Coverage Report

 /*
  * 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.analyzer;
 
 import java.io.IOException;
 import java.io.UnsupportedEncodingException;
 import java.net.URLEncoder;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
 import java.util.Set;
 import java.util.StringTokenizer;
 import java.util.logging.Level;
 import java.util.logging.Logger;
 import org.apache.lucene.document.Document;
 import org.apache.lucene.index.CorruptIndexException;
 import org.apache.lucene.queryparser.classic.ParseException;
 import org.apache.lucene.search.ScoreDoc;
 import org.apache.lucene.search.TopDocs;
 import org.owasp.dependencycheck.Engine;
 import org.owasp.dependencycheck.analyzer.exception.AnalysisException;
 import org.owasp.dependencycheck.data.cpe.CpeMemoryIndex;
 import org.owasp.dependencycheck.data.cpe.Fields;
 import org.owasp.dependencycheck.data.cpe.IndexEntry;
 import org.owasp.dependencycheck.data.cpe.IndexException;
 import org.owasp.dependencycheck.data.lucene.LuceneUtils;
 import org.owasp.dependencycheck.data.nvdcve.CveDB;
 import org.owasp.dependencycheck.data.nvdcve.DatabaseException;
 import org.owasp.dependencycheck.dependency.Confidence;
 import org.owasp.dependencycheck.dependency.Dependency;
 import org.owasp.dependencycheck.dependency.Evidence;
 import org.owasp.dependencycheck.dependency.EvidenceCollection;
 import org.owasp.dependencycheck.dependency.Identifier;
 import org.owasp.dependencycheck.dependency.VulnerableSoftware;
 import org.owasp.dependencycheck.utils.DependencyVersion;
 import org.owasp.dependencycheck.utils.DependencyVersionUtil;
 
 /**
  * CPEAnalyzer is a utility class that takes a project dependency and attempts to discern if there is an associated CPE.
  * It uses the evidence contained within the dependency to search the Lucene index.
  *
  * @author Jeremy Long <jeremy.long@owasp.org>
  */
 public class CPEAnalyzer implements Analyzer {
     /**
      * The Logger.
      */
     private static final Logger LOGGER = Logger.getLogger(CPEAnalyzer.class.getName());
     /**
      * The maximum number of query results to return.
      */
     static final int MAX_QUERY_RESULTS = 25;
     /**
      * The weighting boost to give terms when constructing the Lucene query.
      */
     static final String WEIGHTING_BOOST = "^5";
     /**
      * A string representation of a regular expression defining characters utilized within the CPE Names.
      */
     static final String CLEANSE_CHARACTER_RX = "[^A-Za-z0-9 ._-]";
     /**
      * A string representation of a regular expression used to remove all but alpha characters.
      */
     static final String CLEANSE_NONALPHA_RX = "[^A-Za-z]*";
     /**
      * The additional size to add to a new StringBuilder to account for extra data that will be written into the string.
      */
     static final int STRING_BUILDER_BUFFER = 20;
     /**
      * The CPE in memory index.
      */
     private CpeMemoryIndex cpe;
     /**
      * The CVE Database.
      */
     private CveDB cve;
 
     /**
      * Returns the name of this analyzer.
      *
      * @return the name of this analyzer.
      */
     @Override
     public String getName() {
         return "CPE Analyzer";
     }
 
     /**
      * Returns the analysis phase that this analyzer should run in.
      *
      * @return the analysis phase that this analyzer should run in.
      */
     @Override
     public AnalysisPhase getAnalysisPhase() {
         return AnalysisPhase.IDENTIFIER_ANALYSIS;
     }
 
     /**
      * Creates the CPE Lucene Index.
      *
      * @throws Exception is thrown if there is an issue opening the index.
      */
     @Override
     public void initialize() throws Exception {
         this.open();
     }
 
