public ActionResult DigitalSignatureValidation(string InsideBrowser)
{
SignatureValidationMesssage message = new SignatureValidationMesssage();
FileStream fileStreamInput = new FileStream(ResolveApplicationDataPath("DigitalSignature.pdf"), FileMode.Open, FileAccess.Read);
//Load an existing signed PDF document
PdfLoadedDocument ldoc = new PdfLoadedDocument(fileStreamInput);
//Get signature field.
PdfLoadedSignatureField lSigFld = ldoc.Form.Fields[0] as PdfLoadedSignatureField;
//X509Certificate2Collection to check the signer's identity using root certificates.
X509CertificateCollection collection = new X509CertificateCollection();
//Read the certificate file.
FileStream pfxFile = new FileStream(ResolveApplicationDataPath(@"PDF.pfx"), FileMode.Open, FileAccess.Read, FileShare.ReadWrite);
byte[] data = new byte[pfxFile.Length];
pfxFile.Read(data, 0, data.Length);
//Create new X509Certificate2 with the root certificate.
X509Certificate2 certificate = new X509Certificate2(data, "password123");
//Add the certificate to the collection.
collection.Add(certificate);
//Validate signature and get the validation result
PdfSignatureValidationResult result = lSigFld.ValidateSignature(collection);
StringBuilder builder = new StringBuilder();
builder.AppendLine("Signature is " + result.SignatureStatus);
builder.AppendLine();
builder.AppendLine("--------Validation Summary--------");
builder.AppendLine();
//Checks whether the document is modified or not
bool isModified = result.IsDocumentModified;
if (isModified)
{
builder.AppendLine("The document has been altered or corrupted since the signature was applied.");
}
else
{
builder.AppendLine("The document has not been modified since the signature was applied.");
}
//Signature details
builder.AppendLine("Digitally signed by " + lSigFld.Signature.Certificate.IssuerName);
builder.AppendLine("Valid From : " + lSigFld.Signature.Certificate.ValidFrom);
builder.AppendLine("Valid To : " + lSigFld.Signature.Certificate.ValidTo);
builder.AppendLine("Signature Algorithm : " + result.SignatureAlgorithm);
builder.AppendLine("Hash Algorithm : " + result.DigestAlgorithm);
//Revocation validation details
builder.AppendLine("OCSP revocation status : " + result.RevocationResult.OcspRevocationStatus);
if (result.RevocationResult.OcspRevocationStatus == RevocationStatus.None && result.RevocationResult.IsRevokedCRL)
{
builder.AppendLine("CRL is revoked.");
}
//Close the document
ldoc.Close(true);
message.Message = builder.ToString();
return(View("DigitalSignatureValidation", message));
}
void OnButtonClicked(object sender, EventArgs e)
{
label2.Hidden = false;
StringBuilder builder = new StringBuilder();
Stream docStream = typeof(DigitalSignatureValidation).GetTypeInfo().Assembly.GetManifestResourceStream("SampleBrowser.Samples.PDF.Assets.SignedDocument.pdf");
//Load the PDF document into the loaded document object.
PdfLoadedDocument loadedDocument = new PdfLoadedDocument(docStream);
//Get signature field
PdfLoadedSignatureField lSigFld = loadedDocument.Form.Fields[0] as PdfLoadedSignatureField;
//X509Certificate2Collection to check the signer's identity using root certificates
X509CertificateCollection collection = new X509CertificateCollection();
//Get the certificate stream from .pfx file.
Stream certificateStream = typeof(DigitalSignatureValidation).GetTypeInfo().Assembly.GetManifestResourceStream("SampleBrowser.Samples.PDF.Assets.PDF.pfx");
byte[] data = new byte[certificateStream.Length];
certificateStream.Read(data, 0, data.Length);
//Create new X509Certificate2 with the root certificate
X509Certificate2 certificate = new X509Certificate2(data, "password123");
//Add the certificate to the collection
collection.Add(certificate);
//Validate signature and get the validation result
PdfSignatureValidationResult result = lSigFld.ValidateSignature(collection);
builder.AppendLine("Signature is " + result.SignatureStatus);
builder.AppendLine();
builder.AppendLine("--------Validation Summary--------");
builder.AppendLine();
//Checks whether the document is modified or not
bool isModified = result.IsDocumentModified;
if (isModified)
{
builder.AppendLine("The document has been altered or corrupted since the signature was applied.");
}
else
{
builder.AppendLine("The document has not been modified since the signature was applied.");
}
//Signature details
builder.AppendLine("Digitally signed by " + lSigFld.Signature.Certificate.IssuerName);
builder.AppendLine("Valid From : " + lSigFld.Signature.Certificate.ValidFrom);
builder.AppendLine("Valid To : " + lSigFld.Signature.Certificate.ValidTo);
builder.AppendLine("Signature Algorithm : " + result.SignatureAlgorithm);
builder.AppendLine("Hash Algorithm : " + result.DigestAlgorithm);
//Revocation validation details
builder.AppendLine("OCSP revocation status : " + result.RevocationResult.OcspRevocationStatus);
if (result.RevocationResult.OcspRevocationStatus == RevocationStatus.None && result.RevocationResult.IsRevokedCRL)
{
builder.AppendLine("CRL is revoked.");
}
//Close the PDF document
loadedDocument.Close(true);
label2.Text = builder.ToString();
}
