Lost Password - Revision history

Aroberts at 20:45, 9 May 2014

2014-05-09T20:45:01Z

Psullivan: /* Resetting the Password */

2014-02-20T23:13:59Z

Resetting the Password

Psullivan: /* Resetting the Password */

2014-02-20T23:10:19Z

Resetting the Password

Psullivan: /* Ubuntu 12.04 */

2014-02-02T00:29:14Z

Ubuntu 12.04

Psullivan at 22:31, 28 January 2014

2014-01-28T22:31:15Z

Psullivan: /* Shadow Folder Method */

2014-01-28T22:23:45Z

Shadow Folder Method

Psullivan: /* Resetting the Password */

2014-01-28T21:22:58Z

Resetting the Password

Psullivan: /* Booting into Single User Mode with GRUB */

2014-01-03T19:21:34Z

Booting into Single User Mode with GRUB

Psullivan: /* Booting into Single User Mode with GRUB */

2014-01-03T19:14:46Z

Booting into Single User Mode with GRUB

Aroberts: /* Ubuntu 12.04 */

2013-12-28T20:53:47Z

Ubuntu 12.04

← Older revision		Revision as of 20:45, 9 May 2014
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		+	{{Migrated}}
		+
		+	[https://docs.google.com/document/d/1BoeY2M321pI5HwZhBxd7Ny032MQvpYaNviInjHlGSm0/edit?usp=sharing]
		+
	The following applies to most linux boxen. It can be used to recover a lost password and is also called "rooting" the box.		The following applies to most linux boxen. It can be used to recover a lost password and is also called "rooting" the box.

@@ Line 42: / Line 42: @@
     bin:x:1:1:bin:/bin:/bin/false
     jsmith:x:1000:100:John Smith:/home/jsmith:/bin/bash
-In that example the first two lines are system accounts, but the third line is a user account that could be granted sudo access, with the first word of it (jsmith) being the correct username. User accounts can be distinguished by the number after the second ":" being 1000 or greater, and they will usually be towards the bottom of the list. If the list is particularly long and you don't see anything that fits the criteria (often the case when the Guest account has been used a lot) you may need to scroll up the list by pressing Shift+PageUp.
+In that example the first two lines are system accounts, but the third line is a user account that could be granted sudo access, with the first word of it (jsmith) being the correct username. User accounts can be distinguished by the number after the second ":" being 1000 or greater, and they will usually be towards the bottom of the list. If the list is particularly long and you don't see anything that fits the criteria (often the case when the Guest account has been used a lot) you may need to scroll up the list by pressing Shift+PageUp. Press PageDown to return to the command prompt below the list.

@@ Line 36: / Line 36: @@
 To reset your password you need to be able to specify the username for which the password is to be changed. Note that the name displayed on your login screen may not be the same as your formal username, instead being a "friendly" name that you provided at some point. For example, if your name on the login screen reads something like "John Doe" then that is almost certainly the "friendly" name, while your formal username is likely to be something more like "jdoe".
-To view usernames currently active on the system enter the command
+If you're unsure what the exact username you need to add is, type the following command:
- ls /home
+   cat /etc/passwd
 Once you have identified your username, enter the following command with your specific username substituted:
-   passwd -yourusername-
+   passwd yourusername
 You will be prompted to enter a new password, then to enter the password a second time to confirm nothing was mistyped.

@@ Line 17: / Line 17: @@
 Proceed to "Resetting the Password" section of this page.
-===Ubuntu 12.04 ===
+===Xubuntu 12.04 ===
 ''Note that after performing step 1 you have a limited time to perform step 2, so please read the instructions fully before beginning the process.''
 #Power on the computer (shut it down first or simply reboot if it is already running).

