Archive for August, 2021

Identifying an AWS RDS-hosted database by its tag information

August 27, 2021 Leave a comment

Recently, I was working on a task where I wanted to set up an automated process to create manual database snapshots for a database hosted in Amazon’s RDS service. Normally this is a straightforward process because you can use the database’s unique identifier when requesting the database snapshot to be created.

However in this case, the database was being created as part of an Elastic Beanstalk configuration. This meant that there was the potential for the database in question to be removed from RDS and a new one set up, which meant a new unique identifier for the database I wanted to create manual database snapshots from.

The Elastic Beanstalk configuration does tag the database, using a Name tag specified in the Elastic Beanstalk configuration, so the answer seemed obvious: Use the tag information to identify the database. That way, even if the database identifier changed (because a new database had been created), the automated process could find the new database on its own and continue to make snapshots.

One hitch: Within the AWS API, RDS lists only the following three API calls to interact with tags.

ListTagsForResource would seem to be the answer, but the hitch there is that you have to have the database’s Amazon Resource Name (ARN) identifier available first and then use that to list the tags associated with the database:

aws rds add-tags-to-resource --resource-name arn:aws:rds:us-east-1:123456789102:db:dev-test-db-instance --tags Key=Name

I was coming at it from the other end – I wanted to use the tag information to find the database. RDS’s API doesn’t support that.

Fortunately, the RDS API is not the only way to read tags from an RDS database. For more details, please see below the jump.

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Using the Jamf Pro API to report on which Macs are assigned to a particular person

August 26, 2021 2 comments

Every so often, it may be necessary to generate a report from Jamf Pro on which computers are assigned to a particular person. To assist with this task, I’ve written a script which uses the Jamf Pro Classic API to search through the computer inventory records and generate a report in .tsv format.

For more details, please see below the jump.

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Codesigning, untrusted certificate authorities and why certain apps aren’t launching

August 24, 2021 4 comments

A number of folks noticed that certain older applications they use on macOS stopped working as of August 24th, 2021. As of this date, this appears to affect the following applications among others:

Note: This list is not complete, it’s just the ones I’m aware of as of August 24, 2021.

Why this is happening goes back to an episode in 2018, where Symantec had to get out of the PKI certificate issuing business because of a number of issues discovered with how Symantec had been issuing certificates.

As part of these issues, Apple issued an advisory that a number of Symantec Certificate Authority (CA) root certificates were to be distrusted by Apple on a timeline which concluded with the full distrust of Symantec CAs on February 25, 2020.

While this primarily affected website operators, Symantec also issued certificates from the affected Symantec CAs which were used to provide code signing for applications. An example of this is RSA SecurID Software Token 4.2.1.

Update 8-26-2021: RSA has released RSA SecurID Software Token 4.2.2 to resolve the issue with RSA SecurID Software Token 4.2.1. For more details, please see the link below:

In the case of SecureID, this app relies on Qt Core for user interface support and ships copies of the QT Core framework along with the SecureID app. SecurID stores this in the following location:


If you take a look at the installer, you can see where the files are supposed to go.

Screen Shot 2021 08 24 at 6 25 25 PM

However, the actual file which is causing the issue is buried further down in the following location:


Screen Shot 2021 08 24 at 6 27 36 PM

This file is important because the QT Core framework is shipped without Apple’s code signing, which is to say that QT is not using an Apple Developer ID signing certificate to sign QT Core. Instead, QT ships a code signing certificate chain and that information is stored in the QtCore.cire file.

One of the certificates in the code signing certificate chain is using VeriSign Class 3 Public Primary Certification Authority – G5 as its root certificate authority (root CA). That root CA is one of the Symantec CAs which is no longer trusted by Apple.

Screen Shot 2021 08 24 at 6 03 58 PM

To summarize: the SecureID app has a component which is signed by a not-trusted certificate. This is causing SecureID to not trust that component, which then prevents the app from launching correctly.


Why is this happening now?

Apple released updates on August 23, 2021 for both XProtect (now version 2150) and Malware Removal Tool (now version 1.82). My assumption is that XProtect’s update included instructions to no longer accept code signing from the distrusted Symantec CAs. XProtect checks executable code on launch, so it would be working with Gatekeeper to detect and block the no-longer-trusted code signing.

What should you do?

See if your vendor has released an updated version of the app which is having problems. If they haven’t yet, I recommend contacting them to make sure they’re aware of the problem.

Hat tip to all the folks working on this issue in the MacAdmins Slack for helping diagnose the issue and why it is happening.

Downloading and installing macOS Big Sur via macOS Recovery’s Terminal

August 4, 2021 5 comments

Every so often, you may find yourself in a situation where you need to reinstall macOS Big Sur and everything is failing on you. Installing from macOS Recovery? Not working via the usual methods. Building a USB installer? Left the flash drive in your other pants. Using DFU mode and Apple Configurator on an Apple Silicon Mac? You need a second Mac to use this process and you just have the one Mac available.

For those situations, there’s one more option when you’ve exhausted all of the others. For more details, please see below the jump.

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