Accessing a Pi-Hole behind an Apache reverse proxy

Update 2019-09-15: Finally got around to looking into this and it turns out all I had to change was “ProxyPreserveHost Off” to “ProxyPreserveHost  On” to get things working. I’ve updated the original post to reflect the changes. I also didn’t note in my original host that I purposely restricted access to the apache virtual host to and (my internal networks). You’ll want to update the “Allow from” lines to reflect your internal networks OR remove the “<Location /></Location>” all together to make it accessible from anywhere (not recommended).

Update 2019-08-19: I just recently found out that this proxy configuration only allows read-only access to the Pi-Hole UI. I was attempting to white-list a domain and it was failing when accessing my Pi-Hole via the proxy. I had to go directly to the box’s FQDN to white-list a domain. I will leave this post for reference and update it when I figure out a fix to this problem.

Update 2019-09-29: My first Lets Encrypt certificate came due for auto-renewal and failed because of my original configuration. I’ve updated the apache configuration below so Lets Encrypt can access the non-SSL /.well-known directory to automatically renew certificates.

Original Post

Today I got tired of accessing my Pi-Hole over HTTP, having to remember to put /admin/ in the URL and having to load up a browse that wasn’t Vivaldi or Firefox because they don’t have an easy way to ignore Strict-Transport-Security for my domain.

I checked out some documentation about adding SSL to the Pi-Hole directly but have concerns that future updates will wipe out all the custom configuration to lighttpd. According to this you also have to be careful when enabling SSL on your Pi-Hole as it could interfere with blocking.

I already have an Apache webserver running so configuring it to reverse-proxy seemed like an easier task, plus if for some reason I wanted to access my Pi-Hole from the general internet (without VPN) it would be simple to enable that.

Here is the reverse proxy configuration I used with a restriction to my two internal networks and a redirect from HTTP to HTTPS:

<VirtualHost *:80>
       DocumentRoot /var/www/html
       CustomLog logs/ combined
       ErrorLog logs/

	<Location /.well-known>
		Order allow,deny
		Allow from all

	<Location />
		Order deny,allow
		Deny from all
		Allow from
		Allow from
		Allow from

       RewriteEngine On
       RewriteRule ^(.well-known)($|/) - [L]
       RewriteCond %{SERVER_PORT} 80
       RewriteRule ^(.*)$ [R,L]

<VirtualHost *:443>
        DocumentRoot /var/www/html
        CustomLog logs/ combined
        ErrorLog logs/

	<Location />
		Order deny,allow
		Deny from all
		Allow from
		Allow from
		Allow from

        RewriteEngine On
        RewriteRule ^/$ /admin [R]

        # The below line is not required so I have commented it out but left it in place
        # in case I am wrong. I no longer use Apache so I can't test. If this config doesn't
        # work uncomment the below line.
        # ProxyRequests On
        ProxyPass /
        ProxyPassReverse /
        ProxyPreserveHost On

        SSLEngine on
        SSLHonorCipherOrder off
        Header always set Strict-Transport-Security "max-age=63072000; includeSubDomains"

        SSLProtocol all -SSLv2 -SSLv3 -TLSv1 -TLSv1.1

        SSLCertificateFile /etc/letsencrypt/live/
        SSLCertificateKeyFile /etc/letsencrypt/live/
        SSLCertificateChainFile /etc/letsencrypt/live/

I am aware that my SSL configuration is not the best. I’m waiting for CentOS 8 to come out before migrating off my existing CentOS 6 server.

To find the best SSL configuration for your OS and Web Server I recommend checking out Mozilla’s SSL Configuration Generator:

Specter/Meltdown performance impact on my Lenovo T450S

Did some quick benchmarks tonight with the mitigation’s enabled and disabled.

I’m losing over 10% performance on a Broadwell i5-5300U





If you want to try yourself here is how you can disable the mitigation’s. Run the following from Command Prompt or PowerShell. Make sure you ‘Run as Administrator’.

reg add "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management" /v FeatureSettingsOverride /t REG_DWORD /d 3 /f

reg add "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management" /v FeatureSettingsOverrideMask /t REG_DWORD /d 3 /f

Once you’ve changed these registry keys reboot your PC.

This is obviously not recommended for production as you’re disabling important security updates on your system.

To re-enable the protections run the following:

reg add "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management" /v FeatureSettingsOverride /t REG_DWORD /d 0 /f

reg add "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management" /v FeatureSettingsOverrideMask /t REG_DWORD /d 3 /f



VeraCrypt CLI Benchmark Script

I was setting up VeraCrypt on a Raspberry Pi 2 the other day so I could use it as a backup target for my main server and was curious how fast, hahaha just kidding, I mean how slow VeraCrypt would be.

To my disappointment VeraCrypt does not provide a method for running the benchmark built into the GUI via the CLI.

