/**
* Find the issuer certificates of a given certificate.
*
* @param cert
* The certificate for which an issuer should be found.
* @param pkixParams
* @return A <code>Collection</code> object containing the issuer
* <code>X509Certificate</code>s. Never <code>null</code>.
*
* @exception Exception
* if an error occurs.
*/
internal static ICollection FindIssuerCerts(
X509Certificate cert,
PkixBuilderParameters pkixParams)
{
X509CertStoreSelector certSelect = new X509CertStoreSelector();
ISet certs = new HashSet();
try
{
certSelect.Subject = cert.IssuerDN;
}
catch (IOException ex)
{
throw new Exception(
"Subject criteria for certificate selector to find issuer certificate could not be set.", ex);
}
try
{
certs.AddAll(PkixCertPathValidatorUtilities.FindCertificates(certSelect, pkixParams.GetStores()));
certs.AddAll(PkixCertPathValidatorUtilities.FindCertificates(certSelect, pkixParams.GetAdditionalStores()));
}
catch (Exception e)
{
throw new Exception("Issuer certificate cannot be searched.", e);
}
return(certs);
}
/**
* 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.GetTargetCertConstraints();
if (!(certSelect is X509CertStoreSelector))
{
throw new PkixCertPathBuilderException(
"TargetConstraints must be an instance of "
+ typeof(X509CertStoreSelector).FullName + " for "
+ Platform.GetTypeName(this) + " class.");
}
ISet targets = new HashSet();
try
{
targets.AddAll(PkixCertPathValidatorUtilities.FindCertificates((X509CertStoreSelector)certSelect, pkixParams.GetStores()));
// TODO Should this include an entry for pkixParams.GetAdditionalStores() too?
}
catch (Exception e)
{
throw new PkixCertPathBuilderException(
"Error finding target certificate.", e);
}
if (targets.IsEmpty)
{
throw new PkixCertPathBuilderException("No certificate found matching targetContraints.");
}
PkixCertPathBuilderResult result = null;
IList certPathList = Platform.CreateArrayList();
// check all potential target certificates
foreach (X509Certificate cert in targets)
{
result = Build(cert, pkixParams, certPathList);
if (result != null)
{
break;
}
}
if (result == null && certPathException != null)
{
throw new PkixCertPathBuilderException(certPathException.Message, certPathException.InnerException);
}
if (result == null && certPathException == null)
{
throw new PkixCertPathBuilderException("Unable to find certificate chain.");
}
return(result);
}
/**
* Fetches complete CRLs according to RFC 3280.
*
* @param dp The distribution point for which the complete CRL
* @param cert The <code>X509Certificate</code> or
* {@link Essensoft.AspNetCore.Security.x509.X509AttributeCertificate} for
* which the CRL should be searched.
* @param currentDate The date for which the delta CRLs must be valid.
* @param paramsPKIX The extended PKIX parameters.
* @return A <code>Set</code> of <code>X509CRL</code>s with complete
* CRLs.
* @throws Exception if an exception occurs while picking the CRLs
* or no CRLs are found.
*/
internal static ISet GetCompleteCrls(
DistributionPoint dp,
object cert,
DateTime currentDate,
PkixParameters paramsPKIX)
{
X509CrlStoreSelector crlselect = new X509CrlStoreSelector();
try
{
ISet issuers = new HashSet();
if (cert is X509V2AttributeCertificate)
{
issuers.Add(((X509V2AttributeCertificate)cert)
.Issuer.GetPrincipals()[0]);
}
else
{
issuers.Add(GetIssuerPrincipal(cert));
}
PkixCertPathValidatorUtilities.GetCrlIssuersFromDistributionPoint(dp, issuers, crlselect, paramsPKIX);
}
catch (Exception e)
{
throw new Exception("Could not get issuer information from distribution point.", e);
}
if (cert is X509Certificate)
{
crlselect.CertificateChecking = (X509Certificate)cert;
}
else if (cert is X509V2AttributeCertificate)
{
crlselect.AttrCertChecking = (IX509AttributeCertificate)cert;
}
crlselect.CompleteCrlEnabled = true;
ISet crls = CrlUtilities.FindCrls(crlselect, paramsPKIX, currentDate);
if (crls.IsEmpty)
{
