EJBCA Development - Moving towards Continuous Delivery (finally...)

So a slightly more informal post from me, but I'd like to talk about a few of the changes we've been making in our development process here in the EJBCA team, and how they affect you as our customers.
I officially took on the role as Product Owner of EJBCA a bit less than a year ago without it really existing beforehand. How we got to that point is mostly historical and tied to our roots as an open source project. Tomas, EJBCAs founder and PrimeKey's current CTO was (and still is) EJBCA's face to the world, and with a small and tight development team around him responsibility for features, product cycles and roadmap was mostly ad-hoc, and this is where I came in nigh eight years ago as a developer.
In the time that has passed since then we've grown quite a bit and our user base has grown even more; as we mature from being a scrappy little FOSS project to what will hopefully be seen as a solid and well built software suite that can contend with the best of them.

Changes are coming, some which you all may notice directly and others that hopefully will be felt by us being quicker to adapt, better att keeping our deadlines and delivering better quality on the first try. One of the changes which has been silently in place for a while, but which I feel brave enough to advertise now is that we've moved towards continuous delivery:

A snapshot of our public repository. 

Since a while back the EJBCA team has been running on three week sprints, and with some tinkering we've finally gotten to the point where we can reliably produce a deliverable at the end of each sprint. Pictured above is the first Alpha of EJBCA 6.11.0, which we released at the end of the sprint on Wednesday. On Wednesday in three weeks it'll be joined by the next Alpha, and so forth until the release.
These Alpha releases are available for download for all Enterprise customers, the purpose of which is primarily for you guys to be able to evaluate and give feedback on ongoing development. In the future I'll also to try figure out a good way of showcasing the contents of each Alpha, while also making sure that there is some form of VM available for those of you who don't have a testing environment ready to deploy to.

EJBCA 6.10.0.1 Patch Release

Just a quick note, we just released a patch release of EJBCA 6.10.0. In it we've fixed a couple of corner cases for CAA, as well a library used in the CMP Proxy which we had missed renaming in our configuration files.

Presenting EJBCA 6.10: Customized RA Layouts and CMP Keypair Generation

Happy halloween to all, we the Plucky Khobolds of PKI have been toiling away at another release.

Customized RA Layouts

Speaking of costumes and dressing up, EJBCA 6.10 introduces an extremely neat feature to the RA web: not only the ability to upload custom stylesheets and logos on the CA web to be used in the RA, and not only setting these per role, but having these transmitted to a remote RA over the Peers protocol. This means that the look-and-feel of an RA placed in an entirely different country than the CA can be modified CA-side without even  requiring a restart of the RA, and it can be done for multiple users depending on their role.

Adding a custom style is trivial, just go to System Configuration and click on the Custom RA Styles-tab. From there simply upload an archive containing a modified copy of the RA's stylesheets and/or a custom logo, and then give it a name.

Thereafter you may simply go to the Administrator Roles-screen, where there now is a new column to set a custom stylesheet for each role if one wishes.

ROCA

On the theme of scares and frights, we're sure that nobody missed the ROCA vulnerability that was made public this month, as written about here. While EJBCA has never used Infineon libraries for key generation (and to the best of our knowledge, none of our supported HSM vendors do either), we've still been capable of signing weak keys submitted from other sources. Fortunately since we introduced the RSA Key Validator back in EJBCA 6.9, adding a ROCA check there as well was trivial. For those of you running or planning on running RSA Key validation, we strongly recommend activating checking for ROCA weak keys.

Central Keypair Generation over CMP

On the CMP side we've added the concept of Central Key Generation which allows for a request for a keypair generated CA side to be transmitted and returned over CMP.

Other Fixes

Certificate Transparency has been given the ability to specify, apart from the minimum number of required logs, which logs which are considered mandatory to write to - this in anticipation of new requirements from Chrome coming in 2018. We've also kept working on our CAA validator, hammering out various corner cases and parallelising DNS lookups for certificates containing multiple DNSNames.