This is the nice benchmark you can run from the GUI:


So I took some time this weekend and wrote a simple BASH script you can use to benchmark the CLI version of VeraCrypt.

I only tested it with VeraCrupt 1.18a. Chances are if you run it with a previous version you’ll get some really fast times for the new Encryption/Hashes they added in 1.18 because the test won’t actually run.

The benchmark I wrote simply outputs how long it takes to create and encrypt a container of a specific size. It’s not quite as good as the GUI version which outputs the actual speed but it’s at least something. I think this will work on any version of Linux. I tried to use only build-in system utilities and since I wrote it on CentOS 6 means I probably used some of the oldest GNU utilities still commonly used.

During my testing I found that having a container size to small would result in all times being nearly the same with the exception of ripemd160 and streebog. To get better results I recommend using at least a 1GB test file size on modern hardware. Even at 1GB you can see the sample from my main server has each encryption and hash type only varying by 2-45 seconds.

Here is a sample of what the script outputs:

I will admit I don’t fully understand these results. I would have expected much more variety in timing between the different types of encryption under a single hash type. Especially on the Raspberry Pi 2.

The script does a simply container creation benchmark in it’s default state. However if you add <USERNAME RUNNING BENCHMARK> ALL=NOPASSWD: <PATH TO bin/veracrypt>  to your sudo file and change FILLCONTAINER=0  to FILLCONTAINER=1  it will perform file write speed benchmark.

and here is the script itself:

# Simple Veracrypt CLI Benchmark Script
# Tested on Veracrypt: v1.18a
# Created by: Eric Schewe
# Created on: 2016-09-03
# Version: 1.1
# Last updated: 2016-06-05 16:38
# Source:

#Benchmark size in bytes. Uncomment which ever size you'd like to use.
#If you want to add your own sizes make sure they are multiples of 26214400 (25MB)
#CONTAINERSIZE=104857600 #100MB
#CONTAINERSIZE=209715200 #200MB
#CONTAINERSIZE=524288000 #500MB

#This determines if we are going to write data into the containers we create
#You must temporarily alter your sudo file for this to work by adding this line:
#Be sure to remove this line from your sudo file once your completed benchmarking

#All the hashes currently supported by VeraCrypt
HASH=(sha256 sha512 whirlpool ripemd160 streebog)
#All the encryption methods currently supported by VeraCrupt
ENCRYPTION=(AES Twofish Camellia Kuznyechik Serpent Gost89 AES-Twofish AES-Twofish-Serpent Serpent-AES Serpent-Twofish-AES Twofish-Serpent)
#Get the cpu model of the system running the benchmark
CPUINFO=`cat /proc/cpuinfo |grep -oP "model name.*?:(.*)" | uniq |sed "s/model name.*: //"`
#Hostname of system running the benchmark
#Start time in a good format (
STARTTIME=`date "+%Y-%m-%d - %k:%M:%S"`
#And a Unix Timestamp to calculate elapsed time easily
#Calculate the megabyte size of the container being created
CONTAINERSIZEMB=`echo "$CONTAINERSIZE / 1024 / 1024" |bc`

#For output

#Output the benchmark header based on the type of benchmark we are doing
if [ $FILLCONTAINER -eq 1 ];
echo "- Veracrypt Benchmark"
echo "- Started: $STARTTIME"
echo "- Hostname: $HOSTNAME"
echo "- CPU: $CPUINFO"
echo "- Container Size: $CONTAINERSIZEMB megabytes"
if [ $FILLCONTAINER -eq 1 ];
  printf "%-10s | %-30s | %-15s | %-15s | %-15s \n" "HASH" "ENCRYPTION" "VOL CREATE TIME " "VOL FILL TIME " "SPEED (MB/sec)"
  printf "%-10s | %-30s | %-1s \n" "HASH" "ENCRYPTION" "TIME"

#Loop through each HASH
for a in "${HASH[@]}"

  #Loop through each ENCRYPTION method for this HASH
  for b in "${ENCRYPTION[@]}"
    #Grab a random 320 character string and re-use it for all encryptions done for the current HASH
    < /dev/urandom tr -dc _A-Z-a-z-0-9 | head -c${1:-320} > randomString.txt 2>&1
    #Grab a random 64 character password (maximum length VeraCrypt supports)
    RANDOMPASSWORD=`< /dev/urandom tr -dc _A-Z-a-z-0-9 | head -c${1:-64};echo;`
    #General a container name that shouldn't conflict with anything already in the directory
    CONTANIERNAME=`echo -n $RANDOMPASSWORD | md5sum -t |head -c${1:-24}`".vc"

