how to add digital signature to pdf in vb.net code using itextsharp

You can use the PdfSignature class of Free Spire.PDF library to add digital signature to pdf in vb.net code with ease.

https://www.e-iceblue.com/Tutorials/Spire.PDF/Spire.PDF-Program-Guide/PDF-Protection-Create-Digital-Signature-in-PDF-with-C-VB.NET.html

Code example:

Imports System
Imports System.Drawing
Imports Spire.Pdf
Imports Spire.Pdf.Security
Imports Spire.Pdf.Graphics
Namespace AddVisibleSignature
Class Program
Shared Sub Main(ByVal args() As String)
'Create a PdfDocument object
Dim doc As PdfDocument = New PdfDocument()
'Load a sample PDF file
doc.LoadFromFile("C:\\Users\\Administrator\\Desktop\\sample.pdf")
'Load the certificate
Dim cert As PdfCertificate = New PdfCertificate("C:\\Users\\Administrator\\Desktop\\MyCertificate.pfx","e-iceblue")
'Create a PdfSignature object and specify its position and size
Dim signature As PdfSignature = New PdfSignature(doc,doc.Pages(doc.Pages.Count - 1),cert,"MySignature")
Dim rectangleF As RectangleF = New RectangleF(doc.Pages(0).ActualSize.Width - 260 - 54,200,260,110)
signature.Bounds = rectangleF
signature.Certificated = True
'Set the graphics mode to ImageAndSignDetail
signature.GraphicsMode = GraphicMode.SignImageAndSignDetail
'Set the signature content
signature.NameLabel = "Signer:"
signature.Name = "Gary"
signature.ContactInfoLabel = "Phone:"
signature.ContactInfo = "0123456"
signature.DateLabel = "Date:"
signature.Date = DateTime.Now
signature.LocationInfoLabel = "Location:"
signature.LocationInfo = "USA"
signature.ReasonLabel = "Reason:"
signature.Reason = "I am the author"
signature.DistinguishedNameLabel = "DN:"
signature.DistinguishedName = signature.Certificate.IssuerName.Name
'Set the signature image source
signature.SignImageSource = PdfImage.FromFile("C:\\Users\\Administrator\\Desktop\\handwrittingSignature.png")
'Set the signature font
signature.SignDetailsFont = New PdfTrueTypeFont(New Font("Arial Unicode MS", 12f, FontStyle.Regular))
'Set the document permission to forbid changes but allow form fill
signature.DocumentPermissions = PdfCertificationFlags.ForbidChanges | PdfCertificationFlags.AllowFormFill
'Save to file
doc.SaveToFile("VisiableSignature.pdf")
doc.Close()
End Sub
End Class
End Namespace

5 Replies

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Leon D4y ago
Accepted answer
You can use the PdfSignature class of Free Spire.PDF library to add digital signature to pdf in vb.net code with ease.
https://www.e-iceblue.com/Tutorials/Spire.PDF/Spire.PDF-Program-Guide/PDF-Protection-Create-Digital-Signature-in-PDF-with-C-VB.NET.html

Code example:
Imports System
Imports System.Drawing
Imports Spire.Pdf
Imports Spire.Pdf.Security
Imports Spire.Pdf.Graphics

Namespace AddVisibleSignature
    Class Program
        Shared  Sub Main(ByVal args() As String)
            'Create a PdfDocument object
            Dim doc As PdfDocument =  New PdfDocument()

            'Load a sample PDF file
            doc.LoadFromFile("C:\\Users\\Administrator\\Desktop\\sample.pdf")

            'Load the certificate
            Dim cert As PdfCertificate =  New PdfCertificate("C:\\Users\\Administrator\\Desktop\\MyCertificate.pfx","e-iceblue")

            'Create a PdfSignature object and specify its position and size
            Dim signature As PdfSignature =  New PdfSignature(doc,doc.Pages(doc.Pages.Count - 1),cert,"MySignature")
            Dim rectangleF As RectangleF =  New RectangleF(doc.Pages(0).ActualSize.Width - 260 - 54,200,260,110)
            signature.Bounds = rectangleF
            signature.Certificated = True

            'Set the graphics mode to ImageAndSignDetail
            signature.GraphicsMode = GraphicMode.SignImageAndSignDetail

            'Set the signature content
            signature.NameLabel = "Signer:"
            signature.Name = "Gary"
            signature.ContactInfoLabel = "Phone:"
            signature.ContactInfo = "0123456"
            signature.DateLabel = "Date:"
            signature.Date = DateTime.Now
            signature.LocationInfoLabel = "Location:"
            signature.LocationInfo = "USA"
            signature.ReasonLabel = "Reason:"
            signature.Reason = "I am the author"
            signature.DistinguishedNameLabel = "DN:"
            signature.DistinguishedName = signature.Certificate.IssuerName.Name

            'Set the signature image source
            signature.SignImageSource = PdfImage.FromFile("C:\\Users\\Administrator\\Desktop\\handwrittingSignature.png")

            'Set the signature font
            signature.SignDetailsFont = New PdfTrueTypeFont(New Font("Arial Unicode MS", 12f, FontStyle.Regular))

            'Set the document permission to forbid changes but allow form fill
            signature.DocumentPermissions = PdfCertificationFlags.ForbidChanges | PdfCertificationFlags.AllowFormFill

            'Save to file
            doc.SaveToFile("VisiableSignature.pdf")
            doc.Close()
        End Sub
    End Class
End Namespace
+2
Kip Hackman4y ago
It is paid.
+1
Uday Dodiya4y ago
Kip Hackman LeadTools Is Free Or Paid?
+2
Kip Hackman4y ago
You can use LEADTOOLS PDF Pro SDK technology inside your application.
https://www.leadtools.com/sdk/products/pdf-pro
You can leverage the PDFFile class, which will allow you to add a digital signature certificate to a PDF file. Note that you can leverage the PDFDocument class to parse digital signatures with LEADTOOLS as well.
I know you stated that you are using VB.NET, but the C# .NET tutorial below should provide code that can be easily converted to VB on how to digitally sign PDFs.
https://www.leadtools.com/help/sdk/v22/tutorials/dotnet-console-add-a-digital-signature-to-a-pdf.html
+2
Uday Dodiya4y ago
Is spire pdf dll is totally free or paid?
+1