From an upgrade perspective we're happy to see many legacy installations (EJBCA 4.0 and older) beginning to upgrade towards more modern versions of EJBCA, and have received some bug reports specific to older deployments which we've fixed in this release. Currently we support upgrading directly from EJBCA 5.0.16 or later. EJBCA 6.10 introduces no database changes, so upgrading from 6.9.x doesn't involve any automatic or manual upgrade steps.

Introducing the EJBCA RA, Part 3: Architecture of an RA Proxy

This blog post will describe features in EJBCA Enterprise which will not be released to the Community Edition. If you're interested in what you read about here and would like to learn more, please mail sales@primekey.com 

Hello there and welcome back to the next feature of our RA series, which is going to discuss a bit about the RA, what led to it and who needs it. I know it's very much belayed, but we've had our hands full with our regular releases =)

The What? 

So for those of you reading who are either running EJBCA in small scale or internally, the new EJBCA RA interface is just a fancy new frontend for EJBCA. We know that many of you are running your own RA services through our SOAP interface, others via CMP or SCEP. 

For those of you running EJBCA Community, that is where it will end once we release the RA into a community release. Those of you running EJBCA Enterprise, or who might have plans on doing so, this is where you perk your ears.

The interface is actually just the tip of the iceberg, because what hides behind it is actually a fully armed and operational battle station RA Proxy.

The Why? 

Many of you already running large scale CA installations will be more than aware of this issue, but I'll say it plainly: exposing your CA server to the internet is a bad thing. You're suddenly vulnerable to every security vulnerability, zero-day and attack vector known to mankind, and a CA is a more than inviting target. 

Yet, most CAs (barring root CAs) need some form of exposure, if not to just publish CRLs and answer OCSP requests. For this reason CAs will be placed behind a firewall allowing only outbound communication, through which CRLs can be published to servers outside the firewall and to VAs placed in the DMZ.

When using EJBCA as a VA, those of you who have been in the game long enough know that we used to support a VA publisher (now considered legacy) that published directly to the VA database (using an extra port opened in the firewall), which has since then been replaced with EJBCA Peers (an Enterprise feature) which allow the CA to communicate to the VA running TLS, with the protocol only making use of outbound communication (with replies) in order to fulfill to security requirements. 

Legacy Features 

RA functionality is on the other hand more difficult, since the communication is by its very nature inbound. Up until EJBCA 6.6.0, PrimeKey offered some solutions for an RA wishing to communicate with a CA sitting behind a one-way firewall: 

• The ExternalRA - known to some of our enterprise customers, the old EJBCA ExternalRA (also known as ExtRA) is an asynchronous proxy designed to run in the DMZ. The ExternalRA doesn't provide more than a very rudimentary RA interface, but instead intercepts SOAP messages and stores them in a message database. By opening an outbound database port in the firewall (much as was done for the legacy VA), the CA can poll the ExternalRA's database and thus handle registration requests. 
• The SCEP and CMP Proxies - while similar to the ExternalRA solution (and sharing some of its codebase) the SCEP and CMP proxies fill a similar role, intercepting inbound communications and storing the payload in the database for future polling. 

The legacy stack, using legacy PrimeKey icons. 

All in all, these solutions are not entirely without warrant. While slow due to their asynchronous nature and extremely limited in terms of communications feature sets, they do not only provide RAs with a means to communicate with a secure CA but also mitigate some DOS attacks by vetting inbound communications before the CA needs to handle them. 

The How?

As I mentioned before, back in EJBCA 6.3.0 we introduced the EJBCA Peers protocol, in essence a method for two EJBCA instances to be able to communicate with each other over TLS, but in practice a secure alternative to direct database publishing for VAs (see this old blogpost). EJBCA finally saw the long awaited expansion of the Peers protocol to also encompass RA communications, and in doing so introduced new demands. 

Our Initial Implementation

While designing the protocol to communicate between CA and VA, one constraint that we introduced was generality: there should in essence be no difference between a CA installation of EJBCA compared to a VA installation. We want our customers to be able to follow a standard installation procedure up until the point where it's time to designate the purpose of the actual instance, and this counts doubly when using a PrimeKey appliance. Between a CA and VA this is relatively simple: an instance is always a CA, and can also act as a VA for an externally imported CA. Communication is always initiated by the CA. 

