On Sun, Nov 25, 2018 at 10:42 AM Rainer Jung <rainer.j...@kippdata.de>
wrote:
> In our Java code, what happens is a call to unwrap() in OpenSSLEngine.
> This call writes I think 146 bytes, then checks
> pendingReadableBytesInSSL(). That call in turn calls SSL.readFromSSL()
> and gets back "0" (from SSL_read()). Up in unwrap() we then skip the
> while loop and finally return with BUFFER_UNDERFLOW. Then we hang,
> probably because the data was read by OpenSSL and no more socket event
> happens. If I artificially add another call to
> pendingReadableBytesInSSL() which triggers another SSL_read(), the hang
> does not occur.
>
> IMHO TLS 1.0 is not such a big problem, but we should at least document
> it when we do a new release.
>
> Last time, Mark fixed pendingReadableBytesInSSL (=
SSL.pendingReadableBytesInSSL) not working by using a fake read
(SSL.readFromSSL(ssl, EMPTY_ADDR, 0)) to start a new record. So then we
actually need to make *two* fake reads (if the result of the first is zero)
and we would be fine ? This OpenSSL API sounds ridiculously bad ... (IMO)
So you made it sound like it would work:
Index: java/org/apache/tomcat/util/net/openssl/OpenSSLEngine.java
===================================================================
--- java/org/apache/tomcat/util/net/openssl/OpenSSLEngine.java (revision
1847712)
+++ java/org/apache/tomcat/util/net/openssl/OpenSSLEngine.java (working
copy)
@@ -635,6 +635,9 @@
// See https://www.openssl.org/docs/manmaster/ssl/SSL_pending.html
clearLastError();
int lastPrimingReadResult = SSL.readFromSSL(ssl, EMPTY_ADDR, 0);
// priming read
+ if (lastPrimingReadResult == 0) {
+ lastPrimingReadResult = SSL.readFromSSL(ssl, EMPTY_ADDR, 0);
+ }
// check if SSL_read returned <= 0. In this case we need to check
the error and see if it was something
// fatal.
if (lastPrimingReadResult <= 0) {
Rémy
