Decrypt weblogic passwords:

Set environment by going to:
source $DOMAIN_HOME/bin/setDomainEnv.sh

Go to --> cd $DOMAIN_HOME/security  and create a file decrypt.py with below contents:

from weblogic.security.internal import *  
from weblogic.security.internal.encryption import *

encryptionService = SerializedSystemIni.getEncryptionService(".")  
clearOrEncryptService = ClearOrEncryptedService(encryptionService)

passwd = raw_input("Enter encrypted password of one which you wanted to decrypt : ")

plainpwd = passwd.replace("\\", "")

print "Plain Text password is: " + clearOrEncryptService.decrypt(plainpwd)  

Go to $DOMAIN_HOME/config/jdbc and get the encrypted password for any data source you need

Run the command java weblogic.WLST decrypt.py in cd $DOMAIN_HOME/security

Input your encrypted password while prompted. 

java weblogic.WLST plainpassword.py  
Initializing WebLogic Scripting Tool (WLST) ...  
Welcome to WebLogic Server Administration Scripting Shell  
Type help() for help on available commands  
Enter encrypted password of one which you wanted to decrypt : {AES}LsGaddassssvQDyibmejXFkf1tWxyndNArAhZ3M5GcnjXWUpJs=  
Plain Text password is: ######