     /**
      * Opens the data source.
      *
      * @throws IOException when the Lucene directory to be queried does not exist or is corrupt.
      * @throws DatabaseException when the database throws an exception. This usually occurs when the database is in use
      * by another process.
      */
     public void open() throws IOException, DatabaseException {
         LOGGER.log(Level.FINE, "Opening the CVE Database");
         cve = new CveDB();
         cve.open();
         LOGGER.log(Level.FINE, "Creating the Lucene CPE Index");
         cpe = CpeMemoryIndex.getInstance();
         try {
             cpe.open(cve);
         } catch (IndexException ex) {
             LOGGER.log(Level.FINE, "IndexException", ex);
             throw new DatabaseException(ex);
         }
     }
 
     /**
      * Closes the data sources.
      */
     @Override
     public void close() {
         if (cpe != null) {
             cpe.close();
         }
         if (cve != null) {
             cve.close();
         }
     }
 
     /**
      * Searches the data store of CPE entries, trying to identify the CPE for the given dependency based on the evidence
      * contained within. The dependency passed in is updated with any identified CPE values.
      *
      * @param dependency the dependency to search for CPE entries on.
      * @throws CorruptIndexException is thrown when the Lucene index is corrupt.
      * @throws IOException is thrown when an IOException occurs.
      * @throws ParseException is thrown when the Lucene query cannot be parsed.
      */
     protected void determineCPE(Dependency dependency) throws CorruptIndexException, IOException, ParseException {
         Confidence confidence = Confidence.HIGHEST;
 
         String vendors = addEvidenceWithoutDuplicateTerms("", dependency.getVendorEvidence(), confidence);
         String products = addEvidenceWithoutDuplicateTerms("", dependency.getProductEvidence(), confidence);
         /* bug fix for #40 - version evidence is not showing up as "used" in the reports if there is no
          * CPE identified. As such, we are "using" the evidence and ignoring the results. */
         addEvidenceWithoutDuplicateTerms("", dependency.getVersionEvidence(), confidence);
 
         int ctr = 0;
         do {
             if (!vendors.isEmpty() && !products.isEmpty()) {
                 final List<IndexEntry> entries = searchCPE(vendors, products, dependency.getProductEvidence().getWeighting(),
                         dependency.getVendorEvidence().getWeighting());
 
                 for (IndexEntry e : entries) {
                     if (verifyEntry(e, dependency)) {
                         final String vendor = e.getVendor();
                         final String product = e.getProduct();
                         determineIdentifiers(dependency, vendor, product);
                     }
                 }
             }
             confidence = reduceConfidence(confidence);
             if (dependency.getVendorEvidence().contains(confidence)) {
                 vendors = addEvidenceWithoutDuplicateTerms(vendors, dependency.getVendorEvidence(), confidence);
             }
             if (dependency.getProductEvidence().contains(confidence)) {
                 products = addEvidenceWithoutDuplicateTerms(products, dependency.getProductEvidence(), confidence);
             }
             /* bug fix for #40 - version evidence is not showing up as "used" in the reports if there is no
              * CPE identified. As such, we are "using" the evidence and ignoring the results. */
             if (dependency.getVersionEvidence().contains(confidence)) {
                 addEvidenceWithoutDuplicateTerms("", dependency.getVersionEvidence(), confidence);
             }
         } while ((++ctr) < 4);
     }
 
     /**
      * Returns the text created by concatenating the text and the values from the EvidenceCollection (filtered for a
      * specific confidence). This attempts to prevent duplicate terms from being added.<br/<br/> Note, if the evidence
      * is longer then 200 characters it will be truncated.
      *
      * @param text the base text.
      * @param ec an EvidenceCollection
      * @param confidenceFilter a Confidence level to filter the evidence by.
      * @return the new evidence text
      */
     private String addEvidenceWithoutDuplicateTerms(final String text, final EvidenceCollection ec, Confidence confidenceFilter) {
         final String txt = (text == null) ? "" : text;
         final StringBuilder sb = new StringBuilder(txt.length() + (20 * ec.size()));
         sb.append(' ').append(txt).append(' ');
         for (Evidence e : ec.iterator(confidenceFilter)) {
             String value = e.getValue();
 