    #Create a VeraCrypt volume and time it, little grep to get the only time we care about from the output
    VOLUMECREATETIME=`(time veracrypt --create $CONTANIERNAME --size=$CONTAINERSIZE --password $RANDOMPASSWORD --encryption $b --hash $a --filesystem FAT --pim=2048 --random-source=randomString.txt --keyfiles= --volume-type=Normal) 2>&1 |grep -i "real" |sed "s/real//" |sed "s/ //g"`

    if [ $FILLCONTAINER -eq 1 ];
      #Figure out the directory name we are going to mount the volume to and then create it
      DIRNAME=`echo -n $RANDOMPASSWORD | md5sum -t |head -c${1:-24}`
      mkdir $DIRNAME
      #Mount the container to the directory we just created
      veracrypt --mount $CONTANIERNAME --hash $a --password=$RANDOMPASSWORD $DIRNAME --pim=2048 --keyfiles= --protect-hidden=no >/dev/null 2>&1
      #Get the start time for filling up the container
      FILLSTARTTIME=`date +%s`
      #Fill the container with 25MB files
      VOLUMEFILLTIME=`(time (for (( i=1; i<=$FILLFILECOUNT; i++ )); do dd if=/dev/urandom of=$DIRNAME/$i".dat" bs=26214400 count=1 status=none conv=fdatasync; done)) 2>&1 |grep -i "real" |sed "s/real//" |sed "s/ //g"`
      #Get the end time for filling up the container
      FILLENDTIME=`date +%s`
      #Math to calculate elapsed seconds and then how many MB/sec we did
      FILLSPEED=`echo "scale=3; $FILLFILECOUNT * 26214400 / $FILLELAPSED / 1024 / 1024" |bc -l`
      #Output the results
      printf "%-10s | %-30s | %-15s | %-8s | %-15s \n" "$a" "$b" "$VOLUMECREATETIME" "$VOLUMEFILLTIME" "$FILLSPEED"
      #Umount the container and clean up before the next container is created
      veracrypt -d $CONTANIERNAME >/dev/null 2>&1
      rm -rf $DIRNAME
      printf "%-10s | %-30s | %-1s \n" "$a" "$b" "$VOLUMECREATETIME"

    #Cleanup before next volume is created
    rm -f randomString.txt


  #Output a footer to signify the completion of this HASH
  if [ $FILLCONTAINER -eq 1 ];
    echo $LONGHEADER

#UNIX timestamp when we're all done. Then do some math and conversions
ENDTIMEUNIX=`date +%s`
ELAPSEDTIME=`date [email protected]$ELAPSEDTIME -u +%H:%M:%S`

#Output summary footer
echo "- Completed on `date "+%Y-%m-%d - %k:%M:%S"`"
echo "- Elapsed Time (HH:MM:SS): $ELAPSEDTIME"

if [ $FILLCONTAINER -eq 1 ];

I’m not super confident in the output. Some of the numbers leave me scratching my head. It’s completely possible I’ve got something totally wrong with this script. Please feel free to post comments/revisions.

Access Supermicro BMC via SSH tunnels

I’ve got a server at home with a Supermicro motherboard that has a BMC in it. The BMC allows me to access a web interface on a dedicated network interface on the motherboard which will let me control the server in the event the OS has frozen or the hardware has powered down. This is extremely useful if something goes wrong at home while I’m out of town and need to power cycle my server remotely.

The problem I have is that my VPN server is a VM hosted on the server in question. So if the server is down I can’t VPN home and access the BMC. I could forward the ports through my firewall but there is a more secure way of doing things so why not?

I got my hands on a Raspberry Pi2 with the intent of connecting it up so I could remotely access it via SSH in the event my main server was offline at home. From the RPi2 I could then load up a browser and access the BMC interface on my server. One big problem though. While I could access the web interface and power cycle the server I could not access the Java based KVM that comes included with the BMC. The KVM lets you access the server as if you were physically in front of it with a keyboard and mouse AND connect media to the server remotely such as a ISO for some diagnostic software if needed. Unfortunately no matter how much I tried I could not get the Java WebApp to work on my RPi2.

Instead I opted to just use SSH tunnels to connect to the BMC via the RPi2. Again this worked great for the WebUI but failed when using the Java KVM. I did find a work around though and it’s pretty simple. When you’re on the Supermicro BMC page and you start the Java KVM you get a download for a “launch.jnlp” file. Save that to your local computer.

