/// <summary>
/// Attaches a timestamp to signed CMS object.
/// </summary>
/// <param name="timestamp">TSP response returned from Time-Stamping Authority.</param>
/// <param name="signerInfoIndex">Signature index to attach the timestamp.</param>
/// <exception cref="NotSupportedException">
/// Time-Stamp Response contains invalid content type.
/// </exception>
/// <exception cref="ArgumentException">
/// Data returned from Time-Stamping Authority does not contain valid response.
/// </exception>
/// <exception cref="ArgumentNullException">
/// <strong>response</strong> parameter is null.
/// </exception>
/// <exception cref="IndexOutOfRangeException">
/// <strong>signerInfoIndex</strong> value exceeds the number of attached signatures.
/// </exception>
/// <remarks>Call <see cref="Encode"/> method to get timestamped object.</remarks>
public void AddTimestamp(TspResponse timestamp, Int32 signerInfoIndex)
{
if (timestamp == null)
{
throw new ArgumentNullException(nameof(timestamp));
}
if (timestamp.Status.ResponseStatus != TspResponseStatus.Granted || timestamp.Status.ErrorCode != TspFailureStatus.None)
{
throw new ArgumentException("The time-stamp response is not successful.");
}
X509Attribute attribute;
DefaultSignedPkcs7 tspCms = timestamp.GetSignedCms();
switch (timestamp.ResponseType.Value)
{
case PKCS_7_DATA:
// add timestamp signing certs to original CMS
foreach (X509Certificate2 tspCert in tspCms.Certificates)
{
if (!Certificates.Contains(tspCert))
{
Certificates.Add(tspCert);
}
}
// for Authenticode timestamp, we add SignerInfo from timestamp CMS
var asn = new Asn1Reader(tspCms.SignerInfos.Encode());
attribute = new X509Attribute(new Oid(COUNTER_SIGN), asn.GetPayload());
break;
case TST_TOKEN_INFO:
attribute = new X509Attribute(new Oid(RFC_COUNTER_SIGN), tspCms.RawData);
break;
default: throw new NotSupportedException("Time-Stamp response contains invalid content type.");
}
var signerInfoBuilder = new PkcsSignerInfoBuilder(SignerInfos[signerInfoIndex]);
X509Attribute attr = signerInfoBuilder.UnauthenticatedAttributes[COUNTER_SIGN];
if (attr != null)
{
signerInfoBuilder.UnauthenticatedAttributes.Remove(attr);
}
attr = signerInfoBuilder.UnauthenticatedAttributes[RFC_COUNTER_SIGN];
if (attr != null)
{
signerInfoBuilder.UnauthenticatedAttributes.Remove(attr);
}
signerInfoBuilder.AddUnauthenticatedAttribute(attribute);
SignerInfos[signerInfoIndex] = signerInfoBuilder.Encode();
}
/// <summary>
/// Timestamps the specified signature using external Time-Stamp Authority.
/// </summary>
/// <param name="tsaUrl">
/// An URL to a Time-Stamp Authority.
/// </param>
/// <param name="hashAlgorithm">
/// Hash algorithm to use by TSA to sign response.
/// </param>
/// <param name="signerInfoIndex">
/// A zero-based index of signature to timestamp. Default value is 0.
/// </param>
/// <remarks>This method adds an RFC3161 Counter Signature.</remarks>
public void AddTimestamp(String tsaUrl, Oid hashAlgorithm, Int32 signerInfoIndex = 0)
{
var tspReq = new TspRfc3161Request(hashAlgorithm, cms.SignerInfos[signerInfoIndex].EncryptedHash)
{
TsaUrl = new Uri(tsaUrl)
};
TspResponse rsp = tspReq.SendRequest();
var builder = new SignedCmsBuilder(cms);
builder.AddTimestamp(rsp, 0);
decode(builder.Encode().RawData);
}
