using Spire.Pdf;
using Spire.Pdf.Graphics;
using Spire.Pdf.Security;
using System.Drawing;


namespace SignPDFwithTimestamp
{
    class Program
    {
        static void Main(string[] args)
        {
            //create a PdfDocument object and load a PDF file
            PdfDocument doc = new PdfDocument();
            doc.LoadFromFile(@"C:\Users\Administrator\Desktop\Example.pdf");

            //load the certificate .pfx file
            PdfCertificate cert = new PdfCertificate(@"C:\Users\Administrator\Desktop\gary.pfx", "e-iceblue");

            //add a signature to the specified position
            PdfSignature signature = new PdfSignature(doc, doc.Pages[0], cert, "signature");
            signature.Bounds = new RectangleF(new PointF(350, 700), new SizeF(180, 90));

            //set the signature content
            signature.NameLabel = "Digitally signed by:Gary";
            signature.LocationInfoLabel = "Location:";
            signature.LocationInfo = "CN";
            signature.ReasonLabel = "Reason: ";
            signature.Reason = "Ensure authenticity";
            signature.ContactInfoLabel = "Contact Number: ";
            signature.ContactInfo = "028-81705109";
            signature.DocumentPermissions = PdfCertificationFlags.AllowFormFill | PdfCertificationFlags.ForbidChanges;
            signature.GraphicsMode = GraphicMode.SignImageAndSignDetail;
            signature.SignImageSource = PdfImage.FromFile(@"C:\Users\Administrator\Desktop\company-logo.jpg");

            //configure a timestamp server
            string url = "http://timestamp.wosign.com/rfc3161";
            signature.ConfigureTimestamp(url);

            //save to file
            doc.SaveToFile("output.pdf");
        }
    }
}

Imports Spire.Pdf
Imports Spire.Pdf.Graphics
Imports Spire.Pdf.Security
Imports System.Drawing


Namespace SignPDFwithTimestamp
	Class Program
		Private Shared Sub Main(args As String())
			'create a PdfDocument object and load a PDF file
Dim doc As PdfDocument =  New PdfDocument() 
doc.LoadFromFile("C:\Users\Administrator\Desktop\Example.pdf")
 
'load the certificate .pfx file
Dim cert As PdfCertificate =  New PdfCertificate("C:\Users\Administrator\Desktop\gary.pfx","e-iceblue") 
 
'add a signature to the specified position
Dim signature As PdfSignature =  New PdfSignature(doc,doc.Pages(0),cert,"signature") 
signature.Bounds = New RectangleF(New PointF(350, 700), New SizeF(180, 90))
 
'set the signature content
signature.NameLabel = "Digitally signed by:Gary"
signature.LocationInfoLabel = "Location:"
signature.LocationInfo = "CN"
signature.ReasonLabel = "Reason: "
signature.Reason = "Ensure authenticity"
signature.ContactInfoLabel = "Contact Number: "
signature.ContactInfo = "028-81705109"
signature.DocumentPermissions = PdfCertificationFlags.AllowFormFill | PdfCertificationFlags.ForbidChanges
signature.GraphicsMode = GraphicMode.SignImageAndSignDetail
signature.SignImageSource = PdfImage.FromFile("C:\Users\Administrator\Desktop\company-logo.jpg")
 
'configure a timestamp server
Dim url As String =  "http://timestamp.wosign.com/rfc3161" 
signature.ConfigureTimestamp(url)
 
