DKIM

September 28, 2023 Leave a comment

DKIM. No, it’s not a new singer/rapper/influencer/whatever. It’s a DNS controlled Email Authentication mechanism. What does that mean? Well, if you want a technical explanation, go see my article on Authorization vs Authentication, since that is important to understand if you want to understand DKIM. DKIM stands for DomainKeys Identified Mail. It uses a feature of Public Key Authentication to allow receiving mail servers to verify that the message is not modified in transit and that the sender is authentic. …

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Authentication VS Authorization: A Quick Explanation

August 15, 2023 Leave a comment

The authentication vs authorization dichotomy is something every IT person should learn. The two concepts are often confused with one another, likely because they both start with “Auth.” Also because, from an end user perspective, the two work together so seamlessly that it’s hard to tell where one starts and the other stops. The difference is important, though.…

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Hardening Microsoft Solutions from Attacks

January 30, 2019 Leave a comment

Take a minute to go over this post from Dirk-jan Mollema. Go ahead and read it. I’ll wait…

Did you realize how scary that kind of attack is? As an IT guy who specializes in Exchange server and loves studying security, that article scared the snot out of me. Based on my experience with organizations of all sizes I can say with a good bit of authority that almost every Exchange organization out there is probably vulnerable to this attack.…

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If You Have a Cisco Firewall, Disable this Feature NOW!!!

May 22, 2017 Leave a comment

I don’t often have an opportunity to post a rant in an IT blog (And even less opportunity to create a click-bait headline), but here goes nothing! Cisco’s method of doing ESMTP packet inspection is INCREDIBLY STUPID and you should disable it immediately. Why do I say that? Because when Cisco ASAs/whatever they call them these days are configured to perform packet inspection on ESMTP traffic, the preferred option of doing so is to block the STARTTLS verb entirely.*…

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ADFS or Password Sync: Which one do you use?

February 9, 2017 Leave a comment

I’ve run into a number of people who get confused about this subject when trying to determine how to get their On-Prem accounts and Office 365 synced and working properly. Most often, people are making a comment somewhere that says, “Just use Password sync, it’s just as good and doesn’t require a server,” or something similar.…

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Disabling Direct Access Forced Tunneling

April 14, 2016 Leave a comment

So you’re trying to get Direct Access (DA) running in your environment and you suddenly realized that your test machine can no longer access…anything. Well, this may be due to the “accidental” enabling of “Forced Tunneling” in your DA configuration. How do you fix it? You can pretty easily reconfigure your DA configuration to disable Forced Tunneling, but unless your test machine is directly connected to your AD environment, you’ll never be able to get the Group Policy updates on your test machine.…

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Anatomy of a Certificate Error

January 29, 2016 Leave a comment

The most important step in diagnosing a specific security error involves determining what the error is telling you. There are a few things that can cause certificate errors, and what you do depends entirely on what is causing the error to begin with. Once you know what the error is telling you, it becomes much easier to figure out what you need to do next.…

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