/*

  * This file is part of dependency-check-core.

  *

  * Licensed under the Apache License, Version 2.0 (the "License");

  * you may not use this file except in compliance with the License.

  * You may obtain a copy of the License at

  *

  *     http://www.apache.org/licenses/LICENSE-2.0

  *

  * Unless required by applicable law or agreed to in writing, software

  * distributed under the License is distributed on an "AS IS" BASIS,

  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

  * See the License for the specific language governing permissions and

  * limitations under the License.

  *

  * Copyright (c) 2012 Jeremy Long. All Rights Reserved.

  */

 package org.owasp.dependencycheck.data.nvdcve;

 import java.io.IOException;

 import java.io.UnsupportedEncodingException;

 import java.sql.CallableStatement;

 import java.sql.Connection;

 import java.sql.PreparedStatement;

 import java.sql.ResultSet;

 import java.sql.SQLException;

 import java.sql.Statement;

 import java.util.ArrayList;

 import java.util.HashMap;

 import java.util.HashSet;

 import java.util.List;

 import java.util.Locale;

 import java.util.Map;

 import java.util.Map.Entry;

 import java.util.MissingResourceException;

 import java.util.Properties;

 import java.util.ResourceBundle;

 import java.util.Set;

 import org.owasp.dependencycheck.data.cwe.CweDB;

 import org.owasp.dependencycheck.dependency.Reference;

 import org.owasp.dependencycheck.dependency.Vulnerability;

 import org.owasp.dependencycheck.dependency.VulnerableSoftware;

 import org.owasp.dependencycheck.utils.DBUtils;

 import org.owasp.dependencycheck.utils.DependencyVersion;

 import org.owasp.dependencycheck.utils.DependencyVersionUtil;

 import org.owasp.dependencycheck.utils.Pair;

 import org.owasp.dependencycheck.utils.Settings;

 import org.slf4j.Logger;

 import org.slf4j.LoggerFactory;

 /**

  * The database holding information about the NVD CVE data.

  *

  * @author Jeremy Long

  */

 public class CveDB {

     /**

      * The logger.

      */

     private static final Logger LOGGER = LoggerFactory.getLogger(CveDB.class);

     /**

      * Database connection

      */

     private Connection conn;

     /**

      * The bundle of statements used when accessing the database.

      */

     private ResourceBundle statementBundle = null;

     /**

      * Creates a new CveDB object and opens the database connection. Note, the connection must be closed by the caller by calling

      * the close method.

      *

      * @throws DatabaseException thrown if there is an exception opening the database.

      */

     public CveDB() throws DatabaseException {

         super();

         try {

             open();

             try {

                 final String databaseProductName = conn.getMetaData().getDatabaseProductName();

                 LOGGER.debug("Database dialect: {}", databaseProductName);

                 final Locale dbDialect = new Locale(databaseProductName);

                 statementBundle = ResourceBundle.getBundle("data/dbStatements", dbDialect);

             } catch (SQLException se) {

                 LOGGER.warn("Problem loading database specific dialect!", se);

                 statementBundle = ResourceBundle.getBundle("data/dbStatements");

             }

             databaseProperties = new DatabaseProperties(this);

         } catch (DatabaseException ex) {

             throw ex;

         }

     }

     /**

      * Returns the database connection.

      *

      * @return the database connection

      */

     protected Connection getConnection() {

         return conn;

     }

     /**

      * Opens the database connection. If the database does not exist, it will create a new one.

      *

      * @throws DatabaseException thrown if there is an error opening the database connection

      */

     public final void open() throws DatabaseException {

         if (!isOpen()) {

             conn = ConnectionFactory.getConnection();

         }

     }

     /**

      * Closes the DB4O database. Close should be called on this object when it is done being used.