             //hack to get around the fact that lucene does a really good job of recognizing domains and not
             // splitting them. TODO - put together a better lucene analyzer specific to the domain.
             if (value.startsWith("http://")) {
                 value = value.substring(7).replaceAll("\\.", " ");
             }
             if (value.startsWith("https://")) {
                 value = value.substring(8).replaceAll("\\.", " ");
             }
             if (sb.indexOf(" " + value + " ") < 0) {
                 sb.append(value).append(' ');
             }
         }
         return sb.toString().trim();
     }
 
     /**
      * Reduces the given confidence by one level. This returns LOW if the confidence passed in is not HIGH.
      *
      * @param c the confidence to reduce.
      * @return One less then the confidence passed in.
      */
     private Confidence reduceConfidence(final Confidence c) {
         if (c == Confidence.HIGHEST) {
             return Confidence.HIGH;
         } else if (c == Confidence.HIGH) {
             return Confidence.MEDIUM;
         } else {
             return Confidence.LOW;
         }
     }
 
     /**
      * <p>
      * Searches the Lucene CPE index to identify possible CPE entries associated with the supplied vendor, product, and
      * version.</p>
      *
      * <p>
      * If either the vendorWeightings or productWeightings lists have been populated this data is used to add weighting
      * factors to the search.</p>
      *
      * @param vendor the text used to search the vendor field
      * @param product the text used to search the product field
      * @param vendorWeightings a list of strings to use to add weighting factors to the vendor field
      * @param productWeightings Adds a list of strings that will be used to add weighting factors to the product search
      * @return a list of possible CPE values
      * @throws CorruptIndexException when the Lucene index is corrupt
      * @throws IOException when the Lucene index is not found
      * @throws ParseException when the generated query is not valid
      */
     protected List<IndexEntry> searchCPE(String vendor, String product,
             Set<String> vendorWeightings, Set<String> productWeightings)
             throws CorruptIndexException, IOException, ParseException {
         final ArrayList<IndexEntry> ret = new ArrayList<IndexEntry>(MAX_QUERY_RESULTS);
 
         final String searchString = buildSearch(vendor, product, vendorWeightings, productWeightings);
         if (searchString == null) {
             return ret;
         }
 
         final TopDocs docs = cpe.search(searchString, MAX_QUERY_RESULTS);
         for (ScoreDoc d : docs.scoreDocs) {
             if (d.score >= 0.08) {
                 final Document doc = cpe.getDocument(d.doc);
                 final IndexEntry entry = new IndexEntry();
                 entry.setVendor(doc.get(Fields.VENDOR));
                 entry.setProduct(doc.get(Fields.PRODUCT));
 //                if (d.score < 0.08) {
 //                    System.out.print(entry.getVendor());
 //                    System.out.print(":");
 //                    System.out.print(entry.getProduct());
 //                    System.out.print(":");
 //                    System.out.println(d.score);
 //                }
                 entry.setSearchScore(d.score);
                 if (!ret.contains(entry)) {
                     ret.add(entry);
                 }
             }
         }
         return ret;
     }
 
