PDF Text Signatures

Even though the most common signatures are Image signatures it also possible with Aloaha to create text signatures.

Please have a look at the example below.

'This sample script demonstrates how to sign PDF Document
'with Adobe.PPKMS signatures
'Copyright 2006 Wrocklage Intermedia GmbH
'Redistribution without permission not allowed
'Signature API only enabled with Aloaha 25+ licenses

Dim pdf 'aloaha object
Dim reason 'signature reason
Dim location 'signature physical location
Dim infile 'inputpdf
Dim outfile 'outputpdf - can be the same as inputpdf
Dim cert 'certificate to be used. Can be either UniqueContainerName or Serialnumber

reason = "I created this document"
location = "I am in the office"

'set unique container name of certificate. serialnumber can be also used.
cert ="6e3f233ba3664e4f733a981c4b461016_d47eb964-b63d-4abb-a9f3-7d692cd54574"

'set file names
infile = "c:\pdf\input.pdf"
outfile = "c:\pdf\output.pdf"

'create object
Set pdf = CreateObject("aloahapdf.edit") 

   'set the text content of the signature.
   'Empty string creates a invisible signature 
   'pdf.signaturecontent=""

   'A string with some spaces as content create a
   'transparent signature. (if incremental signature is disabled)
   'pdf.signaturecontent="   "
   
pdf.signaturecontent="Signed at@@lf@@@@date@@@@lf@@with @@signature@@'s digital certificate.@@lf@@No further signature necessary." 

   'please note that position is set to 0,0,0,0 - registry settings will be used! 

   Call pdf.sign_pdf_file(CStr(infile), CStr(outfile), 0, 0, 0, 0, 0, 0, CStr(reason), CStr(location), CStr(cert), "") 

Set pdf = nothing 



 Download above sample (1,22 KB)

Text Signature Placeholders

It is possible to use placeholders in the signaturecontent variable. Possible placeholders are:

@@date@@ = Computer date and time
@@lf@@ = Line Feed
@@signature@@ = Certificate Subject Name

If other variables are needed please contact our support.

PKCS #1 vs PKCS #7

Aloaha decides automatically if it should use PKCS #1 or PKCS #7 embedded signatures. To force Aloaha to use PKCS #7 please use function Sign_File instead of sign_pdf_file. The parameter for both functions are identically.