The DNS infrastructure contains a growing number of critical information such as services records pointing to authentication services, TLSA records, SSH fingerprints and the like. DNSSEC signs this information, the client can trust the information DNS sends. It protects against forged information through cache poisoning. This article shows how to achieve a DNSSEC protected DNS environment with the help of FreeIPA This article was taking some time to write as I wanted to see how it behaves in the long ….Read More
Tag: DNS
Using MTA-STS to enhance email transport security and privacy
Overview SMTP is broken by design. It comes from a time when communication partners trusted each other and the NSA was intercepting facsimiles and phone calls instead of internet traffic. To enhance privacy, in 2002 RFC 3208 was added to the SMTP protocol. Unfortunately STARTTLS is only optional, it is not allowed to only accept encrypted connections. The RFC states: A publicly-referenced SMTP server MUST NOT require the use of the STARTTLS extension in order to deliver mail locally. That ….Read More
Using Unbound for recursive DNS lookup
Some organizations decide to use its internal authoritative DNS servers as recursive DNS because of easiness and reverse lookup of internal RFC 1918 networks works out of the box. That should be avoided for (at least) two reasons: Cache poisoning can cause security nightmares Authoritative answers are never cached and can cause a high load on the DNS servers. Cache poisoning is a problem that can lead to severe problems, as more and more information is stored in DNS. Examples: ….Read More
Providing SRV and TXT records for Kerberos and LDAP with dnsmasq
What if you have an application such as OVirt/RHEV-M that relies on DNS services records and you dont have the possibility to add them to the DNS servers because the DNS admins do not like to do its job? Fake them! DNSMasq is your friend 🙂 Install dnsmasq on the server in question and configure /etc/resolv.conf to query first dnsmask on localhost. yum -y install dnsmasq chkconfig dnsmasq on Assuming your subdomain is called example.com and your ldap and kerberos ….Read More