ACME v2 and Wildcard Certificate Support is Live

We have some good news, letsencrypt support wildcard certificates! For more details click here.

The key phrase on the post is this:

Certbot has ACME v2 support since Version 0.22.0.

unfortunately -at this momment- using certbot on a centos6 is not so trivial, so here is an alternative approach using:

• acme.sh
• PowerDNS

acme.sh

acme.sh is a pure Unix shell script implementing ACME client protocol.

# curl -LO https://github.com/Neilpang/acme.sh/archive/2.7.7.tar.gz
# tar xf 2.7.7.tar.gz

# cd acme.sh-2.7.7/

[acme.sh-2.7.7]# ./acme.sh --version
https://github.com/Neilpang/acme.sh
v2.7.7

PowerDNS

I have my own Authoritative Na,e Server based on powerdns software.

PowerDNS has an API for direct control, also a built-in web server for statistics.

To enable these features make the appropriate changes to pdns.conf

api=yes
api-key=0123456789ABCDEF
webserver-port=8081

and restart your pdns service.

To read more about these capabilities, click here: Built-in Webserver and HTTP API

testing the API:

# curl -s -H 'X-API-Key: 0123456789ABCDEF' http://127.0.0.1:8081/api/v1/servers/localhost | jq .

{
  "zones_url": "/api/v1/servers/localhost/zones{/zone}",
  "version": "4.1.1",
  "url": "/api/v1/servers/localhost",
  "type": "Server",
  "id": "localhost",
  "daemon_type": "authoritative",
  "config_url": "/api/v1/servers/localhost/config{/config_setting}"
}

Enviroment

export PDNS_Url="http://127.0.0.1:8081"
export PDNS_ServerId="localhost"
export PDNS_Token="0123456789ABCDEF"
export PDNS_Ttl=60

Prepare Destination

I want to save the certificates under /etc/letsencrypt directory.
By default, acme.sh will save certificate files under /root/.acme.sh/balaskas.gr/ path.

I use selinux and I want to save them under /etc and on similar directory as before, so:

# mkdir -pv /etc/letsencrypt/acme.sh/balaskas.gr/

Create WildCard Certificate

Run:

# ./acme.sh
  --issue
  --dns dns_pdns
  --dnssleep 30
  -f
  -d balaskas.gr
  -d *.balaskas.gr
  --cert-file /etc/letsencrypt/acme.sh/balaskas.gr/cert.pem
  --key-file  /etc/letsencrypt/acme.sh/balaskas.gr/privkey.pem
  --ca-file   /etc/letsencrypt/acme.sh/balaskas.gr/ca.pem
  --fullchain-file /etc/letsencrypt/acme.sh/balaskas.gr/fullchain.pem

HSTS

Using HTTP Strict Transport Security means that the browsers probably already know that you are using a single certificate for your domains. So, you need to add every domain in your wildcard certificate.

Web Server

Change your VirtualHost

from something like this:

SSLCertificateFile /etc/letsencrypt/live/balaskas.gr/cert.pem
SSLCertificateKeyFile /etc/letsencrypt/live/balaskas.gr/privkey.pem
Include /etc/letsencrypt/options-ssl-apache.conf
SSLCertificateChainFile /etc/letsencrypt/live/balaskas.gr/chain.pem

to something like this:

SSLCertificateFile    /etc/letsencrypt/acme.sh/balaskas.gr/cert.pem
SSLCertificateKeyFile /etc/letsencrypt/acme.sh/balaskas.gr/privkey.pem
Include /etc/letsencrypt/options-ssl-apache.conf
SSLCertificateChainFile /etc/letsencrypt/acme.sh/balaskas.gr/fullchain.pem

and restart your web server.

Browser

Quallys

Qualys SSL Server Test)

Validation

X509v3 Subject Alternative Name

# openssl x509 -text -in /etc/letsencrypt/acme.sh/balaskas.gr/cert.pem | egrep balaskas

        Subject: CN=balaskas.gr
                DNS:*.balaskas.gr, DNS:balaskas.gr

Continuous Deployment with GitLab: how to build and deploy a RPM Package with GitLab CI

I would like to automate building custom rpm packages with gitlab using their CI/CD functionality. This article is a documentation of my personal notes on the matter.

[updated: 2018-03-20 gitlab-runner Possible Problems]

Installation

You can find notes on how to install gitlab-community-edition here: Installation methods for GitLab. If you are like me, then you dont run a shell script on you machines unless you are absolutely sure what it does. Assuming you read script.rpm.sh and you are on a CentOS 7 machine, you can follow the notes below and install gitlab-ce manually:

Import gitlab PGP keys

# rpm --import https://packages.gitlab.com/gitlab/gitlab-ce/gpgkey 

# rpm --import https://packages.gitlab.com/gitlab/gitlab-ce/gpgkey/gitlab-gitlab-ce-3D645A26AB9FBD22.pub.gpg

Gitlab repo

# curl -s 'https://packages.gitlab.com/install/repositories/gitlab/gitlab-ce/config_file.repo?os=centos&dist=7&source=script' \
  -o /etc/yum.repos.d/gitlab-ce.repo 

Install Gitlab

# yum -y install gitlab-ce

Configuration File

The gitlab core configuration file is /etc/gitlab/gitlab.rb
Remember that every time you make a change, you need to reconfigure gitlab:

# gitlab-ctl reconfigure

My VM’s IP is: 192.168.122.131. Update the external_url to use the same IP or add a new entry on your hosts file (eg. /etc/hosts).

external_url 'http://gitlab.example.com'

Run: gitlab-ctl reconfigure for updates to take effect.

Firewall

To access the GitLab dashboard from your lan, you have to configure your firewall appropriately.

You can do this in many ways:

• Accept everything on your http service
  # firewall-cmd --permanent --add-service=http

• Accept your lan:
  # firewall-cmd --permanent --add-source=192.168.122.0/24

• Accept only tcp IPv4 traffic from a specific lan
  # firewall-cmd --permanent --direct --add-rule ipv4 filter INPUT 0 -p tcp -s 192.168.0.0/16 -j ACCEPT

or you can complete stop firewalld (but not recommended)

• Stop your firewall
  # systemctl stop firewalld

okay, I think you’ve got the idea.

Reload your firewalld after every change on it’s zones/sources/rules.

# firewall-cmd --reload

success

Browser

Point your browser to your gitlab installation:

http://192.168.122.131/

this is how it looks the first time:

and your first action is to Create a new password by typing a password and hitting the Change your password button.

Login

First Page

New Project

I want to start this journey with a simple-to-build project, so I will try to build libsodium,
a modern, portable, easy to use crypto library.

New project --> Blank project

I will use this libsodium.spec file as the example for the CI/CD.

Docker

The idea is to build out custom rpm package of libsodium for CentOS 6, so we want to use docker containers through the gitlab CI/CD. We want clean & ephemeral images, so we will use containers as the building enviroments for the GitLab CI/CD.

Installing docker is really simple.

Installation

# yum -y install docker 

Run Docker

# systemctl restart docker
# systemctl enable  docker

Download image

Download a fresh CentOS v6 image from Docker Hub:

# docker pull centos:6 

Trying to pull repository docker.io/library/centos ...
6: Pulling from docker.io/library/centos
ca9499a209fd: Pull complete
Digest: sha256:551de58ca434f5da1c7fc770c32c6a2897de33eb7fde7508e9149758e07d3fe3

View Docker Images

# docker images

REPOSITORY          TAG                 IMAGE ID            CREATED             SIZE
docker.io/centos    6                   609c1f9b5406        7 weeks ago         194.5 MB

Gitlab Runner

Now, it is time to install and setup GitLab Runner.

In a nutshell this program, that is written in golang, will listen to every change on our repository and run every job that it can find on our yml file. But lets start with the installation:

# curl -s 'https://packages.gitlab.com/install/repositories/runner/gitlab-runner/config_file.repo?os=centos&dist=7&source=script' \
  -o /etc/yum.repos.d/gitlab-runner.repo

# yum -y install gitlab-runner

GitLab Runner Settings

We need to connect our project with the gitlab-runner.

 Project --> Settings --> CI/CD

or in our example:
http://192.168.122.131/root/libsodium/settings/ci_cd

click on the expand button on Runner’s settings and you should see something like this:

Register GitLab Runner

Type into your terminal:

# gitlab-runner register

following the instructions

[root@centos7 ~]# gitlab-runner register
Running in system-mode.                            

Please enter the gitlab-ci coordinator URL (e.g. https://gitlab.com/):
http://192.168.122.131/

Please enter the gitlab-ci token for this runner:
s6ASqkR8H9JysMSaFoLT

Please enter the gitlab-ci description for this runner:
[centos7]: 

Please enter the gitlab-ci tags for this runner (comma separated):

Whether to lock the Runner to current project [true/false]:
[true]: 

Registering runner... succeeded                     runner=s6ASqkR8

Please enter the executor: docker, ssh, virtualbox, docker-ssh+machine, kubernetes, docker-ssh, parallels, shell, docker+machine:
docker

Please enter the default Docker image (e.g. ruby:2.1):
centos:6

Runner registered successfully. Feel free to start it, but if it's running already the config should be automatically reloaded!
[root@centos7 ~]#

by refreshing the previous page we will see a new active runner on our project.

The Docker executor

We are ready to setup our first executor to our project. That means we are ready to run our first CI/CD example!

In gitlab this is super easy, just add a

New file --> Template --> gitlab-ci.yml --> based on bash

Dont forget to change the image from busybox:latest to centos:6

that will start a pipeline

GitLab Continuous Integration

Below is a gitlab ci test file that builds the rpm libsodium :

.gitlab-ci.yml

image: centos:6

before_script:
  - echo "Get the libsodium version and name from the rpm spec file"
  - export LIBSODIUM_VERS=$(egrep '^Version:' libsodium.spec | awk '{print $NF}')
  - export LIBSODIUM_NAME=$(egrep '^Name:'    libsodium.spec | awk '{print $NF}')

run-build:
  stage: build
  artifacts:
    untracked: true
  script:
    - echo "Install rpm-build package"
    - yum -y install rpm-build
    - echo "Install BuildRequires"
    - yum -y install gcc
    - echo "Create rpmbuild directories"
    - mkdir -p rpmbuild/{BUILD,RPMS,SOURCES,SPECS,SRPMS}
    - echo "Download source file from github"
    - curl -s -L https://github.com/jedisct1/$LIBSODIUM_NAME/releases/download/$LIBSODIUM_VERS/$LIBSODIUM_NAME-$LIBSODIUM_VERS.tar.gz -o rpmbuild/SOURCES/$LIBSODIUM_NAME-$LIBSODIUM_VERS.tar.gz
    - rpmbuild -D "_topdir `pwd`/rpmbuild" --clean -ba `pwd`/libsodium.spec

run-test:
  stage: test
  script:
    - echo "Test it, Just test it !"
    - yum -y install rpmbuild/RPMS/x86_64/$LIBSODIUM_NAME-$LIBSODIUM_VERS-*.rpm

run-deploy:
  stage: deploy
  script:
    - echo "Do your deploy here"

GitLab Artifacts

Before we continue I need to talk about artifacts

Artifacts is a list of files and directories that we produce at stage jobs and are not part of the git repository. We can pass those artifacts between stages, but you have to remember that gitlab can track files that only exist under the git-clone repository and not on the root fs of the docker image.

