Posts Tagged ‘package management’

iSH, the best free SSH / Telnet client for iOS iPhone, iPad equivallent of MobaXterm and fully functional Alpine Linux emulator

Wednesday, February 8th, 2023

ish-linux-terminal-emulator-for-iphone-ipad-ios-logo-screenshoticon

Since few months I've switched my old BLU r1 HD Phone (a great old low budget phone for its price) to a friend's iPhone 10 ( X ) who gifted it for me. Coming from Android world, everyone who has experience with it is a pain in the ass as some of the Apps, which are into Google's play store does not have the same equivalent into Apple's install Package manager tool AppStore. Some of the crucial tools which I was interested as a freshly new migrated user from Android to iPhone was to have a decent SSH / Telnet client and Terminal, with which I can easily connect to my Linux servers both home and work. 

As Android Phone user, to connect and manage my SSH sessions I used most often some of the most popular Connectbot / SSHDroid / JuiceSSH.
On Android I've usually installed all of these tools but most frequently used Connectbot, which quickly become my favourite SSH client for Android over time.

The reasons why I really loved Connectbot and used it on Android OS in short:

  • It is Completely free
  • Ad-free
  • Open-source (too bad not Free software but still step better)
  • Copy and paste text between Applications
  • Customizable interface (i.e. font size, keyboard layout, SSH auth agent, etc.)


connectbot-android-ssh-remote-connect-client-screenshot

I've seen some people used and preferred Termius but never myself really liked this client, as it was including some Advertisements or for don't remember why reason.
Switching to iOS mobile operating system, of course was quite a shock especially the moment I found out the standard loved SSH Remote Client programs are used are not available or have only a paid version. Thus it took me quite a while of a research and googling until I found some decent stuff.

termius-ssh-telnet-client-ios-screenshot

Tried for a time with Termius as well but again, its Ads and lack of some functionality pissed me off, so I've moved on to Shelly.

shelly-iphone-ssh-telnet-client-ios-screenshot

Shelly is really not a bad tool but has limitation over the SSH sessions you can add and other limitations, which can only be unlocked with an "Upgrade", to its paid version, thus I decided after few weeks of attempts to make it my remote server management mobile tool for iPhone, I've dropped it off as well.

Then I found the Blink Shell App – Blink Shell is a professional, desktop grade terminal for iOS. As overall the tool is really great and is easy to use but again to have it used in its full power you need the paid version and until you pay for it every now and then you got interruption of your shell for some really annoying ads.
Thus even though I used it for a times this few tools with whom basicly you can do basic remote ssh / telnet session operations eventually,  started looking for a better SSH Client Free alternative for iPhone Users.

Then came a friend at home for a dinner my dear friend Milen (Static) and he show me iOS.
The moment I saw this tool I totally loved it, for its simplicity and its resemblance to a classical TTY Physical old Linux console I used back in the days and its ability to resemble easily any improved functionaltiy through simple screen (multiple session management) command tool or tmux.

Wait, what's iSH ? And why it is the Best SSH / Telnet client to manage your servers remotely on iOS Mobiles (iPhone and IPads) ? 

iSH is a project to get a Linux shell environment running locally on your iOS device, using a usermode x86 emulator.


In other wors iSH is Linux emulator with busybox and a package ports for many of the standard Linux tools you get by simple apt-get / yum or if I have to compare you get via the MobaXterm's advanced apt-cyg (Cygwin packages) tool capabilities.

Once iSH is installed it comes with pre-installed apk command line package management tool, with which you can install stuff like openssh-client / screen / tmux / mc (midnight commander) etc. apk, is an apt like command like tool which uses as a basis for installing its packages Alpine Linux repositories.
Alpine Linux is perhaps little known as it is not one of these main stream disributions, such as Fedora or Ubuntu, but for those more concerned about security  Alpine Linux is well known as it is a security-oriented, lightweight Linux distribution based on musl libc and busybox. What makes the Linux even more attractive and perhaps the reason why the iSH developers decided to use it as a basis for their iSH emulator is it being actively developed and its tightened security makes it a good compliment to the quite closed and security focused mobile platform iOS.

iSH is available straight from AppStore , so to use it install it and run it (it is really a great news that iOS does not require iphone to be jailbreak – ed, and it is an ordinary installable software straight from AppStore):
iSH, already comes with some of the standard programs you would expect in a Linux environment such as Vi, wget, zip / unzip, and tar.
However to fit it better for my use over ssh and improve its capabilities, as well as support and use multiple Virtual windows ssh, just like you do on a Linux xterm
run from ish shell: 