'save to file
doc.SaveToFile("output.pdf")
		End Sub
	End Class
End Namespace

PdfDocument pdf = new PdfDocument();
pdf.LoadFromFile("Sample.pdf", "e-iceblue");

pdf.Security.UserPassword = string.Empty;

pdf.SaveToFile("Decrypted.pdf");

using Spire.Pdf;

namespace RemovePassword
{
    class Program
    {
        static void Main(string[] args)
        {
            PdfDocument pdf = new PdfDocument();
            pdf.LoadFromFile("Sample.pdf", "e-iceblue");

            pdf.Security.UserPassword = string.Empty;

            pdf.SaveToFile("Decrypted.pdf");
        }
    }
}

Imports Spire.Pdf

Namespace RemovePassword
	Class Program
		Private Shared Sub Main(args As String())
			Dim pdf As New PdfDocument()
pdf.LoadFromFile("Sample.pdf", "e-iceblue")
pdf.Security.UserPassword = String.Empty
pdf.SaveToFile("Decrypted.pdf")
		End Sub
	End Class
End Namespace

PdfDocument doc = new PdfDocument();
doc.Pages.Add();

string javaScript = "var rightNow = new Date();"
                    + "var endDate = new Date('October 20, 2016 23:59:59');"
                    + "if(rightNow.getTime() > endDate)"
                    + "app.alert('This Document has expired, please contact us for a new one.',1);"
                    + "this.closeDoc();";

PdfJavaScriptAction js = new PdfJavaScriptAction(javaScript);

doc.AfterOpenAction = js;

doc.SaveToFile("ExpiryDate.pdf", FileFormat.PDF);

using Spire.Pdf;
using Spire.Pdf.Actions;

namespace AddExpiryDate
{
    class Program
    {
        static void Main(string[] args)
        {
            PdfDocument doc = new PdfDocument();
            doc.Pages.Add();

            string javaScript = "var rightNow = new Date();"
                     + "var endDate = new Date('October 20, 2016 23:59:59');"
                     + "if(rightNow.getTime() > endDate)"
                     + "app.alert('This Document has expired, please contact us for a new one.',1);"
                     + "this.closeDoc();";
            PdfJavaScriptAction js = new PdfJavaScriptAction(javaScript);
            doc.AfterOpenAction = js;
            doc.SaveToFile("ExpiryDate.pdf", FileFormat.PDF);
        }
    }
}

Imports Spire.Pdf
Imports Spire.Pdf.Actions

Namespace AddExpiryDate
	Class Program
		Private Shared Sub Main(args As String())
			Dim doc As PdfDocument = New PdfDocument()
doc.Pages.Add()
 
String javaScript = "var rightNow = new Date();"
                    + "var endDate = new Date('October 20, 2016 23:59:59');"
                    + "if(rightNow.getTime() > endDate)"
                    + "app.alert('This Document has expired, please contact us for a new one.',1);"
                    Dim "this.closeDoc();" As +
Dim js As PdfJavaScriptAction = New PdfJavaScriptAction(javaScript)
doc.AfterOpenAction = js
doc.SaveToFile("ExpiryDate.pdf", FileFormat.PDF)
		End Sub
	End Class
End Namespace

PdfDocument doc = new PdfDocument();
doc.LoadFromFile("UPS.pdf");

List<PdfSignature> signatures = new List<PdfSignature>();

var form = (PdfFormWidget)doc.Form;
for (int i = 0; i < form.FieldsWidget.Count; ++i)
{
    var field = form.FieldsWidget[i] as PdfSignatureFieldWidget;
    if (field != null && field.Signature != null)
    {
        PdfSignature signature = field.Signature;
        signatures.Add(signature);
    }
}

PdfSignature signatureOne = signatures[0];
X509Certificate2Collection collection = signatureOne.Certificates;

using System;
using System.Collections.Generic;
using System.Security.Cryptography.X509Certificates;
using Spire.Pdf;
using Spire.Pdf.Security;
using Spire.Pdf.Widget;

namespace Get_all_certificates_in_PDF_signature
{
    class Program
    {
        static void Main(string[] args)
        {
            PdfDocument doc = new PdfDocument();
            doc.LoadFromFile("UPS.pdf");
            List<PdfSignature> signatures = new List<PdfSignature>();
            var form = (PdfFormWidget)doc.Form;
            for (int i = 0; i < form.FieldsWidget.Count; ++i)
            {
                var field = form.FieldsWidget[i] as PdfSignatureFieldWidget;

                if (field != null && field.Signature != null)
                {
                    PdfSignature signature = field.Signature;
                    signatures.Add(signature);
                }
            }
            PdfSignature signatureOne = signatures[0];
            X509Certificate2Collection collection = signatureOne.Certificates;
            foreach (var certificate in collection)
            {
                Console.WriteLine(certificate.Subject);
            }            
            Console.ReadKey();
        }
    }
}