GitLab Continuous Delivery

We have successfully build an rpm file!! Time to deploy it to another machine. To do that, we need to add the secure shell private key to gitlab secret variables.

Project --> Settings --> CI/CD

stage: deploy

Lets re-write gitlab deployment state:

variables:
  DESTINATION_SERVER: '192.168.122.132'

run-deploy:
  stage: deploy
  script:
    - echo "Create ssh root directory"
    - mkdir -p ~/.ssh/ && chmod 700 ~/.ssh/

    - echo "Append secret variable to the ssh private key file"
    - echo -e "$SSH_PRIVATE_test_KEY" > ~/.ssh/id_rsa
    - chmod 0600 ~/.ssh/id_rsa

    - echo "Install SSH client"
    - yum -y install openssh-clients

    - echo "Secure Copy the libsodium rpm file to the destination server"
    - scp -o StrictHostKeyChecking=no rpmbuild/RPMS/x86_64/$LIBSODIUM_NAME-$LIBSODIUM_VERS-*.rpm  $DESTINATION_SERVER:/tmp/

    - echo "Install libsodium rpm file to the destination server"
    - ssh -o StrictHostKeyChecking=no $DESTINATION_SERVER yum -y install /tmp/$LIBSODIUM_NAME-$LIBSODIUM_VERS-*.rpm

and we can see that our pipeline has passed!

Possible Problems:

that will probable fail!

because our docker images don’t recognize gitlab.example.com.

Disclaimer: If you are using real fqdn - ip then you will probably not face this problem. I am referring to this issue, only for people who will follow this article step by step.

Easy fix:

# export -p EXTERNAL_URL="http://192.168.122.131" && yum -y reinstall gitlab-ce

GitLab Runner

GitLab Runner is not running !

# gitlab-runner verify
Running in system-mode.                            

Verifying runner... is alive                        runner=e9bbcf90
Verifying runner... is alive                        runner=77701bad

#  gitlab-runner status
gitlab-runner: Service is not running.

# gitlab-runner install  -u gitlab-runner -d /home/gitlab-runner/

# systemctl is-active gitlab-runner
inactive

# systemctl enable gitlab-runner
# systemctl start gitlab-runner

# systemctl is-active gitlab-runner
active

# systemctl | egrep gitlab-runner
  gitlab-runner.service     loaded active running   GitLab Runner

# gitlab-runner status
gitlab-runner: Service is running!

# ps -e fuwww | egrep -i gitlab-[r]unner
root      5116  0.4  0.1  63428 16968 ?        Ssl  07:44   0:00 /usr/bin/gitlab-runner run --working-directory /home/gitlab-runner/ --config /etc/gitlab-runner/config.toml --service gitlab-runner --syslog --user gitlab-runner

Encrypted files in Dropbox

As we live in the age of smartphones and mobility access to the cloud, the more there is the need to access our files from anywhere. We need our files to be available on any computer, ours (private) or others (public). Traveling with your entire tech equipment is not always a good idea and with the era of cloud you dont need to bring everything with you.

There are a lot of cloud hosting files providers out there. On wikipedia there is a good Comparison of file hosting services article you can read.

I’ve started to use Dropbox for that reason. I use dropbox as a public digital bucket, to store and share public files. Every digital asset that is online is somehow public and only when you are using end-to-end encryption then you can say that something is more secure than before.

I also want to store some encrypted files on my cloud account, without the need to trust dropbox (or any cloud hosting file provider for that reason). As an extra security layer on top of dropbox, I use encfs and this blog post is a mini tutorial of a proof of concept.

EncFS - Encrypted Virtual Filesystem

(definition from encfs github account)

EncFS creates a virtual encrypted filesystem which stores encrypted data in the rootdir directory and makes the unencrypted data visible at the mountPoint directory. The user must supply a password which is used to (indirectly) encrypt both filenames and file contents.

That means that you can store your encrypted files somewhere and mount the decrypted files on folder on your computer.

Disclaimer: I dont know how secure is encfs. It is an extra layer that doesnt need any root access (except the installation part) for end users and it is really simple to use. There is a useful answer on stackexchange that you night like to read .

For more information on enfs you can also visit EncFS - Wikipedia Page

Install EncFS

• archlinux

  $ sudo pacman -S --noconfirm encfs

• fedora

  $ sudo dnf -y install fuse-encfs

• ubuntu

  $ sudo apt-get install -y encfs

How does Encfs work ?

• You have two(2) directories. The source and the mountpoint.
• You encrypt and store the files in the source directory with a password.
• You can view/edit your files in cleartext, in the mount point.

1. Create a folder inside dropbox
   eg. /home/ebal/Dropbox/Boostnote

2. Create a folder outside of dropbox
   eg. /home/ebal/Boostnote

both folders are complete empty.

3. Choose a long password.
   just for testing, I am using a SHA256 message digest from an image that I can found on the internet!
   eg. sha256sum /home/ebal/secret.png

that means, I dont know the password but I can re-create it whenever I hash the image.

BE Careful This suggestion is an example - only for testing. The proper way is to use a random generated long password from your key password manager eg. KeePassX

How does dropbox works?

The dropbox-client is monitoring your /home/ebal/Dropbox/ directory for any changes so that can sync your files on your account.

You dont need dropbox running to use encfs.

Running the dropbox-client is the easiest way, but you can always use a sync client eg. rclone to sync your encrypted file to dropbox (or any cloud storage).

I guess it depends on your thread model. For this proof-of-concept article I run dropbox-client daemon in my background.

Create and Mount

Now is the time to mount the source directory inside dropbox with our mount point:

$ sha256sum /home/ebal/secret.png |
    awk '{print $1}' |
    encfs -S -s -f /home/ebal/Dropbox/Boostnote/ /home/ebal/Boostnote/

Reminder: EncFs works with absolute paths!

Check Mount Point

$ mount | egrep -i encfs

encfs on /home/ebal/Boostnote type fuse.encfs
(rw,nosuid,nodev,relatime,user_id=1001,group_id=1001,default_permissions)

View Files on Dropbox

Files inside dropbox:

View Files on the Mount Point

Unmount EncFS Mount Point

When you mount the source directory, encfs has an option to auto-umount the mount point on idle.
Or you can use the below command on demand:

$ fusermount -u /home/ebal/Boostnote

On another PC

The simplicity of this approach is when you want to access these files on another PC.
dropbox-client has already synced your encrypted files.
So the only thing you have to do, is to type on this new machine the exact same command as in Create & Mount chapter.

$ sha256sum /home/ebal/secret.png |
    awk '{print $1}' |
    encfs -S -s -f /home/ebal/Dropbox/Boostnote/ /home/ebal/Boostnote/

Android

How about Android ?

You can use Cryptonite.

Cryptonite can use EncFS and TrueCrypt on Android and you can find the app on Google Play

I’ve listened two audiobooks this month, both on DevOps methodology or more accurate on continuous improving of streamflow.

also started audible - amazon for listening audiobooks. The android app is not great but decent enough, although most of the books are DRM.

The first one is The Goal - A Process of Ongoing Improvement by: Eliyahu M. Goldratt, Jeff Cox

I can not stress this enough: You Have To Read this book. This novel is been categorized under business and it is been written back in 1984. You will find innovating even for today’s business logic. This book is the bases of “The Phoenix Project” and you have to read it before the The Phoenix Project. You will understand in details how lean and agile methodologies drive us to DevOps as a result of Ongoing Improvement.

https://www.audible.com/pd/Business/The-Goal-Audiobook/B00IFG88SM

The second book is The DevOps Handbook or How to Create World-Class Agility, Reliability, and Security in Technology Organizations by By: Gene Kim, Patrick Debois, John Willis, Jez Humble Narrated by: Ron Butler

I have this book in both hardcopy and audiobook. It is indeed a handbook. If you are just now starting on devops you need to read it. Has stories of companies that have applied the devops practices and It is really well structured. My suggestion is to keep notes when reading/listening to this book. Keep notes and re-read them.

https://www.audible.com/pd/Business/The-DevOps-Handbook-Audiobook/B0767HHZLZ

systemd

Latest systemd version now contains the systemd-importd daemon .

That means that we can use machinectl to import a tar or a raw image from the internet to use it with the systemd-nspawn command.

so here is an example

machinectl

from my archlinux box:

# cat /etc/arch-release

Arch Linux release

CentOS 7

We can download the tar centos7 docker image from the docker hub registry:

# machinectl pull-tar --verify=no https://github.com/CentOS/sig-cloud-instance-images/raw/79db851f4016c283fb3d30f924031f5a866d51a1/docker/centos-7-docker.tar.xz

...
Created new local image 'centos-7-docker'.
Operation completed successfully.
Exiting.

we can verify that:

# ls -la /var/lib/machines/centos-7-docker

total 28
dr-xr-xr-x 1 root root   158 Jan  7 18:59 .
drwx------ 1 root root   488 Feb  1 21:17 ..
-rw-r--r-- 1 root root 11970 Jan  7 18:59 anaconda-post.log
lrwxrwxrwx 1 root root     7 Jan  7 18:58 bin -> usr/bin
drwxr-xr-x 1 root root     0 Jan  7 18:58 dev
drwxr-xr-x 1 root root  1940 Jan  7 18:59 etc
drwxr-xr-x 1 root root     0 Nov  5  2016 home
lrwxrwxrwx 1 root root     7 Jan  7 18:58 lib -> usr/lib
lrwxrwxrwx 1 root root     9 Jan  7 18:58 lib64 -> usr/lib64
drwxr-xr-x 1 root root     0 Nov  5  2016 media
drwxr-xr-x 1 root root     0 Nov  5  2016 mnt
drwxr-xr-x 1 root root     0 Nov  5  2016 opt
drwxr-xr-x 1 root root     0 Jan  7 18:58 proc
dr-xr-x--- 1 root root   120 Jan  7 18:59 root
drwxr-xr-x 1 root root   104 Jan  7 18:59 run
lrwxrwxrwx 1 root root     8 Jan  7 18:58 sbin -> usr/sbin
drwxr-xr-x 1 root root     0 Nov  5  2016 srv
drwxr-xr-x 1 root root     0 Jan  7 18:58 sys
drwxrwxrwt 1 root root   140 Jan  7 18:59 tmp
drwxr-xr-x 1 root root   106 Jan  7 18:58 usr
drwxr-xr-x 1 root root   160 Jan  7 18:58 var

systemd-nspawn

Now test we can test it:

[root@myhomepc ~]# systemd-nspawn --machine=centos-7-docker

Spawning container centos-7-docker on /var/lib/machines/centos-7-docker.
Press ^] three times within 1s to kill container.

