antipaucity

fighting the lack of good ideas

a fairly comprehensive squid configuration for proxying all the http things

After combing through the docs and several howtos on deploying the Squid proxy server – none of which really did everything I wanted, of course – I’ve finally gotten to the format below.

Installing Squid is easy-peasy – it’s in the standard package repos for the major platforms (CentOS/Fedora/RHEL, Ubuntu/Debian, etc) – so just run yum install squid or apt install squid on your platform of choice (my exact install command on Ubuntu 18.04 was apt -y install squid net-tools apache2-utils).

What I wanted was an “open” (password-protected) proxy server with disk-based caching enabled that would cover all of the ports I could reasonably expect to run into.

Why “open”? Because I want to be able to turn it on and off on various mobile devices which may (or may not) have stable-ish public IPs.

Here is the config as I have it deployed, minus sensitive/site-specific items (usernames, passwords, port, etc), of course:


A working /etc/squid/squid.conf

acl SSL_ports port 443
acl SSL_ports port 8443
acl Safe_ports port 80		# http
acl Safe_ports port 21		# ftp
acl Safe_ports port 443		# https
acl Safe_ports port 1025-65535	# unregistered ports
acl Safe_ports port 280		# http-mgmt
acl Safe_ports port 488		# gss-http
acl Safe_ports port 777		# multiling http
acl Safe_ports port 8080
acl CONNECT method CONNECT

auth_param basic program /usr/lib/squid/basic_ncsa_auth /etc/squid/.htpasswd
auth_param basic children 15
# after "realm", put some descriptive, clever, or otherwise-identifying string that will appear when you login
auth_param basic realm Insert Incredibly Witty Title Here
auth_param basic credentialsttl 5 hours
acl password proxy_auth REQUIRED
http_access allow password

# Deny requests to certain unsafe ports
http_access deny !Safe_ports

# Deny CONNECT to other than secure SSL ports
http_access deny CONNECT !SSL_ports

# Only allow cachemgr access from localhost
http_access allow localhost manager
http_access deny manager

#http_access allow localnet
http_access allow localhost

# And finally deny all other access to this proxy
# commented-out to allow "open" use (ie password authenticated)
#http_access deny all

# Squid normally listens to port 3128
# change this line if you want it to listen on something other port
# http_port 

# Uncomment and adjust the following to add a disk cache directory.
#cache_dir ufs /var/spool/squid 100 16 256
# format is      
cache_dir ufs /tmp/squid-cache 768 16 256

# Leave coredumps in the first cache dir
coredump_dir /var/spool/squid

# Add any of your own refresh_pattern entries above these.
#
refresh_pattern ^ftp:		1440	20%	10080
refresh_pattern ^gopher:	1440	0%	1440
refresh_pattern -i (/cgi-bin/|\?) 0	0%	0
refresh_pattern (Release|Packages(.gz)*)$      0       20%     2880
refresh_pattern .		0	20%	4320

via off
forwarded_for off

request_header_access Allow allow all 
request_header_access Authorization allow all 
request_header_access WWW-Authenticate allow all 
request_header_access Proxy-Authorization allow all 
request_header_access Proxy-Authenticate allow all 
request_header_access Cache-Control allow all 
request_header_access Content-Encoding allow all 
request_header_access Content-Length allow all 
request_header_access Content-Type allow all 
request_header_access Date allow all 
request_header_access Expires allow all 
request_header_access Host allow all 
request_header_access If-Modified-Since allow all 
request_header_access Last-Modified allow all 
request_header_access Location allow all 
request_header_access Pragma allow all 
request_header_access Accept allow all 
request_header_access Accept-Charset allow all 
request_header_access Accept-Encoding allow all 
request_header_access Accept-Language allow all 
request_header_access Content-Language allow all 
request_header_access Mime-Version allow all 
request_header_access Retry-After allow all 
request_header_access Title allow all 
request_header_access Connection allow all 
request_header_access Proxy-Connection allow all 
request_header_access User-Agent allow all 
request_header_access Cookie allow all 
request_header_access All deny allroot

Finalize your Squid server system settings

Things you need to do once you do the above (prepend sudo to each command below if youre not logged-in as root:

  1. Enable Squid to start at boot: systemctl enable squid
  2. Create the cache directories: squid -z
  3. Create a DNS entry for your proxy host (if you want it usable outside your home network, and don’t want to reference it by IP address only)
  4. Create the authentication file (located at /etc/squid/.htpasswd in this example): touch /etc/squid/.htpasswd
  5. Create a username and password: htpasswd -c /etc/squid/.htpasswd (don’t forget this username/password combination!)
  6. Start Squid: systemctl start squid

Configure your browser to use your new proxy

Here’s where you need to go and what you need to change in Firefox:

  1. Navigate to about:preferences
  2. Click on Settings… under Network Proxy
  3. Enter your proxy host details:

To verify your proxy settings are correct, visit IPv4.cf with both the proxy off, and then again with it on.

If your reported IP address changes between visits (with the second check being your Squid server IP) – congratulations! You have successfully deployed a Squid proxy caching server.

results from running pi-hole for several weeks

I came across pi-hole recently – an ad blocker and DNS service that you can run on a Raspberry Pi in Raspian (or any Debian or Ubuntu (ie Debian-like)) system. Using pi-hole should obviate the need for running ad-blockers in your browser (so long as you’re on a network that is running DNS queries through pi-hole).

I’ve seen some people running it on CentOS – but I’ve had issues with that combination, so am keeping to the .deb-based distros (specifically, I’m running it on the smallest droplet size from Digital Ocean with Ubuntu 16.04).

First the good – it is truly stupidly-simple to get setup and running. A little too simple – not because tools should have to be hard to use, but because there’s not much configuration that goes in the automated script. Also, updating the blacklist and whitelist are easy – though they don’t always update via the web portal as you’d hope.

Second, configuration is almost all manual: so, if you want to use more than 2 upstream DNS hosts (I personally want to hit both Google and Freenom upstream), for example, there is manual file editing. Or if you want to have basic auth enabled for the web portal, you need to not only add it manually, but you need to re-add it manually after any updates.

Third, the bad. This is not a pi-hole issue, per se, but it is still relevant: most devices that you would configure to use DNS for your home (or maybe even enterprise) want at least two entries (eg your cable modem, or home wifi router). You can set only one DNS provider with some devices, but not all. Which goes towards showing how pi-hole might not be best run outside your network – if you run piggy-back DHCP and DNS both off your RPi, and not off the wireless router you’re probably running, then you’re OK. But if your wireless router / cable modem demands multiple DNS entries, you either need to run multiple pi-hole servers somewhere, or you need to realize not everything will end up going through the hole.

Pi-hole sets up lighttpd instance (which you don’t have to use) so you can see a pretty admin panel:

pihole

I added basic authentication to the admin subdirectory by adding the following lines to /etc/lighttpd/lighttpd.conf after following this tutorial:

#add http basic auth
auth.backend = "htdigest"
auth.backend.htdigest.userfile = "/etc/lighttpd/.htpasswd/lighttpd-htdigest.user"
auth.require = ("/admin" =>
( "method" => "digest",
"realm" => "rerss",
"require" => "valid-user" )
)

I also have 4 upstream DNS providers in /etc/dnsmasq.d/01-pihole.conf:

server=80.80.80.80
server=8.8.8.8
server=8.8.4.4
server=80.80.81.81

I still need to SSLify the page, but that’s coming.

The 8.8.* addresses are Google’s public DNS. The 80.80.* addresses are Freenom’s. There are myriad more free DNS providers out there – these are just the ones I use.

So what’s my tl;dr on pi-hole? It’s pretty good. It needs a little work to get it more stable between updates – but it’s very close. And I bet if I understood a little more of the setup process, I could probably make a fix to the update script that wouldn’t clobber (or would restore) any custom settings I have in place.

change your default font in windows 10

Starting from a tutorial I found recently, I want to share how to change your default font in Windows 10 – but in a shorter edition than that long one (and in, I think, a less-confusing way).

Back in the Good Ole Days™, you could easily change system font preferences by right-clicking on your desktop, and going into the themes and personalization tab to set whatever you wanted however you wanted (this is also where you could turn off (or back on) icons on your desktop (like My Documents), set window border widths, colors for everything, etc).

Windows 10 doesn’t let you do that through any form of Control Panel anymore, so you need to break-out the Registry Editor*.

0th, Start regedit

WindowsKey-R brings up the Run dialog – type regedit to start the Registry Editor

2016-07-27 (3)

NOTE: you should back-up any keys you plan to edit, just in case you forget what you did, want to revert, or make a mistake.