← Older revision		Revision as of 22:31, 28 January 2014
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	To find your username you can use <code>ls /home</code>		To find your username you can use <code>ls /home</code>
−
−	~~==For Macs==~~
−
−	~~For Mac computers at the yaboot prompt enter:~~
−
−	~~Linux rw init=/bin/bash~~
−
−	~~Once you get to the # prompt you will need to reset the terminal~~
−
−	~~reset~~
−
−	~~Now check the username~~
−
−	~~ls /home~~
−
−	~~and reset the users password~~
−
−	~~passwd usernamehere~~

	==Reset root password==		==Reset root password==

@@ Line 51: / Line 51: @@
 After a few seconds your system will reboot. The recovery menu may display again briefly before the computer restarts but will continue to reboot without any input. If you are presented with the GRUB menu again while rebooting then simply press the Enter key to select the first item on the menu and normal startup will continue.
-==Shadow Folder Method==
+==Temporary Password Change==
-Also note that if they have a Root Password set you will need to use the [[#Live CD Method]] to reset it.
+Use a temporary password change to gain access to a specific user account for troubleshooting without permanently changing or removing the user's password.
-===The Shorter Way===
+Follow instructions above for [[Lost_Password#Booting_into_Single_User_Mode_with_GRUB]] to reach the root prompt in recovery mode, but do not reset the password yet.
-===The Longer Way===
+Enter the following command, substituting today's date (in a numeric format such as 20140128) for 'DATE'.
-This method temporarily replaces the /etc/shadow directory and allows you to reset their password so you can login.
+Continue following the password reset instructions at [[Lost_Password#Booting_into_Single_User_Mode_with_GRUB]] to set a new password for the account you need to access.
-#Login via Terminal (alt-ctrl-F2 from GUI login, OR drop into Root Shell via Recovery Mode).
+With the changed password you should now be able to complete whatever troubleshooting tasks are necessary.
-===Restoring Their Old Shadow Directory===
+Once you are ready to restore the user's password you will need to reach the root prompt in recovery mode as previously instructed, then run the following command, substituting the previously entered date for 'DATE':
-#Login via Terminal (alt-ctrl-F2 from GUI login, OR drop into Root Shell via Recovery Mode).
+  cp /etc/shadow.bak.DATE /etc/shadow
-#Run :
-  cp /etc/shadow.bak.[ISO DATE] /etc/shadow
+Verify the backup shadow file was restored correctly by running the command
-This copies the contents of the backed up Shadow directory to the current Shadow Directory.  You may need to verify the correct name of the backup by looking in the /etc directory.
+ ls -la /etc/shadow
-#Reboot
+Compare the output of that command to this:
 ==Live CD method==

@@ Line 34: / Line 34: @@
 ===Resetting the Password===
-#At the root prompt, enter
+To view usernames currently active on the system enter the command
-  passwd yourusername
+ ls /home
-If you are unsure of the users name, enter the following command;
+The list that follows (there may only be one or two items if you are the only user of the computer) will indicate all existing home directories, which correspond to users on the system. If you have never changed the default user account on your computer your will probably only see <code>oem</code>.
-# Alternatively type startx  and you will be put in a graphical environment where you can use the normal tools.
+You will be prompted to enter a new password, then to enter the password a second time to confirm nothing was mistyped.
 ==Shadow Folder Method==

@@ Line 10: / Line 10: @@
 #After a few seconds you will see the GRUB menu, which is characterized by a lines that will say '''...kernel 3.2...'''. If the system continues to boot normally and arrives at the regular login screen or desktop you will need to restart and try again. If you are repeatedly failing to reach the GRUB menu try quickly and repeatedly tapping the shift key until the menu appears instead of just holding it down.
 #Hit the down arrow key (usually only once) until it arrives on the first line that ends with '''recovery mode''' and press enter.
-#This will bring up a menu of recovery mode options.
+#Select "Root" from the recovery mode menu that appears to enter a shell environment with root privileges.
-#Select "Root" to enter a shell environment with root privileges.
+#You should now see a prompt at the bottom of the screen that reads
 Proceed to "Resetting the Password" section of this page.
@@ Line 21: / Line 23: @@
 #After a few seconds you will see the GRUB menu, which is characterized by a lines that will say '''...kernel 3.2...'''. If the system continues to boot normally and arrives at the regular login screen or desktop you will need to restart and try again. If you are repeatedly failing to reach the GRUB menu try quickly and repeatedly tapping the shift key until the menu appears instead of just holding it down.
 #Hit the down arrow key (usually only once) until it arrives on the first line that ends with '''recovery mode''' and press enter.
-#This will bring up a menu of recovery mode options.
+#Select "Root" from the recovery mode menu that appears to enter a shell environment with root privileges. Note that until further steps are completed your file system will be in "read only" mode and you will not be able to make any persistent changes to the system.
 #You should now see a prompt at the bottom of the screen that reads

