gistfile1.groovy

def password = null

def askPassword() {
    return 'security -q find-generic-password -g -l omw-release -w'.execute().text.trim()
}

afterEvaluate {
    validateReleaseSigning.doFirst {
        password = askPassword()
        signingConfig.storePassword = password
        signingConfig.keyPassword = password
    }
}