1st, Navigate to the right key area
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\FontSubstitutes

2016-07-27&&

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Fonts

2016-07-27 (1)Are where you’ll need to be to make these changes.

2nd, Blank entries for Segoe UI

For all of the “Segoe UI” entries in Fonts, change their Data field to blank (“”)

3rd, Add a Segoe UI substitute font

In FontSubstitutes, click Edit->String Value. Name it “Segoe UI” (without the quotes). In the “Value data” field, enter your preferred font name. I used Lucida Console.

2016-07-27 (2)

4th, Logout, or reboot, and login again to see your changes take effect.

* You can also download my registry keys, which have the substitution already done here. And you can pick any other font instead of Lucida Console you like – just edit the key file in your favorite text editor (I like TextPad) before merging into your Registry.

turn on spf filtering with postfix and centos 7

After running my new server for a while, I was noticing an unusually-high level of bogus email arriving in my inbox – mail that was being spoofed to look like it was coming from myself (to myself).

After a great deal of research, I learned there is a component of the DNS specification that allows for TEXT or SPF records. Sender Policy Framework was developed to help mail servers identify whether or not messages are being sent by authorized servers for their representative domains.

While there is a huge amount of stuff that could be added into a SPF record, what I am using for my domains is:

"v=spf1 mx -all"

Note: some DNS providers (like Digital Ocean) will make you use a TEXT record instead of a dedicated SPF record (which my registrar / DNS provider Pairnic supports).

If they require it be via TEXT record, it’ll look something like this: TXT @ "v=spf1 a include:_spf.google.com ~all"

Starting with this old how-to I found for CentOS 6, I added the policy daemon for Postfix (though it’s now in Python and not Perl) thusly:

yum install pypolicyd-spf

(I already had the EPEL yum repository installed – to get it setup, follow their directions, found here.)

Then I edited the master.cf config file for Postfix, adding the following at the bottom:

policy unix - n n - 0 spawn user=nobody argv=/bin/python /usr/libexec/postfix/policyd-spf

Note: those are actually tabs in my config file – but spaces work, too.

When you’re done with your edits and record additions, restart Postfix:

systemctl restart postfix

Then you’ll see messages like this in your /var/log/maillog file:

Apr 23 18:58:59 khopesh postfix/smtpd[18199]: NOQUEUE: reject: RCPT from unknown[197.27.40.169]: 550 5.7.1 <warren@datente.com>: Recipient address rejected: Message rejected due to: SPF fail - not authorized. Please see http://www.openspf.net/Why?s=mfrom;id=warren@datente.com;ip=197.27.40.169;r=warren@datente.com; from=<warren@datente.com> to=<warren@datente.com> proto=ESMTP helo=<[197.27.40.169]>

And if you follow the directive to go visit the “Why” page on OpenSPF, you’ll see something like this explanation:


Why did SPF cause my mail to be rejected?

What is SPF?

SPF is an extension to Internet e-mail. It prevents unauthorized people from forging your e-mail address (see the introduction). But for it to work, your own or your e-mail service provider’s setup may need to be adjusted. Otherwise, the system may mistake you for an unauthorized sender.

Note that there is no central institution that enforces SPF. If a message of yours gets blocked due to SPF, this is because (1) your domain has declared an SPF policy that forbids you to send through the mail server through which you sent the message, and (2) the recipient’s mail server detected this and blocked the message.

warren@datente.com rejected a message that claimed an envelope sender address of warren@datente.com. warren@datente.com received a message from 197.27.40.169 that claimed an envelope sender address of warren@datente.com.

However, the domain datente.com has declared using SPF that it does not send mail through 197.27.40.169. That is why the message was rejected.


how did i never know about .ssh/config?

I’m sure folks have tried to explain this to me before, but it wasn’t until today that it finally clicked – using .ssh/config will save you a world of hurt when managing various systems from a Linux host (I imagine it works on other platforms, too – but I’ve only started using it on CentOS).

Following directions I found here, I started a config file on a server I use as a jump box. In it I have an entry for my web server, and I’ll be adding other frequently-accessed servers to it as time goes on.