# apk add openssh-client
# apk add screen
# apk add vim
# apk add mc


ish-screenshot-terminal3-linux-emulator-iphone-alpine

ish-screenshot-terminal2-linux-emulator-iphone-alpine

ish-screenshot-terminal1-linux-emulator-iphone-alpine-linux

I also like to have a Midnight Commander and VIM Text editor installed out of the box to be able to move around in Ncurses interface through my iPhone.

ish-iphone-keyboard-key-shortcuts

Note that, just like most GNU / Linux distributions, iOS shell will run a normal bash shell.
From there on to use iSH as my default SSH client and enable my just installed GNU screen some Windowing beauty for readability whence I use the screen with multiple ssh logins to different servers as well make the screen Virtual consoles to have ability for scroll back and scroll up of console text to work, I do set up the following .screenrc inside my /home/iPhoneuser

The .screenrc to setup on the iSH to easify your work with screen is as follows:
 

# An alternative hardstatus to display a bar at the bottom listing the
# windownames and highlighting the current windowname in blue. (This is only
# enabled if there is no hardstatus setting for your terminal)
hardstatus on
hardstatus alwayslastline
hardstatus string "%{.bW}%-w%{.rW}%n %t%{-}%+w %=%{..G} %H %{..Y} %m/%d %C%a "
# Enable scrolling fix the annoying screen scrolling problem
termcapinfo xterm* ti@:te@
# Scroll up
bindkey -d "^[[5S" eval copy "stuff 5\025"
bindkey -m "^[[5S" stuff 5\025

# Scroll down
bindkey -d "^[[5T" eval copy "stuff 5\004"
bindkey -m "^[[5T" stuff 5\004

# Scroll up more
bindkey -d "^[[25S" eval copy "stuff \025"
bindkey -m "^[[25S" stuff \025

# Scroll down more
bindkey -d "^[[25T" eval copy "stuff \004"
bindkey -m "^[[25T" stuff \004

You can download the same .screenrc file from here straight with wget from the console:

# wget https://www.pc-freak.net/files/.screenrc


Run GNU screen manager

 

 # screen

You will end up with a screen session, to open a new session for Virtual Terminal use virtual keyboard from ISH and Press

CTRL + A + C

To open other Virtual Windows inside screen just press CTRL + A + C as many times as you need it, each session will appear ina small window on the down corner as you can see in screenshot

ish-terminal-with-screen-multiple-virtual-terminals-screenshot-iphone-ios

To move across the Screen unnamed 3 Virtual Windows 0 ash 1 ash and 2 ash use the Virtual keyboard

for next WIndow use key combination:
 

CTRL + A + N (where + is just to indicate you have to press them once after another and not actually press the + 🙂 )


For Previous Window use:

CTRL + A + P

Or use CTRL + A and type 

:number 3 (where number is the number of window)

The available iSH commands without adding any further packages which are part of the busybox install are as follows:

Available /bin/ directory commands:

arch  ash  base64  bbconfig  busybox  cat  chgrp  chmod  chown  conspy  cp  date  dd  df  dmesg  dnsdomainname  dumpkmap  echo  ed  egrep  false  fatattr  fdflush  fgrep  fsync  getopt  grep  gunzip  gzip  hostname  ionice  iostat  ipcalc  kbd_mode  kill  link  linux32  linux64  ln  login  ls  lzop  makemime  mkdir  mknod  mktemp  more  mount  mountpoint  mpstat  mv  netstat  nice  pidof  ping  ping6  pipe_progress  printenv  ps  pwd  reformime  rev  rm  rmdir  run-parts  sed  setpriv  setserial  sh  sleep  stty  su  sync  tar  touch  true  umount  uname  usleep  watch  zcat  