      */

     public void close() {

         if (conn != null) {

             try {

                 conn.close();

             } catch (SQLException ex) {

                 LOGGER.error("There was an error attempting to close the CveDB, see the log for more details.");

                 LOGGER.debug("", ex);

             } catch (Throwable ex) {

                 LOGGER.error("There was an exception attempting to close the CveDB, see the log for more details.");

                 LOGGER.debug("", ex);

             }

             conn = null;

         }

     }

     /**

      * Returns whether the database connection is open or closed.

      *

      * @return whether the database connection is open or closed

      */

     public boolean isOpen() {

         return conn != null;

     }

     /**

      * Commits all completed transactions.

      *

      * @throws SQLException thrown if a SQL Exception occurs

      */

     public void commit() throws SQLException {

         //temporary remove this as autocommit is on.

         //if (conn != null) {

         //    conn.commit();

         //}

     }

     /**

      * Cleans up the object and ensures that "close" has been called.

      *

      * @throws Throwable thrown if there is a problem

      */

     @Override

     @SuppressWarnings("FinalizeDeclaration")

     protected void finalize() throws Throwable {

         LOGGER.debug("Entering finalize");

         close();

         super.finalize();

     }

     /**

      * Database properties object containing the 'properties' from the database table.

      */

     private DatabaseProperties databaseProperties;

     /**

      * Get the value of databaseProperties.

      *

      * @return the value of databaseProperties

      */

     public DatabaseProperties getDatabaseProperties() {

         return databaseProperties;

     }

     /**

      * Searches the CPE entries in the database and retrieves all entries for a given vendor and product combination. The returned

      * list will include all versions of the product that are registered in the NVD CVE data.

      *

      * @param vendor the identified vendor name of the dependency being analyzed

      * @param product the identified name of the product of the dependency being analyzed

      * @return a set of vulnerable software

      */

     public Set<VulnerableSoftware> getCPEs(String vendor, String product) {

         final Set<VulnerableSoftware> cpe = new HashSet<VulnerableSoftware>();

         ResultSet rs = null;

         PreparedStatement ps = null;

         try {

             ps = getConnection().prepareStatement(statementBundle.getString("SELECT_CPE_ENTRIES"));

             ps.setString(1, vendor);

             ps.setString(2, product);

             rs = ps.executeQuery();

             while (rs.next()) {

                 final VulnerableSoftware vs = new VulnerableSoftware();

                 vs.setCpe(rs.getString(1));

                 cpe.add(vs);

             }

         } catch (SQLException ex) {

             LOGGER.error("An unexpected SQL Exception occurred; please see the verbose log for more details.");

             LOGGER.debug("", ex);

         } finally {

             DBUtils.closeResultSet(rs);

             DBUtils.closeStatement(ps);

         }

         return cpe;

     }

     /**

      * Returns the entire list of vendor/product combinations.

      *

      * @return the entire list of vendor/product combinations

      * @throws DatabaseException thrown when there is an error retrieving the data from the DB

      */

     public Set<Pair<String, String>> getVendorProductList() throws DatabaseException {

         final Set<Pair<String, String>> data = new HashSet<Pair<String, String>>();

         ResultSet rs = null;

         PreparedStatement ps = null;

         try {

             ps = getConnection().prepareStatement(statementBundle.getString("SELECT_VENDOR_PRODUCT_LIST"));

             rs = ps.executeQuery();

             while (rs.next()) {

                 data.add(new Pair<String, String>(rs.getString(1), rs.getString(2)));

             }

         } catch (SQLException ex) {

             final String msg = "An unexpected SQL Exception occurred; please see the verbose log for more details.";

             throw new DatabaseException(msg, ex);

         } finally {

             DBUtils.closeResultSet(rs);

             DBUtils.closeStatement(ps);

         }

         return data;

     }

     /**

      * Returns a set of properties.