if (cert is IX509AttributeCertificate)
{
IX509AttributeCertificate aCert = (IX509AttributeCertificate)cert;
throw new Exception("No CRLs found for issuer \"" + aCert.Issuer.GetPrincipals()[0] + "\"");
}
else
{
X509Certificate xCert = (X509Certificate)cert;
throw new Exception("No CRLs found for issuer \"" + xCert.IssuerDN + "\"");
}
}
return(crls);
}
internal static DateTime GetValidCertDateFromValidityModel(
PkixParameters paramsPkix,
PkixCertPath certPath,
int index)
{
if (paramsPkix.ValidityModel != PkixParameters.ChainValidityModel)
{
return(GetValidDate(paramsPkix));
}
// if end cert use given signing/encryption/... time
if (index <= 0)
{
return(PkixCertPathValidatorUtilities.GetValidDate(paramsPkix));
// else use time when previous cert was created
}
if (index - 1 == 0)
{
DerGeneralizedTime dateOfCertgen = null;
try
{
X509Certificate cert = (X509Certificate)certPath.Certificates[index - 1];
Asn1OctetString extVal = cert.GetExtensionValue(
IsisMttObjectIdentifiers.IdIsisMttATDateOfCertGen);
dateOfCertgen = DerGeneralizedTime.GetInstance(extVal);
}
catch (ArgumentException)
{
throw new Exception(
"Date of cert gen extension could not be read.");
}
if (dateOfCertgen != null)
{
try
{
return(dateOfCertgen.ToDateTime());
}
catch (ArgumentException e)
{
throw new Exception(
"Date from date of cert gen extension could not be parsed.",
e);
}
}
}
return(((X509Certificate)certPath.Certificates[index - 1]).NotBefore);
}
internal static void ProcessAttrCert5(
IX509AttributeCertificate attrCert,
PkixParameters pkixParams)
{
try
{
attrCert.CheckValidity(PkixCertPathValidatorUtilities.GetValidDate(pkixParams));
}
catch (CertificateExpiredException e)
{
throw new PkixCertPathValidatorException(
"Attribute certificate is not valid.", e);
}
catch (CertificateNotYetValidException e)
{
throw new PkixCertPathValidatorException(
"Attribute certificate is not valid.", e);
}
}
internal static void AddAdditionalStoresFromCrlDistributionPoint(
CrlDistPoint crldp,
PkixParameters pkixParams)
{
if (crldp != null)
{
DistributionPoint[] dps = null;
try
{
dps = crldp.GetDistributionPoints();
}
catch (Exception e)
{
throw new Exception(
"Distribution points could not be read.", e);
}
for (int i = 0; i < dps.Length; i++)
{
DistributionPointName dpn = dps[i].DistributionPointName;
// look for URIs in fullName
if (dpn != null)
{
if (dpn.PointType == DistributionPointName.FullName)
{
GeneralName[] genNames = GeneralNames.GetInstance(
dpn.Name).GetNames();
// look for an URI
for (int j = 0; j < genNames.Length; j++)
{
if (genNames[j].TagNo == GeneralName.UniformResourceIdentifier)
{
string location = DerIA5String.GetInstance(
genNames[j].Name).GetString();
PkixCertPathValidatorUtilities.AddAdditionalStoreFromLocation(
location, pkixParams);
}
}
}
}
}
}
}
internal static void ProcessAttrCert7(
IX509AttributeCertificate attrCert,
PkixCertPath certPath,
PkixCertPath holderCertPath,
PkixParameters pkixParams)
{
// TODO:
// AA Controls
// Attribute encryption
// Proxy
ISet critExtOids = attrCert.GetCriticalExtensionOids();
// 7.1
// process extensions
// target information checked in step 6 / X509AttributeCertStoreSelector
if (critExtOids.Contains(X509Extensions.TargetInformation.Id))
{
try
{
TargetInformation.GetInstance(PkixCertPathValidatorUtilities
.GetExtensionValue(attrCert, X509Extensions.TargetInformation));
}
catch (Exception e)
{
throw new PkixCertPathValidatorException(
"Target information extension could not be read.", e);
}
}
critExtOids.Remove(X509Extensions.TargetInformation.Id);
foreach (PkixAttrCertChecker checker in pkixParams.GetAttrCertCheckers())
{
checker.Check(attrCert, certPath, holderCertPath, critExtOids);
}
if (!critExtOids.IsEmpty)
{
throw new PkixCertPathValidatorException(
"Attribute certificate contains unsupported critical extensions: "
+ critExtOids);
}
}
/**
* Validates an attribute certificate with the given certificate path.
