Your keychain password lets you automatically authenticate applications and services stored in Keychain Access. When the account is created the keychain password is set to match the login password for the account.

When you change the login password in the User & Groups preferences, the keychain password is automatically updated to match it.

If the keychain password does not match the login password for the account, the user is required to authenticate to unlock the keychain.

The keychain password is available only to the account user and not the administrator. If the login password is reset by the administrator, the keychain password is not changed. The user is asked to reset the keychain password during the next login. If the login password was reset because the old password was forgotten, the keys, passwords, and other information in the keychain will not be accessible, and the account will need to use a new keychain.

Although you normally should use the default keychain password, you can change it.


  1. Open Keychain Access, located in the Utilities folder in Launchpad.
  2. Choose Edit > “Change Password for Keychain (keychain name).”
  3. If the keychain is locked, type the password to unlock it, and then click OK.
  4. Type the current password for this keychain.
  5. Type a new password, and then type it again to verify. The keychain password should usually match the login password for the account.
  6. Click OK.


I forgot my Keychain Password. As I follow the steps, after clicking ""Reset to my default Keychain""a new window showing ""UNIX[Invalid argument]"". Give me a solution to reset my Keychain Password.


Step by Step


Try repairing your keychain.  It typically asks for the original keychain password but it should, typically, be your login password.  To repair your keychain follow the steps below:

  1. Go to Keychain Access in the upper-left
  2. Select "Keychain First Aid"
  3. Enter your username and password and select "Repair" then click "Start"
  4. After your keychain as been repaired, go to "Preferences"
  5. Select "Reset my Default Keychian"
  6. Enter whatever you want the new password to be and you should be good to go.


In Short: Keychain acess>file>add keychain> then set as default or if that doesn work delete the keychain in File>Delete keychain then File>Add new keychain


How do i reset my Keychain password? Setup Keychain


The Keychain is designed to be fairly secure. Even if you reset the admin password, you still don't have access to a user's keychain. All you can do is reset the keychain itself, and start a new one. Essentially setting aside the old one (in case you later remember the password).

 

From a security standpoint, it's a good thing. A stolen Mac doesn't hand over all your passwords to a thief, even if he knows the procedure for circumventing the admin password.

 

Here is an Apple document describing the keychain, and how to change the password, if you know the old one.

 

Step 1 Click Here

 

If you don't know the old one. (resetting)

 

Step 2 Click Here

 

Here's is a screenshot of Keychain Preferences, showing the "reset" button.


Screen Shot 2012-05-08 at 4.45.14 PM.png


Resetting your keychain in Mac OS X - Apple

 

If you can't sign in with two-step verification using your Apple ID - Apple Keychain

 

 

Also it is important you get generate a recovery key for future reference .. 

 

https://appleid.apple.com/account/manage



Reset Keychain Password without old password?


An administrator can change your login password without knowing the old password. The is no way for anyone to change a keychain password without knowing the old password.


Normally your login password is the same as the keychain password. For you to change your login password, you need to enter the old password and new password. 

After the software changes your login password, an attempt is made to change the keychain password. This only succeeds if the old password you entered is the current keychain password.

If not, then the current keychain password remain unchanged.

When an administrator overrides you old login password with a new password, the old password is never entered into the software. Without the old login password,

 the software can not change the keychain password. If you do not know the old password (i.e. the current keychain password), then you have to "Create a new login keychain". 

Doing so erases all the passwords stored in the keychain.


How to delete or fix your Keychain after changing your password?


Try running Keychains Repair Tool by opening Keychain from you Utilities folder, then from the menu bar choose Keychain Access,

 then Keychain First Aid, then enter your password, verify then start it. If there are any problems click Repair then Start. (via Apple site)

If that doesn't work then try Resetting your Keychain. Via Apple's Instructions you just need to do these steps:

  1. Open Keychain Access, which is in the Utilities folder within the Applications folder.
  2. From the Keychain Access menu, choose Preferences.
  3. Click General, then click Reset My Default Keychain.
  4. Authenticate with your account login password.
  5. Quit Keychain Access then Restart your computer.