Thanks, nerderati, man pages … and whomever else tried to explain this to me before but I didn’t grok.

an even cleaner facebook most recent feed

Several months ago, I wrote-up a brief how-to on just showing the most recent news feed on Facebook.

I added a new Chrome extension today that helps speed-up your Facebook experience – Facebook Flat. It makes your Facebook views “flat” from a design perspective (no pun intended, but the extension falls a little flat when on highres screens with a fully-expanded browser window): it removes ads, reduces the color scheme, and generally makes it smoother.

If you combine this extension with loading https://m.facebook.com/home.php?sk=h_chr as your Facebook view (the mobile web edition in chronological order), the posts no longer fully-fill the screen, but instead stay centered as just a news feed in the middle of your screen.

Combine with something like Auto Refresh, and you can automate a clean view for your Facebook feed.

putting owncloud 8 on a subdomain instead of a subdirectory on centos 7

After moving to a new server, I wanted to finally get ownCloud up and running (over SSL, of course) on it.

And I like subdomains for different services, so I wanted to put it at sub.domain.tld. This turns out to be not as straight-forward as one might otherwise hope, sadly – ownCloud expects to be installed to domain.tld/owncloud (and plops itself into /var/www/owncloud by default (or sometimes /var/www/html/owncloud).

My server is running CentOS 7, Apache 2.4, and MariaDB (a drop-in replacement for MySQL). This overview is going to presume you’re running the same configuration – feel free to spin one up quickly at Digital Ocean to try this yourself.

Start with the ownCloud installation instructions, which will point you to the openSUSE build service page, where you’ll follow the steps to add the ownCloud community repo to your yum repo list, and install ownCloud. (In my last how-to, 8.0 was current – 8.2 rolled-out since I installed 8.1 a couple days ago.)

Here is where you need to go “off the reservation” to get it ready to actually install.

Add a VirtualHost directive to redirect http://sub.domain.tld to https://sub.domain.tld (cipher suite list compiled thusly):


<VirtualHost *:80>
ServerName sub.domain.tld
Redirect permanent / https://sub.domain.tld/
</VirtualHost>

Configure an SSL VirtualHost directive to listen for sub.domain.tld:


<VirtualHost *:443>
SSLCertificateFile /etc/letsencrypt/live/sub.domain.tld/cert.pem
SSLCertificateKeyFile /etc/letsencrypt/live/sub.domain.tld/privkey.pem
SSLCertificateChainFile /etc/letsencrypt/live/sub.domain.tld/fullchain.pem
DocumentRoot /var/www/subdomain
ServerName sub.domain.tld
ErrorLog logs/subdomain-error_log
CustomLog logs/subdomain-access_log "%t %h %{SSL_PROTOCOL}x %{SSL_CIPHER}x \"%r\" %b"
ServerAdmin user@domain.tld
SSLEngine on
SSLProtocol all -SSLv2 -SSLv3
SSLCipherSuite ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256:ECDHE-ECDSA-AES256-SHA384:ECDHE-RSA-AES256-SHA384:ECDHE-ECDSA-AES128-SHA256:ECDHE-RSA-AES128-SHA256
SSLHonorCipherOrder on
SSLOptions +StdEnvVars
<Directory "/var/www/cgi-bin">
SSLOptions +StdEnvVars
SetEnvIf User-Agent ".*MSIE.*" nokeepalive ssl-unclean-shutdown downgrade-1.0 force-response-1.0
# allow .htaccess to change things
<Directory "/var/www/subdomain">
Options All +Indexes +FollowSymLinks
AllowOverride All
Order allow,deny
Allow from all
</Directory>
</VirtualHost>

Comment-out every line in (or remove) /etc/httpd/conf.d/owncloud.conf.

Move /var/www/html/owncloud/* to /var/www/subdomain.

Make sure permissions are correct on /var/www/subdomain:

  • chown -R :apache /var/www/subdomain

Run the command-line installer: /var/www/subdomain/occ maintenance:install

Fix ownership of the config file, /var/www/subdomain/config/config.php to root:apache.

In config.php,

  • change trusted domains from ‘localhost‘ to ‘sub.domain.tld
  • make sure ‘datadirectory‘ is equal to /var/www/subdomain/data
  • change ‘overwrite.cli.url‘ from ‘localhost‘ to ‘https://sub.domain.tld

Navigate to http://sub.domain.tld, and follow the prompts – and you should be a happy camper.