Available /usr/bin/ commands:    

awk  basename  beep  blkdiscard  bunzip2  bzcat  bzip2  cal  chvt  cksum  clear  cmp  comm  cpio  crontab  cryptpw  cut  dc  deallocvt  diff  dirname  dos2unix  du  dumpleases  eject  env  expand  expr  factor  fallocate  find  flock  fold  free  fuser  getconf  getent  groups  hd  head  hexdump  hostid  iconv  id  install  ipcrm  ipcs  killall  ldd  less  logger  lsof  lsusb  lzcat  lzma  lzopcat  md5sum  mesg  microcom  mkfifo  mkpasswd  nc  nl  nmeter  nohup  nproc  nsenter  nslookup  od  passwd  paste  patch  pgrep  pkill  pmap  printf  pscan  pstree  pwdx  readlink  realpath  renice  reset  resize  scanelf  seq  setkeycodes  setsid  sha1sum  sha256sum  sha3sum  sha512sum  showkey  shred  shuf  smemcap  sort  split  ssl_client  strings  sum  tac  tail  tee  test  time  timeout  top  tr  traceroute  traceroute6  truncate  tty  ttysize  udhcpc6  unexpand  uniq  unix2dos  unlink  unlzma  unlzop  unshare  unxz  unzip  uptime  uudecode  uuencode  vi  vlock  volname  wc  wget  which  whoami  whois  xargs  xxd  xzcat  yes  


If you're a maniac developer you can even use iSH, to do some programs development with vim with Python / Perl or PHP as these are available from the Alpine repositories and installable via a simple apk add packagename for security experts nmap and some security tools are also available but unfortunately not everything is still working as this project is in active development and iOS has some security limitations if OS is not ROOTED 🙂

Hence some of the packages you can install via apk manager will be failing actually.
There is a list of What works and what doesn't still on iSH on the project github wiki check it out here.

There is much more funny stuff you can do with it, and actually my quick research on how people use iSH on their phones lead me to some Videos talking about iOS and Ethical hacking etc, but I'll stop here as I dont have the time to dig deeper to it. 
If you know or have some good use of iSH or some other goody you are using as a hack please share in comments.

Enjoy ! 🙂

How to Recover deleted /var/lib/dpkg directory on Debian / Ubuntu Linux server

Wednesday, October 6th, 2021

how-to-recover-accidently-deleted-var-lib-dpkg-directory-on-debian-gnu-linux

Sometimes you might do something stupid, in the hurry like running the wrong rm  command and ending up deleting /var/lib/dpkg on your Debian / Ubuntu system.

by either wrongly issuing the rm to a directory or mistyping rm -r /var/lib/dpkg.
I know this is pretty dumb but sometimes we're all dumb, if you do so and you try to do the regular

root@debian:/ # apt update && apt upgrade

or try to install some random package onwards you will end up with error message:

E: Could not open lock file /var/lib/dpkg/lock – open (2: No such file or directory)

Ending up with this error, does totally blocks your further system administration activities with both apt / aptitude / apt-get as well as with dpkg package management tool.

 

1. The /var/backups recovery directory

Thankfully, by Gods mercy some of Debian Linux system architects has foreseen such issues might occur and have integrated into it the automatic periodic creation of some important files into directory /var/backups/

Hence the next step is to check what kind of backups are available, there:

