/**
* 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);
}
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);
}