[root@centos-7-docker ~]#
[root@centos-7-docker ~]#
[root@centos-7-docker ~]# cat /etc/redhat-release
CentOS Linux release 7.4.1708 (Core)
[root@centos-7-docker ~]#
[root@centos-7-docker ~]# exit
logout
Container centos-7-docker exited successfully.

and now returning to our system:

[root@myhomepc ~]#
[root@myhomepc ~]#
[root@myhomepc ~]# cat /etc/arch-release
Arch Linux release

Ubuntu 16.04.4 LTS

ubuntu example:

# machinectl pull-tar --verify=no https://github.com/tianon/docker-brew-ubuntu-core/raw/46511cf49ad5d2628f3e8d88e1f8b18699a3ad8f/xenial/ubuntu-xenial-core-cloudimg-amd64-root.tar.gz

# systemd-nspawn --machine=ubuntu-xenial-core-cloudimg-amd64-root

Spawning container ubuntu-xenial-core-cloudimg-amd64-root on /var/lib/machines/ubuntu-xenial-core-cloudimg-amd64-root.
Press ^] three times within 1s to kill container.
Timezone Europe/Athens does not exist in container, not updating container timezone.
root@ubuntu-xenial-core-cloudimg-amd64-root:~# 

root@ubuntu-xenial-core-cloudimg-amd64-root:~# cat /etc/os-release 

NAME="Ubuntu"
VERSION="16.04.4 LTS (Xenial Xerus)"
ID=ubuntu
ID_LIKE=debian
PRETTY_NAME="Ubuntu 16.04.4 LTS"
VERSION_ID="16.04"
HOME_URL="http://www.ubuntu.com/"
SUPPORT_URL="http://help.ubuntu.com/"
BUG_REPORT_URL="http://bugs.launchpad.net/ubuntu/"
VERSION_CODENAME=xenial
UBUNTU_CODENAME=xenial

root@ubuntu-xenial-core-cloudimg-amd64-root:~# exit

logout
Container ubuntu-xenial-core-cloudimg-amd64-root exited successfully.

# cat /etc/os-release 

NAME="Arch Linux"
PRETTY_NAME="Arch Linux"
ID=arch
ID_LIKE=archlinux
ANSI_COLOR="0;36"
HOME_URL="https://www.archlinux.org/"
SUPPORT_URL="https://bbs.archlinux.org/"
BUG_REPORT_URL="https://bugs.archlinux.org/"

Network-Bound Disk Encryption

I was reading the redhat release notes on 7.4 and came across: Chapter 15. Security

New packages: tang, clevis, jose, luksmeta

Network Bound Disk Encryption (NBDE) allows the user to encrypt root volumes of the hard drives on physical and virtual machines without requiring to manually enter password when systems are rebooted.

That means, we can now have an encrypted (luks) volume that will be de-crypted on reboot, without the need of typing a passphrase!!!

Really - really useful on VPS (and general in cloud infrastructures)

Useful Links

• https://github.com/latchset/tang
• https://github.com/latchset/jose
• https://github.com/latchset/clevis

CentOS 7.4 with Encrypted rootfs

(aka client machine)

Below is a test centos 7.4 virtual machine with an encrypted root filesystem:

/boot

/

Tang Server

(aka server machine)

Tang is a server for binding data to network presence. This is a different centos 7.4 virtual machine from the above.

Installation

Let’s install the server part:

# yum -y install tang

Start socket service:

# systemctl restart tangd.socket

Enable socket service:

# systemctl enable tangd.socket

TCP Port

Check that the tang server is listening:

# netstat -ntulp | egrep -i systemd

tcp6    0    0 :::80    :::*    LISTEN    1/systemd

Firewall

Dont forget the firewall:

Firewall Zones

# firewall-cmd --get-active-zones

public
  interfaces: eth0

Firewall Port

# firewall-cmd --zone=public --add-port=80/tcp --permanent

or

# firewall-cmd --add-port=80/tcp --permanent

success

Reload

# firewall-cmd --reload

success

We have finished with the server part!

Client Machine - Encrypted rootfs

Now it is time to configure the client machine, but before let’s check the encrypted partition:

CryptTab

Every encrypted block devices is configured under crypttab file:

[root@centos7 ~]# cat /etc/crypttab

luks-3cc09d38-2f55-42b1-b0c7-b12f6c74200c UUID=3cc09d38-2f55-42b1-b0c7-b12f6c74200c none 

FsTab

and every filesystem that is static mounted on boot, is configured under fstab:

[root@centos7 ~]# cat /etc/fstab

UUID=c5ffbb05-d8e4-458c-9dc6-97723ccf43bc          /boot  xfs  defaults  0 0

/dev/mapper/luks-3cc09d38-2f55-42b1-b0c7-b12f6c74200c  /  xfs  defaults,x-systemd.device-timeout=0 0 0

Installation

Now let’s install the client (clevis) part that will talk with tang:

# yum -y install clevis clevis-luks clevis-dracut

Configuration

with a very simple command:

# clevis bind luks -d /dev/vda2 tang '{"url":"http://192.168.122.194"}'

The advertisement contains the following signing keys:

FYquzVHwdsGXByX_rRwm0VEmFRo

Do you wish to trust these keys? [ynYN] y

You are about to initialize a LUKS device for metadata storage.
Attempting to initialize it may result in data loss if data was
already written into the LUKS header gap in a different format.
A backup is advised before initialization is performed.

Do you wish to initialize /dev/vda2? [yn] y

Enter existing LUKS password:

we’ve just configured our encrypted volume against tang!

Luks MetaData

We can verify it’s luks metadata with:

[root@centos7 ~]# luksmeta show -d /dev/vda2

0   active empty
1   active cb6e8904-81ff-40da-a84a-07ab9ab5715e
2 inactive empty
3 inactive empty
4 inactive empty
5 inactive empty
6 inactive empty
7 inactive empty

dracut

We must not forget to regenerate the initramfs image, that on boot will try to talk with our tang server:

[root@centos7 ~]# dracut -f

Reboot

Now it’s time to reboot!

A short msg will appear in our screen, but in a few seconds and if successfully exchange messages with the tang server, our server with de-crypt the rootfs volume.

Tang messages

To finish this article, I will show you some tang msg via journalct:

Initialization

Getting the signing key from the client on setup:

Jan 31 22:43:09 centos7 systemd[1]: Started Tang Server (192.168.122.195:58088).
Jan 31 22:43:09 centos7 systemd[1]: Starting Tang Server (192.168.122.195:58088)...
Jan 31 22:43:09 centos7 tangd[1219]: 192.168.122.195 GET /adv/ => 200 (src/tangd.c:85)

reboot

Client is trying to decrypt the encrypted volume on reboot

Jan 31 22:46:21 centos7 systemd[1]: Started Tang Server (192.168.122.162:42370).
Jan 31 22:46:21 centos7 systemd[1]: Starting Tang Server (192.168.122.162:42370)...
Jan 31 22:46:22 centos7 tangd[1223]: 192.168.122.162 POST /rec/Shdayp69IdGNzEMnZkJasfGLIjQ => 200 (src/tangd.c:168)

Ready Player One by Ernest Cline

I’ve listened to the audiobook, Narrated by Wil Wheaton.

The book is AMAZING! Taking a trip down memory lane to ’80s pop culture, video games, music & movies. A sci-fi futuristic book that online gamers are trying to solve puzzles on a easter egg hunt for the control of oasis, a virtual reality game.

You can find more info here

Fabric

Fabric is a Python (2.5-2.7) library and command-line tool for streamlining the use of SSH for application deployment or systems administration tasks.

You can find the documentation here

Installation

# yum -y install epel-release

# yum -y install fabric

Hello World

# cat > fabfile.py <<EOF
> def hello():
>     print("Hello world!")
>
> EOF

and run it

# fab hello -f ./fabfile.py

Hello world!

Done.

A more complicated example

def HelloWorld():
        print("Hello world!")

def hello(name="world"):
        print("Hello %s!" % name )

# fab HelloWorld -f ./fabfile.py
Hello world!

Done.

# fab hello -f ./fabfile.py
Hello world!

Done.

# fab hello:name=ebal -f ./fabfile.py
Hello ebal!

Done.

A remote example

from fabric.api import run , env

env.use_ssh_config = True

def HelloWorld():
    print("Hello world!")

def hello(name="world"):
    print("Hello %s!" % name )

def uptime():
    run('uptime')

ssh configuration file

with the below variable declaration
(just remember to import env)
fabric can use the ssh configuration file of your system

  env.use_ssh_config = True

and run it against server test

$ fab -H test uptime -f ./fabfile.py

[test] Executing task 'uptime'
[test] run: uptime
[test] out:  20:21:30 up 10 days, 11 min,  1 user,  load average: 0.00, 0.00, 0.00
[test] out: 

Done.
Disconnecting from 192.168.122.1:22... done.

2FA SSH aka OpenSSH OATH, Two-Factor Authentication

prologue

Good security is based on layers of protection. At some point the usability gets in the way. My thread model on accessing systems is to create a different ssh pair of keys (private/public) and only use them instead of a login password. I try to keep my digital assets separated and not all of them under the same basket. My laptop is encrypted and I dont run any services on it, but even then a bad actor can always find a way.

Back in the days, I was looking on Barada/Gort. Barada is an implementation of HOTP: An HMAC-Based One-Time Password Algorithm and Gort is the android app you can install to your mobile and connect to barada. Both of these application have not been updated since 2013/2014 and Gort is even removed from f-droid!

