The Top Ten Hardcore F5 Security Features in BIG-IP 14.0

(tmos)# modify /sys db systemauth.disablerootlogin value true

 

The admin account is more difficult to disable: https://support.f5.com/csp/article/K14943

Do note that if you roll-forward a configuration, it will retain your existing credentials (not force you to change), nor will it enforce password policy by default. We felt that too much of the Internet would simply break if we did that without warning. But we might next time.

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Number 4 [ TMOS ] - Local Attestation for TPM Chain of Custody

Do you guys remember those confusing days when the United States Tailored Access Operations (TAO) group was accused of intercepting and installing surveillance software on those Cisco routers before they were shipped overseas? Or the Bloomberg Super Micro accusations from, oh, two days ago? People were understandably freaked out by these apocolyptic scenarios and turned to alcohol, mystics, and Trusted Platform Modules (TPM).

A TPM is a hardware module implements security functions to provide the ability to determine a trusted computing environment, allowing for an increased assurance of trust that a device behaves for its intended purpose. TPM Chain of Custody provides assurance that the software loaded on your platform at startup time has the same signature as the software that is loaded by F5 when the system is manufactured.

Platform support
These platforms include a Trusted Platform Module (TPM).

• BIG-IP i2000 Series
• BIG-IP i4000 Series
• BIG-IP i5000 Series
• BIG-IP i7000 Series
• BIG-IP i10000 Series
• BIG-IP i11000 Series
• BIG-IP i15000 Series
• VIPRION B4450 blade

You can check the validity of the F5 TMOS platform software by running the following tmsh command.

 

You should see a message like this “System Integrity Status: Valid." I have no idea what you’re supposed to do if it doesn’t say Valid. Have a quick drink and speed dial your swami? Oh, I know, open a ticket. And send me your passwords just in case.

If you download and install an update, and you’re happy with it, the -a option will write the new checksums to the TPM.

You can read more about the TPM here.

   https://support.f5.com/kb/en-us/products/big-ip_ltm/manuals/product/big-ip-system-essentials-14-0-0/11.html

And FYI, regarding the Super Micro thing. As per our official statement, F5 doesn't use Super Micro; we design our own boards and control the manufacturing tests and processes used by our contract manufacturer. And we take multiple steps to validate and ensure the integrity of all firmware and software loaded on our systems during the manufacturing process. And of course, we have the TPM now!

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Alright dear reader, if you’ve gotten this far, your frontal lobes have expanded 8% from all this hardcore technical goodness you’re probably bleeding from your ears.  Push your brains back into your ear canals using two pencils and take a deep breath because we’re going to push through to the top three!

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Number 3 [SSL Orchestrator] – TLS Forward Proxy Revocation checking 

“Revocation is the Achilles heel of PKI.”– Pavel Chekov, first mate, NCC-1701D

If you’re not familiar with the SSL Orchestrator you should be! It’s the perfect tool for decrypting outbound (and now inbound) traffic to send to all your security inspection devices. Your favorite b-list F5 celebrity recorded a lightboard describing how it works and why you need it. 

Version 14 adds forward certificate revocation checking to the SSL Orchestrator. Suppose Red Man is at the agricultural office and he visits a website whose certificate had been revoked. Prior to version 14, Red man would be unaware of the revocation and would blithely click around and possibly expose his credentials. But now, the SSL Orchestrator can do an OCSP check and then terminate the session on revocation, protecting young Red Man (and you).

Seems simple, right? Actually, to make this work we basically made the “ServerSSL” TLS profile work the same as the much more powerful ClientSSL profile. So now ServerSSL can do OCSP and CRLDP certificate checks, the latter of which is meaningless in the forward proxy case but quite powerful in the inbound federal or enterprise space.

66% of popular Internet sites (according my developer’s documentation) offer some kind of revocation checking. Now the SSL Orchestrator can take advantage of these revocation checks so that Red Man can be protected from malicious man-in-the-middle devices (as opposed to benevolent man-in-the-middle like the SSL Orchestrator).

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Number 2 [ LTM ] – Ultra-secure ECDSA keys in HSM 

Nothing says serious like a FIPS 140-2 hardware security module (HSM). A good one will keep your keys secret, your beers cold and costs more than my first three cars. Guess who wrote the first F5 + FIPS implementation? Yours truly, back in 2002! “Shut up, David, you say that every top ten list!” 

Back then, sonny, we didn’t have these new-fangled elliptic curve digital signature algorithm (ECDSA) keys that all the millennials are using now, and even if we did we couldn’t put them into an HSM, because HSMs only supported RSA keys, like God intended.