     /**
      * <p>
      * Builds a Lucene search string by properly escaping data and constructing a valid search query.</p>
      *
      * <p>
      * If either the possibleVendor or possibleProducts lists have been populated this data is used to add weighting
      * factors to the search string generated.</p>
      *
      * @param vendor text to search the vendor field
      * @param product text to search the product field
      * @param vendorWeighting a list of strings to apply to the vendor to boost the terms weight
      * @param productWeightings a list of strings to apply to the product to boost the terms weight
      * @return the Lucene query
      */
     protected String buildSearch(String vendor, String product,
             Set<String> vendorWeighting, Set<String> productWeightings) {
         final String v = vendor; //.replaceAll("[^\\w\\d]", " ");
         final String p = product; //.replaceAll("[^\\w\\d]", " ");
         final StringBuilder sb = new StringBuilder(v.length() + p.length()
                 + Fields.PRODUCT.length() + Fields.VENDOR.length() + STRING_BUILDER_BUFFER);
 
         if (!appendWeightedSearch(sb, Fields.PRODUCT, p, productWeightings)) {
             return null;
         }
         sb.append(" AND ");
         if (!appendWeightedSearch(sb, Fields.VENDOR, v, vendorWeighting)) {
             return null;
         }
         return sb.toString();
     }
 
     /**
      * This method constructs a Lucene query for a given field. The searchText is split into separate words and if the
      * word is within the list of weighted words then an additional weighting is applied to the term as it is appended
      * into the query.
      *
      * @param sb a StringBuilder that the query text will be appended to.
      * @param field the field within the Lucene index that the query is searching.
      * @param searchText text used to construct the query.
      * @param weightedText a list of terms that will be considered higher importance when searching.
      * @return if the append was successful.
      */
     private boolean appendWeightedSearch(StringBuilder sb, String field, String searchText, Set<String> weightedText) {
         sb.append(" ").append(field).append(":( ");
 
         final String cleanText = cleanseText(searchText);
 
         if ("".equals(cleanText)) {
             return false;
         }
 
         if (weightedText == null || weightedText.isEmpty()) {
             LuceneUtils.appendEscapedLuceneQuery(sb, cleanText);
         } else {
             final StringTokenizer tokens = new StringTokenizer(cleanText);
             while (tokens.hasMoreElements()) {
                 final String word = tokens.nextToken();
                 String temp = null;
                 for (String weighted : weightedText) {
                     final String weightedStr = cleanseText(weighted);
                     if (equalsIgnoreCaseAndNonAlpha(word, weightedStr)) {
                         temp = LuceneUtils.escapeLuceneQuery(word) + WEIGHTING_BOOST;
                         if (!word.equalsIgnoreCase(weightedStr)) {
                             temp += " " + LuceneUtils.escapeLuceneQuery(weightedStr) + WEIGHTING_BOOST;
                         }
                     }
                 }
                 if (temp == null) {
                     temp = LuceneUtils.escapeLuceneQuery(word);
                 }
                 sb.append(" ").append(temp);
             }
         }
         sb.append(" ) ");
         return true;
     }
 
     /**
      * Removes characters from the input text that are not used within the CPE index.
      *
      * @param text is the text to remove the characters from.
      * @return the text having removed some characters.
      */
     private String cleanseText(String text) {
         return text.replaceAll(CLEANSE_CHARACTER_RX, " ");
     }
 
     /**
      * Compares two strings after lower casing them and removing the non-alpha characters.
      *
      * @param l string one to compare.
      * @param r string two to compare.
      * @return whether or not the two strings are similar.
      */
     private boolean equalsIgnoreCaseAndNonAlpha(String l, String r) {
         if (l == null || r == null) {
             return false;
         }
 
         final String left = l.replaceAll(CLEANSE_NONALPHA_RX, "");
         final String right = r.replaceAll(CLEANSE_NONALPHA_RX, "");
         return left.equalsIgnoreCase(right);
     }
 
     /**
      * Ensures that the CPE Identified matches the dependency. This validates that the product, vendor, and version
      * information for the CPE are contained within the dependencies evidence.
      *
      * @param entry a CPE entry.
      * @param dependency the dependency that the CPE entries could be for.
      * @return whether or not the entry is valid.
      */
     private boolean verifyEntry(final IndexEntry entry, final Dependency dependency) {
         boolean isValid = false;
 
         if (collectionContainsString(dependency.getProductEvidence(), entry.getProduct())
                 && collectionContainsString(dependency.getVendorEvidence(), entry.getVendor())) {
             //&& collectionContainsVersion(dependency.getVersionEvidence(), entry.getVersion())
             isValid = true;
         }
         return isValid;
     }
 
