Category: System Administration

Exchange SMTP – Sender Reputation DB

Our Exchange server was refusing mail

451 4.7.0 Temporary server error. Please try again later. PRX5

Attempts to send mail would connect, send data, and then hang for a few seconds before returning the tempfail error.

Looks like there’s “sender reputation” data stored at .\Exchange Server\V15\TransportRoles\data\SenderReputation that is used. Since I’m not actually doing filtering on the Exchange server, stopping the transport services, moving the files out of the folder, and then re-starting the services rebuilt the data and allowed mail to send again.

Linux: Getting Drive Serial Number

[lisa@FVD01 /mnt/lisa/]# smartctl -i /dev/sdc
smartctl 7.5 2025-04-30 r5714 [x86_64-linux-6.15.7-200.fc42.x86_64] (local build)
Copyright (C) 2002-25, Bruce Allen, Christian Franke, www.smartmontools.org

=== START OF INFORMATION SECTION ===
Model Family: Western Digital Red (CMR)
Device Model: WDC WD40EFRX-68N32N0
Serial Number: WD-WCC7K4HY5TKD
LU WWN Device Id: 5 0014ee 2b9a3d0c5
Firmware Version: 82.00A82
User Capacity: 4,000,787,030,016 bytes [4.00 TB]
Sector Sizes: 512 bytes logical, 4096 bytes physical
Rotation Rate: 5400 rpm
Form Factor: 3.5 inches
Device is: In smartctl database 7.5/5706
ATA Version is: ACS-3 T13/2161-D revision 5
SATA Version is: SATA 3.1, 6.0 Gb/s (current: 6.0 Gb/s)
Local Time is: Tue Dec 2 17:24:27 2025 EST
SMART support is: Available – device has SMART capability.
SMART support is: Enabled

2025-12-02 17:24:27 [root@FPP01 /mnt/MythAndZoneminder/]# smartctl -i /dev/sda
smartctl 7.5 2025-04-30 r5714 [x86_64-linux-6.15.7-200.fc42.x86_64] (local build)
Copyright (C) 2002-25, Bruce Allen, Christian Franke, www.smartmontools.org

=== START OF INFORMATION SECTION ===
Model Family: Western Digital Red (CMR)
Device Model: WDC WD40EFRX-68N32N0
Serial Number: WD-WCC7K7JZSZ0E
LU WWN Device Id: 5 0014ee 264576d5e
Firmware Version: 82.00A82
User Capacity: 4,000,787,030,016 bytes [4.00 TB]
Sector Sizes: 512 bytes logical, 4096 bytes physical
Rotation Rate: 5400 rpm
Form Factor: 3.5 inches
Device is: In smartctl database 7.5/5706
ATA Version is: ACS-3 T13/2161-D revision 5
SATA Version is: SATA 3.1, 6.0 Gb/s (current: 6.0 Gb/s)
Local Time is: Tue Dec 2 17:24:38 2025 EST
SMART support is: Available – device has SMART capability.
SMART support is: Enabled

 

SSL Cert Validity Periods Being Reduced

The CA/B Forum has decided to reduce the length of time digital certificates can be valid. The change is a gradual reduction that I expect is designed to make manual certificate renewal more and more cumbersome and drive people toward automating certificate management.

Currently: 398 days although many vendors issue certs for one year.
March 15, 2026: 200 days. Increased renewal frequency means manual tracking and renewal becomes more challenging.
March 15, 2027: 100 days. Manual tracking and renewal is painful, but possible.
March 15, 2029: 47 days. Automation is basically a requirement.

 

Getting Cert Info From Host

An OpenSSL command to retrieve the cert chain from a host and parse out the CN and expiry info

[lisa@linux05 ~]# openssl s_client -connect 10.5.5.75:443 -servername lisa.rushworth.us -showcerts </dev/null 2>/dev/null | sed -n ‘/BEGIN CERTIFICATE/,/END CERTIFICATE/p’ | openssl x509 -noout -subject -startdate -enddate -nameopt RFC2253
subject=CN=lisa.rushworth.us
notBefore=Sep 2 03:28:34 2025 GMT
notAfter=Dec 1 03:28:33 2025 GMT

PingFederate – OGNL Customization of AuthnContext

After a recent merger, we have added federated authentication in our PingFederate environment that allows the incoming company to continue to use their Entra (ADFS) logon process to authenticate through PingFederate. All of the IDs exist in our directory, and contract attributes are populated based on the local account. But the authentication is handled by their existing system. It’s really cool, and works for 99.9% of the applications. One, however, was not happy with the resultant attribute contract. It worked fine for me, logging in directly with PingFederate. Anyone who authenticated through Entra, however, got a very specific error:

AuthenticatingAuthority array contains a value which is not a wellformed absolute uri

And, yes, I concur – there is absolutely an element in the AuthenticatingAuthority array that is not a well-formed absolute URI

Luckily, there appears to be a solution. On the ACS URL tab, select “Show Advanced Customizations”

A screenshot of a computer AI-generated content may be incorrect.

