B4X

PDF Signature Appearance Text Substitution Keywords

See more PDF Signatures Examples

This example demonstrates the text substitution keywords that can be used in the PDF signature's appearance text.

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

B4X

Dim success As Boolean = False

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

Dim pdf As ChilkatPdf
pdf.Initialize("pdf")

'  Load a PDF to be signed.
success = pdf.LoadFile("qa_data/pdf/empty.pdf")
If success = False Then
    Log(pdf.LastErrorText)
    Return
End If


'  Options for signing are specified in JSON.
Dim json As ChilkatJsonObject
json.Initialize

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

'  Put the signature on page 1, top left
json.UpdateInt("page", 1)
json.UpdateString("appearance.y", "top")
json.UpdateString("appearance.x", "left")

'  Use a font scale of 7.0
json.UpdateString("appearance.fontScale", "7.0")

'  The appearance of the PDF signature can contain any number of text lines.
'  Chilkat has defined a number of special keywords that can be used in any text line.
'  Each keyword is replaced with the actual value.
'  For example, "cert_cn" is replaced with the certificate subject's common name (CN).

'  Here we are creating a signature with many lines of text, to demonstrate each
'  keyword.
json.UpdateString("appearance.text[0]", "Date/time in PDF format: current_dt")
json.UpdateString("appearance.text[1]", "Current Local date/time: current_datetime")
json.UpdateString("appearance.text[2]", "GMT Timestamp: current_timestamp_gmt")
json.UpdateString("appearance.text[3]", "Local Timestamp: current_timestamp_local")
json.UpdateString("appearance.text[4]", "GMT RFC822 date/time: current_rfc822_dt_gmt")
json.UpdateString("appearance.text[5]", "Local RFC822 date/time: current_rfc822_dt_local")
json.UpdateString("appearance.text[6]", "Cert DN (Distinguished Name): cert_dn")
json.UpdateString("appearance.text[7]", "Cert Common Name: cert_cn")
json.UpdateString("appearance.text[8]", "Cert Organizational ID (2.5.4.97): cert_org_id")
json.UpdateString("appearance.text[9]", "Cert Email: cert_email")
json.UpdateString("appearance.text[10]", "Cert Organization: cert_organization")
json.UpdateString("appearance.text[11]", "Cert Organziational Unit: cert_ou")
json.UpdateString("appearance.text[12]", "Cert State: cert_state")
json.UpdateString("appearance.text[13]", "Cert Country: cert_country")
json.UpdateString("appearance.text[14]", "Cert Locality: cert_locality")
json.UpdateString("appearance.text[15]", "Cert Serial Number (hex): cert_serial_hex")
json.UpdateString("appearance.text[16]", "Cert Serial Number (decimal): cert_serial_dec")
json.UpdateString("appearance.text[17]", "Cert Thumbprint: cert_thumbprint")
json.UpdateString("appearance.text[18]", "Cert Issuer Common Name: cert_issuer_cn")

Dim jpgData As ChilkatBinData
jpgData.Initialize
success = jpgData.LoadFile("qa_data/jpg/seal1.jpg")
If success = False Then
    Log("Failed to load the JPG image.")
    Return
End If

success = pdf.SetSignatureJpeg(jpgData)
If success = False Then
    Log(pdf.LastErrorText)
    Return
End If


'  Specify that we want to display the JPG image in the center with 33% opacity.
json.UpdateString("appearance.image", "custom-jpg")
json.UpdateString("appearance.imagePlacement", "center")
json.UpdateString("appearance.imageOpacity", "33")

'  Load the signing certificate. (Use your own certificate.)
Dim cert As ChilkatCert
cert.Initialize("cert")
success = cert.LoadPfxFile("qa_data/pfx/myPdfSigningCert.pfx", "pfx_password")
If success = False Then
    Log(cert.LastErrorText)
    Return
End If


'  Tell the pdf object to use the certificate for signing.
success = pdf.SetSigningCert(cert)
If success = False Then
    Log(pdf.LastErrorText)
    Return
End If


success = pdf.SignPdf(json, "qa_output/hello_signed.pdf")
If success = False Then
    Log(pdf.LastErrorText)
    Return
End If


Log("The PDF has been successfully cryptographically signed.")

'  The appearance of the signature appears in Adobe Acrobat as shown here:

'  (image:https://example-code.com/images/pdf_signature_text_replacements.jpg/endImage)