     /**
      * Used to determine if the EvidenceCollection contains a specific string.
      *
      * @param ec an EvidenceCollection
      * @param text the text to search for
      * @return whether or not the EvidenceCollection contains the string
      */
     private boolean collectionContainsString(EvidenceCollection ec, String text) {
 
         //<editor-fold defaultstate="collapsed" desc="This code fold contains an old version of the code, delete once more testing is done">
         //        String[] splitText = text.split("[\\s_-]");
         //
         //        for (String search : splitText) {
         //            //final String search = text.replaceAll("[\\s_-]", "").toLowerCase();
         //            if (ec.containsUsedString(search)) {
         //                return true;
         //            }
         //        }
         //</editor-fold>
         //TODO - likely need to change the split... not sure if this will work for CPE with special chars
         if (text == null) {
             return false;
         }
         final String[] words = text.split("[\\s_-]");
         final List<String> list = new ArrayList<String>();
         String tempWord = null;
         for (String word : words) {
             /*
              single letter words should be concatenated with the next word.
              so { "m", "core", "sample" } -> { "mcore", "sample" }
              */
             if (tempWord != null) {
                 list.add(tempWord + word);
                 tempWord = null;
             } else if (word.length() <= 2) {
                 tempWord = word;
             } else {
                 list.add(word);
             }
         }
         if (tempWord != null && !list.isEmpty()) {
             final String tmp = list.get(list.size() - 1) + tempWord;
             list.add(tmp);
         }
         boolean contains = true;
         for (String word : list) {
             contains &= ec.containsUsedString(word);
         }
         return contains;
     }
 
     /**
      * Analyzes a dependency and attempts to determine if there are any CPE identifiers for this dependency.
      *
      * @param dependency The Dependency to analyze.
      * @param engine The analysis engine
      * @throws AnalysisException is thrown if there is an issue analyzing the dependency.
      */
     @Override
     public void analyze(Dependency dependency, Engine engine) throws AnalysisException {
         try {
             determineCPE(dependency);
         } catch (CorruptIndexException ex) {
             throw new AnalysisException("CPE Index is corrupt.", ex);
         } catch (IOException ex) {
             throw new AnalysisException("Failure opening the CPE Index.", ex);
         } catch (ParseException ex) {
             throw new AnalysisException("Unable to parse the generated Lucene query for this dependency.", ex);
         }
     }
 
