Obtain password masked out by the EnvInject plugin in Jenkins

jenkins-get-masked-passwd.groovy

# The EnvInject is a pretty old Jenkins plugin, but it happens to be still in use
# and if a password masked by it is forgotten, it can be retrieved as below. 

# Suppose it is a global password configured on the 'Configure System' page on Jenkins. 
  
# Log into the Jenkins server host and look for the encrypted string in envInject.xml. 
cd /var/lib/jenkins
vim envInject.xml

# Go to the groovy script console of the Jenkins server (https://JENKINS_HOST:JENKINS_PORT/script), and run below script
println(hudson.util.Secret.fromString('{SamPLEEnctyptEdString}') )