PowerShell

Create CMS Signed File (PDF) with Multiple Signing Certificates

See more Digital Signatures Examples

Demonstrates how to sign a file by adding multiple signatures (multiple certificates). This example signs a PDF file to produce an output file that is a CMS signature wrapping the original PDF. (Note: This is different than modifying a PDF by injecting a signature into the PDF file format.)

Note: This example requires Chilkat v9.5.0.83 or greater.

PowerShell

Add-Type -Path "C:\chilkat\ChilkatDotNet47-x64\ChilkatDotNet47.dll"

$success = $false

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

$crypt = New-Object Chilkat.Crypt2

# ------------ This example requires Chilkat v9.5.0.83 or greater.

$cert1 = New-Object Chilkat.Cert
$success = $cert1.LoadPfxFile("qa_data/pfx/cert_test123.pfx","test123")
if ($success -ne $true) {
    $($cert1.LastErrorText)
    exit
}

$cert2 = New-Object Chilkat.Cert
$success = $cert2.LoadPfxFile("qa_data/pfx/test_secret.pfx","secret")
if ($success -ne $true) {
    $($cert2.LastErrorText)
    exit
}

# ------------ This example requires Chilkat v9.5.0.83 or greater.

# Tell the crypt component to use both certificates for signing. 
# When we create the signature, it will be signed by both certificates.
$success = $crypt.AddSigningCert($cert1)
if ($success -ne $true) {
    $($crypt.LastErrorText)
    exit
}

$success = $crypt.AddSigningCert($cert2)
if ($success -ne $true) {
    $($crypt.LastErrorText)
    exit
}

# The CadesEnabled property applies to all methods that create PKCS7 signatures. 
# To create a CAdES-BES signature, set this property equal to true. 
$crypt.CadesEnabled = $true

$crypt.HashAlgorithm = "sha256"

# We can sign any type of file, creating a .p7s as output.
# The .p7s contains the signature and also embeds the data of the file that is signed.
$inFile = "qa_data/pdf/sample.pdf"
$p7sFile = "qa_output/sample.pdf.p7s"

# Create the CAdES-BES attached signature, which contains the original data.
# Note: Chilkat's function naming is not accurate.  CreateP7M creates a PKCS7 signature where the signed file
# is contained within the signature.  CreateP7S creates a detached PKCS7 signature where the signed file
# is NOT contained within the signature.  We want the data to be contained in the signature, therefore
# we call CreateP7M even though we are naming our output file .p7s.
$success = $crypt.CreateP7M($inFile,$p7sFile)
if ($success -eq $false) {
    $($crypt.LastErrorText)
    exit
}

# Verify the .p7s file and extract the original file from the .p7s. 
$extractedToFilePath = "qa_output/sample.pdf"
$success = $crypt.VerifyP7M($p7sFile,$extractedToFilePath)
if ($success -eq $false) {
    $($crypt.LastErrorText)
    exit
}

$("Success!")