(PowerShell) Verify a CAdES-BES Signature and Examine Signature Contents

Demonstrates how to validate a .p7m (.p7s) signature and examine the contents of the signature.

Chilkat .NET Downloads Chilkat .NET Assemblies

Add-Type -Path "C:\chilkat\ChilkatDotNet47-9.5.0-x64\ChilkatDotNet47.dll"

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

$crypt = New-Object Chilkat.Crypt2

$outputFile = "qa_output/original.xml"
$inFile = "qa_data/p7m/fattura_signature.xml.p7m"

# Verify the signature and extract the contained file, which in this case is XML.
$success = $crypt.VerifyP7M($inFile,$outputFile)
if ($success -eq $false) {
    $($crypt.LastErrorText)
    exit
}

$("Signature validated.")

# Now let's examine the information about the signature.
$json = $crypt.LastJsonData()
if ($crypt.LastMethodSuccess -eq $false) {
    # This should never be the case...
    $("No information available.")
    exit
}

$json.EmitCompact = $false
$($json.Emit())

# Here's an example of the information about the signature:
# {
#   "pkcs7": {
#     "verify": {
#       "certs": [
#         {
#           "issuerCN": "Xyz EU Qualified Certificates CA G1",
#           "serial": "99A28A51AC389999"
#         }
#       ],
#       "useConstructedOctets": true,
#       "digestAlgorithms": [
#         "sha256"
#       ],
#       "signerInfo": [
#         {
#           "cert": {
#             "subjectKeyIdentifier": "5VM4x8AWnXf07yzbXuLtbb0U3yY=",
#             "digestAlgOid": "2.16.840.1.101.3.4.2.1",
#             "digestAlgName": "SHA256"
#           },
#           "signingAlgOid": "1.2.840.113549.1.1.11",
#           "signingAlgName": "RSA-SHA256-PKCSV-1_5",
#           "authAttr": {
#             "1.2.840.113549.1.9.3": {
#               "name": "contentType",
#               "oid": "1.2.840.113549.1.7.1"
#             },
#             "1.2.840.113549.1.9.5": {
#               "name": "signingTime",
#               "utctime": "190901152340Z"
#             },
#             "1.2.840.113549.1.9.4": {
#               "name": "messageDigest",
#               "digest": "y+gd/zAQK33A//HInhaZba7w1fUJleV9AHbP1Ntx6U0="
#             },
#             "1.2.840.113549.1.9.16.2.47": {
#               "name": "signingCertificateV2",
#               "der": "MIH4MI..w4vv0="
#             }
#           }
#         }
#       ]
#     }
#   }
# }

# Use this online tool to generate parsing code from sample JSON: 
# Generate Parsing Code from JSON

$authAttrSigningTimeUtctime = New-Object Chilkat.DtObj

$i = 0
$count_i = $json.SizeOfArray("pkcs7.verify.certs")
while ($i -lt $count_i) {
    $json.I = $i
    $issuerCN = $json.StringOf("pkcs7.verify.certs[i].issuerCN")
    $serial = $json.StringOf("pkcs7.verify.certs[i].serial")
    $i = $i + 1
}

$i = 0
$count_i = $json.SizeOfArray("pkcs7.verify.digestAlgorithms")
while ($i -lt $count_i) {
    $json.I = $i
    $strVal = $json.StringOf("pkcs7.verify.digestAlgorithms[i]")
    $i = $i + 1
}

$i = 0
$count_i = $json.SizeOfArray("pkcs7.verify.signerInfo")
while ($i -lt $count_i) {
    $json.I = $i
    $certSubjectKeyIdentifier = $json.StringOf("pkcs7.verify.signerInfo[i].cert.subjectKeyIdentifier")
    $certDigestAlgOid = $json.StringOf("pkcs7.verify.signerInfo[i].cert.digestAlgOid")
    $certDigestAlgName = $json.StringOf("pkcs7.verify.signerInfo[i].cert.digestAlgName")
    $signingAlgOid = $json.StringOf("pkcs7.verify.signerInfo[i].signingAlgOid")
    $signingAlgName = $json.StringOf("pkcs7.verify.signerInfo[i].signingAlgName")
    $authAttrContentTypeName = $json.StringOf("pkcs7.verify.signerInfo[i].authAttr.`"1.2.840.113549.1.9.3`".name")
    $authAttrContentTypeOid = $json.StringOf("pkcs7.verify.signerInfo[i].authAttr.`"1.2.840.113549.1.9.3`".oid")
    $authAttrSigningTimeName = $json.StringOf("pkcs7.verify.signerInfo[i].authAttr.`"1.2.840.113549.1.9.5`".name")
    $json.DtOf("pkcs7.verify.signerInfo[i].authAttr.`"1.2.840.113549.1.9.5`".utctime",$false,$authAttrSigningTimeUtctime)
    $authAttrMessageDigestName = $json.StringOf("pkcs7.verify.signerInfo[i].authAttr.`"1.2.840.113549.1.9.4`".name")
    $authAttrMessageDigestDigest = $json.StringOf("pkcs7.verify.signerInfo[i].authAttr.`"1.2.840.113549.1.9.4`".digest")
    $authAttrSigningCertificateV2Name = $json.StringOf("pkcs7.verify.signerInfo[i].authAttr.`"1.2.840.113549.1.9.16.2.47`".name")
    $authAttrSigningCertificateV2Der = $json.StringOf("pkcs7.verify.signerInfo[i].authAttr.`"1.2.840.113549.1.9.16.2.47`".der")
    $i = $i + 1
}