@@ Line 5: / Line 5: @@
 ===Ubuntu 10.04 ===
-#start the computer booting up, and hold down the right shift key.
+''Note that after performing step 1 you have a limited time to perform step 2, so please read the instructions fully before beginning the process.''
-#After a few (or 10 or 20) seconds you will see the grub menu, which is characterized by a lines that will say '''...kernel 2.6...'''
+#Power on the computer (shut it down first or simply reboot if it is already running).
-#Hit the down arrow once to get to a line that ends with '''recovery mode''' and press enter.
+#When the BIOS information or manufacturer's logo "splash" screen appears start holding down the right shift key. If your computer does not usually display BIOS information or a manufacturer's logo you may need to start holding down the shift key immediately after pressing the power button.
-#This will bring up a menu with many options.
+#After a few seconds you will see the GRUB menu, which is characterized by a lines that will say '''...kernel 3.2...'''. If the system continues to boot normally and arrives at the regular login screen or desktop you will need to restart and try again. If you are repeatedly failing to reach the GRUB menu try quickly and repeatedly tapping the shift key until the menu appears instead of just holding it down.
+#Hit the down arrow key (usually only once) until it arrives on the first line that ends with '''recovery mode''' and press enter.
-The two that you're looking for are '''netroot''' and '''root'''.
+#This will bring up a menu of recovery mode options.
-#Selecting "Netroot" will set up networking and mount the file system in read write mode (which is needed for making changes), and then drop you to a root shell.
+#Select "Root" to enter a shell environment with root privileges.
 Proceed to "Resetting the Password" section of this page.
 ===Ubuntu 12.04 ===
-#start the computer, immediately after the BIOS information has passed, press and hold down the left shift key.
+''Note that after performing step 1 you have a limited time to perform step 2, so please read the instructions fully before beginning the process.''
-#After a few seconds (maybe as much as 10 seconds), you will see the grub menu, which is characterized by a lines that will say '''...kernel 3.2...'''
+#Power on the computer (shut it down first or simply reboot if it is already running).
-#Hit the down arrow key until it arrives on a line that ends with '''recovery mode''' and press enter.
+#When the BIOS information or manufacturer's logo "splash" screen appears start holding down the right shift key. If your computer does not usually display BIOS information or a manufacturer's logo you may need to start holding down the shift key immediately after pressing the power button.
-#This will bring up a menu with many options.
+#After a few seconds you will see the GRUB menu, which is characterized by a lines that will say '''...kernel 3.2...'''. If the system continues to boot normally and arrives at the regular login screen or desktop you will need to restart and try again. If you are repeatedly failing to reach the GRUB menu try quickly and repeatedly tapping the shift key until the menu appears instead of just holding it down.
+#Hit the down arrow key (usually only once) until it arrives on the first line that ends with '''recovery mode''' and press enter.
-Look for the menu entry that says '''Root'''
+#This will bring up a menu of recovery mode options.
+#Select "Root" to enter a shell environment with root privileges. Note that until further steps are completed your file system will be in "read only" mode and you will not be able to make any persistent changes to the system.
-#Selecting"Root" will drop you to a root shell without the file system being mounted in read/write mode.
+#You should now see a prompt at the bottom of the screen that reads
     root@freekbox:~#
@@ Line 39: / Line 34: @@
-#at the root prompt, enter
+#At the root prompt, enter
    passwd yourusername
 replace 'yourusername' with the username you're trying to reset, or 'oem' if it has not been changed

@@ Line 34: / Line 34: @@
 To mount the file system in read/write mode, type in the following command at the prompt;
-    mount -o,remount,rw /
+    mount -o remount,rw /
 ===Resetting the Password===