*
* <p>
* <code>params</code> must be an instance of
* <code>ExtendedPkixParameters</code>.
* </p><p>
* The target constraints in the <code>params</code> must be an
* <code>X509AttrCertStoreSelector</code> with at least the attribute
* certificate criterion set. Obey that also target informations may be
* necessary to correctly validate this attribute certificate.
* </p><p>
* The attribute certificate issuer must be added to the trusted attribute
* issuers with {@link ExtendedPkixParameters#setTrustedACIssuers(Set)}.
* </p>
* @param certPath The certificate path which belongs to the attribute
* certificate issuer public key certificate.
* @param params The PKIX parameters.
* @return A <code>PKIXCertPathValidatorResult</code> of the result of
* validating the <code>certPath</code>.
* @throws InvalidAlgorithmParameterException if <code>params</code> is
* inappropriate for this validator.
* @throws CertPathValidatorException if the verification fails.
*/
public virtual PkixCertPathValidatorResult Validate(
PkixCertPath certPath,
PkixParameters pkixParams)
{
IX509Selector certSelect = pkixParams.GetTargetConstraints();
if (!(certSelect is X509AttrCertStoreSelector))
{
throw new ArgumentException(
"TargetConstraints must be an instance of " + typeof(X509AttrCertStoreSelector).FullName,
"pkixParams");
}
IX509AttributeCertificate attrCert = ((X509AttrCertStoreSelector)certSelect).AttributeCert;
PkixCertPath holderCertPath = Rfc3281CertPathUtilities.ProcessAttrCert1(attrCert, pkixParams);
PkixCertPathValidatorResult result = Rfc3281CertPathUtilities.ProcessAttrCert2(certPath, pkixParams);
X509Certificate issuerCert = (X509Certificate)certPath.Certificates[0];
Rfc3281CertPathUtilities.ProcessAttrCert3(issuerCert, pkixParams);
Rfc3281CertPathUtilities.ProcessAttrCert4(issuerCert, pkixParams);
Rfc3281CertPathUtilities.ProcessAttrCert5(attrCert, pkixParams);
// 6 already done in X509AttrCertStoreSelector
Rfc3281CertPathUtilities.ProcessAttrCert7(attrCert, certPath, holderCertPath, pkixParams);
Rfc3281CertPathUtilities.AdditionalChecks(attrCert, pkixParams);
DateTime date;
try
{
date = PkixCertPathValidatorUtilities.GetValidCertDateFromValidityModel(pkixParams, null, -1);
}
catch (Exception e)
{
throw new PkixCertPathValidatorException(
"Could not get validity date from attribute certificate.", e);
}
Rfc3281CertPathUtilities.CheckCrls(attrCert, pkixParams, issuerCert, date, certPath.Certificates);
return(result);
}
internal static void AddAdditionalStoresFromAltNames(
X509Certificate cert,
PkixParameters pkixParams)
{
// if in the IssuerAltName extension an URI
// is given, add an additinal X.509 store
if (cert.GetIssuerAlternativeNames() != null)
{
IEnumerator it = cert.GetIssuerAlternativeNames().GetEnumerator();
while (it.MoveNext())
{
// look for URI
IList list = (IList)it.Current;
//if (list[0].Equals(new Integer(GeneralName.UniformResourceIdentifier)))
if (list[0].Equals(GeneralName.UniformResourceIdentifier))
{
// found
string temp = (string)list[1];
PkixCertPathValidatorUtilities.AddAdditionalStoreFromLocation(temp, pkixParams);
}
}
}
}
/**
* Checks if an attribute certificate is revoked.
*
* @param attrCert Attribute certificate to check if it is revoked.
* @param paramsPKIX PKIX parameters.
* @param issuerCert The issuer certificate of the attribute certificate
* <code>attrCert</code>.
* @param validDate The date when the certificate revocation status should
* be checked.
* @param certPathCerts The certificates of the certification path to be
* checked.
*
* @throws CertPathValidatorException if the certificate is revoked or the
* status cannot be checked or some error occurs.
