isimSoftware PDF Signer
The main function of isimSoftware PDF Signer is to sign PDF documents using X.509 digital certificates. Using this product you can quickly sign multiple PDF files (bulk sign) by selecting input and output directory. This is ideal for bulk signing of a large number of corporate documents rather than signing each one individually.
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isimSoftware PDF Signer
The main function of isimSoftware PDF Signer is to sign PDF documents using X.509 digital certificates. Using this product you can quickly sign multiple PDF files (bulk sign) by selecting input and output directory. This is ideal for bulk signing of a large number of corporate documents rather than signing each one individually.
Benefits:
– Support for certificates issued on smart card, USB token, eToken, DSC, QSCD
– Support for eIDAS digital certificates (EU Regulation 910/2014)
– Time Stamping
– SHA-256, SHA-384, SHA-512 support
– Elliptic Curve support
– PAdES ETSI EN 319 142-1 and LTV (Long Term Validation)
– Encryption
– Bypass smart card/USB dongle PIN
If you need more features (watch folder, logging, email and FTP upload), you can try isimSoftware PDF Signer Server.
Configurable Signature Appearance – isimSoftware PDF Signer provides a fully configurable appearance for its digital signatures. The positioning of the signature appearance is configurable, plus on which pages of the document it should appear (first page, last page or all pages).
PKI Interoperability – isimSoftware PDF Signer is completely PKI neutral and will work with PKI components from any vendor (this includes CAs, certificates, CRLs, smartcards, etc.).
Timestamping – Like signatures, timestamps are easier to verify when they’re associated with a timestamp authority’s trusted certificate. Including a timestamp helps to prove that the document wasn’t changed after you had signed it and it reduces the chances of an invalid signature.
Long-Term Validation Purposes – Using our software you can sign and timestamp PDF documents for long-term validation purposes. isimSoftware PDF Signer supports advanced digital signatures which include embedded RFC 3161 compliant secure timestamps. Such signatures can be verified even after the signer’s certificate expires or is revoked.
SHA-256, SHA-384, SHA-512 Algorithms and RSA 2048 – Our software can digitally sign and time stamp PDF documents using SHA1, SHA-256, SHA-384 or SHA-512 hash algorithms and RSA 2048 or higher key length.
PAdES Standard – isimSoftware PDF Signer is compatible with PAdES ETSI EN 319 142-1 and LTV (Long Term Validation).
Document Certification – When you certify a PDF, you indicate that you approve of its contents.
Requirements:
– A digital certificate (eIDAS qualified digital certificates QSCD are supported)
– Windows 8 or later (including Windows 11 and Windows Server 2022)
Licensing:
The license for isimSoftware PDF Signer is a lifetime license. There is no additional cost like monthly / annual fees or fees per use. When a new version is released you can continue using your purchased version as usual.
PDF Signer User Manual
Introduction
The main function of PDF Signer is to sign PDF documents using X.509 digital certificates. Using this product you can quickly sign multiple PDF files (bulk sign) by selecting input and output directory. This is ideal for bulk signing of a large number of corporate documents rather than signing each one individually.
The positioning of the signature appearance is configurable, plus on which pages of the document it should appear (first page, last page or all pages).
Product Installation
We recommend to install the product using an Administrator account.
After the setup file is verified, the operating system might request your permission to install this program.
Digital Certificates
Digital Certificate Location
To digitally sign a PDF file a digital certificate is needed. The digital certificates are stored in two places:
- in Microsoft Store
- in PFX on P12 files
The certificates stored on Microsoft Store are available by opening Internet Explorer – Tools
menu – Internet Options – Content tab – Certificates button (see below).
For PDF digital signatures, the certificates stored on Personal tab are used. These certificates have a public and a private key.
The digital signature is created by using the private key of the certificate. The private key can be stored on the file system (imported PFX files), on a cryptographic smart card (like Aladdin eToken or SafeNet iKey) or on a HSM (Hardware Security Module).
Signing certificates available on Microsoft Store
Another way to store a digital certificate is a PFX (or P12) file. This file contain the public and the private key of the certificate. This file is protected by a password in order to keep safe the key pair.
