public static Org.BouncyCastle.Asn1.Asn1EncodableVector GetTimestamp(byte[] signature, string url, string user, string pass)
{
byte[] tsImprint = PdfEncryption.DigestComputeHash("SHA256", signature);
int size = 6500;
ITSAClient tsc = new TSAClientBouncyCastle(url, user, pass, size, "SHA256");
String ID_TIME_STAMP_TOKEN = "1.2.840.113549.1.9.16.2.14"; // RFC 3161 id-aa-timeStampToken
Asn1InputStream tempstream = new Asn1InputStream(new MemoryStream(tsc.GetTimeStampToken(tsImprint)));
Asn1EncodableVector unauthAttributes = new Asn1EncodableVector();
Asn1EncodableVector v = new Asn1EncodableVector();
v.Add(new DerObjectIdentifier(ID_TIME_STAMP_TOKEN)); // id-aa-timeStampToken
Asn1Sequence seq = (Asn1Sequence)tempstream.ReadObject();
v.Add(new DerSet(seq));
unauthAttributes.Add(new DerSequence(v));
return(unauthAttributes);
}
public byte[] signPdf(byte[] inputPdf, byte[] sigImg, string signatureField)
{
this.getCRLList();
Console.WriteLine("Read PDF");
PdfReader reader = new PdfReader(inputPdf);
MemoryStream output = new MemoryStream();
PdfStamper stamper = PdfStamper.CreateSignature(reader, output, '\0', null, true);
PdfSignatureAppearance sap = stamper.SignatureAppearance;
sap.Reason = "test";
sap.Location = "Bangkok";
// Set Signature Image
if (sigImg != null)
{
sap.SignatureGraphic = Image.GetInstance(sigImg);
sap.ImageScale = -1;
sap.SignatureRenderingMode = PdfSignatureAppearance.RenderingMode.GRAPHIC;
}
// Set Signature Field
if (signatureField.Equals("") || signatureField == null)
{
Rectangle location = new Rectangle(10, 10, 300, 100);
sap.SetVisibleSignature(location, 1, "signatureField");
}
else
{
sap.SetVisibleSignature(signatureField);
}
sap.CertificationLevel = PdfSignatureAppearance.NOT_CERTIFIED;
//Create TSA server
ITSAClient tsaClient = null;
Boolean isTsaConnected = false;
if (tsa)
{
tsaClient = new TSAClientBouncyCastle(tsaUrl, tsaUsername, tsaPassword);
for (int retry = 0; retry < 5; retry++)
{
try
{
//int hash = tsaClient.GetHashCode();
string testString = "test";
byte[] digest;
using (SHA256Managed sha256 = new SHA256Managed())
{
digest = sha256.ComputeHash(Encoding.UTF8.GetBytes(testString));
}
tsaClient.GetTimeStampToken(digest);
isTsaConnected = true;
break;
}
catch (Exception e)
{
Console.WriteLine(e.StackTrace);
}
Console.WriteLine("retry " + (retry + 1));
}
}
//Do Signing Check not null timestamp and crl
if (tsaClient != null && crlList != null && isTsaConnected)
{
try
{
MakeSignature.SignDetached(sap, this.signature, chain, this.crlList, null, tsaClient, 0, CryptoStandard.CADES);
}
catch (Exception e)
{
Console.WriteLine(e.StackTrace);
}
}
else
{
Console.WriteLine("Cannot sign the PDF file.");
return(null);
}
reader.Close();
stamper.Close();
signature = null;
return(output.ToArray());
}