'''' This code is part of Document Solutions for PDF .NET demos.'' Copyright (c) MESCIUS inc. All rights reserved.''Imports SystemImports System.IOImports System.Collections.GenericImports System.Security.CryptographyImports System.Security.Cryptography.X509CertificatesImports GrapeCity.Documents.PdfImports GrapeCity.Documents.Pdf.Security
'' This sample shows how to sign a PDF with a .p12 file'' containing a digital certificate that uses PKCS#12'' (Public Key Cryptography Standard #12) encryption.Public Class SignWithP12    Function CreatePDF(ByVal stream As Stream) As Integer        Dim doc = New GcPdfDocument()        Using s = File.OpenRead(Path.Combine("Resources", "PDFs", "SignWithP12.pdf"))            doc.Load(s)
            Dim p12 = Path.Combine("Resources", "Misc", "DsPdfTest2KeyStore.p12")            Dim sp = New SignatureProperties() With {                .SignatureBuilder = New Pkcs7SignatureBuilder() With {                    .CertificateChain = SecurityUtils.GetCertificateChain(p12, "qq")                },                .SignatureField = doc.AcroForm.Fields(0)            }            sp.SignatureAppearance.Caption = "PKCS #12"            doc.Sign(sp, stream)        End Using
        '' Done.        Return doc.Pages.Count    End FunctionEnd Class