      *

      * @return the properties from the database

      */

     Properties getProperties() {

         final Properties prop = new Properties();

         PreparedStatement ps = null;

         ResultSet rs = null;

         try {

             ps = getConnection().prepareStatement(statementBundle.getString("SELECT_PROPERTIES"));

             rs = ps.executeQuery();

             while (rs.next()) {

                 prop.setProperty(rs.getString(1), rs.getString(2));

             }

         } catch (SQLException ex) {

             LOGGER.error("An unexpected SQL Exception occurred; please see the verbose log for more details.");

             LOGGER.debug("", ex);

         } finally {

             DBUtils.closeStatement(ps);

             DBUtils.closeResultSet(rs);

         }

         return prop;

     }

     /**

      * Saves a property to the database.

      *

      * @param key the property key

      * @param value the property value

      */

     void saveProperty(String key, String value) {

         try {

             try {

                 final PreparedStatement mergeProperty = getConnection().prepareStatement(statementBundle.getString("MERGE_PROPERTY"));

                 try {

                     mergeProperty.setString(1, key);

                     mergeProperty.setString(2, value);

                     mergeProperty.executeUpdate();

                 } finally {

                     DBUtils.closeStatement(mergeProperty);

                 }

             } catch (MissingResourceException mre) {

                 // No Merge statement, so doing an Update/Insert...

                 PreparedStatement updateProperty = null;

                 PreparedStatement insertProperty = null;

                 try {

                     updateProperty = getConnection().prepareStatement(statementBundle.getString("UPDATE_PROPERTY"));

                     updateProperty.setString(1, value);

                     updateProperty.setString(2, key);

                     if (updateProperty.executeUpdate() == 0) {

                         insertProperty = getConnection().prepareStatement(statementBundle.getString("INSERT_PROPERTY"));

                         insertProperty.setString(1, key);

                         insertProperty.setString(2, value);

                         insertProperty.executeUpdate();

                     }

                 } finally {

                     DBUtils.closeStatement(updateProperty);

                     DBUtils.closeStatement(insertProperty);

                 }

             }

         } catch (SQLException ex) {

             LOGGER.warn("Unable to save property '{}' with a value of '{}' to the database", key, value);

             LOGGER.debug("", ex);

         }

     }

     /**

      * Retrieves the vulnerabilities associated with the specified CPE.

      *

      * @param cpeStr the CPE name

      * @return a list of Vulnerabilities

      * @throws DatabaseException thrown if there is an exception retrieving data

      */

     public List<Vulnerability> getVulnerabilities(String cpeStr) throws DatabaseException {

         final VulnerableSoftware cpe = new VulnerableSoftware();

         try {

             cpe.parseName(cpeStr);

         } catch (UnsupportedEncodingException ex) {

             LOGGER.trace("", ex);

         }

         final DependencyVersion detectedVersion = parseDependencyVersion(cpe);

         final List<Vulnerability> vulnerabilities = new ArrayList<Vulnerability>();

         PreparedStatement ps = null;

         ResultSet rs = null;

         try {

             ps = getConnection().prepareStatement(statementBundle.getString("SELECT_CVE_FROM_SOFTWARE"));

             ps.setString(1, cpe.getVendor());

             ps.setString(2, cpe.getProduct());

             rs = ps.executeQuery();

             String currentCVE = "";

             final Map<String, Boolean> vulnSoftware = new HashMap<String, Boolean>();

             while (rs.next()) {

                 final String cveId = rs.getString(1);

                 if (!currentCVE.equals(cveId)) { //check for match and add

                     final Entry<String, Boolean> matchedCPE = getMatchingSoftware(vulnSoftware, cpe.getVendor(), cpe.getProduct(), detectedVersion);

                     if (matchedCPE != null) {

                         final Vulnerability v = getVulnerability(currentCVE);

                         v.setMatchedCPE(matchedCPE.getKey(), matchedCPE.getValue() ? "Y" : null);

                         vulnerabilities.add(v);

                     }

                     vulnSoftware.clear();

                     currentCVE = cveId;