     /**
      * Retrieves a list of CPE values from the CveDB based on the vendor and product passed in. The list is then
      * validated to find only CPEs that are valid for the given dependency. It is possible that the CPE identified is a
      * best effort "guess" based on the vendor, product, and version information.
      *
      * @param dependency the Dependency being analyzed
      * @param vendor the vendor for the CPE being analyzed
      * @param product the product for the CPE being analyzed
      * @throws UnsupportedEncodingException is thrown if UTF-8 is not supported
      */
     private void determineIdentifiers(Dependency dependency, String vendor, String product) throws UnsupportedEncodingException {
         final Set<VulnerableSoftware> cpes = cve.getCPEs(vendor, product);
         DependencyVersion bestGuess = new DependencyVersion("-");
         Confidence bestGuessConf = null;
         final List<IdentifierMatch> collected = new ArrayList<IdentifierMatch>();
         for (Confidence conf : Confidence.values()) {
             for (Evidence evidence : dependency.getVersionEvidence().iterator(conf)) {
                 final DependencyVersion evVer = DependencyVersionUtil.parseVersion(evidence.getValue());
                 if (evVer == null) {
                     continue;
                 }
                 for (VulnerableSoftware vs : cpes) {
                     DependencyVersion dbVer;
                     if (vs.getRevision() != null && !vs.getRevision().isEmpty()) {
                         dbVer = DependencyVersionUtil.parseVersion(vs.getVersion() + "." + vs.getRevision());
                     } else {
                         dbVer = DependencyVersionUtil.parseVersion(vs.getVersion());
                     }
                     if (dbVer == null //special case, no version specified - everything is vulnerable
                             || evVer.equals(dbVer)) { //yeah! exact match
                         final String url = String.format("http://web.nvd.nist.gov/view/vuln/search?cpe=%s", URLEncoder.encode(vs.getName(), "UTF-8"));
                         final IdentifierMatch match = new IdentifierMatch("cpe", vs.getName(), url, IdentifierConfidence.EXACT_MATCH, conf);
                         collected.add(match);
                     } else {
                         //TODO the following isn't quite right is it? need to think about this guessing game a bit more.
                         if (evVer.getVersionParts().size() <= dbVer.getVersionParts().size()
                                 && evVer.matchesAtLeastThreeLevels(dbVer)) {
                             if (bestGuessConf == null || bestGuessConf.compareTo(conf) > 0) {
                                 if (bestGuess.getVersionParts().size() < dbVer.getVersionParts().size()) {
                                     bestGuess = dbVer;
                                     bestGuessConf = conf;
                                 }
                             }
                         }
                     }
                 }
                 if (bestGuessConf == null || bestGuessConf.compareTo(conf) > 0) {
                     if (bestGuess.getVersionParts().size() < evVer.getVersionParts().size()) {
                         bestGuess = evVer;
                         bestGuessConf = conf;
                     }
                 }
             }
         }
         final String cpeName = String.format("cpe:/a:%s:%s:%s", vendor, product, bestGuess.toString());
         final String url = null; //String.format("http://web.nvd.nist.gov/view/vuln/search?cpe=%s", URLEncoder.encode(cpeName, "UTF-8"));
         if (bestGuessConf == null) {
             bestGuessConf = Confidence.LOW;
         }
         final IdentifierMatch match = new IdentifierMatch("cpe", cpeName, url, IdentifierConfidence.BEST_GUESS, bestGuessConf);
         collected.add(match);
 
         Collections.sort(collected);
         final IdentifierConfidence bestIdentifierQuality = collected.get(0).getConfidence();
         final Confidence bestEvidenceQuality = collected.get(0).getEvidenceConfidence();
         for (IdentifierMatch m : collected) {
             if (bestIdentifierQuality.equals(m.getConfidence())
                     && bestEvidenceQuality.equals(m.getEvidenceConfidence())) {
                 final Identifier i = m.getIdentifier();
                 if (bestIdentifierQuality == IdentifierConfidence.BEST_GUESS) {
                     i.setConfidence(Confidence.LOW);
                 } else {
                     i.setConfidence(bestEvidenceQuality);
                 }
                 dependency.addIdentifier(i);
             }
         }
     }
 
     /**
      * The confidence whether the identifier is an exact match, or a best guess.
      */
     private enum IdentifierConfidence {
 
         /**
          * An exact match for the CPE.
          */
         EXACT_MATCH,
         /**
          * A best guess for the CPE.
          */
         BEST_GUESS
     }
 
     /**
      * A simple object to hold an identifier and carry information about the confidence in the identifier.
      */
     private static class IdentifierMatch implements Comparable<IdentifierMatch> {
 
         /**
          * Constructs an IdentifierMatch.
          *
          * @param type the type of identifier (such as CPE)
          * @param value the value of the identifier
          * @param url the URL of the identifier
          * @param identifierConfidence the confidence in the identifier: best guess or exact match
          * @param evidenceConfidence the confidence of the evidence used to find the identifier
          */
         IdentifierMatch(String type, String value, String url, IdentifierConfidence identifierConfidence, Confidence evidenceConfidence) {
             this.identifier = new Identifier(type, value, url);
             this.confidence = identifierConfidence;
             this.evidenceConfidence = evidenceConfidence;
         }
         //<editor-fold defaultstate="collapsed" desc="Property implementations: evidenceConfidence, confidence, identifier">
         /**
          * The confidence in the evidence used to identify this match.
          */
         private Confidence evidenceConfidence;
 