Synchronise your user account and keychain passwords!

The password of your macOS user account might not match the password of your login keychain. Either create a new login keychain or update it with your new password.

After you or your Mac administrator resets the password of your macOS user account, your Mac might ask you to update your keychain password or enter the password of your login keychain. It might also tell you that the system was unable to unlock your login keychain. That's because your login keychain is still using your old password.

If you don't know your old password, the solution is to create a new login keychain.

If you know your old password, use that password to update your existing login keychain:

Open the Keychain Access app, which is in the the Utilities folder of your Applications folder.

From the Edit menu, choose “Change Password for Keychain 'login.'”

Enter the old password of your user account in the Current Password field. This is the password you were using before the password was reset.

Enter the new password of your user account in the New Password field. This is the password you're now using to log in to your Mac. Enter the same password in the Verify field.

Click OK when done, then quit Keychain Access.

Taken from mac apple sites: Here



How do I get my lost Mac Keychain password back


If you're the administrator and you've forgotten the password to the login keychain and the administrator password, I am afraid you've permanently lost the contents of your keychain. However, you can recover from the situation without reinstalling the entire OS.


First, reset the administrator password using the Mac OS X disc:

  1. Insert the Mac OS X Install disc and restart the computer.
  2. When you hear the startup tone, hold down the C key until you see the spinning gear.
  3. When the Installer appears, choose Utilities > Reset Password.
  4. Follow the onscreen instructions to change the password.
  5. Quit the Installer and restart your computer while holding down the mouse button to eject the disc.

After the Mac has restarted, you'd normally now need to change the password for the keychain called "login" to match the new admin password, but since you've forgotten it you'll need to delete the old login keychain. Do the following steps:

  1. Open Keychain Access, located in /Applications/Utilities.
  2. Choose Keychain List from the Edit menu.
  3. Select the "login" keychain.
  4. Click Delete (the "-" button).

The login keychain will now be empty. The next time the keychain is needed you'll have to manually enter the appropriate password and then you'll be asked if you want to store the password in the keychain.

reset keychain password without old password


The password of your macOS user account might not match the password of your login keychain. Either create a new login keychain or update it with your new password.



After you or your Mac administrator resets the password of your macOS user account, your Mac might ask you to update your keychain password or enter the password of your login keychain. It might also tell you that the system was unable to unlock your login keychain. That's because your login keychain is still using your old password. 



If you don't know your old password

If you don't know your old password, the solution is to create a new login keychain.



If you know your old password

If you know your old password, use that password to update your existing login keychain:

  1. Open the Keychain Access app, which is in the the Utilities folder of your Applications folder.
  2. From the list of keychains on the left side of the window, select "login." 
  3. From the Edit menu in the menu bar, choose “Change Password for Keychain 'login.'”
  4. Enter the old password of your user account in the Current Password field. This is the password you were using before the password was reset.
  5. Enter the new password of your user account in the New Password field. This is the password you're now using to log in to your Mac. Enter the same password in the Verify field.
  6. Click OK when done, then quit Keychain Access. 


Change or reset the password of a macOS user account


You can change the password that you use to log in to your Mac, or reset the password if you don't remember it. 

The password of your macOS user account is also known as your login password. It's the password that you use to log in to your Mac and make certain changes, such as installing software.



Change your password

If you know your password and can use it to log in to your account, you can change your password in Users & Groups preferences:

  1. Choose System Preferences from the Apple menu, then click Users & Groups.
  2. Select your user name from the list of users.
  3. Click the Change Password button, then follow the onscreen instructions.





Reset your password

If you don't remember your password, or it isn't working, you might be able to reset it using one of the methods described below. But first try these simpler solutions:

  • Make sure that you're typing the correct uppercase or lowercase characters. If your keyboard has Caps Lock turned on, the password field shows a Caps Lock symbol 
  • If the password field shows a question mark, click it to display a password hint that might help you to remember.
  • Try to log in without a password. If that works, you can then add a password by following the steps to change your password.
  • Try to log in with the Apple ID password that you use for iCloud. If you just changed that password and the new password isn't working, try the old password first. If that works, you should be able to use the new password from then on.