                 }

                 final String cpeId = rs.getString(2);

                 final String previous = rs.getString(3);

                 final Boolean p = previous != null && !previous.isEmpty();

                 vulnSoftware.put(cpeId, p);

             }

             //remember to process the last set of CVE/CPE entries

             final Entry<String, Boolean> matchedCPE = getMatchingSoftware(vulnSoftware, cpe.getVendor(), cpe.getProduct(), detectedVersion);

             if (matchedCPE != null) {

                 final Vulnerability v = getVulnerability(currentCVE);

                 v.setMatchedCPE(matchedCPE.getKey(), matchedCPE.getValue() ? "Y" : null);

                 vulnerabilities.add(v);

             }

         } catch (SQLException ex) {

             throw new DatabaseException("Exception retrieving vulnerability for " + cpeStr, ex);

         } finally {

             DBUtils.closeResultSet(rs);

             DBUtils.closeStatement(ps);

         }

         return vulnerabilities;

     }

     /**

      * Gets a vulnerability for the provided CVE.

      *

      * @param cve the CVE to lookup

      * @return a vulnerability object

      * @throws DatabaseException if an exception occurs

      */

     private Vulnerability getVulnerability(String cve) throws DatabaseException {

         PreparedStatement psV = null;

         PreparedStatement psR = null;

         PreparedStatement psS = null;

         ResultSet rsV = null;

         ResultSet rsR = null;

         ResultSet rsS = null;

         Vulnerability vuln = null;

         try {

             psV = getConnection().prepareStatement(statementBundle.getString("SELECT_VULNERABILITY"));

             psV.setString(1, cve);

             rsV = psV.executeQuery();

             if (rsV.next()) {

                 vuln = new Vulnerability();

                 vuln.setName(cve);

                 vuln.setDescription(rsV.getString(2));

                 String cwe = rsV.getString(3);

                 if (cwe != null) {

                     final String name = CweDB.getCweName(cwe);

                     if (name != null) {

                         cwe += ' ' + name;

                     }

                 }

                 final int cveId = rsV.getInt(1);

                 vuln.setCwe(cwe);

                 vuln.setCvssScore(rsV.getFloat(4));

                 vuln.setCvssAccessVector(rsV.getString(5));

                 vuln.setCvssAccessComplexity(rsV.getString(6));

                 vuln.setCvssAuthentication(rsV.getString(7));

                 vuln.setCvssConfidentialityImpact(rsV.getString(8));

                 vuln.setCvssIntegrityImpact(rsV.getString(9));

                 vuln.setCvssAvailabilityImpact(rsV.getString(10));

                 psR = getConnection().prepareStatement(statementBundle.getString("SELECT_REFERENCES"));

                 psR.setInt(1, cveId);

                 rsR = psR.executeQuery();

                 while (rsR.next()) {

                     vuln.addReference(rsR.getString(1), rsR.getString(2), rsR.getString(3));

                 }

                 psS = getConnection().prepareStatement(statementBundle.getString("SELECT_SOFTWARE"));

                 psS.setInt(1, cveId);

                 rsS = psS.executeQuery();

                 while (rsS.next()) {

                     final String cpe = rsS.getString(1);

                     final String prevVersion = rsS.getString(2);

                     if (prevVersion == null) {

                         vuln.addVulnerableSoftware(cpe);

                     } else {

                         vuln.addVulnerableSoftware(cpe, prevVersion);

                     }

                 }

             }

         } catch (SQLException ex) {

             throw new DatabaseException("Error retrieving " + cve, ex);

         } finally {

             DBUtils.closeResultSet(rsV);

             DBUtils.closeResultSet(rsR);

             DBUtils.closeResultSet(rsS);

             DBUtils.closeStatement(psV);

             DBUtils.closeStatement(psR);

             DBUtils.closeStatement(psS);

         }

         return vuln;

     }

     /**

      * Updates the vulnerability within the database. If the vulnerability does not exist it will be added.

