Exemple #1
0
        private PkixCertPathBuilderResult Build(
            IX509AttributeCertificate attrCert,
            X509Certificate tbvCert,
            PkixBuilderParameters pkixParams,
            IList tbvPath)
        {
            // If tbvCert is readily present in tbvPath, it indicates having run
            // into a cycle in the
            // PKI graph.
            if (tbvPath.Contains(tbvCert))
            {
                return(null);
            }

            // step out, the certificate is not allowed to appear in a certification
            // chain
            if (pkixParams.GetExcludedCerts().Contains(tbvCert))
            {
                return(null);
            }

            // test if certificate path exceeds maximum length
            if (pkixParams.MaxPathLength != -1)
            {
                if (tbvPath.Count - 1 > pkixParams.MaxPathLength)
                {
                    return(null);
                }
            }

            tbvPath.Add(tbvCert);

            PkixCertPathBuilderResult builderResult = null;

//			X509CertificateParser certParser = new X509CertificateParser();
            PkixAttrCertPathValidator validator = new PkixAttrCertPathValidator();

            try
            {
                // check whether the issuer of <tbvCert> is a TrustAnchor
                if (PkixCertPathValidatorUtilities.FindTrustAnchor(tbvCert, pkixParams.GetTrustAnchors()) != null)
                {
                    PkixCertPath certPath = new PkixCertPath(tbvPath);
                    PkixCertPathValidatorResult result;

                    try
                    {
                        result = validator.Validate(certPath, pkixParams);
                    }
                    catch (Exception e)
                    {
                        throw new Exception("Certification path could not be validated.", e);
                    }

                    return(new PkixCertPathBuilderResult(certPath, result.TrustAnchor,
                                                         result.PolicyTree, result.SubjectPublicKey));
                }
                else
                {
                    // add additional X.509 stores from locations in certificate
                    try
                    {
                        PkixCertPathValidatorUtilities.AddAdditionalStoresFromAltNames(tbvCert, pkixParams);
                    }
                    catch (CertificateParsingException e)
                    {
                        throw new Exception("No additional X.509 stores can be added from certificate locations.", e);
                    }

                    // try to get the issuer certificate from one of the stores
                    ISet issuers = new HashSet();
                    try
                    {
                        issuers.AddAll(PkixCertPathValidatorUtilities.FindIssuerCerts(tbvCert, pkixParams));
                    }
                    catch (Exception e)
                    {
                        throw new Exception("Cannot find issuer certificate for certificate in certification path.", e);
                    }

                    if (issuers.IsEmpty)
                    {
                        throw new Exception("No issuer certificate for certificate in certification path found.");
                    }

                    foreach (X509Certificate issuer in issuers)
                    {
                        // if untrusted self signed certificate continue
                        if (PkixCertPathValidatorUtilities.IsSelfIssued(issuer))
                        {
                            continue;
                        }

                        builderResult = Build(attrCert, issuer, pkixParams, tbvPath);

                        if (builderResult != null)
                        {
                            break;
                        }
                    }
                }
            }
            catch (Exception e)
            {
                certPathException = new Exception("No valid certification path could be build.", e);
            }

            if (builderResult == null)
            {
                tbvPath.Remove(tbvCert);
            }

            return(builderResult);
        }
Exemple #2
0
        /**
         * Build and validate a CertPath using the given parameter.
         *
         * @param params PKIXBuilderParameters object containing all information to
         *            build the CertPath
         */
        public virtual PkixCertPathBuilderResult Build(
            PkixBuilderParameters pkixParams)
        {
            // search target certificates

            IX509Selector certSelect = pkixParams.GetTargetConstraints();

            if (!(certSelect is X509AttrCertStoreSelector))
            {
                throw new PkixCertPathBuilderException(
                          "TargetConstraints must be an instance of "
                          + typeof(X509AttrCertStoreSelector).FullName
                          + " for "
                          + typeof(PkixAttrCertPathBuilder).FullName + " class.");
            }

            ICollection targets;

            try
            {
                targets = PkixCertPathValidatorUtilities.FindCertificates(
                    (X509AttrCertStoreSelector)certSelect, pkixParams.GetStores());
            }
            catch (Exception e)
            {
                throw new PkixCertPathBuilderException("Error finding target attribute certificate.", e);
            }

            if (targets.Count == 0)
            {
                throw new PkixCertPathBuilderException(
                          "No attribute certificate found matching targetContraints.");
            }

            PkixCertPathBuilderResult result = null;

            // check all potential target certificates
            foreach (IX509AttributeCertificate cert in targets)
            {
                X509CertStoreSelector selector   = new X509CertStoreSelector();
                X509Name[]            principals = cert.Issuer.GetPrincipals();
                ISet issuers = new HashSet();
                for (int i = 0; i < principals.Length; i++)
                {
                    try
                    {
                        selector.Subject = principals[i];