Talking with friends on our upcoming trip to 34C4, discussing some security subjects, I thought it was time to review my previous inquiry on ssh-2FA. Most of my friends are using yubikeys. I would love to try some, but at this time I dont have the time to order/test/apply to my machines. To reduce any risk, the idea of combining a bastion/jump-host server with 2FA seemed to be an easy and affordable solution.

OpenSSH with OATH

As ssh login is based on PAM (Pluggable Authentication Modules), we can use Gnu OATH Toolkit. OATH stands for Open Authentication and it is an open standard. In a nutshell, we add a new authorization step that we can verify our login via our mobile device.

Below are my personal notes on how to setup oath-toolkit, oath-pam and how to synchronize it against your android device. These are based on centos 6.9

EPEL

We need to install the epel repository:

# yum -y install https://dl.fedoraproject.org/pub/epel/6/x86_64/epel-release-6-8.noarch.rpm

Searching packages

Searching for oath

# yum search oath

the results are similar to these:

liboath.x86_64       : Library for OATH handling
liboath-devel.x86_64 : Development files for liboath
liboath-doc.noarch   : Documentation files for liboath

pam_oath.x86_64      : A PAM module for pluggable login authentication for OATH
gen-oath-safe.noarch : Script for generating HOTP/TOTP keys (and QR code)
oathtool.x86_64      : A command line tool for generating and validating OTPs

Installing packages

We need to install three packages:

• pam_oath is the PAM for OATH
• oathtool is the gnu oath-toolkit
• gen-oath-safe is the program that we will use to sync our mobile device with our system

# yum -y install pam_oath oathtool gen-oath-safe

FreeOTP

Before we continue with our setup, I believe now is the time to install FreeOTP

FreeOTP looks like:

HOTP

Now, it is time to generate and sync our 2FA, using HOTP

Generate

You should replace username with your USER_NAME !

# gen-oath-safe username HOTP

Sync

and scan the QR with FreeOTP

You can see in the top a new entry!

Save

Do not forget to save your HOTP key (hex) to the gnu oath-toolkit user file.

eg.

Key in Hex: e9379dd63ec367ee5c378a7c6515af01cf650c89

# echo "HOTP username - e9379dd63ec367ee5c378a7c6515af01cf650c89" > /etc/liboath/oathuserfile

verify:

# cat /etc/liboath/oathuserfile

HOTP username - e9379dd63ec367ee5c378a7c6515af01cf650c89

OpenSSH

The penultimate step is to setup our ssh login with the PAM oath library.

Verify PAM

# ls -l /usr/lib64/security/pam_oath.so

-rwxr-xr-x 1 root root 11304 Nov 11  2014 /usr/lib64/security/pam_oath.so

SSHD-PAM

# cat /etc/pam.d/sshd

In modern systems, the sshd pam configuration file seems:

#%PAM-1.0
auth       required pam_sepermit.so
auth       include      password-auth
account    required     pam_nologin.so
account    include      password-auth
password   include      password-auth
# pam_selinux.so close should be the first session rule
session    required     pam_selinux.so close
session    required     pam_loginuid.so
# pam_selinux.so open should only be followed by sessions to be executed in the user context
session    required     pam_selinux.so open env_params
session    required     pam_namespace.so
session    optional     pam_keyinit.so force revoke
session    include      password-auth

We need one line in the top of the file.

I use something like this:

auth       sufficient /usr/lib64/security/pam_oath.so  debug   usersfile=/etc/liboath/oathuserfile window=5 digits=6

Depending on your policy and thread model, you can switch sufficient to requisite , you can remove debug option. In the third field, you can try typing just the pam_path.so without the full path and you can change the window to something else:

eg.

auth requisite pam_oath.so usersfile=/etc/liboath/oathuserfile window=10 digits=6

Restart sshd

In every change/test remember to restart your ssh daemon:

# service sshd restart

Stopping sshd:                                             [  OK  ]
Starting sshd:                                             [  OK  ]

SELINUX

If you are getting some weird messages, try to change the status of selinux to permissive and try again. If the selinux is the issue, you have to review selinux audit logs and add/fix any selinux policies/modules so that your system can work properly.

# getenforce
Enforcing

# setenforce 0

# getenforce
Permissive

Testing

The last and most important thing, is to test it !

Links

• 34C3 - https://events.ccc.de/congress/2017/wiki/index.php/Main_Page
• HOTP - https://tools.ietf.org/html/rfc4226
• OATH - https://openauthentication.org/
• FreeOTP - https://freeotp.github.io
• Gnu OATH ToolKit - http://www.nongnu.org/oath-toolkit/index.html
• PAM - https://www.linux.com/news/understanding-pam

Post Scriptum

The idea of using OATH & FreeOTP can also be applied to login into your laptop as PAM is the basic authentication framework on a linux machine. You can use OATH in every service that can authenticate it self through PAM.

How to install Signal dekstop to archlinux

Download Signal Desktop

eg. latest version v1.0.41

$ curl -s https://updates.signal.org/desktop/apt/pool/main/s/signal-desktop/signal-desktop_1.0.41_amd64.deb \
    -o /tmp/signal-desktop_1.0.41_amd64.deb

Verify Package

There is a way to manually verify the integrity of the package, by checking the hash value of the file against a gpg signed file. To do that we need to add a few extra steps in our procedure.

Download Key from the repository

$ wget -c https://updates.signal.org/desktop/apt/keys.asc

--2017-12-11 22:13:34--  https://updates.signal.org/desktop/apt/keys.asc
Loaded CA certificate '/etc/ssl/certs/ca-certificates.crt'
Connecting to 127.0.0.1:8118... connected.
Proxy request sent, awaiting response... 200 OK
Length: 3090 (3.0K) [application/pgp-signature]
Saving to: ‘keys.asc’

keys.asc                          100%[============================================================>]   3.02K  --.-KB/s    in 0s      

2017-12-11 22:13:35 (160 MB/s) - ‘keys.asc’ saved [3090/3090]

Import the key to your gpg keyring

$ gpg2 --import keys.asc

gpg: key D980A17457F6FB06: public key "Open Whisper Systems <support@whispersystems.org>" imported
gpg: Total number processed: 1
gpg:               imported: 1

you can also verify/get public key from a known key server

$ gpg2 --verbose --keyserver pgp.mit.edu --recv-keys 0xD980A17457F6FB06

gpg: data source: http://pgp.mit.edu:11371
gpg: armor header: Version: SKS 1.1.6
gpg: armor header: Comment: Hostname: pgp.mit.edu
gpg: pub  rsa4096/D980A17457F6FB06 2017-04-05  Open Whisper Systems <support@whispersystems.org>
gpg: key D980A17457F6FB06: "Open Whisper Systems <support@whispersystems.org>" not changed
gpg: Total number processed: 1
gpg:              unchanged: 1

Here is already in place, so no changes.

Download Release files

$ wget -c https://updates.signal.org/desktop/apt/dists/xenial/Release

$ wget -c https://updates.signal.org/desktop/apt/dists/xenial/Release.gpg

Verify Release files

$ gpg2 --no-default-keyring --verify Release.gpg Release

gpg: Signature made Sat 09 Dec 2017 04:11:06 AM EET
gpg:                using RSA key D980A17457F6FB06
gpg: Good signature from "Open Whisper Systems <support@whispersystems.org>" [unknown]
gpg: WARNING: This key is not certified with a trusted signature!
gpg:          There is no indication that the signature belongs to the owner.
Primary key fingerprint: DBA3 6B51 81D0 C816 F630  E889 D980 A174 57F6 FB06

That means that Release file is signed from whispersystems and the integrity of the file is not changed/compromized.

Download Package File

We need one more file and that is the Package file that contains the hash values of the deb packages.

$ wget -c https://updates.signal.org/desktop/apt/dists/xenial/main/binary-amd64/Packages

But is this file compromized?
Let’s check it against Release file:

$ sha256sum Packages

ec74860e656db892ab38831dc5f274d54a10347934c140e2a3e637f34c402b78  Packages

$ grep ec74860e656db892ab38831dc5f274d54a10347934c140e2a3e637f34c402b78 Release

 ec74860e656db892ab38831dc5f274d54a10347934c140e2a3e637f34c402b78     1713 main/binary-amd64/Packages

yeay !

Verify deb Package

Finally we are now ready to manually verify the integrity of the deb package:

$ sha256sum signal-desktop_1.0.41_amd64.deb

9cf87647e21bbe0c1b81e66f88832fe2ec7e868bf594413eb96f0bf3633a3f25  signal-desktop_1.0.41_amd64.deb

$ egrep 9cf87647e21bbe0c1b81e66f88832fe2ec7e868bf594413eb96f0bf3633a3f25 Packages

SHA256: 9cf87647e21bbe0c1b81e66f88832fe2ec7e868bf594413eb96f0bf3633a3f25

Perfect, we are now ready to continue

Extract under tmp filesystem

$ cd /tmp/

$ ar vx signal-desktop_1.0.41_amd64.deb

x - debian-binary
x - control.tar.gz
x - data.tar.xz

Extract data under tmp filesystem

$ tar xf data.tar.xz

Move Signal-Desktop under root filesystem

# sudo mv opt/Signal/ /opt/Signal/

Done

Actually, that’s it!

Run

Run signal-desktop as a regular user:

$ /opt/Signal/signal-desktop

Signal Desktop

Proxy

Define your proxy settings on your environment:

declare -x ftp_proxy="proxy.example.org:8080"
declare -x http_proxy="proxy.example.org:8080"
declare -x https_proxy="proxy.example.org:8080"

Signal

Autonomous by Annalee Newitz

The year is 2144. A group of anti-patent scientists are working to reverse engineer drugs in free labs, for (poor) people to have access to them. Agents of International Property Coalition are trying to find the lead pirate-scientist and stop any patent violation by any means necessary. In this era, without a franchise (citizenship) autonomous robots and people are slaves. But only a few of the bots have are autonomous. Even then, can they be free ? Can androids choose their own gender identity ? Transhumanism and extension life drugs are helping people to live a longer and better life.

A science fiction novel without Digital Rights Management (DRM).

Fighting Spam

Fighting email spam in modern times most of the times looks like this:

Rspamd

Rspamd is a rapid spam filtering system. Written in C with Lua script engine extension seems to be really fast and a really good solution for SOHO environments.

In this blog post, I'’ll try to present you a quickstart guide on working with rspamd on a CentOS 6.9 machine running postfix.

DISCLAIMER: This blog post is from a very technical point of view!