      *

      * @param vuln the vulnerability to add to the database

      * @throws DatabaseException is thrown if the database

      */

     public void updateVulnerability(Vulnerability vuln) throws DatabaseException {

         PreparedStatement selectVulnerabilityId = null;

         PreparedStatement deleteVulnerability = null;

         PreparedStatement deleteReferences = null;

         PreparedStatement deleteSoftware = null;

         PreparedStatement updateVulnerability = null;

         PreparedStatement insertVulnerability = null;

         PreparedStatement insertReference = null;

         PreparedStatement selectCpeId = null;

         PreparedStatement insertCpe = null;

         PreparedStatement insertSoftware = null;

         try {

             selectVulnerabilityId = getConnection().prepareStatement(statementBundle.getString("SELECT_VULNERABILITY_ID"));

             deleteVulnerability = getConnection().prepareStatement(statementBundle.getString("DELETE_VULNERABILITY"));

             deleteReferences = getConnection().prepareStatement(statementBundle.getString("DELETE_REFERENCE"));

             deleteSoftware = getConnection().prepareStatement(statementBundle.getString("DELETE_SOFTWARE"));

             updateVulnerability = getConnection().prepareStatement(statementBundle.getString("UPDATE_VULNERABILITY"));

             final String[] ids = {"id"};

             insertVulnerability = getConnection().prepareStatement(statementBundle.getString("INSERT_VULNERABILITY"),

                     //Statement.RETURN_GENERATED_KEYS);

                     ids);

             insertReference = getConnection().prepareStatement(statementBundle.getString("INSERT_REFERENCE"));

             selectCpeId = getConnection().prepareStatement(statementBundle.getString("SELECT_CPE_ID"));

             insertCpe = getConnection().prepareStatement(statementBundle.getString("INSERT_CPE"),

                     //Statement.RETURN_GENERATED_KEYS);

                     ids);

             insertSoftware = getConnection().prepareStatement(statementBundle.getString("INSERT_SOFTWARE"));

             int vulnerabilityId = 0;

             selectVulnerabilityId.setString(1, vuln.getName());

             ResultSet rs = selectVulnerabilityId.executeQuery();

             if (rs.next()) {

                 vulnerabilityId = rs.getInt(1);

                 // first delete any existing vulnerability info. We don't know what was updated. yes, slower but atm easier.

                 deleteReferences.setInt(1, vulnerabilityId);

                 deleteReferences.execute();

                 deleteSoftware.setInt(1, vulnerabilityId);

                 deleteSoftware.execute();

             }

             DBUtils.closeResultSet(rs);

             rs = null;

             if (vulnerabilityId != 0) {

                 if (vuln.getDescription().contains("** REJECT **")) {

                     deleteVulnerability.setInt(1, vulnerabilityId);

                     deleteVulnerability.executeUpdate();

                 } else {

                     updateVulnerability.setString(1, vuln.getDescription());

                     updateVulnerability.setString(2, vuln.getCwe());

                     updateVulnerability.setFloat(3, vuln.getCvssScore());

                     updateVulnerability.setString(4, vuln.getCvssAccessVector());

                     updateVulnerability.setString(5, vuln.getCvssAccessComplexity());

                     updateVulnerability.setString(6, vuln.getCvssAuthentication());

                     updateVulnerability.setString(7, vuln.getCvssConfidentialityImpact());

                     updateVulnerability.setString(8, vuln.getCvssIntegrityImpact());

                     updateVulnerability.setString(9, vuln.getCvssAvailabilityImpact());

                     updateVulnerability.setInt(10, vulnerabilityId);

                     updateVulnerability.executeUpdate();