*/
internal static void CheckCrls(
IX509AttributeCertificate attrCert,
PkixParameters paramsPKIX,
X509Certificate issuerCert,
DateTime validDate,
IList certPathCerts)
{
if (paramsPKIX.IsRevocationEnabled)
{
// check if revocation is available
if (attrCert.GetExtensionValue(X509Extensions.NoRevAvail) == null)
{
CrlDistPoint crldp = null;
try
{
crldp = CrlDistPoint.GetInstance(
PkixCertPathValidatorUtilities.GetExtensionValue(
attrCert, X509Extensions.CrlDistributionPoints));
}
catch (Exception e)
{
throw new PkixCertPathValidatorException(
"CRL distribution point extension could not be read.", e);
}
try
{
PkixCertPathValidatorUtilities
.AddAdditionalStoresFromCrlDistributionPoint(crldp, paramsPKIX);
}
catch (Exception e)
{
throw new PkixCertPathValidatorException(
"No additional CRL locations could be decoded from CRL distribution point extension.", e);
}
CertStatus certStatus = new CertStatus();
ReasonsMask reasonsMask = new ReasonsMask();
Exception lastException = null;
bool validCrlFound = false;
// for each distribution point
if (crldp != null)
{
DistributionPoint[] dps = null;
try
{
dps = crldp.GetDistributionPoints();
}
catch (Exception e)
{
throw new PkixCertPathValidatorException(
"Distribution points could not be read.", e);
}
try
{
for (int i = 0; i < dps.Length &&
certStatus.Status == CertStatus.Unrevoked &&
!reasonsMask.IsAllReasons; i++)
{
PkixParameters paramsPKIXClone = (PkixParameters)paramsPKIX
.Clone();
CheckCrl(dps[i], attrCert, paramsPKIXClone,
validDate, issuerCert, certStatus, reasonsMask,
certPathCerts);
validCrlFound = true;
}
}
catch (Exception e)
{
lastException = new Exception(
"No valid CRL for distribution point found.", e);
}
}
/*
* If the revocation status has not been determined, repeat the
* process above with any available CRLs not specified in a
* distribution point but issued by the certificate issuer.
*/
if (certStatus.Status == CertStatus.Unrevoked &&
!reasonsMask.IsAllReasons)
{
try
{
/*
* assume a DP with both the reasons and the cRLIssuer
* fields omitted and a distribution point name of the
* certificate issuer.
*/
Asn1Object issuer = null;
try
{
issuer = new Asn1InputStream(
attrCert.Issuer.GetPrincipals()[0].GetEncoded()).ReadObject();
}
catch (Exception e)
{
throw new Exception(
"Issuer from certificate for CRL could not be reencoded.",
e);
}
DistributionPoint dp = new DistributionPoint(
new DistributionPointName(0, new GeneralNames(
new GeneralName(GeneralName.DirectoryName, issuer))), null, null);
PkixParameters paramsPKIXClone = (PkixParameters)paramsPKIX.Clone();
CheckCrl(dp, attrCert, paramsPKIXClone, validDate,
issuerCert, certStatus, reasonsMask, certPathCerts);
validCrlFound = true;
}
catch (Exception e)
{
lastException = new Exception(
"No valid CRL for distribution point found.", e);
}
}
if (!validCrlFound)
{
throw new PkixCertPathValidatorException(
"No valid CRL found.", lastException);
}
if (certStatus.Status != CertStatus.Unrevoked)
{
// This format is enforced by the NistCertPath tests
string formattedDate = certStatus.RevocationDate.Value.ToString(
"ddd MMM dd HH:mm:ss K yyyy");
string message = "Attribute certificate revocation after "
+ formattedDate;
message += ", reason: "
+ Rfc3280CertPathUtilities.CrlReasons[certStatus.Status];
throw new PkixCertPathValidatorException(message);
}
if (!reasonsMask.IsAllReasons &&
certStatus.Status == CertStatus.Unrevoked)
{
certStatus.Status = CertStatus.Undetermined;
}
if (certStatus.Status == CertStatus.Undetermined)
{
throw new PkixCertPathValidatorException(
"Attribute certificate status could not be determined.");
}
}
else
{
if (attrCert.GetExtensionValue(X509Extensions.CrlDistributionPoints) != null ||
attrCert.GetExtensionValue(X509Extensions.AuthorityInfoAccess) != null)
{
throw new PkixCertPathValidatorException(
"No rev avail extension is set, but also an AC revocation pointer.");
}
}
}
}
/**
*
* Checks a distribution point for revocation information for the
* certificate <code>attrCert</code>.
*
* @param dp The distribution point to consider.
* @param attrCert The attribute certificate which should be checked.
* @param paramsPKIX PKIX parameters.
