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I need to authenticate so that I can use the VNC Server and Viewer and be able to access the Pi's screen from another computer. When I download the VNC Server I have to authenticate and enter a password for the username "pi" . The password is not "raspberry" and I do not remember if I changed it or not (i am a newbie to this). I have been working on a project for a long time and I don't wanna have to reset the whole pi. Is there a solution to reset the password or "find " it somewhere so that I can keep working? Thanks

xoani
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2 Answers2

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The hashed password is stored in /etc/shadow. There is no efficient way to find out what the password is, by design.

However, it is easy to reset as long as you have physical access. Start a Linux on a computer. It can be an installed Linux or a Live Linux on a PC, or it can be a Linux on a PI. Find the line with the password of the PI in the /etc/shadow of an original SD card image. Mount your SD card, you may need an extra SD card reader for this. Replace the line with the password with the original value. You have reset the password to the original value.

RalfFriedl
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  • Ah, no wonder I could not find /etc/shadow. So I need another linux on a Pi. I have have feeling that I am a head trying to catch the tail. I will study it again and try once more. – tlfong01 May 09 '19 at 09:08
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    For anyone in need - this is the sha-512 hash for the default "raspberry" password: pi:$6$SBgOl43F$QTRz0W27/786iJiN5YLlrsce7g3taQv8TiQYfcfBTXmwPs.jw5lOzu2ciZwHSFTaw16R.UaAr6ZR.ZRO6lWDR1 – php_nub_qq Sep 29 '21 at 07:58
  • Seems that this hash is not working with 2022-01-28 release of Raspberry Pi OS – ShockwaveNN Feb 07 '22 at 12:30
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to reset your password:

  • Power down and pull the SD card out from your Pi and put it into your computer.
  • Open the file 'cmdline.txt' and add 'init=/bin/sh' to the end. This will cause the machine to boot to single user mode.
  • Put the SD card back in the Pi and boot.
  • When the prompt comes up, type 'su' to log in as root (no password needed).
  • Type "passwd pi" and then follow the prompts to enter a new password.
  • Shut the machine down, then pull the card again and put the cmdline.txt file back the way it was by removing the 'init=/bin/sh' bit.

more information: https://web.archive.org/web/20160228052651/http://mapledyne.com/ideas/2015/8/4/reset-lost-admin-password-for-raspberry-pi

Hope this helps!

das Keks
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Xilef
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  • I tried it just now. But it doesn't work. The problem is that I am using Rpi3B+ with the newest Raspbian Version 2019April. I changed the cmdline.txt as instructed. However as usual, the system boots to GUI desktop. Anyway I go to terminal and typed su. Then I got the error message, not allowing me to log in. I guess Mapledyne's method does not work for Raspbian 2019April. – tlfong01 May 08 '19 at 13:52
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    This is unnecessarily complex. – RalfFriedl May 08 '19 at 16:49
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    @tlfong01 It worked for me. But this link is better https://howtoraspberrypi.com/recover-password-raspberry-pi/ – xoani May 09 '19 at 09:04
  • Ah, your new link says it is "2018 update". Perhaps it implies 2017 or earlier suggestions might not work for 2018 Stretch. I will try your new link again. Many thanks. – tlfong01 May 09 '19 at 09:10
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    Authentication token manipulation error ? – user3728501 Mar 11 '21 at 14:55
  • I cannot find the cmdline.txt file. Where is it supposed to be? – user171780 Apr 14 '22 at 14:27
  • from @xoani 's link: adding mount -o remount, rw / before supplying passwd pi command can eliminate errors like "Authentication token manipulation error" – Mohit Aug 24 '22 at 17:48
  • And if mount -o remount, rw / gives you an error, try this instead mount -o remount,rw /dev/mmcblk0p2 / – kschnack Jun 06 '23 at 07:16