Wednesday, November 8, 2017

EJBCA 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.

Wednesday, November 1, 2017

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.


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.

Monday, October 30, 2017

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 

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!

Mike Agrenius Kushner
Product Owner EJBCA

Thursday, October 19, 2017

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.

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!

Mike Agrenius Kushner,
Product Owner EJBCA

Tuesday, September 19, 2017

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.

Markus Kilås
Product Owner SignServer

Post-quantum algorithms for digital
signing in Public Key Infrastructures



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)

Tuesday, August 29, 2017

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. 


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. 

Mike Agrenius Kushner,
Product Owner EJBCA

Saturday, July 15, 2017

Introducing the EJBCA RA, Part 2.2: Migrating from the Public Web (continued)

Hey folks, and welcome back. The last post was dragging on a bit, so I decided at the last minute to split it up. This post will cover the rest of the RA (as implemented in EJBCA 6.8.0) before I get into a bit more technical and architectural stuff in the next post(s).

So, sit back and enjoy the continuation of the tour.

Request Management/Approvals

A big part of being an RA is naturally approving requests. To begin with, let's take a look at the Manage Requests screen. You'll notice four tabs:

  • To Approve - a list of all requests that you as a logged in administrator may approve or deny
  • Pending Approval - a list of all currently pending requests to which you have view access, including those that you may approve yourself. 
  • Processed - a list of past requests to which you have view access.
  • Custom Search - a standard search screen, allowing you to filter and search through all requests to which you have view access. 
So let's return to the scion of the Widget fortune and our example from the last blog post, Alan Widget and his quest for certificates. So you'll remember that his enrollment request was sent of for approval? Well, over on their end the ever friendly neighborly RA administrator was on the case. Receiving an e-mail notification about Alan's request, they log in to the RA and check the To Approve-tab.

As expected, here we see Alan's request waiting for review. Clicking on the Review-link, the administrator is shown all pertinent information having to due with Alan's request.

We could mention here that we've only set up a simple cumulative approval profile for this action for the sake of simplicity. We could have also used the more complex partitioned profiles which were introduced in EJBCA 6.6.0, but I'll probably write a bit more about those in a future blog post.

You'll notice that there is an edit button at the bottom of the screen, which allows the administrator to edit some information in Alan's request. Doing so would invalidate the administrator as an approver though, as they would be considered party to the request itself. Instead they choose to approve, which changes the request's status to Executed, will send a notification mail off to Alan and allow him to retrieve his certificate.

Heading over to the Processed-tab, the administrator can now see Alan's request listed, and likewise under the Custom Search-tab.

Search Functions

That ends the final epic saga of Alan Widget and his quest for certificates, so we'll move on to the remaining pages on the RA interface in EJBCA 6.8.0. Clicking on the Search option in the top menu reveals two choices: Certificates and End Entities

Certificate Search

Being able to search for certificates is a brand new feature in EJBCA, and is only implemented in the RA interface. It provides options for searching for partial matches against Subject DN, SAN, username or against the full serial number. Certificates can also be filtered by end entity profile, certificate profile, issuer and status. 

Extra search options include specifying more results to be shown per screen and mechanisms for searching for more precise issuance, expiry and revocation dates. Note that result size is restricted to avoid murdering the database. I would also like to point out that the listed certificates will be restricted to those CA to which the RA is authorized to. 

End Entity Search

The End Entity search is gives roughly the same options as the certificate search screen, and will likely feel familiar to those of you used to the End Entity search screen from the CA interface. 

CA/CRL Overview 

The CA Certificates and CRL screen remains largely unchanged from the public web.

Notice from the screenshot that the WidgetCorp SubCA is slightly indented to show that it's subservient to the WidgetCorp Root CA

Role Management

The last screen to review is the Role Management screen, which was first introduced in EJBCA 6.8.0. Clicking on the menu will show two options: Roles and Role Members. 

At this point you may be wondering why we've moved roles management out into the RA interface, when there is an excellent (well, more or less) equivalent already written in the CA interface? Well, for many use cases this won't make much sense, in particular when CA and RA are on the same machine. It starts getting interesting when the CA is located in a secure environment, using one or many RAs placed in the DMZ to communicate. As these would by bare minimum be physically separated and in different security zones, this allows senior RA administrators some freedom to administrate their own personell, without being forced to enter the CA security zone. This functionality becomes even more pertinent when CA and RA are physically separated, or not even being operated by the same business entities. 


The roles screen will display a table of all roles to which the current administrator and RA are authorized to see, sorted by name and namespace. The standard options for editing, deleting and cloning roles exist, as well as for creating roles and reviewing role members. 

If we click on Create New Role will bring us to the following screen, which will be similar for editing or cloning. 

Notice that what you see is a simplified rules management screen, restricted to only RA functions and access to Certificate Authorities and End Entity Profiles.

Role Members

Had we instead clicked on the Members link in the previous table, we would have ended up in the same screen as the Role Members menu option. Displayed is a table of all available role members which this RA and administrator is authorized to view, which can be further narrowed down by identifier (common name, certificate serial number, etc), role or CA. 

Choosing to add a role member will lead us on to a familiar screen where we can specify role for the member, what CA has issued the certificate for that member and by what means we identify that certificate. There is also a field for making remarks pertaining to that member.

That brings us to the end of our tour for the EJBCA RA as implemented in EJBCA 6.8.0. I hope that you've learnt something, and you'll join me in future blog posts as we add and modify functionality. We're not done yet though! Fact is that the EJBCA RA is not only a fancy new user interface, but part of a brand spanking new feature: for EJBCA Enterprise customers an instance of EJBCA can be set up to act as a synchronous external RA for another EJBCA instance acting as CA, communicating securely using EJBCA Peers, even through a one-way firewall. 

Will we introduced this functionality back in EJBCA 6.6.0, in the next blog post I'm going to explain how such a setup would look like on an architectural level, and provide an easy walkthrough for how to set it up!

Mike Agrenius Kushner
Product Owner EJBCA