Installation

We are going to install rspamd via know rpm repositories:

Epel Repository

We need to install epel repository first:

# yum -y install http://fedora-mirror01.rbc.ru/pub/epel/6/x86_64/epel-release-6-8.noarch.rpm

Rspamd Repository

Now it is time to setup the rspamd repository:

# curl https://rspamd.com/rpm-stable/centos-6/rspamd.repo -o /etc/yum.repos.d/rspamd.repo

Install the gpg key

# rpm --import http://rspamd.com/rpm-stable/gpg.key

and verify the repository with # yum repolist

repo id     repo name
base        CentOS-6 - Base
epel        Extra Packages for Enterprise Linux 6 - x86_64
extras      CentOS-6 - Extras
rspamd      Rspamd stable repository
updates     CentOS-6 - Updates

Rpm

Now it is time to install rspamd to our linux box:

# yum -y install rspamd

# yum info rspamd

Name        : rspamd
Arch        : x86_64
Version     : 1.6.3
Release     : 1
Size        : 8.7 M
Repo        : installed
From repo   : rspamd
Summary     : Rapid spam filtering system
URL         : https://rspamd.com
License     : BSD2c
Description : Rspamd is a rapid, modular and lightweight spam filter. It is designed to work
            : with big amount of mail and can be easily extended with own filters written in
            : lua.

Init File

We need to correct rspamd init file so that rspamd can find the correct configuration file:

# vim /etc/init.d/rspamd

# ebal, Wed, 06 Sep 2017 00:31:37 +0300
## RSPAMD_CONF_FILE="/etc/rspamd/rspamd.sysvinit.conf"
RSPAMD_CONF_FILE="/etc/rspamd/rspamd.conf"

or

# ln -s /etc/rspamd/rspamd.conf /etc/rspamd/rspamd.sysvinit.conf

Start Rspamd

We are now ready to start for the first time rspamd daemon:

# /etc/init.d/rspamd restart

syntax OK
Stopping rspamd:                                           [FAILED]
Starting rspamd:                                           [  OK  ]

verify that is running:

# ps -e fuwww | egrep -i rsp[a]md

root      1337  0.0  0.7 205564  7164 ?        Ss   20:19   0:00 rspamd: main process
_rspamd   1339  0.0  0.7 206004  8068 ?        S    20:19   0:00  _ rspamd: rspamd_proxy process
_rspamd   1340  0.2  1.2 209392 12584 ?        S    20:19   0:00  _ rspamd: controller process
_rspamd   1341  0.0  1.0 208436 11076 ?        S    20:19   0:00  _ rspamd: normal process   

perfect, now it is time to enable rspamd to run on boot:

# chkconfig rspamd on

# chkconfig --list | egrep rspamd
rspamd          0:off   1:off   2:on    3:on    4:on    5:on    6:off

Postfix

In a nutshell, postfix will pass through (filter) an email using the milter protocol to another application before queuing it to one of postfix’s mail queues. Think milter as a bridge that connects two different applications.

Rspamd Proxy

In Rspamd 1.6 Rmilter is obsoleted but rspamd proxy worker supports milter protocol. That means we need to connect our postfix with rspamd_proxy via milter protocol.

Rspamd has a really nice documentation: https://rspamd.com/doc/index.html
On MTA integration you can find more info.

# netstat -ntlp | egrep -i rspamd

output:

tcp        0      0 0.0.0.0:11332               0.0.0.0:*                   LISTEN      1451/rspamd
tcp        0      0 0.0.0.0:11333               0.0.0.0:*                   LISTEN      1451/rspamd
tcp        0      0 127.0.0.1:11334             0.0.0.0:*                   LISTEN      1451/rspamd
tcp        0      0 :::11332                    :::*                        LISTEN      1451/rspamd
tcp        0      0 :::11333                    :::*                        LISTEN      1451/rspamd
tcp        0      0 ::1:11334                   :::*                        LISTEN      1451/rspamd  

# egrep -A1 proxy /etc/rspamd/rspamd.conf

worker "rspamd_proxy" {
    bind_socket = "*:11332";
    .include "$CONFDIR/worker-proxy.inc"
    .include(try=true; priority=1,duplicate=merge) "$LOCAL_CONFDIR/local.d/worker-proxy.inc"
    .include(try=true; priority=10) "$LOCAL_CONFDIR/override.d/worker-proxy.inc"
}

Milter

If you want to know all the possibly configuration parameter on postfix for milter setup:

# postconf | egrep -i milter

output:

milter_command_timeout = 30s
milter_connect_macros = j {daemon_name} v
milter_connect_timeout = 30s
milter_content_timeout = 300s
milter_data_macros = i
milter_default_action = tempfail
milter_end_of_data_macros = i
milter_end_of_header_macros = i
milter_helo_macros = {tls_version} {cipher} {cipher_bits} {cert_subject} {cert_issuer}
milter_macro_daemon_name = $myhostname
milter_macro_v = $mail_name $mail_version
milter_mail_macros = i {auth_type} {auth_authen} {auth_author} {mail_addr} {mail_host} {mail_mailer}
milter_protocol = 6
milter_rcpt_macros = i {rcpt_addr} {rcpt_host} {rcpt_mailer}
milter_unknown_command_macros =
non_smtpd_milters =
smtpd_milters = 

We are mostly interested in the last two, but it is best to follow rspamd documentation:

# vim /etc/postfix/main.cf

Adding the below configuration lines:

# ebal, Sat, 09 Sep 2017 18:56:02 +0300

## A list of Milter (mail filter) applications for new mail that does not arrive via the Postfix smtpd(8) server.
on_smtpd_milters = inet:127.0.0.1:11332

## A list of Milter (mail filter) applications for new mail that arrives via the Postfix smtpd(8) server.
smtpd_milters = inet:127.0.0.1:11332

## Send macros to mail filter applications
milter_mail_macros = i {auth_type} {auth_authen} {auth_author} {mail_addr} {client_addr} {client_name} {mail_host} {mail_mailer}

## skip mail without checks if something goes wrong, like rspamd is down !
milter_default_action = accept

Reload postfix

# postfix reload

postfix/postfix-script: refreshing the Postfix mail system

Testing

netcat

From a client:

$ nc 192.168.122.96 25

220 centos69.localdomain ESMTP Postfix
EHLO centos69
250-centos69.localdomain
250-PIPELINING
250-SIZE 10240000
250-VRFY
250-ETRN
250-ENHANCEDSTATUSCODES
250-8BITMIME
250 DSN
MAIL FROM: <root@example.org>
250 2.1.0 Ok
RCPT TO: <root@localhost>
250 2.1.5 Ok
DATA
354 End data with <CR><LF>.<CR><LF>
test
.
250 2.0.0 Ok: queued as 4233520144
^]

Logs

Looking through logs may be a difficult task for many, even so it is a task that you have to do.

MailLog

# egrep 4233520144 /var/log/maillog

Sep  9 19:08:01 localhost postfix/smtpd[1960]: 4233520144: client=unknown[192.168.122.1]
Sep  9 19:08:05 localhost postfix/cleanup[1963]: 4233520144: message-id=<>
Sep  9 19:08:05 localhost postfix/qmgr[1932]: 4233520144: from=<root@example.org>, size=217, nrcpt=1 (queue active)
Sep  9 19:08:05 localhost postfix/local[1964]: 4233520144: to=<root@localhost.localdomain>, orig_to=<root@localhost>, relay=local, delay=12, delays=12/0.01/0/0.01, dsn=2.0.0, status=sent (delivered to mailbox)
Sep  9 19:08:05 localhost postfix/qmgr[1932]: 4233520144: removed

Everything seems fine with postfix.

Rspamd Log

# egrep -i 4233520144 /var/log/rspamd/rspamd.log

2017-09-09 19:08:05 #1455(normal) <79a04e>; task; rspamd_message_parse: loaded message; id: <undef>; queue-id: <4233520144>; size: 6; checksum: <a6a8e3835061e53ed251c57ab4f22463>

2017-09-09 19:08:05 #1455(normal) <79a04e>; task; rspamd_task_write_log: id: <undef>, qid: <4233520144>, ip: 192.168.122.1, from: <root@example.org>, (default: F (add header): [9.40/15.00] [MISSING_MID(2.50){},MISSING_FROM(2.00){},MISSING_SUBJECT(2.00){},MISSING_TO(2.00){},MISSING_DATE(1.00){},MIME_GOOD(-0.10){text/plain;},ARC_NA(0.00){},FROM_NEQ_ENVFROM(0.00){;root@example.org;},RCVD_COUNT_ZERO(0.00){0;},RCVD_TLS_ALL(0.00){}]), len: 6, time: 87.992ms real, 4.723ms virtual, dns req: 0, digest: <a6a8e3835061e53ed251c57ab4f22463>, rcpts: <root@localhost>

It works !

Training

If you have already a spam or junk folder is really easy training the Bayesian classifier with rspamc.

I use Maildir, so for my setup the initial training is something like this:

 # cd /storage/vmails/balaskas.gr/evaggelos/.Spam/cur/ 

# find . -type f -exec rspamc learn_spam {} \;

Auto-Training

I’ve read a lot of tutorials that suggest real-time training via dovecot plugins or something similar. I personally think that approach adds complexity and for small companies or personal setup, I prefer using Cron daemon:

 @daily /bin/find /storage/vmails/balaskas.gr/evaggelos/.Spam/cur/ -type f -mtime -1 -exec rspamc learn_spam {} \;

That means every day, search for new emails in my spam folder and use them to train rspamd.

Training from mbox

First of all seriously ?

Split mbox

There is a nice and simply way to split a mbox to separated files for rspamc to use them.

