# Getting Started¶

How can you get on board? What are the steps to gradually incorporate the ARPA2 projects, and by that the InternetWide Architecture, into your systems?

This chapter describes how you can get on board, and start to use the components that we built for this ever-expanding software stack. We do not target specific use cases yet. The steps described below are global, and reference more detailed instructions (or indicate that this software is still being worked on).

## Adopting PKCS #11 (standardised secret store)¶

In case you haven’t heard of PKCS #11, it is an API that is designed to conceal secret and private keys from being observed, or exported in plain view. These objects are the cornerstones of cryptographic protection, and being unable to replicate them is helpful to your security and privacy.

Status: There is a wide array of mature software choices for PKCS #11, ranging from software, through simple USB keys, to high-end, hardened bastions that would rather destroy your keys than release them to a physical intruder.
• PKCS #11 is a foundation on which we built the TLS Pool. We realise it is an extra effort to install and get used to, but PKCS #11 adds great value in terms of flexible security deployments. Once it is setup and running, it should not give any more headaches, other than to attackers after your keys.
• We advise you to get started with SoftHSMv2, because it is a sophisticated and mature open source product. If the need for hardware protection arises later on, you merely swap the library that implements your PKCS #11 API (and juggle keys as deemed necessary).
• If you want to “play” with PKCS #11, you may have a look at your mail or web clients; they often support plugging in PKCS #11 libraries, on which you can then store your local key material and certificates. This is also what the TLS Pool does; it stores private keys behind a PKCS #11 API and links them to certificates that are stored in a local identity database.
• There is a standard for pkcs11: URIs which can describe either tokens or objects (such as keys, certificates, or data) on that token. This is not a location but an identifier, in the sense that it provides selection criteria for a token and, given extra parameters, objects on a token. You will need to supply your software with a library that implements the PKCS #11 API along with each URI.
• When you get started with the TLS Pool, we will talk you through the steps of using PKCS #11 for that purpose. These steps will assume SoftHSMv2 and GnuTLS tooling, but you can easily vary if you feel a need; PKCS #11 solutions are fairly exchangeable, other than that their implemented security level varies drastically.
• When we initiate the IdentityHub, we are going to manage PKCS #11 at a (paid to be trustworthy) hosting provider — or perhaps on your Raspberry Pi at home — and we will then introduce Remote PKCS #11. This will allow you to share your identities anywhere you are, including on your mobile device. And yes, we have concerned ourselves with the security of that design!

## Adopting TLS Pool (splitting security from applications)¶

The TLS Pool is the piece of software that takes security knowledge out of applications. It relies on PKCS #11 and, in part because of that, is not easy to get started. Once it is running however, you should find that it easily “clicks in” and grants you a lot of control over security, in one place for all the applications concerned. As a matter of fact, you can even centralise management.

Status: The TLS Pool works well on servers, but using it on client platforms is a bit awkward. This is mostly due to lacking multi-user support, but if your client is in practice a single-user platform you should be able to use the TLS Pool quite nicely.
• The first thing to do is perhaps to start using the TLS Pool, and use it from the applications that you rely on.
• If your server does not rely on authenticated client identities, than it may suffice to simply use the TLS Tunnel distributed with the TLS Pool. This tool can even use simple scripts to talk a remote server into STARTTLS mode, and then proceed as before.
• If your client wants to use the TLS Pool to authenticate to a server, it may also suffice to use the TLS Tunnel. It will authenticate the client, so this may even add value to non-TLS applications. For instance, you could direct your mail client to a locally hosted SMTP server, which is then redirected by the TLS Tunnel, authenticating with STARTTLS and using credentials kept in the TLS Pool. Dependent on the server side, this may be helpful or confusing to client authentication; the ideal situation being to rely on SASL EXTERNAL authentication, referring back to an identity that was authenticated over TLS.
• Use of the TLS Pool for authentaction by applications is not something that the ARPA2 project can directly influence, but it may help if you ask the producers of your favourite pieces of software to look into it — or if you organise the needed patches. It has been shown repeatedly that the addition of the TLS Pool to an existing application takes about an hour for someone well-versed in the application’s inner structure!
• If you have an application that has “add TLS” on the TODO list, think no longer — adopt the TLS Pool. It will save you a lot of anxiety about security configuration, where to load certificates from and how to handle the accompanying private keys in a secure manner. All this is delegated to the TLS Pool. In fact, it will implement many more things than you would ever be likely to add — and you get it all for free.

## Adopting SteamWorks (LDAP configuration dissemination)¶

The idea of SteamWorks is to offer you with a configuration backbone.

Status: At this point, SteamWorks is in its infancy. A few test setups have shown to work though.
• SteamWorks is founded on LDAP, for which we hope to simplify management through a front-end that takes care of the intricacies of running a complex daemon. SteamWorks uses LDAP SyncRepl as a subscription mechanism for near-instant dissemination of configuration changes to those clients that have subscribed. The design of SteamWorks incorporates components that help to isolate networks from connectivity problems to remote parts of the Internet.
• SteamWorks delivers configuration information to backends, using configuration scripts to determine what information should be taken from where in LDAP, and how to pass it on to those backends. The backends will then store the information in a form suitable for the targeted software system.
• As a first example, the TLS Pool has a backend for SteamWorks, permitting the complexities of TLS configuration to be made centrally, for instance by an administrator. This releases individual users from the concerns that come with the specialised domain of security. As soon as a security problem pops up, a change can be made in the SteamWorks configuration and subscribed clients would virtually immediately pickup the change and process it locally, is the underlying idea.