Introducing RAs into the Mix 

Adding RAs implies another few layers of complexity. Communication goes inherently upstream, breaking the outbound-traffic-only constraint on the CA security environment. Thinking ahead, we realized that proxies can exist in several layers (communications being routed through several instances of EJBCA before reaching their final installation), with any installation acting as CA and RA proxy simultaneously. As developers we direly want to avoid reinventing our own wheel, so we direly want to avoid maintaining one interface for designated RAs and another for RA tasks on the CA. 

We solved this in EJBCA 6.6.0 by adding another layer of abstraction on top of RA calls, the RaMasterApi. The API checks the source of the message, availability of peers upstream to itself and the message type and from that decides on whether to process the message locally or pass it on. 

The beauty if this design is that it's essentially stateless. A new EJBCA instance born to this world can simply be set up to accept incoming peer messages, and that's basically all the configuration required to make it into an RA. Adding an outgoing peer to this instance and configuring it for RA communications would in no way detract from its capacity to act as RA, but it would also relay messages from downstream up to the CA.

Even for the RA, all communications are still initiated by the CA, specifically by the CA leaving long hanging message thread in a pool for the RA to use as needed.

Lastly, the CA is also protected by a rights system, in which any credentials used to identify on the RA are nestled within the credentials set on the CA for the RA itself. In other words, if an RA has been limited to a certain subset of RA operations, and a certain subset of CAs, even logging in with a superadmin certificate on the RA won't allow any more privileges than those allowed to the RA. It means that there are essentially watertight compartments between different RA instances, allowing the CA to serve several different entities with RA services without risk of leaking information between them.

So, in our next and final instalment I'll be showing a quick tutorial on how to set up an RA to speak to a VA and demonstrate some of the concepts I've spoken about in this post. Until then!

Cheers!
Mike Agrenius Kushner
Product Owner EJBCA

Signing weak RSA Keys? Not on our watch!

I'm sure very few of you have missed the rather crippling flaw found in a widely used code library to generate RSA keys which has been named the Return of Coppersmith's Attack, or ROCA for short.

Fortunately none of PrimeKey's products uses these libraries, nor do any of our supported HSM vendors to the best of our knowledge, so no key pairs produced by EJBCA should be affected by this flaw.

Source: https://crocs.fi.muni.cz/_detail/public/papers/roca_impact.png?id=public%3Apapers%3Arsa_ccs17

Nonetheless, EJBCA does run the risk of signing such keys as part of a Certificate Signing Request. As fears of similar flaws have been lifted to us before, in EJBCA 6.9.0 released in late August of this year we introduced the concept of Validators, among them the RSA Key Validator.

For EJBCA 6.10, slated to be released on the 1st of November, we've added functionality to the RSA Key Validator to reject keys affected by the ROCA flaw.

All you need to do after upgrading to EJBCA 6.10.0 or later is to check this box in your validator, and you're set to go!

Cheers!
Mike Agrenius Kushner,
Product Owner EJBCA

Master's Thesis Paper on Post-Quantum Algorithms for Digital Signing in PKI Available Now

Mikael Sjöberg has been with us here at PrimeKey this spring exploring different algorithms suitable for use in PKI even after quantum computers becomes a reality.

As Mikael's mentor I am very pleased with his work and that he choose to do the study at PrimeKey.

The final version of the master's thesis has now been approved.  Read the abstract below or download the full version PDF.

Cheers,
Markus Kilås
Product Owner SignServer

Post-quantum algorithms for digital
signing in Public Key Infrastructures

MIKAEL SJÖBERG

Abstract

One emerging threat to Public Key Infrastructures is the possible development of large-scale quantum computers, which would be able to break the public-key cryptosystems used today. Several possibly post-quantum secure cryptographic algorithms have been proposed but so far they have not been used in many practical settings. The purpose of this thesis was to find post-quantum digital signature algorithms that might be suitable for use in Public Key Infrastructures today.