# awk '/^From / {i++}{print > "msg"i}' Spam

and then feed rspamc:

# ls -1 msg* | xargs rspamc --verbose learn_spam

Stats

# rspamc stat

Results for command: stat (0.068 seconds)
Messages scanned: 2
Messages with action reject: 0, 0.00%
Messages with action soft reject: 0, 0.00%
Messages with action rewrite subject: 0, 0.00%
Messages with action add header: 2, 100.00%
Messages with action greylist: 0, 0.00%
Messages with action no action: 0, 0.00%
Messages treated as spam: 2, 100.00%
Messages treated as ham: 0, 0.00%
Messages learned: 1859
Connections count: 2
Control connections count: 2157
Pools allocated: 2191
Pools freed: 2170
Bytes allocated: 542k
Memory chunks allocated: 41
Shared chunks allocated: 10
Chunks freed: 0
Oversized chunks: 736
Fuzzy hashes in storage "rspamd.com": 659509399
Fuzzy hashes stored: 659509399
Statfile: BAYES_SPAM type: sqlite3; length: 32.66M; free blocks: 0; total blocks: 430.29k; free: 0.00%; learned: 1859; users: 1; languages: 4
Statfile: BAYES_HAM type: sqlite3; length: 9.22k; free blocks: 0; total blocks: 0; free: 0.00%; learned: 0; users: 1; languages: 1
Total learns: 1859

X-Spamd-Result

To view the spam score in every email, we need to enable extended reporting headers and to do that we need to edit our configuration:

# vim /etc/rspamd/modules.d/milter_headers.conf

and just above use add :

    # ebal, Wed, 06 Sep 2017 01:52:08 +0300
    extended_spam_headers = true;

   use = [];

then reload rspamd:

# /etc/init.d/rspamd reload

syntax OK
Reloading rspamd:                                          [  OK  ]

View Source

If your open the email in view-source then you will see something like this:

X-Rspamd-Queue-Id: D0A5728ABF
X-Rspamd-Server: centos69
X-Spamd-Result: default: False [3.40 / 15.00]

Web Server

Rspamd comes with their own web server. That is really useful if you dont have a web server in your mail server, but it is not recommended.

By-default, rspamd web server is only listening to local connections. We can see that from the below ss output

# ss -lp | egrep -i rspamd

LISTEN     0      128                    :::11332                   :::*        users:(("rspamd",7469,10),("rspamd",7471,10),("rspamd",7472,10),("rspamd",7473,10))
LISTEN     0      128                     *:11332                    *:*        users:(("rspamd",7469,9),("rspamd",7471,9),("rspamd",7472,9),("rspamd",7473,9))
LISTEN     0      128                    :::11333                   :::*        users:(("rspamd",7469,18),("rspamd",7473,18))
LISTEN     0      128                     *:11333                    *:*        users:(("rspamd",7469,16),("rspamd",7473,16))
LISTEN     0      128                   ::1:11334                   :::*        users:(("rspamd",7469,14),("rspamd",7472,14),("rspamd",7473,14))
LISTEN     0      128             127.0.0.1:11334                    *:*        users:(("rspamd",7469,12),("rspamd",7472,12),("rspamd",7473,12))

127.0.0.1:11334

So if you want to change that (dont) you have to edit the rspamd.conf (core file):

# vim +/11334 /etc/rspamd/rspamd.conf

and change this line:

bind_socket = "localhost:11334";

to something like this:

bind_socket = "YOUR_SERVER_IP:11334";

or use sed:

# sed -i -e 's/localhost:11334/YOUR_SERVER_IP/' /etc/rspamd/rspamd.conf

and then fire up your browser:

Web Password

It is a good tactic to change the default password of this web-gui to something else.

# vim /etc/rspamd/worker-controller.inc

  # password = "q1";
  password = "password";

always a good idea to restart rspamd.

Reverse Proxy

I dont like having exposed any web app without SSL or basic authentication, so I shall put rspamd web server under a reverse proxy (apache).

So on httpd-2.2 the configuration is something like this:

ProxyPreserveHost On

<Location /rspamd>
    AuthName "Rspamd Access"
    AuthType Basic
    AuthUserFile /etc/httpd/rspamd_htpasswd
    Require valid-user

    ProxyPass http://127.0.0.1:11334
    ProxyPassReverse http://127.0.0.1:11334 

    Order allow,deny
    Allow from all 

</Location>

Http Basic Authentication

You need to create the file that is going to be used to store usernames and password for basic authentication:

# htpasswd -csb /etc/httpd/rspamd_htpasswd rspamd rspamd_passwd
Adding password for user rspamd

restart your apache instance.

bind_socket

Of course for this to work, we need to change the bind socket on rspamd.conf
Dont forget this ;)

bind_socket = "127.0.0.1:11334";

Selinux

If there is a problem with selinux, then:

# setsebool -P httpd_can_network_connect=1

or

# setsebool httpd_can_network_connect_db on

Errors ?

If you see an error like this:
IO write error

when running rspamd, then you need explicit tell rspamd to use:

rspamc -h 127.0.0.1:11334

To prevent any future errors, I’ve created a shell wrapper:

/usr/local/bin/rspamc

#!/bin/sh
/usr/bin/rspamc -h 127.0.0.1:11334 $*

Final Thoughts

I am using rspamd for a while know and I am pretty happy with it.

I’ve setup a spamtrap email address to feed my spam folder and let the cron script to train rspamd.

So after a thousand emails:

Walkaway by Cory Doctorow

Are you willing to walk-away without anything in the world to build a better world ?

In many companies, nagios is the de-facto monitoring tool. Even with new modern alternatives solutions, this opensource project, still, has a large amount of implementations in place. This guide is based on a “clean/fresh” CentOS 6.9 virtual machine.

Epel

An official nagios repository exist in this address: https://repo.nagios.com/
I prefer to install nagios via the EPEL repository:

# yum -y install http://fedora-mirror01.rbc.ru/pub/epel/6/x86_64/epel-release-6-8.noarch.rpm

# yum info nagios | grep Version
Version     : 4.3.2

# yum -y install nagios

Selinux

Every online manual, suggest to disable selinux with nagios. There is a reason for that ! but I will try my best to provide info on how to keep selinux enforced. To write our own nagios selinux policies the easy way, we need one more package:

# yum -y install policycoreutils-python

Starting nagios:

# /etc/init.d/nagios restart

will show us some initial errors in /var/log/audit/audit.log selinux log file

Filtering the results:

# egrep denied /var/log/audit/audit.log | audit2allow

will display something like this:

#============= nagios_t ==============
allow nagios_t initrc_tmp_t:file write;
allow nagios_t self:capability chown;

To create a policy file based on your errors:

# egrep denied /var/log/audit/audit.log | audit2allow -a -M nagios_t

and to enable it:

# semodule -i nagios_t.pp

BE AWARE this is not the only problem with selinux, but I will provide more details in few moments.

Nagios

Now we are ready to start the nagios daemon:

# /etc/init.d/nagios restart

filtering the processes of our system:

# ps -e fuwww | egrep na[g]ios

nagios    2149  0.0  0.1  18528  1720 ?        Ss   19:37   0:00 /usr/sbin/nagios -d /etc/nagios/nagios.cfg
nagios    2151  0.0  0.0      0     0 ?        Z    19:37   0:00  _ [nagios] <defunct>
nagios    2152  0.0  0.0      0     0 ?        Z    19:37   0:00  _ [nagios] <defunct>
nagios    2153  0.0  0.0      0     0 ?        Z    19:37   0:00  _ [nagios] <defunct>
nagios    2154  0.0  0.0      0     0 ?        Z    19:37   0:00  _ [nagios] <defunct>
nagios    2155  0.0  0.0  18076   712 ?        S    19:37   0:00  _ /usr/sbin/nagios -d /etc/nagios/nagios.cfg

super!

Apache

Now it is time to start our web server apache:

# /etc/init.d/httpd restart

Starting httpd: httpd: apr_sockaddr_info_get() failed
httpd: Could not reliably determine the server's fully qualified domain name, using 127.0.0.1 for ServerName

This is a common error, and means that we need to define a ServerName in our apache configuration.

First, we give an name to our host file:

# vim /etc/hosts

for this guide, I ‘ll go with the centos69 but you can edit that according your needs:

127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4 centos69

then we need to edit the default apache configuration file:

# vim /etc/httpd/conf/httpd.conf

#ServerName www.example.com:80
ServerName centos69

and restart the process:

# /etc/init.d/httpd restart

Stopping httpd:      [  OK  ]
Starting httpd:      [  OK  ]

We can see from the netstat command that is running:

# netstat -ntlp | grep 80

tcp        0      0 :::80                       :::*                        LISTEN      2729/httpd      

Firewall

It is time to fix our firewall and open the default http port, so that we can view the nagios from our browser.
That means, we need to fix our iptables !

# iptables -A INPUT -m state --state NEW -m tcp -p tcp --dport 80 -j ACCEPT

this is want we need. To a more permanent solution, we need to edit the default iptables configuration file:

# vim /etc/sysconfig/iptables

and add the below entry on INPUT chain section:

-A INPUT -m state --state NEW -m tcp -p tcp --dport 80 -j ACCEPT

Web Browser

We are ready to fire up our web browser and type the address of our nagios server.
Mine is on a local machine with the IP: 129.168.122.96, so

http://192.168.122.96/nagios/

User Authentication

The default user authentication credentials are:

nagiosadmin // nagiosadmin

but we can change them!

From our command line, we type something similar:

# htpasswd -sb /etc/nagios/passwd nagiosadmin e4j9gDkk6LXncCdDg

so that htpasswd will update the default nagios password entry on the /etc/nagios/passwd with something else, preferable random and difficult password.

ATTENTION: e4j9gDkk6LXncCdDg is just that, a random password that I created for this document only. Create your own and dont tell anyone!

Selinux, Part Two

at this moment and if you are tail-ing the selinux audit file, you will see some more error msgs.

Below, you will see my nagios_t selinux policy file with all the things that are needed for nagios to run properly - at least at the moment.!

module nagios_t 1.0;

require {
        type nagios_t;
        type initrc_tmp_t;
        type nagios_spool_t;
        type nagios_system_plugin_t;
        type nagios_exec_t;
        type httpd_nagios_script_t;
        class capability chown;
        class file { write read open execute_no_trans getattr };
}

#============= httpd_nagios_script_t ==============
allow httpd_nagios_script_t nagios_spool_t:file { open read getattr };

#============= nagios_t ==============
allow nagios_t initrc_tmp_t:file write;
allow nagios_t nagios_exec_t:file execute_no_trans;
allow nagios_t self:capability chown;

#============= nagios_system_plugin_t ==============
allow nagios_system_plugin_t nagios_exec_t:file getattr;

Edit your nagios_t.te file accordingly and then build your selinux policy:

# make -f /usr/share/selinux/devel/Makefile

You are ready to update the previous nagios selinux policy :

# semodule -i nagios_t.pp

Selinux - Nagios package

So … there is an rpm package with the name: nagios-selinux on Version: 4.3.2
you can install it, but does not resolve all the selinux errors in audit file ….. so ….
I think my way is better, cause you can understand some things better and have more flexibility on defining your selinux policy

Nagios Plugins

Nagios is the core process, daemon. We need the nagios plugins - the checks !
You can do something like this:

# yum install nagios-plugins-all.x86_64

but I dont recommend it.

