Use TLSv1 by default

[michaelklishin]

Fixes #258.

[carlhoerberg]

Why not go straight to TLS 1.2?

[michaelklishin]

Not everybody can afford running TLS 1.2. For example, if you have .NET clients using RabbitMQ, they would have to run .NET 4.5. JVM-based apps will have to use JDK 7. And so on.

[michaelklishin]

I understand that different clients can still use earlier TLS versions but as far as recent developments (specifically POODLE) go, there is not a lot of upside to using TLS 1.2.

[carlhoerberg]

TLS 1.0 is vulnerable to the beast attack, 1.1 and 1.2 is not.

Bunny could still default to 1.2, even if old versions of .net or jvm doesn't support it, right?

On Wednesday 22 October 2014 at 02:15, Michael Klishin wrote:

I understand that different clients can still use earlier TLS versions but as far as recent developments (specifically POODLE) go, there is not a lot of upside to using TLS 1.2.

—
Reply to this email directly or view it on GitHub (#259 (comment)).

[dangerp]

Why is the ssl_version even being set explicitly? OpenSSL::SSL::SSLContext will use :SSLv23 by default, which will attempt TLS, and then downgrade to SSLv3 only if TLS is not supported. See https://www.openssl.org/docs/ssl/SSL_CTX_new.html#item_SSLv23_method

[carlhoerberg]

👍 @dangerp

[dangerp]

@carlhoerberg @michaelklishin see my proposed solution in #261

[michaelklishin]

@dangerp Ruby's OpenSSL is virtually undocumented, that's why I wasn't aware of the TLSv1 preference. Thank you.

[dangerp]

I entirely understand. I've been doing a ton of digging the past few days auditing all of the libraries that we have that use SSL, and I started out with the same solution as yours. Took me a while to figure out what the ruby OpenSSL library was doing, and even longer to figure out what the SSLv23 setting actually meant.

For those reading this too lazy to open the link above:

a client will send out TLSv1 client hello messages including extensions and will indicate that it also understands TLSv1.1, TLSv1.2 and permits a fallback to SSLv3. A server will support SSLv3, TLSv1, TLSv1.1 and TLSv1.2 protocols. This is the best choice when compatibility is a concern.

This means that the server gets to decide which protocol to use. If the server supports TLSv1.2, then that is what it will likely choose to respond with.