                 }

             } else {

                 insertVulnerability.setString(1, vuln.getName());

                 insertVulnerability.setString(2, vuln.getDescription());

                 insertVulnerability.setString(3, vuln.getCwe());

                 insertVulnerability.setFloat(4, vuln.getCvssScore());

                 insertVulnerability.setString(5, vuln.getCvssAccessVector());

                 insertVulnerability.setString(6, vuln.getCvssAccessComplexity());

                 insertVulnerability.setString(7, vuln.getCvssAuthentication());

                 insertVulnerability.setString(8, vuln.getCvssConfidentialityImpact());

                 insertVulnerability.setString(9, vuln.getCvssIntegrityImpact());

                 insertVulnerability.setString(10, vuln.getCvssAvailabilityImpact());

                 insertVulnerability.execute();

                 try {

                     rs = insertVulnerability.getGeneratedKeys();

                     rs.next();

                     vulnerabilityId = rs.getInt(1);

                 } catch (SQLException ex) {

                     final String msg = String.format("Unable to retrieve id for new vulnerability for '%s'", vuln.getName());

                     throw new DatabaseException(msg, ex);

                 } finally {

                     DBUtils.closeResultSet(rs);

                     rs = null;

                 }

             }

             insertReference.setInt(1, vulnerabilityId);

             for (Reference r : vuln.getReferences()) {

                 insertReference.setString(2, r.getName());

                 insertReference.setString(3, r.getUrl());

                 insertReference.setString(4, r.getSource());

                 insertReference.execute();

             }

             for (VulnerableSoftware s : vuln.getVulnerableSoftware()) {

                 int cpeProductId = 0;

                 selectCpeId.setString(1, s.getName());

                 try {

                     rs = selectCpeId.executeQuery();

                     if (rs.next()) {

                         cpeProductId = rs.getInt(1);

                     }

                 } catch (SQLException ex) {

                     throw new DatabaseException("Unable to get primary key for new cpe: " + s.getName(), ex);

                 } finally {

                     DBUtils.closeResultSet(rs);

                     rs = null;

                 }

                 if (cpeProductId == 0) {

                     insertCpe.setString(1, s.getName());

                     insertCpe.setString(2, s.getVendor());

                     insertCpe.setString(3, s.getProduct());

                     insertCpe.executeUpdate();

                     cpeProductId = DBUtils.getGeneratedKey(insertCpe);

                 }

                 if (cpeProductId == 0) {

                     throw new DatabaseException("Unable to retrieve cpeProductId - no data returned");

                 }

                 insertSoftware.setInt(1, vulnerabilityId);

                 insertSoftware.setInt(2, cpeProductId);

                 if (s.getPreviousVersion() == null) {

                     insertSoftware.setNull(3, java.sql.Types.VARCHAR);

                 } else {

                     insertSoftware.setString(3, s.getPreviousVersion());

                 }

                 insertSoftware.execute();

             }

         } catch (SQLException ex) {

             final String msg = String.format("Error updating '%s'", vuln.getName());

             LOGGER.debug("", ex);

             throw new DatabaseException(msg, ex);

         } finally {

             DBUtils.closeStatement(selectVulnerabilityId);

             DBUtils.closeStatement(deleteReferences);

             DBUtils.closeStatement(deleteSoftware);

             DBUtils.closeStatement(updateVulnerability);

             DBUtils.closeStatement(deleteVulnerability);

             DBUtils.closeStatement(insertVulnerability);

             DBUtils.closeStatement(insertReference);

             DBUtils.closeStatement(selectCpeId);

             DBUtils.closeStatement(insertCpe);

             DBUtils.closeStatement(insertSoftware);

         }

     }

     /**

      * Checks to see if data exists so that analysis can be performed.