Use the drop-down to select the message type of “AssertionType” and the expression provided at https://support.pingidentity.com/s/article/OGNL-Examples-Message-Customization#rm-authauthority to remove authenticating authority values when multiple are present (which also works when only one is present)

A close-up of a computer screen AI-generated content may be incorrect.

Now I no longer have authenticating authorities but the AuthnContextClassRef is “urn:oasis:names:tc:SAML:2.0:ac:classes:Telephony” … so, in the assertion creation, we need to add SAML_AUTHN_CTX to the attribute contract

A screenshot of a computer AI-generated content may be incorrect.

In the attribute contract fulfillment, map this to a static TEXT string – I am using “urn:oasis:names:tc:SAML:2.0:ac:classes:unspecified” which is used as the default in PingFederate

Final Answer! I have an AuthnContext that does not contain any invalid URI strings and a AuthnContextClassRef that is expected.

 

Quickref: tmux

Our newer servers don’t have screen – and you cannot install it – so I’ve had to start using tmux:

# list running sessions
tmux ls

# Start a new session or reattach to an existing session named LJR
tmux new-session -A -s LJR

# In session, detach
ctrl+b d Detach

# attach to an existing session named LJR
tmux attach-session -t LJR

Did you know … you can import accounts into Cyberark?

Adding one account to CyberArk takes about a dozen clicks. Adding fourteen was going to take me half the day!

Luckily, I discovered that the “Add account” button is actually a drop-down menu that also offers the ability to Add accounts from file

A screenshot of a computer AI-generated content may be incorrect.

Create a CSV file with the following columns:

userName address safeName platformID secret automaticManagementEnabled manualManagementReason groupName logonDomain
user1 server1 OURSAFE Generic Unmanaged abc123 FALSE Platform does not support automatic password management
user2 server2 OURSAFE Generic Unmanaged bcd234 FALSE Platform does not support automatic password management
user3 server3 OURSAFE Generic Unmanaged cde345 FALSE Platform does not support automatic password management
user4 server4 OURSAFE Generic Unmanaged def456 FALSE Platform does not support automatic password management
user5 server5 OURSAFE Generic Unmanaged efg567 FALSE Platform does not support automatic password management

Then browse to select the CSV file. It will show you how many accounts are included in the file – 6 here

A screenshot of a computer AI-generated content may be incorrect.

Click “Upload”. The accounts will be created, and you will see a banner at the top of the site

 

Did you know … you can view just your favorite accounts in CyberArk?

Is your CyberArk account view an overwhelming list of accounts? You are constantly using “Search for accounts” to find one of the three accounts you regularly use because they are buried somewhere in this list?

A screenshot of a computer AI-generated content may be incorrect.

There’s a better way! The star at the left-hand side of each line allows you to mark an account as a “Favorite”. There’s a link under “Views” to just display your favorite accounts. Even better, though, if you click on the ellipsis button to the right of the “Favorites” link, you can select “Set as default”.

A screenshot of a computer AI-generated content may be incorrect.

Now, when you log into CyberArk, you immediately see your curated list of accounts instead of all of them!

A screenshot of a computer AI-generated content may be incorrect.

 

Getting an OAUTH Token for Bearer Auth

Quick script to mint and decode an OAUTH bearer token … requires CLIENT_ID and CLIENT_SECRET variables with data. 

TOKEN_URL='https://oauth.example.com/as/token.oauth2'
INTROSPECT_URL='https://oauth.example.com/as/introspect.oauth2'


TOKEN=$(curl -s -k -X POST "$TOKEN_URL" \
  -H 'Content-Type: application/x-www-form-urlencoded' \
  -u "${CLIENT_ID}:${CLIENT_SECRET}" \
  -d 'grant_type=client_credentials&scope=openid profile email' | jq -r '.access_token')


if [ -z "$TOKEN" ] || [ "$TOKEN" = "null" ]; then
  echo "Failed to obtain access token"
  exit 1
fi

echo "=== JWT HEADER ==="
HEADER=$(echo "$TOKEN" | cut -d '.' -f1)
LEN=$(( ${#HEADER} % 4 ))
if [ $LEN -eq 2 ]; then HEADER="${HEADER}=="; fi
if [ $LEN -eq 3 ]; then HEADER="${HEADER}="; fi
echo "$HEADER" | tr '_-' '/+' | base64 -d 2>/dev/null | jq

echo
echo "=== JWT PAYLOAD ==="
PAYLOAD=$(echo "$TOKEN" | cut -d '.' -f2)
LEN=$(( ${#PAYLOAD} % 4 ))
if [ $LEN -eq 2 ]; then PAYLOAD="${PAYLOAD}=="; fi
if [ $LEN -eq 3 ]; then PAYLOAD="${PAYLOAD}="; fi
echo "$PAYLOAD" | tr '_-' '/+' | base64 -d 2>/dev/null | jq

echo
echo "=== INTROSPECTION ==="
curl -s -k \
  -u "${CLIENT_ID}:${CLIENT_SECRET}" \
  -H 'Content-Type: application/x-www-form-urlencoded' \
  -d "token=$TOKEN" \
  "$INTROSPECT_URL" | jq