* @param validDate The date when the certificate revocation status should
* be checked.
* @param issuerCert Certificate to check if it is revoked.
* @param reasonMask The reasons mask which is already checked.
* @param certPathCerts The certificates of the certification path to be
* checked.
* @throws Exception if the certificate is revoked or the status
* cannot be checked or some error occurs.
*/
private static void CheckCrl(
DistributionPoint dp,
IX509AttributeCertificate attrCert,
PkixParameters paramsPKIX,
DateTime validDate,
X509Certificate issuerCert,
CertStatus certStatus,
ReasonsMask reasonMask,
IList certPathCerts)
{
/*
* 4.3.6 No Revocation Available
*
* The noRevAvail extension, defined in [X.509-2000], allows an AC
* issuer to indicate that no revocation information will be made
* available for this AC.
*/
if (attrCert.GetExtensionValue(X509Extensions.NoRevAvail) != null)
{
return;
}
DateTime currentDate = DateTime.UtcNow;
if (validDate.CompareTo(currentDate) > 0)
{
throw new Exception("Validation time is in future.");
}
// (a)
/*
* We always get timely valid CRLs, so there is no step (a) (1).
* "locally cached" CRLs are assumed to be in getStore(), additional
* CRLs must be enabled in the ExtendedPkixParameters and are in
* getAdditionalStore()
*/
ISet crls = PkixCertPathValidatorUtilities.GetCompleteCrls(dp, attrCert,
currentDate, paramsPKIX);
bool validCrlFound = false;
Exception lastException = null;
IEnumerator crl_iter = crls.GetEnumerator();
while (crl_iter.MoveNext() &&
certStatus.Status == CertStatus.Unrevoked &&
!reasonMask.IsAllReasons)
{
try
{
X509Crl crl = (X509Crl)crl_iter.Current;
// (d)
ReasonsMask interimReasonsMask = Rfc3280CertPathUtilities.ProcessCrlD(crl, dp);
// (e)
/*
* The reasons mask is updated at the end, so only valid CRLs
* can update it. If this CRL does not contain new reasons it
* must be ignored.
*/
if (!interimReasonsMask.HasNewReasons(reasonMask))
{
continue;
}
// (f)
ISet keys = Rfc3280CertPathUtilities.ProcessCrlF(crl, attrCert,
null, null, paramsPKIX, certPathCerts);
// (g)
AsymmetricKeyParameter pubKey = Rfc3280CertPathUtilities.ProcessCrlG(crl, keys);
X509Crl deltaCRL = null;
if (paramsPKIX.IsUseDeltasEnabled)
{
// get delta CRLs
ISet deltaCRLs = PkixCertPathValidatorUtilities.GetDeltaCrls(
currentDate, paramsPKIX, crl);
// we only want one valid delta CRL
// (h)
deltaCRL = Rfc3280CertPathUtilities.ProcessCrlH(deltaCRLs, pubKey);
}
/*
* CRL must be be valid at the current time, not the validation
* time. If a certificate is revoked with reason keyCompromise,
* cACompromise, it can be used for forgery, also for the past.
* This reason may not be contained in older CRLs.