ECDSA keys and certificates are becoming more popular across the Internet. ECDSA usage grows a few percent each quarter, with some periodic larger jumps when a CDN adopts it.

With version 14.0, F5 supports ECDSA keys in our own Cavium N3FIPS HSM cards. Version 14 also supports ECDSA keys in external Net-HSMs like Thales and nCipher.

I, myself, grudgingly switched over to ECDSA keys last year, finally giving up my RSA and DSA keys, which I sold at a garage sale for 0.000006 bitcoin.

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Are you ready for the Number One Most Hardcore Security Feature in version 14.0?  This one is cooler than the other side of the pillow!

Number One [ LTM ] – Support for Curve25519 (X25519).

Of course the most hardcore feature is going to be about cryptography. Put succinctly, Curve25519 is the fastest, coolest and soon-to-be most popular elliptic curve used in transport layer security (TLS). It was discovered by Internet super-god, Daniel J. Bernstein, and released to the public domain unencumbered by patents. You can go look at the source code for it on his site, cr.yp.to. Here’s the link: https://cr.yp.to/ecdh.html

If you’re splitting hairs, Curve25519 describes the actual elliptic curve, and X25519 describes it as a Diffie-Hellman function, where it is used in the client-server TLS handshake.

And if you’re wondering where the digits 25519 come from, it’s actually 2²⁵⁵-19, which, as everyone knows is a prime number, duh. Bernstein claims X25519 is provably secure (doesn’t rely on magic numbers) so is free from nation-state meddling. By design, it’s immune to timing attacks (beware, famous last words).

X25519 is recommended by the IETF TLS committee, and most recently, NIST publicly stated that they are behind it, too. X25519 has 40% lower computational complexity than the standard curve, P-256 so virtual machines should prefer it to P-256. The lower complexity also means that it will be easier on low-CPU devices like the billions found in the Internet of Things (IOT).

X25519 is one of three ‘DH-Groups’ in the Cipher Group configuration screen (the others are the standard NIST curves P-256 and P-384). Because it’s newer, we’ve prioritized X25519 last in the preference list, so unless a client requests it specifically, they won't get it. But you could move it to front of the preference list by using the cool new cipher rules that I introduced in the Top Ten List for version 13.

  # Create a Cipher rule that moves X25519 to the front
  ltm cipher rule Curvy {
    description "X25519 
    priority first" 
    dh-groups X25519:P256:P384
  }
  # Create a Cipher Group that uses it. 
  ltm cipher group CurvyGroup 
    { allow { Curvy { } } } 
  # Insert it into your clientssl profile 
  ltm profile client-ssl x25519 {
    ...
    cipher-group CurvyGroup ciphers none
    ...
  }

And then, to test it, get a distro with OpenSSL 1.1.0h or better, and when you run the s_client command you’ll see the X25519 function in the Server Temp Key field of the output.

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 No client certificate CA names sent 
 Peer signing digest: SHA256 
 Server Temp Key: X25519, 253 bits
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You’re welcome!  But don’t actually use that config above – it’s just an example. You’d want to make sure your cipher group includes all the other common ciphers, too.

Because X25519 is so awesome, it’s already supported by most major browsers, TLS vendors, clouds and CDNs.

Spoiler: TLS 1.3 will rely heavily on X25519. If you’re wondering where TLS 1.3 support was in this Top Ten List, just wait a little longer and keep monitoring DevCentral.

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As Spock would say, “dang, that was a gnarly list, bro, so hardcore.” Let’s recap this Top Ten in short list form:

Top Ten	Module	Hardcore Security Feature
10	ASM / FPS	Name Your Own WAF Cookies
9		Single Page Application support
8	AFM	NXDOMAIN Attack Detection
7	APM	Inline SAML WebSSO
6		ADFS Proxy as a simple Checkbox
5	TMOS	Forced Password Change
4		TPM Chain of Custody
3	LTM / SSL	TLS Forward Proxy Revocation Checking
2		Ultra-Secure ECDSA Keys in HSMs
1		TLS support for Curve25519

 

Honestly (honestly, guys) of all the Top Ten lists I’ve done, this one was the most hardcore. The most technically arcane. The least marketing-friendly. But that’s what makes it the best, and the most satisfying! Because DevCentral is where the technology (see the list) meets the people (that’s you).  

I’ve been running version 14 for all of two days now and I already love it more than bathing. If you're curious what else is in version 14, check out the full list of Version 14 Release Notes.

Enjoy your BIG-IP version 14.0, and boldly upgrade where no man has gone before!

Stay tuned for the next edition of the Top Ten, and follow me on Twitter but not in real life please, I have run out of restraining order forms. Until next time!