code: @Override
      public void makeBuildVariables(AbstractBuild build, Map<String, String> variables) {
          // global var/password pairs
          MaskPasswordsConfig config = MaskPasswordsConfig.getInstance();
          List<VarPasswordPair> globalVarPasswordPairs = config.getGlobalVarPasswordPairs();
          // we can't use variables.putAll() since passwords are ciphered when in varPasswordPairs
          for(VarPasswordPair globalVarPasswordPair: globalVarPasswordPairs) {
              variables.put(globalVarPasswordPair.getVar(), globalVarPasswordPair.getPassword());
          }
  
          // job's var/password pairs
          if(varPasswordPairs != null) {
              // cf. comment above
              for(VarPasswordPair varPasswordPair: varPasswordPairs) {
                  if(StringUtils.isNotBlank(varPasswordPair.getVar())) {
                      variables.put(varPasswordPair.getVar(), varPasswordPair.getPassword());
                  }
              }
          }
      }
docs: Contributes the passwords defined by the user as variables that can be reused
  from build steps (and other places).