Note that a PFX/P12 file can be imported on Microsoft Store (just open the PFX/P12 file and follow the wizard).
Certificates Stored on Smart Cards or USB Tokens
If your certificate is stored on a smart card or USB token (like Aladdin eToken), the certificate must appear on Microsoft Certificate Store in order to be used by the library.
If the certificate not appears on Microsoft Store, you must ask your vendor about how to import the certificate on the MS Store. Usually, the smart card driver or the middleware automatically install the certificate on Microsoft Certificate Store.
You should also look at the middleware options, like below:
Adding the certificate on Microsoft Certificate Store
Adding the certificate on Microsoft Certificate Store
Select the Digital Certificate for Creating PDF Signatures
To digitally sign a PDF, a digital certificate must be selected from Digital Certificates section. The digital certificate used to create the digital signature can be stored on Microsoft Store or a PFX file.
Select the digital certificate
Create a Test Digital Certificate
If no certificates are available on the computer, a test certificate can be created from Create a Digital Certificate section.
This certificate can be set as the default digital certificate used for PDF signatures.
Create a digital certificate
Validating Digital Signatures in Adobe
Every digital certificate is issued by a Root CA (Certification Authority). Some of the Root CA’s are included by default in Windows Certificate Store (Trusted Root Certification Authorities) and only a few are included in Adobe Certificate Store. Microsoft and Adobe use different Certificate Stores different certificate validation procedures.
If the signing certificate (or the Root CA that issued the signing certificate) is not included in Adobe Store, the digital signature is considered “not trusted” when a user open a document with Adobe Reader (see example).
This behavior has nothing to do with the signing engine but with the Adobe certification validation procedure.
To trust a signature the user must add the signing certificate on the Adobe Certificate Store because only a few Root CA’s are considered trusted by default by Adobe certificate validation engine (See this article: http://www.adobe.com/security/partners_cds.html)
Validity Unknown signature
Valid signature
Digital Signature Options
Digital Signature Rectangle
If the checkbox Visible signature box is checked, a signature rectangle will be inserted on the PDF document. The appearance of the digital signature can be customized from the Signature Appearance section.
The default text direction is left to right. To change the text direction to right to left (e.g. for Hebrew language) checkbox Right to Left text must be checked.
The default font file for the digital signature rectangle is Helvetica. It is possible that this font to not include all necessary UNICODE characters like ä, à, â. On this case you will need to use an external font.
The font size is calculated based on the signature rectangle size in order to fit on the signature rectangle (it not have a fixed size). If you want to use a specific font size, it can be secified on the Font size section.
Observation: If the custom position will be used, the corner (0,0) is on the bottom left of the page.
Basic appearance settings
The default digital signature text contains information extracted from the signing certificate, signing date, signing reason and signing location but the digital signature text can be easily customized.
Signature text
Set the Digital Signature Graphic
The digital signature rectangle can contains text, graphic or text with graphic. To add an image on the digital signature rectangle, you can do that from Place an image on the signature box section.
These types of signatures are shown below:
- Image and text, 2. Image as background, 3. Image with no text
Signing Reason and Location
The signing reason and location attributes can be set from the main interface.
Signed by, Reason, Location and Date properties in Adobe
Using SHA256, SHA512 Hash Algorithms
The default hash algorithm used by the library is SHA1 but in some cases, SHA256/384/512 must be used for the digital signature and the Time Stamp Request.
Attention: SHA-256 and SHA-512 hash algorithms are not supported by Windows XP. Note that some smart cards and USB tokens not support SHA-256 and SHA-512 hash algorithms.
Set the hash algorithm
Bypassing the Smart Card PIN
In case the digital signature must be made without user intervention and the certificate is stored on a smart card or USB token, the PIN dialog might be automatically bypassed for some models.
PIN dialog can be bypassed
In order to bypass the PIN dialog window, the Smart Card PIN checkbox must be checked and the right PIN to be entered.DigitalCertificate.SmartCardPin propery must be set. This option bypass the PIN dialog and the file is automatically signed without any user intervention.
