11/2/2022 0 Comments Pritunl api key![]() ![]() The next paragraphs move from theory to practice, and describe the minimum set of steps required to setup the OpenConnect VPN server and client with FreeIPA. #PRITUNL API KEY PASSWORD#This way, VPN authentication will only occur if the user's ticket is fresh, and the user's password will be required otherwise. That is, given the long lifetime of Kerberos tickets, how can we prevent a stolen laptop from being able to access the VPN? That, we address by enforcing a configurable TGT ticket lifetime limit on the VPN server. For that, it is possible, and recommended, to configure FreeIPA to require a second factor authenticator (OTP) as part of the login process.Īnother, equally important concern for the single sign-on, is to prevent re-authentication to the VPN for the whole validity time of a Kerberos key. However, it is desirable to increase the authentication strength when coming from untrusted networks. By stacking multiple authentication methods you could result in having your users trying the different credentials to the different login prompts, effectively training the less security-oriented to try the passwords they were provided anywhere until it works. There can be networks where this is indeed a good design choice, but in other networks it may be not. ![]() Wouldn't that reduce security? Isn't it more secure to ask different credentials from the user to connect to the home network and different credentials to access the services into it? That's a valid concern. The user logs into the Kerberos Authentication Server and the VPN to the FreeIPA managed network is made available with no additional prompts. To address that, we introduced a point system to the OpenConnect VPN server for banning IP addresses when they perform more than a pre-configured amount of requests.Īs a consequence, with the above setup, the login processes is simplified by reducing the required steps to login to a network managed by FreeIPA. However, there is a catch since the OpenConnect server is now a proxy for Kerberos messages, the Kerberos Authentication Server cannot see the real IPs of the clients, and thus cannot prevent a flood of requests which can cause denial of service. Furthermore, the usage of HTTPS ensures that all transactions with the Kerberos server are protected using the OpenConnect server's key, ensuring the privacy of the exchange. Thus, the combination of the two protocols allows the OpenConnect VPN server to operate both as a proxy to KDC and as a Kerberos-enabled service. The MS-KKDCP protocol allows an HTTPS server to behave as a proxy to a Kerberos Authentication Server, and that's the key point which allows the user to obtain the Kerberos ticket over the VPN server protocol. The former enables GSSAPI negotiation over HTTPS, thus allowing a Kerberos ticket to be used to authenticate to the server. In that particular case, we take advantage of the SPNEGO, and the the MS-KKDCP protocols. The protocol followed by the OpenConnect VPN server is HTTPS based, hence, any authentication method available for HTTPS is available to the VPN server as well. How is that done? If the user needs to connect to the VPN in order to access the Kerberos realm, how could he perform Kerberos authentication prior to that? To answer that question we'll first explain the protocols in use. That way, the necessary passwords are asked only once, minimizing login time and frustration. The user logs into the Kerberos realm once and uses the obtained credentials to login to the VPN server as well. Can things be simplified and achieve single sign on over the VPN? We believe yes, and that's the reason we combined the two independent authentications into a single authentication instance. That is, we have two independent secure authentication methods to login to a network, one after the other, consuming the user's time without necessarily increasing the security level. Many times, exactly the same password pair is used for both logins. Before explaining more, let's first explore what the typical login process is on a VPN network.Ĭurrently, with a VPN server/product one needs to login to the VPN server using some username-password pair, and then sign into the Kerberos realm using, again, a username-password pair. Putting the acronyms aside that means that authentication in FreeIPA, which uses Kerberos, is greatly simplified for VPN users. ![]() One of its main features is the addition of MS-KKDCP support and GSSAPI authentication. In March of 2015 the 0.10.0 version of OpenConnect VPN was released. The information may no longer be current. This article was originally published on the Red Hat Customer Portal. ![]()
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