To answer the research question, an extensive literature study was conducted where relevant algorithms were surveyed. Algorithms with high-grade implementations in different cryptographic libraries were benchmarked for performance. Hash-based XMSS and SPHINCS, multivariate-based Rainbow and lattice-based BLISS-B were benchmarked and the results showed that BLISS-B offered the best performance, on par with RSA and ECDSA. All the algorithms did however have relatively large signature sizes and/or key sizes.

Support for post-quantum digital signature algorithms in Public Key Infrastructure products could easily be achieved since many algorithms are implemented in cryptographic libraries. The algorithms that could be recommended for use today were SPHINCS for high-security applications and possibly BLISS-B for lower security applications requiring higher efficiency. The biggest obstacles to widespread deployment of post-quantum algorithms was deemed to be lack of standardisation and either inefficient operations compared to classical algorithms, uncertain security levels, or both.

Full report (PDF)

Presenting EJBCA 6.9.0: Delegated Keypair Generation, Validation and CAA

Greetings to all, and welcome back after a long summer. Just in time for CAA to go live on September 8th, we'd like to present to you all the release of EJBCA 6.9.0. All in all we've fixes about 90 issues during the summer, but we'd like to highlight the four major features of this release: 

Delegated Keypair Generation

As requested by some customers running EJBCA instances as RAs over Peers, this feature is similar to the key recovery feature long used in EJBCA in that it stores generated soft keys encrypted in the database, but with the purpose that the soft keys are generated on the RA (instead of on the CA). The purpose of this is security - where the owner of the RA doesn't wish for the keys to ever be transmitted to the CA but merely be signed. 

Since this feature requires an EJBCA instance running as RA, it only applies to Enterprise customers. 

Validators

In EJBCA 6.9.0 we've introduced the concept of Validators, an API that can perform content validation during certificate creation. To explore this new functionality, look under CA Functions -> Validators

Once there, the Validators management screen should be familiar to most EJBCA users:

All Validators have some common options, as seen at the bottom of each configuration screen:

This allows for setting a description, restricting application of the Validator to certain certificate profiles and to define behavior in cases where the Validator fails (to abort issuance or to merely log and warn), or if the Validator was applied to a value it couldn't validate (such as an RSA validator on an ECC key). 

RSA/ECC Key Validation

Foremost we've implemented Key Validators, which can be applied to a CA to reject incoming signing requests based on inadequate key length or poorly chosen exponents. Both of these validators are quite powerful. Looking at the RSA Validator:

We can see immediately that the Validator gives control over exponent size and modulus, as well as restricting key sizes to either a custom list, to those set by the Certificate Profile or to the CA/B-Forum recommendations. 

Exploring the ECC Validator, we find a similar level of control there:

Lastly, both Key Validators can be restricted to certain time periods, which allows for enforcement of standards from or up until a certain date:

BlackList Validators

We've also developed an API for blacklisting signing requests based on known information. In EJBCA 6.9.0 we've implemented a Key Blacklist Validator, which will check incoming certificate requests against a user defined blacklist of known bad keys. 

Keys can be added to the blacklist using the EJBCA CLI:

This command can also be used to upload a complete list of blacklisted keys. PrimeKey Solutions can provide list of known bad keys as compiled by the metasploit project, contact us for more info. 

Certificate Authority Authentication (CAA) Validation

Last and absolutely not least, EJBCA 6.9.0 can perform CAA checks during or after certificate issuance, as I wrote about last spring. We have implemented CAA support in two methods, the first being a manual CLI tool that can be used to manually verify CAA records:

The second is in the form of a Validator:

This Validator allows specification of issuer, DNS Resolver and whether to validate DNSSEC for results, as well as options for how to handle IODEF statements. Note that EJBCA doesn't support WebService IODEF calls (RFC 5070) yet.

CAA support is an Enterprise only feature. 

Cheers!
Mike Agrenius Kushner,
Product Owner EJBCA