Bypassing the Smart Card PIN
Attention: This feature will NOT work for all available smart card/USB tokens because of the drivers or other security measures. Use this property carefully.
Certify a PDF Digital Signature
When you certify a PDF, you indicate that you approve of its contents. You also specify the types of changes that are permitted for the document to remain certified.
You can apply a certifying signature only if the PDF doesn’t already contain any other signatures. Certifying signatures can be visible or invisible. A blue ribbon icon in the Signatures panel indicates a valid certifying signature.
To certify a digital signature, select the certification type from the main interface.
Certified signature
Include the CRL Revocation Information on the PDF Signature
If the revocation information will not be available online, the digital signature cannot be verified by the Adobe Reader engine so it is recommended to include the CRL on the signature block.
This setting is available on the Digital Certificates window.
Note that some revocation information files (CRL) are very large so resulting signed file will proportionally larger.
PDF Signer will try to include CRL for every digital certificate from the chain.
A PDF digital signature without revocation information
A PDF digital signature that embeds the revocation information
PDF/A Standard
PDF/A is a file format for the long-term archiving of electronic documents. It is based on the PDF Reference Version 1.4 from Adobe Systems Inc. (implemented in Adobe Acrobat 5 and latest versions) and is defined by ISO 19005-1:2005.
PDF Signer can digitally sign PDF/A files.
Observation: In order to save a PDF/A file, all fonts used on the PDF document must be embedded (including the font used on the digital signature rectangle). The digital signature font can be set on the Signature Appearance section.
PDF/A-1b document with digital signature
Time Stamping
Time Stamp the PDF Digital Signature
Timestamping is an important mechanism for the long-term preservation of digital signatures, time sealing of data objects to prove when they were received, protecting copyright and intellectual property and for the provision of notarization services.
To add time stamping information to the PDF digital signature you will need access to a RFC 3161 time stamping server.
Nonce and Policy
The Nonce, if included, allows the client to verify the timeliness of the response when no local clock is available. The nonce is a large random number with a high probability that the client generates it only once (e.g., a 64 bit integer).
Some TSA servers require to set a Time Stamp Server Policy on the Time Stamp Requests. By default, no Time Stamp Server Policy is included on the TSA request.
Validating the Time Stamp Response on Adobe
As digital signatures certificates, the time stamping responses are signed by a certificate issued by a Certification Authority.
If the time stamping certificate (or the Root CA that issued the time stamping certificate) is not included in Adobe Store, the time stamping response could not be verified when a user open a document with Adobe Reader (see example).
This behavior has nothing to do with the signing engine but with the Adobe certification validation procedure.
Encryption
If you want to protect the signed document by preventing actions like printing or content copying you must encrypt it. The document can be encrypted using passwords from Encryption section.
Encryption settings
If the PDF document is signed and encrypted with an User Password, when the document is opened in PDF reader, the PDF document password must be entered.
Password is required to open the document
Owner Password is used to set the password that protects the PDF document for printing or content copying.
When the signed and encrypted document is opened in a PDF reader, the security settings are shown like below.
Security settings for a digitally sign and encrypted document
LTV Signatures (Long Term Validation)
PAdES recognizes that digitally-signed documents may be used or archived for many years – even many decades. At any time in the future, in spite of technological and other advances, it must be possible to validate the document to confirm that the signature was valid at the time it was signed – a concept known as Long-Term Validation (LTV).
In order to have a LTV signature, be sure that on the Digital Certificates settings, the checkbox Include certificate revocation information – Long Term signature (LTV) is checked.
Product Registration
To register the product you will need a serial number. It can be purchased online directly from the product main page.
After you will obtain your serial number, open PDF Signer and click Register Now button.
Batch Signatures (Automatically Made Without User Intervention)
By default, PDF Signer Server is installed on this location:
C:\Program Files\Isim Software\PDF Signer Server\PDF Server.exe.
