Josh Wieder

 One of the sillier things I've done as an AWS/linux admin is provision an EBS disk as swap to an EC2 instance. I kept getting max allocate errors for a script I needed to run to execute a series of database queries. Reprovisioning to a new EC2 instance class with more RAM wasn't feasible at the time for some long-forgotten reason.  I would never do this if I owned the disks - provisioning swap to SSD will greatly reduce the lifetime of the disk, among many reasons why this is less than ideal. But Amazon has plenty of money. I figured I could cheaply provision an EBS volume & buy myself enough swap to complete the query. Then, in some point in the future, I could create a more beautimous solution. Well, if you're a sysadmin you know how this story ends. I moved onto other fires/projects, quickly forgot about the swap situation, and here I am years later, deprovisioning the server, in all its swappy glory. This wouldn't warrant a blog post, except for the fact that I...

This weekend I spent some time migrating a few low-traffic websites from Nginx to AWS S3's static web hosting service. In theory, this is a straightforward process: move content from the old webroot to an S3 bucket that shares the name of the domain, enable static web hosting for the bucket & set a security policy that enables anonymous web users to see that content. In practice, there's a bit more involved: 1. S3 bucket resource paths can change, which will result in DNS failures unless you use a Route 53 hosted zone. You don't need to buy a domain from Amazon to do this, but you do need to use their nameservers. This isn't free, and there is an extra fee for DNSSEC. 2. Want an SSL/TLS certificate? Of course you do. This means generating a certificate within Amazon Certificate Manager. In most circumstances (without "legacy" client support for example), there is no charge for the certificate. But to serve traffic using that certificate requires provisioni...

So you've screwed something up. You made a typo in your sshd_config file. You added a firewall rule, or a route, or some other thing, and lost your network access to your EC2 instance. And of course whatever you broke, you broke permanently - you wrote your firewall rules directly to /etc/sysconfig/iptables, you made your goofy change to /etc/sysconfig/network-scripts/whatever-interface; so rebooting won't make a damn bit of difference. You read the warnings, you know you shouldn't have. But you did anyway. Oh, and you don't have any backups. Or you have backups from three months ago. Restoring from your crappy backups would mean hours to days of non-stop work and consistent downtime. Or Amazon or whatever other company you're using for backups actually broke your backups/lost your backups/never actually provided you with the backups you paid for. Don't panic. You've got this . You remember that Amazon has some sort of Java-based something or other. Its ...

I've written a simple bash script that checks for new files in an AWS S3 bucket and emails any that it finds as a compress (tar.gz) attachment  - you can find it at my Github account under the name "S3-Filer-Mailer". I built it as a supplement for a contact form that relies on S3 as a back-end, rather than a php mailer or database. Using S3 for contact forms is attractive because it is so unattractive to spammers. There is no way to corrupt this sort of setup for spamming or to get hands on a database through the form, because it isn't connected to one. Why not use Amazon's Simple Notification Service (SNS) ? For one, AWS charges more for SNS than it does for S3 queries and downloads. For another, if this sort of functionality is available through SNS it is not clearly documented. Getting back to the topic of security, the script establishes two network connections - one a connection to S3 to retrieve the files, the other sending the email. The S3 connection ...

Scams focused on stealing tax refunds remain highly profitable, despite the fact that they are well known and understood by security professionals and the general public , and have been for years. A variety of distribution methods are used, with the common threads being the use of IRS logos and bureaucratic-sounding language to convince users to click a link, download and execute a file and/or send personally identifying information like a Social Security number. A recent example of one such a scam that I came across is a damning illustration of the failure of online service providers to protect users from obvious and simple malware distribution methods. In the example I wish to discuss today, the distribution method was a spammed email that on a small ISP's installation of SpamAssassin (note: I am not an admin or employee of this system; I'm a customer) received an X-Spam-Status score of 5.3 after being flagged with the following variables: X-Spam-Status: No, score=5.3 re...

Amazon S3 subscribers recently received a form letter like this one: Dear AWS Customer, This message explains some security improvements in our services. Your security is important to us. Please review the entire message carefully to determine whether your use of the services will be affected, and if so what you need to do. As of 12:00 AM PDT May 20, 2015, AWS will discontinue support of SSLv3 for securing connections to S3 buckets. Security research published late last year demonstrated that SSLv3 contained weaknesses in its ability to protect and secure communications. These weaknesses have been addressed in Transport Layer Security (TLS), which is the replacement for SSL. Consistent with our top priority to protect AWS customers, AWS will only support versions of the more modern TLS rather than SSLv3. You are receiving this email because some of your users are accessing Amazon S3 using a browser configured to use SSLv3, or some of your existing applications that use Amazon S3 a...