PDFBOX-5936: refactor for future change, the list of potention issuers is already in getCertificateSet() result

git-svn-id: https://svn.apache.org/repos/asf/pdfbox/trunk@1923254 13f79535-47bb-0310-9956-ffa450edef68

Author: THausherr

examples/src/main/java/org/apache/pdfbox/examples/signature/validation/AddValidationInformation.java

@@ -445,9 +445,9 @@ private void addCrlRevocationInfo(CertSignatureInformation certInfo)
             CertificateVerificationException, URISyntaxException
     {
         X509CRL crl = CRLVerifier.downloadCRLFromWeb(certInfo.getCrlUrl());
-        X509Certificate issuerCertificate = certInfo.getIssuerCertificate();
 
         // find the issuer certificate (usually issuer of signature certificate)
+        X509Certificate issuerCertificate = null;
         for (X509Certificate certificate : certInformationHelper.getCertificateSet())
         {
             if (certificate.getSubjectX500Principal().equals(crl.getIssuerX500Principal()))
@@ -456,6 +456,10 @@ private void addCrlRevocationInfo(CertSignatureInformation certInfo)
                 break;
             }
         }
+        if (issuerCertificate == null)
+        {
+            throw new CertificateVerificationException("Can't find issuer of CRL for " + certInfo.getCrlUrl());
+        }
         crl.verify(issuerCertificate.getPublicKey(), SecurityProvider.getProvider().getName());
         CRLVerifier.checkRevocation(crl, certInfo.getCertificate(), signDate.getTime(), certInfo.getCrlUrl());
         COSStream crlStream = writeDataToStream(crl.getEncoded());