PdfDocument pdfdoc = new PdfDocument();
PdfPageBase page = pdfdoc.Pages.Add();

PdfSignatureField signaturefield = new PdfSignatureField(page, "Signature");

signaturefield.BorderWidth = 1.0f;
signaturefield.BorderStyle = PdfBorderStyle.Solid;
signaturefield.BorderColor = new PdfRGBColor(System.Drawing.Color.Black);
signaturefield.HighlightMode = PdfHighlightMode.Outline;
signaturefield.Bounds = new RectangleF(100, 100, 100, 100);

pdfdoc.Form.Fields.Add(signaturefield);

pdfdoc.SaveToFile("AddSignField.pdf", FileFormat.PDF);

using System.Drawing;
using Spire.Pdf;
using Spire.Pdf.Fields;
using Spire.Pdf.Graphics;

namespace Add_Signature_Filed_to_PDF
{
    class Program
    {
        static void Main(string[] args)
        {
            PdfDocument pdfdoc = new PdfDocument();
            PdfPageBase page = pdfdoc.Pages.Add();

            PdfSignatureField signaturefield = new PdfSignatureField(page, "Signature");
            signaturefield.BorderWidth = 1.0f;
            signaturefield.BorderStyle = PdfBorderStyle.Solid;
            signaturefield.BorderColor = new PdfRGBColor(System.Drawing.Color.Black);
            signaturefield.HighlightMode = PdfHighlightMode.Outline;
            signaturefield.Bounds = new RectangleF(100, 100, 100, 100);
            pdfdoc.Form.Fields.Add(signaturefield);
            pdfdoc.SaveToFile("AddSignField.pdf", FileFormat.PDF);
        }
    }
}

PdfDocument doc = new PdfDocument();

doc.LoadFromFile(@"C:\Users\Administrator\Desktop\Encrypted.pdf");

bool isEncrypted = doc.IsEncrypted;
Console.WriteLine(isEncrypted);

using Spire.Pdf;
using System;


namespace Detect
{
    class Program
    {
        static void Main(string[] args)
        {
            PdfDocument doc = new PdfDocument();
            doc.LoadFromFile(@"C:\Users\Administrator\Desktop\Encrypted.pdf");

            bool isEncrypted = doc.IsEncrypted;
            Console.WriteLine(isEncrypted);
            Console.Read();
        }
    }
}

Imports Spire.Pdf

Namespace Detect
	Class Program
		Private Shared Sub Main(args As String())
			Dim doc As New PdfDocument()
doc.LoadFromFile("C:\Users\Administrator\Desktop\Encrypted.pdf")

Dim isEncrypted As Boolean = doc.IsEncrypted
Console.WriteLine(isEncrypted)
Console.Read()
		End Sub
	End Class
End Namespace

private void btnLoad_Click(object sender, EventArgs e)
{
    OpenFileDialog fileName = new OpenFileDialog();
    fileName.InitialDirectory = Application.StartupPath;
    fileName.Filter = "All files|*.pdf";
    if (fileName.ShowDialog() == DialogResult.OK)
    {
        string Path = fileName.FileName.ToString();
        textBox1.Text = Path;
    }
}