root@debian:/ # ls -al /var/backups/
total 19892
drwxr-xr-x  7 root root      4096 Sep 24 06:25 ./
drwxr-xr-x 22 root root      4096 Dec 21  2020 ../
-rw-r–r–  1 root root    245760 Aug 20 06:25 alternatives.tar.0
-rw-r–r–  1 root root     15910 Aug 14 06:25 alternatives.tar.1.gz
-rw-r–r–  1 root root     15914 May 29 06:25 alternatives.tar.2.gz
-rw-r–r–  1 root root     15783 Jan 29  2021 alternatives.tar.3.gz
-rw-r–r–  1 root root     15825 Nov 20  2020 alternatives.tar.4.gz
-rw-r–r–  1 root root     15778 Jul 16  2020 alternatives.tar.5.gz
-rw-r–r–  1 root root     15799 Jul  4  2020 alternatives.tar.6.gz
-rw-r–r–  1 root root     80417 Aug 19 14:48 apt.extended_states.0
-rw-r–r–  1 root root      8693 Apr 27 22:40 apt.extended_states.1.gz
-rw-r–r–  1 root root      8658 Apr 17 19:45 apt.extended_states.2.gz
-rw-r–r–  1 root root      8601 Apr 15 00:52 apt.extended_states.3.gz
-rw-r–r–  1 root root      8599 Apr  9 00:26 apt.extended_states.4.gz
-rw-r–r–  1 root root      8542 Mar 18  2021 apt.extended_states.5.gz
-rw-r–r–  1 root root      8549 Mar 18  2021 apt.extended_states.6.gz
-rw-r–r–  1 root root   9030483 Jul  4  2020 aptitude.pkgstates.0
-rw-r–r–  1 root root    628958 May  7  2019 aptitude.pkgstates.1.gz
-rw-r–r–  1 root root    534758 Oct 21  2017 aptitude.pkgstates.2.gz
-rw-r–r–  1 root root    503877 Oct 19  2017 aptitude.pkgstates.3.gz
-rw-r–r–  1 root root    423277 Oct 15  2017 aptitude.pkgstates.4.gz
-rw-r–r–  1 root root    420899 Oct 14  2017 aptitude.pkgstates.5.gz
-rw-r–r–  1 root root    229508 May  5  2015 aptitude.pkgstates.6.gz
-rw-r–r–  1 root root        11 Oct 14  2017 dpkg.arch.0
-rw-r–r–  1 root root        43 Oct 14  2017 dpkg.arch.1.gz
-rw-r–r–  1 root root        43 Oct 14  2017 dpkg.arch.2.gz
-rw-r–r–  1 root root        43 Oct 14  2017 dpkg.arch.3.gz
-rw-r–r–  1 root root        43 Oct 14  2017 dpkg.arch.4.gz
-rw-r–r–  1 root root        43 Oct 14  2017 dpkg.arch.5.gz
-rw-r–r–  1 root root        43 Oct 14  2017 dpkg.arch.6.gz
-rw-r–r–  1 root root      1319 Apr 27 22:28 dpkg.diversions.0
-rw-r–r–  1 root root       387 Apr 27 22:28 dpkg.diversions.1.gz
-rw-r–r–  1 root root       387 Apr 27 22:28 dpkg.diversions.2.gz
-rw-r–r–  1 root root       387 Apr 27 22:28 dpkg.diversions.3.gz
-rw-r–r–  1 root root       387 Apr 27 22:28 dpkg.diversions.4.gz
-rw-r–r–  1 root root       387 Apr 27 22:28 dpkg.diversions.5.gz
-rw-r–r–  1 root root       387 Apr 27 22:28 dpkg.diversions.6.gz
-rw-r–r–  1 root root       375 Aug 23  2018 dpkg.statoverride.0
-rw-r–r–  1 root root       247 Aug 23  2018 dpkg.statoverride.1.gz
-rw-r–r–  1 root root       247 Aug 23  2018 dpkg.statoverride.2.gz
-rw-r–r–  1 root root       247 Aug 23  2018 dpkg.statoverride.3.gz
-rw-r–r–  1 root root       247 Aug 23  2018 dpkg.statoverride.4.gz
-rw-r–r–  1 root root       247 Aug 23  2018 dpkg.statoverride.5.gz
-rw-r–r–  1 root root       247 Aug 23  2018 dpkg.statoverride.6.gz
-rw-r–r–  1 root root   3363749 Sep 23 14:32 dpkg.status.0
-rw-r–r–  1 root root    763524 Aug 19 14:48 dpkg.status.1.gz
-rw-r–r–  1 root root    760198 Aug 17 19:41 dpkg.status.2.gz
-rw-r–r–  1 root root    760176 Aug 13 12:48 dpkg.status.3.gz
-rw-r–r–  1 root root    760105 Jul 16 15:25 dpkg.status.4.gz
-rw-r–r–  1 root root    759807 Jun 28 15:18 dpkg.status.5.gz
-rw-r–r–  1 root root    759554 May 28 16:22 dpkg.status.6.gz

drwx——  2 root root      4096 Oct 15  2017 ejabberd-2017-10-15T00:22:30.p1e5J8/
drwx——  2 root root      4096 Oct 15  2017 ejabberd-2017-10-15T00:24:02.dAUgDs/
drwx——  2 root root      4096 Oct 15  2017 ejabberd-2017-10-15T12:29:51.FX27WJ/
drwx——  2 root root      4096 Oct 15  2017 ejabberd-2017-10-15T21:18:26.bPQWlW/
drwx——  2 root root      4096 Jul 16  2019 ejabberd-2019-07-16T00:49:52.Gy3sus/
-rw——-  1 root root      2512 Oct 20  2020 group.bak
-rw——-  1 root shadow    1415 Oct 20  2020 gshadow.bak
-rw——-  1 root root      7395 May 11 22:56 passwd.bak
-rw——-  1 root shadow    7476 May 11 22:56 shadow.bak

