL_get_error() with the
 return value of SSL_write() will yield B<SSL_ERROR_WANT_READ> or
 B<SSL_ERROR_WANT_WRITE>. As at any time a re-negotiation is possible, a
-call to SSL_write() can also cause write operations! The calling process
+call to SSL_write() can also cause read operations! The calling process
 then must repeat the call after taking appropriate action to satisfy the
 needs of SSL_write(). The action depends on the underlying BIO. When using a
 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.
 
+=head1 WARNING
+
+When an SSL_write() operation has to be repeated because of
+B<SSL_ERROR_WANT_READ> or B<SSL_ERROR_WANT_WRITE>, it must be repeated
+with the same arguments.
+
 =head1 RETURN VALUES
 
 The following return values can occur:
@@ -50,9 +63,9 @@ bytes actually written to the TLS/SSL connection.
 The write operation was not successful. Call SSL_get_error() with the return
 value B<ret> to find out, whether an error occurred.
 
-=item -1
+=item E<lt>0
 
-The read operation was not successful, because either an error occurred
+The write operation was not successful, because either an error occurred
 or action must be taken by the calling process. Call SSL_get_error() with the
 return value B<ret> to find out the reason.
 
@@ -61,6 +74,7 @@ return value B<ret> to find out the reason.
 =head1 SEE ALSO
 
 L<SSL_get_error(3)|SSL_get_error(3)>, L<SSL_read(3)|SSL_read(3)>,
+L<SSL_CTX_set_mode(3)|SSL_CTX_set_mode(3)>,
 L<ssl(3)|ssl(3)>, L<bio(3)|bio(3)>
 
 =cut