      *

      * @return <code>true</code> if data exists; otherwise <code>false</code>

      */

     public boolean dataExists() {

         Statement cs = null;

         ResultSet rs = null;

         try {

             cs = conn.createStatement();

             rs = cs.executeQuery("SELECT COUNT(*) records FROM cpeEntry");

             if (rs.next()) {

                 if (rs.getInt(1) > 0) {

                     return true;

                 }

             }

         } catch (SQLException ex) {

             String dd;

             try {

                 dd = Settings.getDataDirectory().getAbsolutePath();

             } catch (IOException ex1) {

                 dd = Settings.getString(Settings.KEYS.DATA_DIRECTORY);

             }

             LOGGER.error("Unable to access the local database.\n\nEnsure that '{}' is a writable directory. "

                     + "If the problem persist try deleting the files in '{}' and running {} again. If the problem continues, please "

                     + "create a log file (see documentation at http://jeremylong.github.io/DependencyCheck/) and open a ticket at "

                     + "https://github.com/jeremylong/DependencyCheck/issues and include the log file.\n\n",

                     dd, dd, Settings.getString(Settings.KEYS.APPLICATION_VAME));

             LOGGER.debug("", ex);

         } finally {

             DBUtils.closeResultSet(rs);

             DBUtils.closeStatement(cs);

         }

         return false;

     }

     /**

      * It is possible that orphaned rows may be generated during database updates. This should be called after all updates have

      * been completed to ensure orphan entries are removed.

      */

     public void cleanupDatabase() {

         PreparedStatement ps = null;

         try {

             ps = getConnection().prepareStatement(statementBundle.getString("CLEANUP_ORPHANS"));

             if (ps != null) {

                 ps.executeUpdate();

             }

         } catch (SQLException ex) {

             LOGGER.error("An unexpected SQL Exception occurred; please see the verbose log for more details.");

             LOGGER.debug("", ex);

         } finally {

             DBUtils.closeStatement(ps);

         }

     }

     /**

      * Determines if the given identifiedVersion is affected by the given cpeId and previous version flag. A non-null, non-empty

      * string passed to the previous version argument indicates that all previous versions are affected.

      *

      * @param vendor the vendor of the dependency being analyzed

      * @param product the product name of the dependency being analyzed

      * @param vulnerableSoftware a map of the vulnerable software with a boolean indicating if all previous versions are affected

      * @param identifiedVersion the identified version of the dependency being analyzed

      * @return true if the identified version is affected, otherwise false

      */

     Entry<String, Boolean> getMatchingSoftware(Map<String, Boolean> vulnerableSoftware, String vendor, String product,

             DependencyVersion identifiedVersion) {

         final boolean isVersionTwoADifferentProduct = "apache".equals(vendor) && "struts".equals(product);

         final Set<String> majorVersionsAffectingAllPrevious = new HashSet<String>();

         final boolean matchesAnyPrevious = identifiedVersion == null || "-".equals(identifiedVersion.toString());

         String majorVersionMatch = null;

         for (Entry<String, Boolean> entry : vulnerableSoftware.entrySet()) {

             final DependencyVersion v = parseDependencyVersion(entry.getKey());

             if (v == null || "-".equals(v.toString())) { //all versions

                 return entry;

             }

             if (entry.getValue()) {

                 if (matchesAnyPrevious) {

                     return entry;

                 }

                 if (identifiedVersion != null && identifiedVersion.getVersionParts().get(0).equals(v.getVersionParts().get(0))) {

                     majorVersionMatch = v.getVersionParts().get(0);

                 }

                 majorVersionsAffectingAllPrevious.add(v.getVersionParts().get(0));

             }

         }

         if (matchesAnyPrevious) {

             return null;

         }

         final boolean canSkipVersions = majorVersionMatch != null && majorVersionsAffectingAllPrevious.size() > 1;

         //yes, we are iterating over this twice. The first time we are skipping versions those that affect all versions

         //then later we process those that affect all versions. This could be done with sorting...

         for (Entry<String, Boolean> entry : vulnerableSoftware.entrySet()) {

             if (!entry.getValue()) {

                 final DependencyVersion v = parseDependencyVersion(entry.getKey());

                 //this can't dereference a null 'majorVersionMatch' as canSkipVersions accounts for this.