Open the launch.jnlp file in your favourite editor and you’ll see something like this:

<jnlp spec="1.0+" codebase="">
    <title>ATEN Java iKVM Viewer</title>
    <description>Java Web Start Application</description>


    <property name="jnlp.packEnabled" value="true"/>
    <property name="jnlp.versionEnabled" value="true"/>
    <j2se version="1.6.0+" java-vm-args="-Xmx128M -Xms128M -Xss1M -XX:PermSize=32M -XX:MaxPermSize=32M"/>
    <jar href="iKVM__V1.69.21.0x0.jar" download="eager" main="true"/>

  <resources os="Windows" arch="x86">
    <nativelib href="libwin_x86__V1.0.5.jar" download="eager"/>
  <resources os="Windows" arch="x86_64">
    <nativelib href="libwin_x86_64__V1.0.5.jar" download="eager"/>
  <resources os="Windows" arch="amd64">
    <nativelib href="libwin_x86_64__V1.0.5.jar" download="eager"/>

  <resources os="Linux" arch="i386">
    <nativelib href="liblinux_x86__V1.0.5.jar" download="eager"/>
  <resources os="Linux" arch="x86">
    <nativelib href="liblinux_x86__V1.0.5.jar" download="eager"/>
  <resources os="Linux" arch="x86_64">
    <nativelib href="liblinux_x86_64__V1.0.5.jar" download="eager"/>
  <resources os="Linux" arch="amd64">
    <nativelib href="liblinux_x86_64__V1.0.5.jar" download="eager"/>

  <resources os="Mac OS X" arch="x86_64">
    <nativelib href="libmac_x86_64__V1.0.5.jar" download="eager"/>

  <resources os="SunOS" arch="sparc">
    <nativelib href="libsun_SPARC__V1.0.5.jar" download="eager"/>

  <application-desc main-class="">

You want to edit a few lines:

Line 1
From: <jnlp spec="1.0+" codebase="">
To: <jnlp spec="1.0+" codebase="http://localhost:5901/">

Line 51
From: <argument></argument>
To: <argument>localhost</argument>

Line 54
From: <argument></argument>
To: <argument>localhost</argument>

And you’re done. Save and close the file.

You’ll notice changed the web port on Line 1 from 80 to 5901 because I know 5901 isn’t in use on my local system. Now all I had to do was setup my SSH Tunnels so that local host 5901 forwarded to remote host 80 and local host 5900/623 forwarded to their respective remote host ports via my RPi2.

There is one catch with this method. Every time you go back into your BMC web-interface and click ‘Launch Console’ it appears the BMC generates a new set of security keys. All this means is if you access your BMC via the normal method and then want to use tunnels again you’ll have to get a new .jnlp file and re-apply the above edits.

How to block the contact import App with Symantec Endpoint

(Updated December 11th, 2012 – 9:115 PST)

TL;DR: Turns out there isn’t an easy way to do this with just Symantec and trying to block the Java App. We blocked * on our gateway anti-spam server and that took care of the problem for the most part.

Original article

We recently experienced a user who signed up for Upon signing up they chose to import their Outlook contacts. This causes a Java Application to download to the users workstation and automatically import their Outlook contacts. Big problem for us because it also imported our entire Global Address List from Exchange. Then spammed our entire organization trying to get more users to sign-up.

Blocking * on our gateway antispam server (Puremessage) took care of the e-mail spam but we wanted to prevent users from running the Java App in the first place on our workstations.

This will go poorly if the users Outlook is hooked into Exchange and you have a substantial global address book.

Blocking the domain that the Java App is downloaded from might be a bad idea. is a redirect to Amazon’s CloudFront service and who knows what amount of legitimate uses there are for it.

Next up was trying to block the Java App as it downloaded. To do this we created a new ‘Application and Device Control’ policy with the following settings:

In a nut shell this policy will monitoring the Java processes for any attempt to write a temporary file that matches the pattern “66c3f8b9-*-temp”. We determined that the first set of characters are static and only the second group change from download to download. After implementing this policy we tried a few random sites with Java on them and didn’t have any problems with legitimate apps being accessed.

In theory this should work until gets wise and changes the prefix on their Java Applet.

I’m open to better ideas if you have them.

Update – December 10th, 2012 – 12:25 PST

Checked out the results of my brilliant plan today and it looks like the temp file name has changed to ‘577a15c9-72a17cab-temp’. So much for that idea. For now I’ve added the new temp file name to our policy but I don’t think this is going to be a practical solution in the long term.

It seems Symantec can’t block the download itself which is a consistent ‘ContactsFinder.jar’ which comes from “”. We also don’t deploy the firewall component which might make this easier.

Update – December 11th, 2012 – 9:06 PST

So I checked again today and the temp files prefix has one again changed. I don’t think this method of blocking is going to be effective.

If you have Symantec Endpoint and have the firewall installed on your users machines you can probably block the download site directly…  or if you have a Proxy server…. or if you have a modern edge firewall. Try blocking “”

I also finally got an e-mail back from Skillpages after requesting my e-mails be removed since I didn’t consent to them being uploaded. Skillpages instructed me to create an account with each e-mail address (effectively agreeing to their ToS and EULA) and then go to and remove my account. Not an acceptable solution in my books.