Java http clients and POODLE

Question

Regarding the POODLE vulnerability, if I understand it correctly, it requires a client that automatically downgrades TLS protocol to SSLv3 when failing to establish a secure channel with a server using higher version protocol advertised by the server.

Do the common java HTTP client libraries, specifically javax.net.ssl.HttpsURLConnection and Apache HttpClient, automatically downgrade the TLS protocol when failing to establish TLS session with a server? If not, am I correct that they are immune from he POODLE attack unless either (a) the server only supports SSLv3, or (b) a logic at a higher level performs the downgrade?

I'm looking for something like http://blog.hagander.net/archives/222-A-few-short-notes-about-PostgreSQL-and-POODLE.html but for Java clients.

Answer 1

Apache HttpClient does not implement any of the TLS protocol aspects. It relies on JSSE APIs to do TLS/SSL handshaking and to establish secure SSL sessions. With the exception of SSL hostname verification logic, as far as TLS/SSL is concerned Apache HttpClient is as secure (or as vulnerable) as the JRE it is running in.

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Update: HttpClient 4.3 by default always uses TLS, so, unless one explicitly configures it to use SSLv3 HttpClient should not be vulnerable to exploits based on POODLE.

This turned out to be wrong. One MUST explicitly remove SSLv3 from the list of supported protocols!

SSLContext sslContext = SSLContexts.custom()
        .useTLS() // Only this turned out to be not enough
        .build();
SSLConnectionSocketFactory sf = new SSLConnectionSocketFactory(
        sslContext,
        new String[] {"TLSv1", "TLSv1.1", "TLSv1.2"},
        null,
        SSLConnectionSocketFactory.BROWSER_COMPATIBLE_HOSTNAME_VERIFIER);
CloseableHttpClient client = HttpClients.custom()
        .setSSLSocketFactory(sf)
        .build();

Update 2: As of version 4.3.6 HttpClient disables all versions of SSL (including SSLv3) by default.

Answer 2

You MUST disable SSL v3.0 on java clients if you use https.

This can be done by adding this property on java 6/7:

-Dhttps.protocols="TLSv1"

And for Java 8 :

-Dhttps.protocols="TLSv1,TLSv1.1,TLSv1.2"

-Djdk.tls.client.protocols="TLSv1,TLSv1.1,TLSv1.2"

Source : http://www.oracle.com/technetwork/java/javase/documentation/cve-2014-3566-2342133.html

Answer 3

Apache HttpClient 4.3.6 disables SSLv3 by default.

Here's an excerpt from Apache HC 4.3.6 release notes

Release 4.3.6

HttpClient 4.3.6 (GA) is a maintenance release that fixes several problems with HttpClient OSGi bundle as well as some other issues reported since release 4.3.5.

Please note that as of this release HttpClient disables all versions of SSL (including SSLv3) in favor of the TLS protocol by default. Those users who wish to continue using SSLv3 need to explicitly enable support for it.

Users of all HttpClient versions are advised to upgrade.

Changelog:

• SSLv3 protocol is disabled by default Contributed by Oleg Kalnichevski

Update: If you are running on JVM having version >= Java 1.8 Update 31 SSLv3 is disabled by default.Check out the release notes

Answer 4

After spending considerable time trying to figure out why TLSv1.2 was being used despite setting -Dhttps.protocols="TLSv1" we finally found this post. The magic flag is indeed -Djdk.tls.client.protocols="TLSv1" and our Apache Axis 1.4 client works again. So in case you move from Java 7 to Java 8 you may need to add this flag as pre JAVA 8 used TLSv1 as default whereas JAVA 8 uses TLSv1.2

Thanks!