                 if (canSkipVersions && !majorVersionMatch.equals(v.getVersionParts().get(0))) {

                     continue;

                 }

                 //this can't dereference a null 'identifiedVersion' because if it was null we would have exited

                 //in the above loop or just after loop (if matchesAnyPrevious return null).

                 if (identifiedVersion.equals(v)) {

                     return entry;

                 }

             }

         }

         for (Entry<String, Boolean> entry : vulnerableSoftware.entrySet()) {

             if (entry.getValue()) {

                 final DependencyVersion v = parseDependencyVersion(entry.getKey());

                 //this can't dereference a null 'majorVersionMatch' as canSkipVersions accounts for this.

                 if (canSkipVersions && !majorVersionMatch.equals(v.getVersionParts().get(0))) {

                     continue;

                 }

                 //this can't dereference a null 'identifiedVersion' because if it was null we would have exited

                 //in the above loop or just after loop (if matchesAnyPrevious return null).

                 if (entry.getValue() && identifiedVersion.compareTo(v) <= 0) {

                     if (!(isVersionTwoADifferentProduct && !identifiedVersion.getVersionParts().get(0).equals(v.getVersionParts().get(0)))) {

                         return entry;

                     }

                 }

             }

         }

         return null;

     }

     /**

      * Parses the version (including revision) from a CPE identifier. If no version is identified then a '-' is returned.

      *

      * @param cpeStr a cpe identifier

      * @return a dependency version

      */

     private DependencyVersion parseDependencyVersion(String cpeStr) {

         final VulnerableSoftware cpe = new VulnerableSoftware();

         try {

             cpe.parseName(cpeStr);

         } catch (UnsupportedEncodingException ex) {

             //never going to happen.

             LOGGER.trace("", ex);

         }

         return parseDependencyVersion(cpe);

     }

     /**

      * Takes a CPE and parses out the version number. If no version is identified then a '-' is returned.

      *

      * @param cpe a cpe object

      * @return a dependency version

      */

     private DependencyVersion parseDependencyVersion(VulnerableSoftware cpe) {

         final DependencyVersion cpeVersion;

         if (cpe.getVersion() != null && !cpe.getVersion().isEmpty()) {

             final String versionText;

             if (cpe.getUpdate() != null && !cpe.getUpdate().isEmpty()) {

                 versionText = String.format("%s.%s", cpe.getVersion(), cpe.getUpdate());

             } else {

                 versionText = cpe.getVersion();

             }

             cpeVersion = DependencyVersionUtil.parseVersion(versionText);

         } else {

             cpeVersion = new DependencyVersion("-");

         }

         return cpeVersion;

     }

     /**

      * This method is only referenced in unused code.

      *

      * Deletes unused dictionary entries from the database.

      */

     public void deleteUnusedCpe() {

         CallableStatement cs = null;

         try {

             cs = getConnection().prepareCall(statementBundle.getString("DELETE_UNUSED_DICT_CPE"));

             cs.executeUpdate();

         } catch (SQLException ex) {

             LOGGER.error("Unable to delete CPE dictionary entries", ex);

         } finally {

             DBUtils.closeStatement(cs);

         }

     }

     /**

      * This method is only referenced in unused code and will likely break on MySQL if ever used due to the MERGE statement.

      *

      * Merges CPE entries into the database.

      *

      * @param cpe the CPE identifier

      * @param vendor the CPE vendor

      * @param product the CPE product

      */

     public void addCpe(String cpe, String vendor, String product) {

         PreparedStatement ps = null;

         try {

             ps = getConnection().prepareCall(statementBundle.getString("ADD_DICT_CPE"));

             ps.setString(1, cpe);

             ps.setString(2, vendor);

             ps.setString(3, product);

             ps.executeUpdate();

         } catch (SQLException ex) {

             LOGGER.error("Unable to add CPE dictionary entry", ex);

         } finally {

             DBUtils.closeStatement(ps);

         }

     }

 }