Considering the situation the important files for us that could, help us restore our previous list of packages, we had installed on the Debian are files under /var/backups/dpkg.status*

Luckily debian based systems keeps backups of its important files that can be used later on for system recovery activities.
Below is a common structure of /var/lib/dpkg on a deb based system.

hipo@debian:/home/hipo$ ls -l /var/lib/dpkg/
total 11504
drwxr-xr-x 2 root root    4096 Aug 19 14:33 alternatives/
-rw-r–r– 1 root root      11 Oct 14  2017 arch
-rw-r–r– 1 root root 2199402 Oct 19  2017 available
-rw-r–r– 1 root root 2197483 Oct 19  2017 available-old
-rw-r–r– 1 root root       8 Sep  6  2012 cmethopt
-rw-r–r– 1 root root    1319 Apr 27 22:28 diversions
-rw-r–r– 1 root root    1266 Nov 18  2020 diversions-old
drwxr-xr-x 2 root root  606208 Sep 23 14:32 info/
-rw-r—– 1 root root       0 Sep 23 14:32 lock
-rw-r—– 1 root root       0 Mar 18  2021 lock-frontend
drwxr-xr-x 2 root root    4096 Sep 17  2012 parts/
-rw-r–r– 1 root root     375 Aug 23  2018 statoverride
-rw-r–r– 1 root root     337 Aug 13  2018 statoverride-old
-rw-r–r– 1 root root 3363749 Sep 23 14:32 status
-rw-r–r– 1 root root 3363788 Sep 23 14:32 status-old
drwxr-xr-x 2 root root    4096 Aug 19 14:48 triggers/
drwxr-xr-x 2 root root    4096 Sep 23 14:32 updates/

 

2. Recreate basic /var/lib/dpkg directory and files structures

As you can see, there are 5 directories and the status file and some other files. 
Hence the first step is to restore the lost directory structure.

hipo@debian: ~$ sudo mkdir -p /var/lib/dpkg/{alternatives,info,parts,triggers,updates}


3. Recover /var/lib/dpkg/status file

Further on recover the dpkg status file from backup

hipo@debian: ~$  sudo cp /var/backups/dpkg.status.0 /var/lib/dpkg/status


4. Check dpkg package installation works again and reinstall base-files

Next check if dpkg – debian package manager is now working, by simply trying to download dpkg*.deb reinstalling it.

root@debian:/root # apt-get download dpkg
# sudo dpkg -i dpkg*.deb

If you get no errors next step is to reinstall base-files which is important package on which dpkg depends.

root@debian:/root # apt-get download base-files

root@debian:/root # sudo dpkg -i base-files*.deb

 

5. Update deb system package list and db consistency

Onwards try to update system package list and check dpkg / apt database consistency.

root@debian:/root # dpkg –audit

root@debian:/root # sudo apt-get update

root@debian:/root # sudo apt-get check


The result should be more of the files in /var/lib/dpkg should appear, thus list the directory again and compare to the earlier given list of it, they should be similar.

root@debian:/root # ls -l /var/lib/dpkg

6. Reinstall completely from source code dpkg, if nothing else works
 

If some files are missing they should get created with a normal daily sysadmin package management tasks so no worries.

In case if after attempting to upgrade the system or install a package with apt, you get some nasty error like:
 

'/usr/local/var/lib/dpkg/status' for reading: No such file or directory


Then the next and final thing to try as a recovery is to download compile from a new and reinstall dpkg from source code!

 

root@debian:/ # wget https://launchpad.net/ubuntu/+archive/primary/+files/dpkg_1.16.1.2ubuntu7.2.tar.bz2
root@debian:/ # tar -xvf dpkg_1.16*

root@debian:/ # cd dpkg-1.16*

root@debian:/ # ./configure

root@debian:/ # make

root@debian:/ # make install


Hopefully you'll have gcc and development tools provided by build-essential .deb package otherwise you have to download and compile this ones as well 🙂
If this doesn't bring you back the installed packages you had priorly (hopefully not), then waste no more time and do a backup of the main things on the server, and reinstall it completely.

The moral out of this incident is always to implement always to your system a good back up system and regularly create backups of /var/lib/dpkg , /etc/ , /usr/local* and other important files on a remote backup server, to be able to easily recover if you do by mistake something whacky.
 

Hope that helped anyone. Cheers 🙂