reset keychain on mac

An essential Mac OS X Keychain guide

Adding New Root Certificate for Keychain

Importing Certificates for Keychain

Get help with iCloud Keychain - Apple Support

Repair Keychain in El Capitan or Sierra

1. Launch Keychain Access (located in Applications/Utilities)
2. Click "Show Keychains" in the lower-left corner of the window.
3. Select the problematic keychain from the left-hand pane.
4. Navigate to the "File" menu and select "Delete Keychain '(name of keychain)'"
5. Check all options for deletion and press "OK"
6. Create a new keychain by going to the "File" menu, then "New" and selecting "New Keychain"
7. You can now make this keychain your default if you desire by selecting it, then going to the "File" menu and selecting "Make '(name of keychain)' Default"

Tutorial: Resolving Keychain Issues

If you can't access your keychain, or forget your password If you can't get into your keychain file because you've forgotten your password or the keychain file appears to be corrupt, there are a couple of options.

First, if you've forgotten your password, you can use the "Keychain First Aid" utility to make the keychain password the same as the login password. This can be accomplished via the following process:

1. Open Keychain Access (located in Applications/Utilities)

2. Go to the "Keychain Access" menu and select "Preferences"

3. Click the "First Aid" tab

4. Make sure the "Synchronize login keychain password" box is checked

5. Close the Preferences window

6. Go to the "Keychain Access" menu and select "Keychain First Aid"

7. Enter your username and password

8. Click the "Repair" button

The second option is to completely delete your keychain then recreate it. This routine is useful if your keychain appears to be corrupt or otherwise inaccessible. This can be accomplished as follows:

1. Launch Keychain Access (located in Applications/Utilities)

2. Click "Show Keychains" in the lower-left corner of the window.

3. Select the problematic keychain from the left-hand pane.

4. Navigate to the "File" menu and select "Delete Keychain '(name of keychain)'"

5. Check all options for deletion and press "OK"

6. Create a new keychain by going to the "File" menu, then "New" and selecting

"New Keychain"

7. You can now make this keychain your default if you desire by selecting it, then

going to the "File" menu and selecting "Make '(name of keychain)' Default"

Login as root and perform repair In some cases, problems with keychains can only be resolved when logged in as the root user.

First, you want to enable the root user:

1. OS X Mountain Lion: Enable and disable the root user

2. OS X Lion: Enable and disable the root user

3. Mac OS X 10.6: Enabling the root user

4. Enabling and using the "root" user in Mac OS X

After enabling the root user, and logging in under this account, again open Keychain Access. First attempt repairs using Keychain First Aid, and failing that, delete then recreate the keychain as described above while logged in as root.

Persistently asked for stored passwords If you are persistently asked for passwords in various applications that you have specified should be remembered in a keychain, your "login" keychain may not be active for one reason or another.

Navigate to ~/Library/Keychains/ (this is the Library folder inside your user's home folder). Find the file named "login.keychain" and double-click it.

Failing that, select the "login" keychain within the Keychain Access application and make sure it is the default keychain by going to the "File" menu and selecting "Make 'Login' Default"

Turn off Keychain synchronization in applications having problems If specific applications are experiencing issues when accessing password-protected material, the Keychain may be to blame.

The above comes from an article published on MacFixit.com.

I don't know why the dialog is incomplete. Could be an issue with your High Sierra installation. You may find some resolution in one of the following:

A Troubleshooting Procedure that may Fix Problems with macOS El Capitan or Later

You should try each, one at a time, then test to see if the problem is fixed before going on to the next.

Be sure to backup your files before proceeding if possible.

1. Shutdown the computer, wait 30 seconds, restart the computer.
2. Disconnect all third-party peripherals.
3. Resetting your Mac’s PRAM and NVRAM
4. Reset the System Management Controller (SMC)
5. Reset your Startup Disk and Sound preferences.
6. Start the computer in Safe Mode. Test in safe mode to see if the problem persists, then restart normally.
7. Use Apple Hardware Test to see if there is any hardware malfunction.
8. Repair the disk by booting from the Recovery HD. Immediately after the chime hold down the Command and Rkeys until the Utility Menu appears. Choose Disk Utility and click on the Continue button. Select the indented (usually, Macintosh HD) volume entry from the side list. Click on the First Aid button in the toolbar. Wait for the Done button to appear. Quit Disk Utility and return to the Utility Menu. Restart the computer from the Apple Menu.
9. Repair permissions on the Home folder: Resolve issues caused by changing the permissions of items in your home folder.
10. Create a New User Account Open Users & Groups preferences. Click on the lock icon and enter your Admin password when prompted. On the left under Current User click on the Add [+] button under Login Options. Setup a new Admin user account. Upon completion log out of your current account then log into the new account. If your problems cease, then consider switching to the new account and transferring your files to it - Transferring files from one User Account to another.

What Mac model? To find the model identifier open System Profiler in the Utilities' folder. It's displayed in the panel on the right. You may also find the complete model information by selecting About This Mac from the Apple menu.

I gave no specific answer because there is not enough information. You asked how to reset the keychain. I provided several links to articles that may be helpful to you. The first group is particular to El Capitan and later. The tutorial is for older versions of OS X which provided more info on editing the keychain.

See the answer in this thread safari keychain and iCloud