*/
/*
* in the chain model signatures stay valid also after the
* certificate has been expired, so they do not have to be in
* the CRL vality time
*/
if (paramsPKIX.ValidityModel != PkixParameters.ChainValidityModel)
{
/*
* if a certificate has expired, but was revoked, it is not
* more in the CRL, so it would be regarded as valid if the
* first check is not done
*/
if (attrCert.NotAfter.CompareTo(crl.ThisUpdate) < 0)
{
throw new Exception(
"No valid CRL for current time found.");
}
}
Rfc3280CertPathUtilities.ProcessCrlB1(dp, attrCert, crl);
// (b) (2)
Rfc3280CertPathUtilities.ProcessCrlB2(dp, attrCert, crl);
// (c)
Rfc3280CertPathUtilities.ProcessCrlC(deltaCRL, crl, paramsPKIX);
// (i)
Rfc3280CertPathUtilities.ProcessCrlI(validDate, deltaCRL,
attrCert, certStatus, paramsPKIX);
// (j)
Rfc3280CertPathUtilities.ProcessCrlJ(validDate, crl, attrCert,
certStatus);
// (k)
if (certStatus.Status == CrlReason.RemoveFromCrl)
{
certStatus.Status = CertStatus.Unrevoked;
}
// update reasons mask
reasonMask.AddReasons(interimReasonsMask);
validCrlFound = true;
}
catch (Exception e)
{
lastException = e;
}
}
if (!validCrlFound)
{
throw lastException;
}
}
/**
* 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);
}
protected virtual PkixCertPathBuilderResult Build(
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);
// X509CertificateParser certParser = new X509CertificateParser();
PkixCertPathBuilderResult builderResult = null;
PkixCertPathValidator validator = new PkixCertPathValidator();
try
{
// check whether the issuer of <tbvCert> is a TrustAnchor
if (PkixCertPathValidatorUtilities.FindTrustAnchor(tbvCert, pkixParams.GetTrustAnchors()) != null)
{
// exception message from possibly later tried certification
// chains
PkixCertPath certPath = null;
try
{
certPath = new PkixCertPath(tbvPath);
}
catch (Exception e)
{
throw new Exception(
"Certification path could not be constructed from certificate list.",
e);
}
PkixCertPathValidatorResult result = null;
try
{
result = (PkixCertPathValidatorResult)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 additiontal X.509 stores can be added from certificate locations.",
e);
}
// try to get the issuer certificate from one of the stores
HashSet 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)
{
builderResult = Build(issuer, pkixParams, tbvPath);
if (builderResult != null)
{
break;
}
}
}
}
catch (Exception e)
{
certPathException = e;
}
if (builderResult == null)
{
tbvPath.Remove(tbvCert);
}
return(builderResult);
}
public virtual PkixCertPathValidatorResult Validate(
PkixCertPath certPath,
PkixParameters paramsPkix)
{
if (paramsPkix.GetTrustAnchors() == null)
{
throw new ArgumentException(
"trustAnchors is null, this is not allowed for certification path validation.",
"parameters");
}
//
// 6.1.1 - inputs
//
//
// (a)
//
IList certs = certPath.Certificates;
int n = certs.Count;
if (certs.Count == 0)
{
throw new PkixCertPathValidatorException("Certification path is empty.", null, certPath, 0);
}
//
// (b)
//
// DateTime validDate = PkixCertPathValidatorUtilities.GetValidDate(paramsPkix);
//
// (c)
//
ISet userInitialPolicySet = paramsPkix.GetInitialPolicies();
//
// (d)
//
TrustAnchor trust;
try
{
trust = PkixCertPathValidatorUtilities.FindTrustAnchor(
(X509Certificate)certs[certs.Count - 1],
paramsPkix.GetTrustAnchors());
}
catch (Exception e)
{
throw new PkixCertPathValidatorException(e.Message, e, certPath, certs.Count - 1);
}
if (trust == null)
{
throw new PkixCertPathValidatorException("Trust anchor for certification path not found.", null, certPath, -1);
}
//
// (e), (f), (g) are part of the paramsPkix object.
//
IEnumerator certIter;
int index = 0;
int i;
// Certificate for each interation of the validation loop
// Signature information for each iteration of the validation loop
//
// 6.1.2 - setup
//
//
// (a)
//
IList[] policyNodes = new IList[n + 1];
for (int j = 0; j < policyNodes.Length; j++)
{
policyNodes[j] = Platform.CreateArrayList();
}
ISet policySet = new HashSet();