Reset using your Apple ID

In some macOS versions, you can use your Apple ID to reset your login password. At the login screen, keep entering a password until you see a message saying that you can reset your password using Apple ID. If you don't see the message after three attempts, your account isn't set up to allow resetting with Apple ID.


  1. Click  next to the Apple ID message, then follow the onscreen instructions to enter your Apple ID and create a new password. You'll be asked to restart when done.
  2. Log in with your new password.
  3. Determine whether to create a new login keychain.



Reset using another admin account

If you know the name and password of an admin account on your Mac, you can use that account to reset the password. 

  1. Log in with the name and password of the other admin account.
  2. Choose System Preferences from the Apple menu, then click Users & Groups.
  3. Click , then enter the admin name and password again.
  4. Select your user name from the list of users.
  5. Click the Reset Password button, then follow the onscreen instructions to create a new password:
  6. Choose Log Out from the Apple menu.
  7. Log in to your account using your new password.
  8. Determine whether to create a new login keychain. 


Reset using the Reset Password assistant (FileVault must be on)

If FileVault is turned on, you might be able to reset your password using the Reset Password assistant:

  1. Wait up to a minute at the login screen, until you see a message saying that you can use the power button on your Mac to shut down and start up again in Recovery OS. If you don't see this message, FileVault isn't on.
  2. Press and hold the power button until your Mac turns off.
  3. Press the power button again to turn on your Mac.
  4. When the Reset Password window appears, follow the onscreen instructions to create a new password.

If you need to connect to Wi-Fi, move your pointer to the top of the screen and use the Wi-Fi menu to connect. To exit without resetting your password, choose Apple menu > Restart.

  1. When done, click Restart.
  2. If you were able to reset your password with the Reset Password assistant, log in to your account using your new password.
  3. Determine whether to create a new login keychain.



Reset using your Recovery Key (FileVault must be on)

If FileVault is turned on and you have a FileVault Recovery Key, you can use that key to reset your password.

  1. At the login screen, keep entering a password until you see a message saying that you can reset your password using your Recovery Key. If you don't see the message after three attempts, FileVault isn't on.
  2. Click  next to the message. The password field changes to a Recovery Key field.
  3. Enter your Recovery Key. Use uppercase characters, and include the hyphens. 
  4. Follow the onscreen instructions to create a new password, then click Reset Password when done.
  5. Determine whether to create a new login keychain.

If you can't log in with your new password after restarting your Mac, take these additional steps:

  1. Restart again, then immediately hold down Command-R or one of the other macOS Recovery key combinations until you see the Apple logo or a spinning globe. 
  2. When you see the macOS Utilities window, choose Utilities > Terminal from the menu bar.
  3. In the Terminal window, type resetpassword, then press Return to open the Reset Password assistant pictured above.
  4. Select ”My password doesn't work when logging in,” then click Next and follow the onscreen instructions for your user account.

Create a new login keychain, if necessary

After resetting your password and logging back in to your account, you might see an alert that the system was unable to unlock your login keychain. This is expected, because the passwords for your user account and login keychain no longer match. Just click the Create New Keychain button in the alert.

If you didn't see an alert about your login keychain, or you see other messages asking for your old password, reset your keychain manually:

  1. Open Keychain Access, which is in the Utilities folder of your Applications folder. 
  2. Choose Preferences from the Keychain Access menu, then click the Reset My Default Keychain button in the preferences window. After you enter your new password, Keychain Access creates an empty login keychain with no password. Click OK to confirm.

    If you don't see a Reset My Default keychain button, close the preferences window and select the “login” keychain from the left side of the Keychain Access window. Press the Delete key, then click Delete References.

  3. Choose Log Out from the Apple menu to return to the login screen.
  4. Log in to your account using your new password. Your account password and login keychain password now match again.