The command line parameters are:
PDF Server.exe <source file | folder> <destination file | folder> [<XML configuration file>]
To automatically sign a PDF file, use the following command:
c:\Program Files\Isim Software\PDF Signer Server>”PDF Server.exe” c:\InputFile.pdf c:\SignedFile.pdf
To automatically sign a folder that contains PDF files, use the following command: c:\Program Files\Isim Software\PDF Signer Server>”PDF Server.exe” c:\InputFolder c:\OutputFolder
Custom Configuration
In some cases, you will need a different signature configuration (e.g. different signature appearance and digital certificates) for different PDF files/folders.
To save a specific configuration, go to File – Save Configuration As and save the configuration on a file. Later, you can use that file in batch mode to apply different signature configuration on your signed PDF file.
To automatically sign a folder that contains PDF files, using a custom configuration, use the following command:
“PDF Server.exe” c:\InputFolder c:\OutputFolder c:\config-client2.xml
Digitally Sign PDF Files Using Windows PowerShell
To digitally sign PDF file using Windows PowerShell, simply download the library above and inspect Signature Library\PowerShell Scripts folder.
The Windows PowerShell script will look below:
#digitally sign a PDF file using a PFX certificate creted on the fly
#the script can be configured to use an existing PFX file or a certificate loaded from Microsoft Store (smart card certificate)
if ($args.Length -eq 0)
{
echo “Usage: signpdf.ps1 <unsigned file> <signed file>”
}
else
{
$DllPath = ‘d:\SignLib.dll’ [System.Reflection.Assembly]::LoadFrom($DllPath)
#create a PFX digital certificate
$generator = new-object -typeName SignLib.Certificates.X509CertificateGenerator(“serial number”)
$pFXFilePassword = “tempP@ssword”
$generator.Subject = “CN=Your Certificate, E=useremail@email.com, O=Organzation”
$generator.Extensions.AddKeyUsage([SignLib.Certificates.CertificateKeyUsage]::DigitalSignatu re)
$generator.Extensions.AddEnhancedKeyUsage([SignLib.Certificates.CertificateEnhancedKeyUsage]
::DocumentSigning)
$certificate = $generator.GenerateCertificate($pFXFilePassword)
#digitally sign the pdf file
$sign = new-object -typeName SignLib.Pdf.PdfSignature(“serial number”)
$sign.LoadPdfDocument([System.IO.File]::ReadAllBytes($args[0]))
$sign.DigitalSignatureCertificate =
[SignLib.Certificates.DigitalCertificate]::LoadCertificate($certificate, $pFXFilePassword)
$sign.SigningReason = “I approve this document”
$sign.SigningLocation = “Europe branch”
$sign.SignaturePage = 1
$sign.SignaturePosition = [SignLib.Pdf.SignaturePosition]::TopRight
echo “Perform the digital signature…” [System.IO.File]::WriteAllBytes($args[1], $sign.ApplyDigitalSignature())
}
How to run the Windows PowerShell script from command line:
powershell -executionPolicy bypass -file d:\signpdf.ps1 d:\unsigned.pdf d:\signedFile.pdf
Digitally Sign PDF Files Using C# or VB.NET
To digitally sign PDF file using C# or VB.NET, download the library above and inspect
Signature Library\VS2008 Projects folder. The C# will look like below:
PdfSignature ps = new PdfSignature(“your serial number”);
//load the PDF document ps.LoadPdfDocument(unsignedDocument); ps.SignaturePosition = SignaturePosition.TopRight; ps.SigningReason = “I approve this document”; ps.SigningLocation = “Accounting department”;
ps.SignaturePosition = SignaturePosition.TopLeft;
//Digital signature certificate can be loaded from various sources
//Load the signature certificate from a PFX or P12 file ps.DigitalSignatureCertificate = DigitalCertificate.LoadCertificate(Environment.CurrentDirectory + “\\cert.pfx”, “123456”);
//Load the certificate from Microsoft Store.
//The smart card or USB token certificates are usually available on Microsoft Certificate Store (start – run – certmgr.msc).
//If the smart card certificate not appears on Microsoft Certificate Store it cannot be used by the library
//ps.DigitalSignatureCertificate = DigitalCertificate.LoadCertificate(false, string.Empty, “Select Certificate”, “Select the certificate for digital signature”);
//write the signed file
File.WriteAllBytes(signedDocument, ps.ApplyDigitalSignature());