These are the defaults :

nagios-plugins-load-2.2.1-4git.el6.x86_64
nagios-plugins-ping-2.2.1-4git.el6.x86_64
nagios-plugins-disk-2.2.1-4git.el6.x86_64
nagios-plugins-procs-2.2.1-4git.el6.x86_64
nagios-plugins-users-2.2.1-4git.el6.x86_64
nagios-plugins-http-2.2.1-4git.el6.x86_64
nagios-plugins-swap-2.2.1-4git.el6.x86_64
nagios-plugins-ssh-2.2.1-4git.el6.x86_64

# yum -y install nagios-plugins-load nagios-plugins-ping nagios-plugins-disk nagios-plugins-procs nagios-plugins-users nagios-plugins-http nagios-plugins-swap nagios-plugins-ssh

and if everything is going as planned, you will see something like this:

PNP4Nagios

It is time, to add pnp4nagios a simple graphing tool and get read the nagios performance data and represent them to graphs.

# yum info pnp4nagios | grep Version
Version     : 0.6.22

# yum -y install pnp4nagios

We must not forget to restart our web server:

# /etc/init.d/httpd restart

Bulk Mode with NPCD

I’ve spent toooooo much time to understand why the default Synchronous does not work properly with nagios v4x and pnp4nagios v0.6x
In the end … this is what it works - so try not to re-invent the wheel , as I tried to do and lost so many hours.

Performance Data

We need to tell nagios to gather performance data from their check:

# vim +/process_performance_data /etc/nagios/nagios.cfg

process_performance_data=1

We also need to tell nagios, what to do with this data:

nagios.cfg

# *** the template definition differs from the one in the original nagios.cfg
#
service_perfdata_file=/var/log/pnp4nagios/service-perfdata
service_perfdata_file_template=DATATYPE::SERVICEPERFDATAtTIMET::$TIMET$tHOSTNAME::$HOSTNAME$tSERVICEDESC::$SERVICEDESC$tSERVICEPERFDATA::$SERVICEPERFDATA$tSERVICECHECKCOMMAND::$SERVICECHECKCOMMAND$tHOSTSTATE::$HOSTSTATE$tHOSTSTATETYPE::$HOSTSTATETYPE$tSERVICESTATE::$SERVICESTATE$tSERVICESTATETYPE::$SERVICESTATETYPE$
service_perfdata_file_mode=a
service_perfdata_file_processing_interval=15
service_perfdata_file_processing_command=process-service-perfdata-file

# *** the template definition differs from the one in the original nagios.cfg
#
host_perfdata_file=/var/log/pnp4nagios/host-perfdata
host_perfdata_file_template=DATATYPE::HOSTPERFDATAtTIMET::$TIMET$tHOSTNAME::$HOSTNAME$tHOSTPERFDATA::$HOSTPERFDATA$tHOSTCHECKCOMMAND::$HOSTCHECKCOMMAND$tHOSTSTATE::$HOSTSTATE$tHOSTSTATETYPE::$HOSTSTATETYPE$
host_perfdata_file_mode=a
host_perfdata_file_processing_interval=15
host_perfdata_file_processing_command=process-host-perfdata-file

Commands

In the above configuration, we introduced two new commands

service_perfdata_file_processing_command  &
host_perfdata_file_processing_command

We need to define them in the /etc/nagios/objects/commands.cfg file :

#
# Bulk with NPCD mode
#
define command {
       command_name    process-service-perfdata-file
       command_line    /bin/mv /var/log/pnp4nagios/service-perfdata /var/spool/pnp4nagios/service-perfdata.$TIMET$
}

define command {
       command_name    process-host-perfdata-file
       command_line    /bin/mv /var/log/pnp4nagios/host-perfdata /var/spool/pnp4nagios/host-perfdata.$TIMET$
}

If everything have gone right … then you will be able to see on a nagios check something like this:

Verify

Verify your pnp4nagios setup:

# wget -c http://verify.pnp4nagios.org/verify_pnp_config

# perl verify_pnp_config -m bulk+npcd -c /etc/nagios/nagios.cfg -p /etc/pnp4nagios/ 

NPCD

The NPCD daemon (Nagios Performance C Daemon) is the daemon/process that will translate the gathered performance data to graphs, so let’s started it:

# /etc/init.d/npcd restart
Stopping npcd:                                             [FAILED]
Starting npcd:                                             [  OK  ]

You should see some warnings but not any critical errors.

Templates

Two new template definition should be created, one for the host and one for the service:

/etc/nagios/objects/templates.cfg

define host {
   name       host-pnp
   action_url /pnp4nagios/index.php/graph?host=$HOSTNAME$&srv=_HOST_' class='tips' rel='/pnp4nagios/index.php/popup?host=$HOSTNAME$&srv=_HOST_
   register   0
}

define service {
   name       srv-pnp
   action_url /pnp4nagios/graph?host=$HOSTNAME$&srv=$SERVICEDESC$' class='tips' rel='/pnp4nagios/popup?host=$HOSTNAME$&srv=$SERVICEDESC$
   register   0
}

Host Definition

Now we need to apply the host-pnp template to our system:

so this configuration: /etc/nagios/objects/localhost.cfg

define host{
        use                     linux-server            ; Name of host template to use
                                                        ; This host definition will inherit all variables that are defined
                                                        ; in (or inherited by) the linux-server host template definition.
        host_name               localhost
        alias                   localhost
        address                 127.0.0.1
        }

becomes:

define host{
        use                     linux-server,host-pnp            ; Name of host template to use
                                                        ; This host definition will inherit all variables that are defined
                                                        ; in (or inherited by) the linux-server host template definition.
        host_name               localhost
        alias                   localhost
        address                 127.0.0.1
        }

Service Definition

And we finally must append the pnp4nagios service template to our services:

srv-pnp

define service{
        use                             local-service,srv-pnp         ; Name of service template to use
        host_name                       localhost

Graphs

We should be able to see graphs like these:

Happy Measurements!

appendix

These are some extra notes on the above article, you need to take in mind:

Services

# chkconfig httpd on
# chkconfig iptables on
# chkconfig nagios on
# chkconfig npcd on 

PHP

If you are not running the default php version on your system, it is possible to get this error msg:

Non-static method nagios_Core::SummaryLink()

There is a simply solution for that, you need to modify the index file to exclude the deprecated php error msgs:

# vim +/^error_reporting /usr/share/nagios/html/pnp4nagios/index.php   

// error_reporting(E_ALL & ~E_STRICT);
error_reporting(E_ALL & ~E_STRICT & ~E_DEPRECATED);

SCAM

Τον τελευταίο καιρό, όλο και περισσότερα email με το παρακάτω (ή παρόμοιο) body φτάνουν στο mailbox μου.
Οι περισσότεροι από εσάς, εύκολα θα διαπιστώσετε πως το παρακάτω είναι google translate, άλλοι πάλι όχι με μια πρώτη ματιά.

Be careful

Είναι, λοιπόν, ένα SCAM email, που προσπαθεί να σας ψαρέψει τα στοιχεία.

Π Ο Τ Ε καμία εταιρεία (πάροχος ή τράπεζα) δεν πρόκειται να σας ζητήσει μέσω email τα στοιχεία σας.

για αυτό Μ Η Ν απαντάτε ΠΟΤΕ σε emails της παρακάτω μορφής.

Actions

Το καλύτερο που έχετε να κάνετε, είναι να προωθήσετε ΑΜΕΣΩΣ το παρακάτω email στο abuse department της εταιρείας σας.

Μπορείτε να βοηθήσετε στην καταπολέμηση της εξάπλωσης αυτού του scam.

Abuse

Τα εκάστοτε abuse departments έχουν εργαλεία που καταγράφουν αυτές τις απόπειρες “ψαρέματος” κι εντοπίζουν τα μολυσμένα PC ή compromised accounts

Με ένα γρήγορο online search βρίσκουμε πολύ γρήγορα μερικά από τα παρακάτω abuse email addresses:

abuse@cosmote.gr
abuse@ote.gr
abuse@forthnet.gr
abuse@wind.gr
abuse@hq.cyta.gr
abuse@hol.gr
postmaster@hol.gr
abuse@nbg.gr
abuse@alpha.gr
support@winbank.gr

Inform Other People

Το καλύτερο που έχετε να κάνετε, είναι να μιλήσετε με τους ανθρώπους του κύκλου σας και να τους ενημερώσετε σχετικά με αυτό.
Μην ξεχνάτε πως εάν τους “χακέψουν” πολύ πιθανά να έχουν στους υπολογιστές τους, δικά σας στοιχεία (από την αποθηκευμένη ατζέντα επαφών)
ή (μερική) πρόσβαση στα email που τους έχετε στείλει κι εσείς.

Οπότε, προστατεύοντάς τους, προστατεύεται και τον εαυτό σας!!

Body

παρακάτω, ένα ενδεικτικό δείγμα. Μπορεί το κείμενο να δείχνει σε άλλο πάροχο ή σε κάποια τράπεζα.
Να έχει κάποιο σύνδεσμο, στον οποίο να πρέπει να πατήσει κάποιος και να συμπληρώσει τα στοιχεία του
ή κάποια φόρμα επικοινωνίας.

Μην ξεχνάτε: Π Ο Τ Ε δεν πρέπει να δίνουμε τα στοιχεία μας, όταν βλέπουμε τέτοια emails.

Cosmote υπηρεσία OTEnet Mail

Μετά την αυτόματη ανανέωση της εγγραφή® σας το διακομιστής αντιμετώπισε κάποια λάθη να μην απαριθμήσω διεύθυνση σας.
Σας ενημερώνουμε ότι δεν μπορείτε να αποκτήσετε πρόσβαση στο λογαριασμό σας! Ή χρησιμοποιήστε το σχετικό προφίλ
αν δεν αναγνωρίσετε τον εαυτό σας σύμφωνα με τους κανονισμούς μας. Παρακαλώ μέσα σε 72 ώρες για να επιβεβαιώσετε
τη διεύθυνση ηλεκτρονικού ταχυδρομείου σας OTEnet Mail, καθώς και όλες τις πληροφορίες που ζητούνται μέσω της παρακάτω φόρμας.

ΕΠΙΒΕΒΑΙΩΣΗ ΤΟΥ ΕΝΤΥΠΟΥ (κάντε κλικ απάντηση και διαβιβάζει τα στοιχεία σας στην υπηρεσία επιβεβαίωσης στη συνέχεια αποστολή)

όνομα:........................
Όνομα:........................
Στοιχεία σύνδεσης (Απαιτείται)
Email OTEnet! :........................
κωδικό πρόσβασης:........................
Εναλλακτικές Email:........................
κωδικό πρόσβασης:........................
χώρα:........................
Ταχυδρομικός κώδικας:........................
τηλέφωνο:........................