         /**
          * Get the value of evidenceConfidence
          *
          * @return the value of evidenceConfidence
          */
         public Confidence getEvidenceConfidence() {
             return evidenceConfidence;
         }
 
         /**
          * Set the value of evidenceConfidence
          *
          * @param evidenceConfidence new value of evidenceConfidence
          */
         public void setEvidenceConfidence(Confidence evidenceConfidence) {
             this.evidenceConfidence = evidenceConfidence;
         }
         /**
          * The confidence whether this is an exact match, or a best guess.
          */
         private IdentifierConfidence confidence;
 
         /**
          * Get the value of confidence.
          *
          * @return the value of confidence
          */
         public IdentifierConfidence getConfidence() {
             return confidence;
         }
 
         /**
          * Set the value of confidence.
          *
          * @param confidence new value of confidence
          */
         public void setConfidence(IdentifierConfidence confidence) {
             this.confidence = confidence;
         }
         /**
          * The CPE identifier.
          */
         private Identifier identifier;
 
         /**
          * Get the value of identifier.
          *
          * @return the value of identifier
          */
         public Identifier getIdentifier() {
             return identifier;
         }
 
         /**
          * Set the value of identifier.
          *
          * @param identifier new value of identifier
          */
         public void setIdentifier(Identifier identifier) {
             this.identifier = identifier;
         }
         //</editor-fold>
         //<editor-fold defaultstate="collapsed" desc="Standard implementations of toString, hashCode, and equals">
 
         /**
          * Standard toString() implementation.
          *
          * @return the string representation of the object
          */
         @Override
         public String toString() {
             return "IdentifierMatch{" + "evidenceConfidence=" + evidenceConfidence
                     + ", confidence=" + confidence + ", identifier=" + identifier + '}';
         }
 
         /**
          * Standard hashCode() implementation.
          *
          * @return the hashCode
          */
         @Override
         public int hashCode() {
             int hash = 5;
             hash = 97 * hash + (this.evidenceConfidence != null ? this.evidenceConfidence.hashCode() : 0);
             hash = 97 * hash + (this.confidence != null ? this.confidence.hashCode() : 0);
             hash = 97 * hash + (this.identifier != null ? this.identifier.hashCode() : 0);
             return hash;
         }
 
         /**
          * Standard equals implementation.
          *
          * @param obj the object to compare
          * @return true if the objects are equal, otherwise false
          */
         @Override
         public boolean equals(Object obj) {
             if (obj == null) {
                 return false;
             }
             if (getClass() != obj.getClass()) {
                 return false;
             }
             final IdentifierMatch other = (IdentifierMatch) obj;
             if (this.evidenceConfidence != other.evidenceConfidence) {
                 return false;
             }
             if (this.confidence != other.confidence) {
                 return false;
             }
             if (this.identifier != other.identifier && (this.identifier == null || !this.identifier.equals(other.identifier))) {
                 return false;
             }
             return true;
         }
         //</editor-fold>
 
         /**
          * Standard implementation of compareTo that compares identifier confidence, evidence confidence, and then the
          * identifier.
          *
          * @param o the IdentifierMatch to compare to
          * @return the natural ordering of IdentifierMatch
          */
         @Override
         public int compareTo(IdentifierMatch o) {
             int conf = this.confidence.compareTo(o.confidence);
             if (conf == 0) {
                 conf = this.evidenceConfidence.compareTo(o.evidenceConfidence);
                 if (conf == 0) {
                     conf = identifier.compareTo(o.identifier);
                 }
             }
             return conf;
         }
     }
 }