                        issuers.AddAll(PkixCertPathValidatorUtilities.FindCertificates(selector, pkixParams.GetStores()));
                    }
                    catch (Exception e)
                    {
                        throw new PkixCertPathBuilderException(
                                  "Public key certificate for attribute certificate cannot be searched.",
                                  e);
                    }
                }

                if (issuers.IsEmpty)
                {
                    throw new PkixCertPathBuilderException("Public key certificate for attribute certificate cannot be found.");
                }

                IList certPathList = Platform.CreateArrayList();

                foreach (X509Certificate issuer in issuers)
                {
                    result = Build(cert, issuer, pkixParams, certPathList);

                    if (result != null)
                    {
                        break;
                    }
                }

                if (result != null)
                {
                    break;
                }
            }

            if (result == null && certPathException != null)
            {
                throw new PkixCertPathBuilderException(
                          "Possible certificate chain could not be validated.",
                          certPathException);
            }

            if (result == null && certPathException == null)
            {
                throw new PkixCertPathBuilderException(
                          "Unable to find certificate chain.");
            }

            return(result);
        }
Exemple #3
0
        /**
         * Searches for a holder public key certificate and verifies its
         * certification path.
         *
         * @param attrCert the attribute certificate.
         * @param pkixParams The PKIX parameters.
         * @return The certificate path of the holder certificate.
         * @throws Exception if
         *             <ul>
         *             <li>no public key certificate can be found although holder
         *             information is given by an entity name or a base certificate
         *             ID</li>
         *             <li>support classes cannot be created</li>
         *             <li>no certification path for the public key certificate can
         *             be built</li>
         *             </ul>
         */
        internal static PkixCertPath ProcessAttrCert1(
            IX509AttributeCertificate attrCert,
            PkixParameters pkixParams)
        {
            PkixCertPathBuilderResult result = null;
            // find holder PKCs
            ISet holderPKCs = new HashSet();

            if (attrCert.Holder.GetIssuer() != null)
            {
                X509CertStoreSelector selector = new X509CertStoreSelector();
                selector.SerialNumber = attrCert.Holder.SerialNumber;
                X509Name[] principals = attrCert.Holder.GetIssuer();
                for (int i = 0; i < principals.Length; i++)
                {
                    try
                    {
//						if (principals[i] is X500Principal)
                        {
                            selector.Issuer = principals[i];
                        }
                        holderPKCs.AddAll(PkixCertPathValidatorUtilities
                                          .FindCertificates(selector, pkixParams.GetStores()));
                    }
                    catch (Exception e)
                    {
                        throw new PkixCertPathValidatorException(
                                  "Public key certificate for attribute certificate cannot be searched.",
                                  e);
                    }
                }
                if (holderPKCs.IsEmpty)
                {
                    throw new PkixCertPathValidatorException(
                              "Public key certificate specified in base certificate ID for attribute certificate cannot be found.");
                }
            }
            if (attrCert.Holder.GetEntityNames() != null)
            {
                X509CertStoreSelector selector   = new X509CertStoreSelector();
                X509Name[]            principals = attrCert.Holder.GetEntityNames();
                for (int i = 0; i < principals.Length; i++)
                {
                    try
                    {
//						if (principals[i] is X500Principal)
                        {
                            selector.Issuer = principals[i];
                        }
                        holderPKCs.AddAll(PkixCertPathValidatorUtilities
                                          .FindCertificates(selector, pkixParams.GetStores()));
                    }
                    catch (Exception e)
                    {
                        throw new PkixCertPathValidatorException(
                                  "Public key certificate for attribute certificate cannot be searched.",
                                  e);
                    }
                }
                if (holderPKCs.IsEmpty)
                {
                    throw new PkixCertPathValidatorException(
                              "Public key certificate specified in entity name for attribute certificate cannot be found.");
                }
            }

            // verify cert paths for PKCs
            PkixBuilderParameters parameters = (PkixBuilderParameters)
                                               PkixBuilderParameters.GetInstance(pkixParams);

            PkixCertPathValidatorException lastException = null;

            foreach (X509Certificate cert in holderPKCs)
            {
                X509CertStoreSelector selector = new X509CertStoreSelector();
                selector.Certificate = cert;
                parameters.SetTargetConstraints(selector);

                PkixCertPathBuilder builder = new PkixCertPathBuilder();

                try
                {
                    result = builder.Build(PkixBuilderParameters.GetInstance(parameters));
                }
                catch (PkixCertPathBuilderException e)
                {
                    lastException = new PkixCertPathValidatorException(
                        "Certification path for public key certificate of attribute certificate could not be build.",
                        e);
                }
            }
            if (lastException != null)
            {
                throw lastException;
            }
            return(result.CertPath);
        }