policySet.Add(Rfc3280CertPathUtilities.ANY_POLICY);
PkixPolicyNode validPolicyTree = new PkixPolicyNode(Platform.CreateArrayList(), 0, policySet, null, new HashSet(),
Rfc3280CertPathUtilities.ANY_POLICY, false);
policyNodes[0].Add(validPolicyTree);
//
// (b) and (c)
//
PkixNameConstraintValidator nameConstraintValidator = new PkixNameConstraintValidator();
// (d)
//
int explicitPolicy;
ISet acceptablePolicies = new HashSet();
if (paramsPkix.IsExplicitPolicyRequired)
{
explicitPolicy = 0;
}
else
{
explicitPolicy = n + 1;
}
//
// (e)
//
int inhibitAnyPolicy;
if (paramsPkix.IsAnyPolicyInhibited)
{
inhibitAnyPolicy = 0;
}
else
{
inhibitAnyPolicy = n + 1;
}
//
// (f)
//
int policyMapping;
if (paramsPkix.IsPolicyMappingInhibited)
{
policyMapping = 0;
}
else
{
policyMapping = n + 1;
}
//
// (g), (h), (i), (j)
//
AsymmetricKeyParameter workingPublicKey;
X509Name workingIssuerName;
X509Certificate sign = trust.TrustedCert;
try
{
if (sign != null)
{
workingIssuerName = sign.SubjectDN;
workingPublicKey = sign.GetPublicKey();
}
else
{
workingIssuerName = new X509Name(trust.CAName);
workingPublicKey = trust.CAPublicKey;
}
}
catch (ArgumentException ex)
{
throw new PkixCertPathValidatorException("Subject of trust anchor could not be (re)encoded.", ex, certPath,
-1);
}
AlgorithmIdentifier workingAlgId = null;
try
{
workingAlgId = PkixCertPathValidatorUtilities.GetAlgorithmIdentifier(workingPublicKey);
}
catch (PkixCertPathValidatorException e)
{
throw new PkixCertPathValidatorException(
"Algorithm identifier of public key of trust anchor could not be read.", e, certPath, -1);
}
// DerObjectIdentifier workingPublicKeyAlgorithm = workingAlgId.Algorithm;
// Asn1Encodable workingPublicKeyParameters = workingAlgId.Parameters;
//
// (k)
//
int maxPathLength = n;
//
// 6.1.3
//
X509CertStoreSelector certConstraints = paramsPkix.GetTargetCertConstraints();
if (certConstraints != null && !certConstraints.Match((X509Certificate)certs[0]))
{
throw new PkixCertPathValidatorException(
"Target certificate in certification path does not match targetConstraints.", null, certPath, 0);
}
//
// initialize CertPathChecker's
//
IList pathCheckers = paramsPkix.GetCertPathCheckers();
certIter = pathCheckers.GetEnumerator();
while (certIter.MoveNext())
{
((PkixCertPathChecker)certIter.Current).Init(false);
}
X509Certificate cert = null;
for (index = certs.Count - 1; index >= 0; index--)
{
// try
// {
//
// i as defined in the algorithm description
//
i = n - index;
//
// set certificate to be checked in this round
// sign and workingPublicKey and workingIssuerName are set
// at the end of the for loop and initialized the
// first time from the TrustAnchor
//
cert = (X509Certificate)certs[index];
//
// 6.1.3
//
Rfc3280CertPathUtilities.ProcessCertA(certPath, paramsPkix, index, workingPublicKey,
workingIssuerName, sign);
Rfc3280CertPathUtilities.ProcessCertBC(certPath, index, nameConstraintValidator);
validPolicyTree = Rfc3280CertPathUtilities.ProcessCertD(certPath, index,
acceptablePolicies, validPolicyTree, policyNodes, inhibitAnyPolicy);
validPolicyTree = Rfc3280CertPathUtilities.ProcessCertE(certPath, index, validPolicyTree);
Rfc3280CertPathUtilities.ProcessCertF(certPath, index, validPolicyTree, explicitPolicy);
//
// 6.1.4
//
if (i != n)
{
if (cert != null && cert.Version == 1)
{
throw new PkixCertPathValidatorException(
"Version 1 certificates can't be used as CA ones.", null, certPath, index);
}
Rfc3280CertPathUtilities.PrepareNextCertA(certPath, index);
validPolicyTree = Rfc3280CertPathUtilities.PrepareCertB(certPath, index, policyNodes,
validPolicyTree, policyMapping);
Rfc3280CertPathUtilities.PrepareNextCertG(certPath, index, nameConstraintValidator);
// (h)
explicitPolicy = Rfc3280CertPathUtilities.PrepareNextCertH1(certPath, index, explicitPolicy);
policyMapping = Rfc3280CertPathUtilities.PrepareNextCertH2(certPath, index, policyMapping);
inhibitAnyPolicy = Rfc3280CertPathUtilities.PrepareNextCertH3(certPath, index, inhibitAnyPolicy);
//
// (i)