## Adopting Kerberos (or await IdentiyHub)¶

We advise you to start using Kerberos as your central authentication mechanism.

Status: Kerberos is very robust, very secure and very well integrated into software. Setting it up is not always easy, but once setup life simplifies to a single-signon system. Note that the one weak point at this time is support for HTTPS — and that we are working on resolving that generically, by adding Kerberos to TLS in the form of TLS-KDH.
• Kerberos offers “single sign-on”, which means that you login once (usually at the start of the day) and continue to use the initial credential received for hours to go. You need to do no further logins, as any new service ticket needed during those hours are derived from your initial start-of-day credential. On top of that, Kerberos is very fast, because it is built on symmetric-key algorithms such as AES-256.
• Kerberos is integrated into many protocols, including SMTP, IMAP, LDAP and SSH. You will be pleasantly surprised by how much faster your SSH logins will be with Kerberos, compared to using the SSH Agent or mundane/manual password entry.
• Be aware that we will offer Kerberos as part of the upcoming project phase, IdentityHub. This means that you should think ahead if you want to setup a quick test platform to cover the time until we get there, or that you prefer to wait a while. Be advised that setting up the KDC is the most difficult part of running Kerberos, which is why we will “web-wrap” it for less technical domain owners, but a straightforward setup on a single node is quite doable for an experienced administrator.
• Be advised that the IdentityHub works towards automated realm crossover between Kerberos realms, in a way that allows clients of on realm to authenticate to another, even if they had not been introduced before. The technique for doing so will likely derive its security from DANE. Note that authentication does not imply authorisation: you may be able to prove to anyone who you are, but the question remains if you are welcome to use any given service.

The RADIUS system and its follow-up Diameter are widely used to centralise authentication, authorisation and accounting within a domain, or secure realm. Although authentication (who is it?) and authorisation (what may he do?) tend to blur in these systems, they will answer questions like Can Jack access the files of Joe? with Yeah or Nay.

Status: RADIUS is very stable, and in principle, so is Diameter. The latter is less often used, but has a few clever extensions. When we come to the ServiceHub, we will standardise on Diameter. Mature systems exist to connect RADIUS and Diameter, so that should not constrain your local choice. New systems should probably consider Diameter, and break with the somewhat overdue tradition of RADIUS.
• As part of IdentityHub, we will support a flexible authorisation framework. It is assumed that a user’s identity is authenticated, and that its access to a resource is questioned. A few examples are:
• We have not standardised the method of asking these questions yet. This is in part due to our desire to retain privacy as much as we can; when we setup the SecureHub, we would prefer to not spread all information to each service, but hopefully answer little more than these direct questions in a way that they can easily cache. And of course that also introduces concerns of efficiency of any such caches and the expediency of updates to them.

## Adopt modern Internet standards (in general)¶

In our work, we are going to make a few radical assumptions about support for modern Internet protocol. Some things simply cannot be done well on IPv4 (thanks to NAT traversal nightmares) and some things are simply not secure without mechanisms like DNSSEC.

Status: Most of these technologies have been around for quite a while, and their software has been well tested. You may find that you are still an early adopter, although you would also be surprised how well the uptake of various modern developments has been in practice.
• Adopt IPv6. Really, when it comes to end-to-end communication you do not want to be dealing with NAT traversal issues. Ask any self-acclaimed SIP expert about their fondness of NAT and they will show you their best daunting-nightmare grinn. We are going to require IPv6 on various parts of our design, simply because it evades problems that are now in the way of progress, and because the inherent complexities of NAT traversal lead to complex code, complex networking problems and poor end-user experiences.
• Adopt DNSSEC. Start signing your zones, and validate your DNS queries. We will require DNSSEC for a number of follow-up projects, for example to validate DANE entries, and perhaps SSHKEY records in DNS. With DNSSEC in place, the DNS is a reliable database of domain-specific information; without DNSSEC, it cannot be used as a foundation for anything that is at risk of being abused.
• Adopt SCTP. This protocol sits next to UDP and TCP, and can actually behave like either. In addition, it can run multiple streams at the same time. Particularly interesting is its support of a reliable, but not necessarily in-order delivery of frames, which happens to be very useful for systems that run on UDP to avoid head-of-line blockage but that need to resend at the application level to achieve a reliable service. We will require SCTP for several of our services, among others for the ServiceHub project where it will be used as a sort of umbilical cord between hosting providers. Chances are that SIP infrastructure will also require SCTP, in support of longer messages that can then include security information.
• Be advised that the IdentityHub and ServiceHub will export DANE records for services. Research by SURFnet had led to the conclusion that the spread administration of DNS, certificates and servers makes DANE a potentially fragile system, but automation can be helpful to overcome that.

## Embrace for more...¶

The InternetWide Architecture encompasses much more. As this project advances, we will update this page with more steps that you can take.