private void btnCheck_Click(object sender, EventArgs e)
{
    //get signatures from PDF
    List signatures = new List();
    using (PdfDocument pdf = new PdfDocument(textBox1.Text))
    {
        PdfFormWidget form = pdf.Form as PdfFormWidget;
        for (int i = 0; i < form.FieldsWidget.Count; i++)
        {
            PdfSignatureFieldWidget field = form.FieldsWidget[i] as PdfSignatureFieldWidget;
            if (field != null && field.Signature != null)
            {
                PdfSignature signature = field.Signature;
                signatures.Add(signature);
            }
        }
        PdfSignature signatureOne = signatures[0];
        //detect if the PDF was modified
        bool modified = signatureOne.VerifyDocModified();
        if (modified == true)
        {
            MessageBox.Show("The document was modified");
        }
    }
}

private void btnLoad_Click(object sender, EventArgs e)
{
    OpenFileDialog fileName = new OpenFileDialog();
    fileName.InitialDirectory = Application.StartupPath;
    fileName.Filter = "All files|*.pdf";
    if (fileName.ShowDialog() == DialogResult.OK)
    {
        string Path = fileName.FileName.ToString();
        textBox1.Text = Path;
    }
}
private void btnCheck_Click(object sender, EventArgs e)
{
    //get signatures from PDF
    List signatures = new List();
    using (PdfDocument pdf = new PdfDocument(textBox1.Text))
    {
        PdfFormWidget form = pdf.Form as PdfFormWidget;
        for (int i = 0; i < form.FieldsWidget.Count; i++)
        {
            PdfSignatureFieldWidget field = form.FieldsWidget[i] as PdfSignatureFieldWidget;
            if (field != null && field.Signature != null)
            {
                PdfSignature signature = field.Signature;
                signatures.Add(signature);
            }
        }
        PdfSignature signatureOne = signatures[0];
        //detect if the PDF was modified
        bool modified = signatureOne.VerifyDocModified();
        if (modified == true)
        {
            MessageBox.Show("The document was modified");
        }
    }
}

PdfDocument pdf = new PdfDocument("test.pdf");

PdfFormWidget widgets = pdf.Form as PdfFormWidget;

for (int i = 0; i < widgets.FieldsWidget.List.Count; i++)
{
    PdfFieldWidget widget = widgets.FieldsWidget.List[i] as PdfFieldWidget;
    if (widget is PdfSignatureFieldWidget)
    {
        widgets.FieldsWidget.RemoveAt(i);
    }
}

pdf.SaveToFile("result.pdf");
System.Diagnostics.Process.Start("result.pdf");

using Spire.Pdf;
using Spire.Pdf.Widget;

namespace RemoveDigitalSignature
{
    class Program
    {
        static void Main(string[] args)
        {
            PdfDocument pdf = new PdfDocument("test.pdf");

            PdfFormWidget widgets = pdf.Form as PdfFormWidget;
            for (int i = 0; i < widgets.FieldsWidget.List.Count; i++)
            {
                PdfFieldWidget widget = widgets.FieldsWidget.List[i] as PdfFieldWidget;
                if (widget is PdfSignatureFieldWidget)
                {
                    widgets.FieldsWidget.RemoveAt(i);
                }
            }

            pdf.SaveToFile("result.pdf");
            System.Diagnostics.Process.Start("result.pdf");
        }
    }
}

Imports Spire.Pdf
Imports Spire.Pdf.Widget

Namespace RemoveDigitalSignature
	Class Program
		Private Shared Sub Main(args As String())
			Dim pdf As New PdfDocument("test.pdf")
Dim widgets As PdfFormWidget = TryCast(pdf.Form, PdfFormWidget)
For i As Integer = 0 To widgets.FieldsWidget.List.Count - 1
	Dim widget As PdfFieldWidget = TryCast(widgets.FieldsWidget.List(i), PdfFieldWidget)
	If TypeOf widget Is PdfSignatureFieldWidget Then

		widgets.FieldsWidget.RemoveAt(i)
	End If
Next

pdf.SaveToFile("result.pdf")
System.Diagnostics.Process.Start("result.pdf")
		End Sub
	End Class
End Namespace