/**
* Validate the time stamp token.
* <p>
* To be valid the token must be signed by the passed in certificate and
* the certificate must be the one referred to by the SigningCertificate
* attribute included in the hashed attributes of the token. The
* certificate must also have the ExtendedKeyUsageExtension with only
* KeyPurposeID.IdKPTimeStamping and have been valid at the time the
* timestamp was created.
* </p>
* <p>
* A successful call to validate means all the above are true.
* </p>
*/
public void Validate(
X509Certificate cert)
{
try
{
byte[] hash = DigestUtilities.CalculateDigest(
certID.GetHashAlgorithm(), cert.GetEncoded());
if (!Arrays.ConstantTimeAreEqual(certID.GetCertHash(), hash))
{
throw new TspValidationException("certificate hash does not match certID hash.");
}
if (certID.IssuerSerial != null)
{
if (!certID.IssuerSerial.Serial.Value.Equals(cert.SerialNumber))
{
throw new TspValidationException("certificate serial number does not match certID for signature.");
}
GeneralName[] names = certID.IssuerSerial.Issuer.GetNames();
X509Name principal = PrincipalUtilities.GetIssuerX509Principal(cert);
bool found = false;
for (int i = 0; i != names.Length; i++)
{
if (names[i].TagNo == 4
&& X509Name.GetInstance(names[i].Name).Equivalent(principal))
{
found = true;
break;
}
}
if (!found)
{
throw new TspValidationException("certificate name does not match certID for signature. ");
}
}
TspUtil.ValidateCertificate(cert);
cert.CheckValidity(tstInfo.GenTime);
if (!tsaSignerInfo.Verify(cert))
{
throw new TspValidationException("signature not created by certificate.");
}
}
catch (CmsException e)
{
if (e.InnerException != null)
{
throw new TspException(e.Message, e.InnerException);
}
throw new TspException("CMS exception: " + e, e);
}
catch (CertificateEncodingException e)
{
throw new TspException("problem processing certificate: " + e, e);
}
catch (SecurityUtilityException e)
{
throw new TspException("cannot find algorithm: " + e.Message, e);
}
}
/**
* verify that the given certificate successfully handles and confirms
* the signature associated with this signer and, if a signingTime
* attribute is available, that the certificate was valid at the time the
* signature was generated.
*/
public bool Verify(
X509Certificate cert)
{
Asn1.Cms.Time signingTime = GetSigningTime();
if (signingTime != null)
{
cert.CheckValidity(signingTime.Date);
}
return DoVerify(cert.GetPublicKey());
}
