public static void Sign(string fileName, string signedFileName, string reason, string location,
string privateKeyFileName, string certFileName, string password)
{
PdfReader reader = new PdfReader(fileName);
PdfWriter write = new PdfWriter(signedFileName);
PdfSigner signer = new PdfSigner(reader, write, false);
PdfSignatureAppearance appearance = signer.GetSignatureAppearance();
appearance.SetReason(reason);
appearance.SetLocation(location);
appearance.SetReuseAppearance(false);
Rectangle rect = new Rectangle(36, 648, 200, 100);
appearance.SetPageRect(rect);
appearance.SetPageNumber(1);
signer.SetFieldName("sig");
IExternalSignature pks = new PrivateKeySignature(ReadPrivateKey(privateKeyFileName, password), GetEncryptionAlgorithm());
X509CertificateParser parser = new X509CertificateParser();
X509Certificate cert = LoadCertificate(certFileName);
X509Certificate[] chain = new X509Certificate[1];
chain[0] = cert;
PdfSigner.CryptoStandard subfilter = GetSubFilter();
signer.SignDetached(pks, chain, null, null, null, 0, subfilter);
}
public void SignAgain(String src, String dest, X509Certificate[] chain, ICipherParameters pk,
String digestAlgorithm, PdfSigner.CryptoStandard subfilter, String reason, String location)
{
PdfReader reader = new PdfReader(src);
PdfSigner signer = new PdfSigner(reader, new FileStream(dest, FileMode.Create),
new StampingProperties().UseAppendMode());
PdfSignatureAppearance appearance = signer.GetSignatureAppearance();
appearance.SetReason(reason);
appearance.SetLocation(location);
appearance.SetReuseAppearance(false);
Rectangle rect = new Rectangle(36, 700, 200, 100);
appearance.SetPageRect(rect).SetPageNumber(1);
signer.SetFieldName("Signature2");
PrivateKeySignature pks = new PrivateKeySignature(pk, digestAlgorithm);
signer.SignDetached(pks, chain, null, null, null, 0, subfilter);
}