Σημείωση: Σε περίπτωση έλλειψης των πληροφοριών που ζητούνται γνωρίζετε ότι αυτό θα διαγράψει οριστικά τη διεύθυνση ηλεκτρονικού ταχυδρομείου σας.

Με εκτίμηση.

Let’s Encrypt

I’ve written some posts on Let’s Encrypt but the most frequently question is how to auto renew a certificate every 90 days.

Disclaimer

This is my mini how-to, on centos 6 with a custom compiled Python 2.7.13 that I like to run on virtualenv from latest git updated certbot. Not a copy/paste solution for everyone!

Cron

Cron doesnt not seem to have something useful to use on comparison to 90 days:

Modification Time

The most obvious answer is to look on the modification time on lets encrypt directory :

eg. domain: balaskas.gr

# find /etc/letsencrypt/live/balaskas.gr -type d -mtime +90 -exec ls -ld {} \;

# find /etc/letsencrypt/live/balaskas.gr -type d -mtime +80 -exec ls -ld {} \;

# find /etc/letsencrypt/live/balaskas.gr -type d -mtime +70 -exec ls -ld {} \;

# find /etc/letsencrypt/live/balaskas.gr -type d -mtime +60 -exec ls -ld {} \;

drwxr-xr-x. 2 root root 4096 May 15 20:45 /etc/letsencrypt/live/balaskas.gr

OpenSSL

# openssl x509 -in <(openssl s_client -connect balaskas.gr:443 2>/dev/null) -noout -enddate

Email

If you have registered your email with Let’s Encrypt then you get your first email in 60 days!

Renewal

Here are my own custom steps:

#  cd /root/certbot.git
#  git pull origin 

#  source venv/bin/activate && source venv/bin/activate
#  cd venv/bin/

#  monit stop httpd 

#  ./venv/bin/certbot renew --cert-name balaskas.gr --standalone 

#  monit start httpd 

#  deactivate

Script

I use monit, you can edit the script accordingly to your needs :

#!/bin/sh

DOMAIN=$1

## Update certbot
cd /root/certbot.git
git pull origin 

# Enable Virtual Environment for python
source venv/bin/activate && source venv/bin/activate 

## Stop Apache
monit stop httpd 

sleep 5

## Renewal
./venv/bin/certbot renew  --cert-name ${DOMAIN} --standalone 

## Exit virtualenv
deactivate 

## Start Apache
monit start httpd

All Together

# find /etc/letsencrypt/live/balaskas.gr -type d -mtime +80 -exec /usr/local/bin/certbot.autorenewal.sh balaskas.gr \;

Systemd Timers

or put it on cron

whatever :P

How to install slack dekstop to archlinux

Download Slack Desktop

eg. latest version

https://downloads.slack-edge.com/linux_releases/slack-2.6.3-0.1.fc21.x86_64.rpm

Extract under root filesystem

# cd /

# rpmextract.sh slack-2.6.3-0.1.fc21.x86_64.rpm

Done

Actually, that’s it!

Run

Run slack-desktop as a regular user:

$ /usr/lib/slack/slack

Slack Desktop

Proxy

Define your proxy settings on your environment:

declare -x ftp_proxy="proxy.example.org:8080"
declare -x http_proxy="proxy.example.org:8080"
declare -x https_proxy="proxy.example.org:8080"

Slack

Iterator

a few months ago, I wrote an article on RecursiveDirectoryIterator, you can find the article here: PHP Recursive Directory File Listing . If you run the code example, you ‘ll see that the output is not sorted.

Object

Recursive Iterator is actually an object, a special object that we can perform iterations on sequence (collection) of data. So it is a little difficult to sort them using known php functions. Let me give you an example:

$Iterator = new RecursiveDirectoryIterator('./');
foreach ($Iterator as $file)
    var_dump($file);

object(SplFileInfo)#7 (2) {
  ["pathName":"SplFileInfo":private]=>
  string(12) "./index.html"
  ["fileName":"SplFileInfo":private]=>
  string(10) "index.html"
}

You see here, the iterator is an object of SplFileInfo class.

Internet Answers

Unfortunately stackoverflow and other related online results provide the most complicated answers on this matter. Of course this is not stackoverflow’s error, and it is really a not easy subject to discuss or understand, but personally I dont get the extra fuzz (complexity) on some of the responses.

Back to basics

So let us go back a few steps and understand what an iterator really is. An iterator is an object that we can iterate! That means we can use a loop to walk through the data of an iterator. Reading the above output you can get (hopefully) a better idea.

We can also loop the Iterator as a simply array.

eg.

$It = new RecursiveDirectoryIterator('./');
foreach ($It as $key=>$val)
    echo $key.":".$val."n";

output:

./index.html:./index.html

Arrays

It is difficult to sort Iterators, but it is really easy to sort arrays!
We just need to convert the Iterator into an Array:

// Copy the iterator into an array
$array = iterator_to_array($Iterator);

that’s it!

Sorting

For my needs I need to reverse sort the array by key (filename on a recursive directory), so my sorting looks like:

krsort( $array );

easy, right?

Just remember that you can use ksort before the array is already be defined. You need to take two steps, and that is ok.

Convert to Iterator

After sorting, we need to change back an iterator object format:

// Convert Array to an Iterator
$Iterator = new ArrayIterator($array);

and that’s it !

Full Code Example

the entire code in one paragraph:

<?php
# ebal, Fri, 07 Jul 2017 22:01:48 +0300

// Directory to Recursive search
$dir = "/tmp/";

// Iterator Object
$files =  new RecursiveIteratorIterator(
          new RecursiveDirectoryIterator($dir)
          );

// Convert to Array
$Array = iterator_to_array ( $files );
// Reverse Sort by key the array
krsort ( $Array );
// Convert to Iterator
$files = new ArrayIterator( $Array );

// Print the file name
foreach($files as $name => $object)
    echo "$namen";

?>

Prologue

Part of my day job is to protect a large mail infrastructure. That means that on a daily basis we are fighting SPAM and try to protect our customers for any suspicious/malicious mail traffic. This is not an easy job. Actually globally is not a easy job. But we are trying and trying hard.

ReplyTo

The last couple months, I have started a project on gitlab gathering the malicious ReplyTo from already identified spam emails. I was looking for a pattern or something that I can feed our antispam engines with so that we can identify spam more accurately. It’s doesnt seem to work as i thought. Spammers can alter their ReplyTo in a matter of minutes!

TheList

Here is the list for the last couple months: ReplyTo
I will -from time to time- try to update it and hopefully someone can find it useful

Free domains

It’s not much yet, but even with this small sample you can see that ~ 50% of phishing goes back to gmail !

    105 gmail.com
     49 yahoo.com
     18 hotmail.com
     17 outlook.com

More Info

You can contact me with various ways if you are interested in more details.

Preferably via encrypted email: PGP: ‘ 0×1c8968af8d2c621f ‘
or via DM in twitter: @ebalaskas

PS

I also keep another list, of suspicious fwds
but keep in mind that it might have some false positives.

Prologue

I should have written this post like a decade ago, but laziness got the better of me.

I use TLS with IMAP and SMTP mail server. That means I encrypt the connection by protocol against the mail server and not by port (ssl Vs tls). Although I do not accept any authentication before STARTTLS command is being provided (that means no cleartext passwords in authentication), I was leaving the PLAIN TEXT authentication mechanism in the configuration. That’s not an actual problem unless you are already on the server and you are trying to connect on localhost but I can do better.

LDAP

I use OpenLDAP as my backend authentication database. Before all, the ldap attribute password must be changed from cleartext to CRAM-MD5

Typing the doveadm command from dovecot with the password method:

# doveadm pw

Enter new password:    test
Retype new password:   test
{CRAM-MD5}e02d374fde0dc75a17a557039a3a5338c7743304777dccd376f332bee68d2cf6

will return the CRAM-MD5 hash of our password (test)

Then we need to edit our DN (distinguished name) with ldapvi:

From:

uid=USERNAME,ou=People,dc=example,dc=org
userPassword: test

To:

uid=USERNAME,ou=People,dc=example,dc=org
userPassword: {CRAM-MD5}e02d374fde0dc75a17a557039a3a5338c7743304777dccd376f332bee68d2cf6

Dovecot

Dovecot is not only the imap server but also the “Simple Authentication and Security Layer” aka SASL service. That means that imap & smtp are speaking with dovecot for authentication and dovecot uses ldap as the backend. To change AUTH=PLAIN to cram-md5 we need to do the below change:

file: 10-auth.conf

From:

auth_mechanisms = plain

To:

auth_mechanisms = cram-md5

Before restarting dovecot, we need to make one more change. This step took me a couple hours to figure it out! On our dovecot-ldap.conf.ext configuration file, we need to tell dovecot NOT to bind to ldap for authentication but let dovecot to handle the authentication process itself:

From:

# Enable Authentication Binds
# auth_bind = yes

To:

# Enable Authentication Binds
auth_bind = no

To guarantee that the entire connection is protected by TLS encryption, change in 10-ssl.conf the below setting:

From:

ssl = yes

To:

ssl = required

SSL/TLS is always required, even if non-plaintext authentication mechanisms are used. Any attempt to authenticate before SSL/TLS is enabled will cause an authentication failure.

After that, restart your dovecot instance.

Testing

# telnet example.org imap

Trying 172.12.13.14 ...
Connected to example.org.
Escape character is '^]'.
* OK [CAPABILITY IMAP4rev1 LITERAL+ SASL-IR LOGIN-REFERRALS ID ENABLE IDLE STARTTLS AUTH=CRAM-MD5] Dovecot ready.

1 LOGIN USERNAME@example.org test

1 NO [ALERT] Unsupported authentication mechanism.
^]
telnet> clo

That meas no cleartext authentication is permitted

MUA

Now the hard part, the mail clients:

RainLoop

My default webmail client since v1.10.1.123 supports CRAM-MD5
To verify that, open your application.ini file under your data folder and search for something like that:

    imap_use_auth_plain = On
    imap_use_auth_cram_md5 = On
    smtp_use_auth_plain = On
    smtp_use_auth_cram_md5 = On

as a bonus, rainloop supports STARTTLS and authentication for imap & smtp, even when talking to 127.0.0.1

Thunderbird

K9