public SignerInfo Generate(DerObjectIdentifier contentType)
{
try
{
/* RFC 3852 5.4
* The result of the message digest calculation process depends on
* whether the signedAttrs field is present. When the field is absent,
* the result is just the message digest of the content as described
*
* above. When the field is present, however, the result is the message
* digest of the complete DER encoding of the SignedAttrs value
* contained in the signedAttrs field.
*/
Asn1Set signedAttr = null;
AlgorithmIdentifier digestEncryptionAlgorithm = sigEncAlgFinder.FindEncryptionAlgorithm(signer.AlgorithmDetails);
AlgorithmIdentifier digestAlg = null;
if (signedGen != null)
{
digestAlg = digester.AlgorithmDetails;
digestCalculator.Stream.Close();
calculatedDigest = digestCalculator.GetResult().Collect();
IDictionary <string, object> parameters = getBaseParameters(contentType, digester.AlgorithmDetails, digestEncryptionAlgorithm, calculatedDigest);
Asn1.Cms.AttributeTable signed = signedGen.GetAttributes(parameters);
signedAttr = getAttributeSet(signed);
// sig must be composed from the DER encoding.
Stream sOut = signerCalculator.Stream;
byte[] data = signedAttr.GetEncoded(Asn1Encodable.Der);
sOut.Write(data, 0, data.Length);
}
else
{
if (digester != null)
{
digestAlg = digester.AlgorithmDetails;
digestCalculator.Stream.Close();
calculatedDigest = digestCalculator.GetResult().Collect();
}
else
{
digestAlg = digAlgFinder.Find(signer.AlgorithmDetails);
calculatedDigest = null;
}
}
signerCalculator.Stream.Close();
byte[] sigBytes = signerCalculator.GetResult().Collect();
Asn1Set unsignedAttr = null;
if (unsignedGen != null)
{
IDictionary <string, object> parameters = getBaseParameters(contentType, digestAlg, digestEncryptionAlgorithm, calculatedDigest);
parameters.Add(CmsAttributeTableParameter.Signature, Arrays.Clone(sigBytes));
Asn1.Cms.AttributeTable unsigned = unsignedGen.GetAttributes(parameters);
unsignedAttr = getAttributeSet(unsigned);
}
return(new SignerInfo(sigId, digestAlg,
signedAttr, digestEncryptionAlgorithm, new DerOctetString(sigBytes), unsignedAttr));
}
catch (IOException e)
{
throw new CmsException("encoding error.", e);
}
}
