I don't remember my android debug.keystore password

Question

Usually the debug.keystore password is just "android".

You can delete it and Eclipse will automatically generate a new one, as described here.

The Default Configuration of debug.keystore file:

Keystore name: "debug.keystore"
Keystore password: "android"
Key alias: "androiddebugkey"
Key password: "android"
CN: "CN=Android Debug,O=Android,C=US"

where is this file located?

For Windows User: C:\Users \ [username]\ .android\debug.keystore

For Mac OS User: ~/.android/debug.keystore

After you will get SHAH1 by below command using Command Prompt:

keytool -list -v -keystore "C:\Users\username.android\debug.keystore" -alias androiddebugkey -storepass android -keypass android

Note :above answer has just information of android studio default configuration to access debug.keystore(debug certificate) file you can make you custom certificate if you want you own password and configuration.

If you are not certain that the password has been set before, try just empty password. It worked for me.

Again you can generate your google api key. Your .keystore file will be, In Eclipse, Windows -> preferences ->Android -> build ->default debug keystore path will be there. You just use that .keystore and generate your api key again by using this link:

http://lokeshatandroid.blogspot.in/2012/05/obtaining-google-maps-api-key.html