VBScript

PDF Sign Unsigned Signature Field

See more PDF Signatures Examples

Demonstrates how to sign a PDF's unsigned signature field.

Note: This example requires Chilkat v9.5.0.85 or greater.

VBScript

Dim fso, outFile
Set fso = CreateObject("Scripting.FileSystemObject")
'Create a Unicode (utf-16) output text file.
Set outFile = fso.CreateTextFile("output.txt", True, True)

success = 0

' This example requires the Chilkat API to have been previously unlocked.
' See Global Unlock Sample for sample code.

set pdf = CreateObject("Chilkat.Pdf")

' Load a PDF containing an unsigned signature field.
success = pdf.LoadFile("qa_data/pdf/unsigned_sig_field/due_diligence.pdf")
If (success = 0) Then
    outFile.WriteLine(pdf.LastErrorText)
    WScript.Quit
End If

' A PDF with an unsigned signature field appears in Adobe Acrobat as shown below.
' (When the mouse pointer is hovered over the field, a tooltip will likely show a message
' such as "Unsigned signature field (Click to sign)".  
' This example code will automatically find the unsigned signature field,
' and signs using your certificate.  It automatically sizes the text to the space alotted
' for the signature.
' (image:https://example-code.com/images/unsignedSigField.jpg/endImage)

' Options for signing are specified in JSON.
set json = CreateObject("Chilkat.JsonObject")

' In most cases, the signingCertificateV2 and signingTime attributes are required.
success = json.UpdateInt("signingCertificateV2",1)
success = json.UpdateInt("signingTime",1)

' We don't specify the page or a specific location because Chilkat will automatically
' find the unsigned signature field and use its location and size and will scale the
' signatures visual appearance (text + graphics) to the correct size required to fit.
' We only need to indicate the desire to fill the unsigned signature field.
success = json.UpdateBool("appearance.fillUnsignedSignatureField",1)

' Starting in Chilkat v9.5.0.90, if a PDF contains multiple unsigned signature fields,
' the field to be signed can be chosen by name:
' To list unsigned signature fields, see this example: List PDF Unsigned Signature Fields
success = json.UpdateString("unsignedSignatureField","doctor_signature")

' Note: If the PDF document contains multiple unsigned signature fields, Chilkat will 
' sign the 1st one found. 

' In this example, the appearance of the digital signature will contain three lines:
' 1) The signing certificate's common name
' 2) The current date/time
' 3) Some arbitrary text.
' The keyword "cert_cn" is replaced with the Certificate's Subject Common Name.
' The keyword "current_dt" is replaced with the current date/time.
' Any number of appearance text lines can be added.
success = json.UpdateString("appearance.text[0]","Digitally signed by: cert_cn")
success = json.UpdateString("appearance.text[1]","current_dt")
success = json.UpdateString("appearance.text[2]","The crazy brown fox jumps over the lazy dog.")

' This signature will include one of the built-in SVG graphics (green-check-grey-circle).
success = json.UpdateString("appearance.image","green-check-grey-circle")
success = json.UpdateString("appearance.imagePlacement","left")

' Load the signing certificate. (Use your own certificate.)
set cert = CreateObject("Chilkat.Cert")
success = cert.LoadPfxFile("qa_data/pfx/myPdfSigningCert.pfx","secret")
If (success = 0) Then
    outFile.WriteLine(cert.LastErrorText)
    WScript.Quit
End If

' Tell the pdf object to use the certificate for signing.
success = pdf.SetSigningCert(cert)
If (success = 0) Then
    outFile.WriteLine(pdf.LastErrorText)
    WScript.Quit
End If

success = pdf.SignPdf(json,"qa_output/due_diligence_signed.pdf")
If (success = 0) Then
    outFile.WriteLine(pdf.LastErrorText)
    WScript.Quit
End If

outFile.WriteLine("The PDF has been successfully cryptographically signed.")

' The appearance of the signature appears in Adobe Acrobat as shown below.
' (image:https://example-code.com/images/signature3.jpg/endImage)

outFile.Close