//
explicitPolicy = Rfc3280CertPathUtilities.PrepareNextCertI1(certPath, index, explicitPolicy);
policyMapping = Rfc3280CertPathUtilities.PrepareNextCertI2(certPath, index, policyMapping);
// (j)
inhibitAnyPolicy = Rfc3280CertPathUtilities.PrepareNextCertJ(certPath, index, inhibitAnyPolicy);
// (k)
Rfc3280CertPathUtilities.PrepareNextCertK(certPath, index);
// (l)
maxPathLength = Rfc3280CertPathUtilities.PrepareNextCertL(certPath, index, maxPathLength);
// (m)
maxPathLength = Rfc3280CertPathUtilities.PrepareNextCertM(certPath, index, maxPathLength);
// (n)
Rfc3280CertPathUtilities.PrepareNextCertN(certPath, index);
ISet criticalExtensions1 = cert.GetCriticalExtensionOids();
if (criticalExtensions1 != null)
{
criticalExtensions1 = new HashSet(criticalExtensions1);
// these extensions are handled by the algorithm
criticalExtensions1.Remove(X509Extensions.KeyUsage.Id);
criticalExtensions1.Remove(X509Extensions.CertificatePolicies.Id);
criticalExtensions1.Remove(X509Extensions.PolicyMappings.Id);
criticalExtensions1.Remove(X509Extensions.InhibitAnyPolicy.Id);
criticalExtensions1.Remove(X509Extensions.IssuingDistributionPoint.Id);
criticalExtensions1.Remove(X509Extensions.DeltaCrlIndicator.Id);
criticalExtensions1.Remove(X509Extensions.PolicyConstraints.Id);
criticalExtensions1.Remove(X509Extensions.BasicConstraints.Id);
criticalExtensions1.Remove(X509Extensions.SubjectAlternativeName.Id);
criticalExtensions1.Remove(X509Extensions.NameConstraints.Id);
}
else
{
criticalExtensions1 = new HashSet();
}
// (o)
Rfc3280CertPathUtilities.PrepareNextCertO(certPath, index, criticalExtensions1, pathCheckers);
// set signing certificate for next round
sign = cert;
// (c)
workingIssuerName = sign.SubjectDN;
// (d)
try
{
workingPublicKey = PkixCertPathValidatorUtilities.GetNextWorkingKey(certPath.Certificates, index);
}
catch (PkixCertPathValidatorException e)
{
throw new PkixCertPathValidatorException("Next working key could not be retrieved.", e, certPath, index);
}
workingAlgId = PkixCertPathValidatorUtilities.GetAlgorithmIdentifier(workingPublicKey);
// (f)
// workingPublicKeyAlgorithm = workingAlgId.Algorithm;
// (e)
// workingPublicKeyParameters = workingAlgId.Parameters;
}
}
//
// 6.1.5 Wrap-up procedure
//
explicitPolicy = Rfc3280CertPathUtilities.WrapupCertA(explicitPolicy, cert);
explicitPolicy = Rfc3280CertPathUtilities.WrapupCertB(certPath, index + 1, explicitPolicy);
//
// (c) (d) and (e) are already done
//
//
// (f)
//
ISet criticalExtensions = cert.GetCriticalExtensionOids();
if (criticalExtensions != null)
{
criticalExtensions = new HashSet(criticalExtensions);
// Requires .Id
// these extensions are handled by the algorithm
criticalExtensions.Remove(X509Extensions.KeyUsage.Id);
criticalExtensions.Remove(X509Extensions.CertificatePolicies.Id);
criticalExtensions.Remove(X509Extensions.PolicyMappings.Id);
criticalExtensions.Remove(X509Extensions.InhibitAnyPolicy.Id);
criticalExtensions.Remove(X509Extensions.IssuingDistributionPoint.Id);
criticalExtensions.Remove(X509Extensions.DeltaCrlIndicator.Id);
criticalExtensions.Remove(X509Extensions.PolicyConstraints.Id);
criticalExtensions.Remove(X509Extensions.BasicConstraints.Id);
criticalExtensions.Remove(X509Extensions.SubjectAlternativeName.Id);
criticalExtensions.Remove(X509Extensions.NameConstraints.Id);
criticalExtensions.Remove(X509Extensions.CrlDistributionPoints.Id);
}
else
{
criticalExtensions = new HashSet();
}
Rfc3280CertPathUtilities.WrapupCertF(certPath, index + 1, pathCheckers, criticalExtensions);
PkixPolicyNode intersection = Rfc3280CertPathUtilities.WrapupCertG(certPath, paramsPkix, userInitialPolicySet,
index + 1, policyNodes, validPolicyTree, acceptablePolicies);
if ((explicitPolicy > 0) || (intersection != null))
{
return(new PkixCertPathValidatorResult(trust, intersection, cert.GetPublicKey()));
}
throw new PkixCertPathValidatorException("Path processing failed on policy.", null, certPath, index);
}
/**
* 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);
}