PowerShell

P7S - Access Signature Information (date/time, certificate used, etc.)

See more Digital Signatures Examples

Examine a PKCS7 signature (.p7s) and get information about it. PowerShell

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

$success = $false

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

# First load the .p7s file into a BinData object..
$bd = New-Object Chilkat.BinData
$success = $bd.LoadFile("qa_data/p7s/sample.p7s")
if ($success -ne $true) {
    $("Failed to load .p7s file.")
    exit
}

$crypt = New-Object Chilkat.Crypt2

# Assuming this is a signature that contains the original data that was signed..
$success = $crypt.OpaqueVerifyBd($bd)
if ($success -eq $false) {
    $($crypt.LastErrorText)
    exit
}

# Examine the last JSON data after signature verification..
$json = New-Object Chilkat.JsonObject
$crypt.GetLastJsonData($json)

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

# Sample output...
# Go to http://tools.chilkat.io/jsonParse.cshtml
# and paste the JSON into the online form to generate JSON parsing code.

# {
#   "pkcs7": {
#     "verify": {
#       "digestAlgorithms": [
#         "sha256"
#       ],
#       "signerInfo": [
#         {
#           "cert": {
#             "serialNumber": "AAC5FC48C0FD8FBB",
#             "issuerCN": "AC ABCDEF RFB v5",
#             "issuerDN": "",
#             "digestAlgOid": "2.16.840.1.101.3.4.2.1",
#             "digestAlgName": "SHA-256"
#           },
#           "contentType": "1.2.840.113549.1.7.1",
#           "signingTime": "180607195054Z",
#           "messageDigest": "trzyxXbZ96z2M4mncyZ7BNMV4yIT92+5sS27Fu64iG8=",
#           "signingAlgOid": "1.2.840.113549.1.1.11",
#           "signerDigest": "trzyxXbZ96z2M4mncyZ7BNMV4yIT92+5sS27Fu64iG8="
#         },
#         {
#           "cert": {
#             "serialNumber": "324FB38ABD59723F",
#             "issuerCN": "AC ABCDEF RFB v5",
#             "issuerDN": "",
#             "digestAlgOid": "2.16.840.1.101.3.4.2.1",
#             "digestAlgName": "SHA-256"
#           },
#           "contentType": "1.2.840.113549.1.7.1",
#           "signingTime": "180608182517Z",
#           "messageDigest": "trzyxXbZ96z2M4mncyZ7BNMV4yIT92+5sS27Fu64iG8=",
#           "signingAlgOid": "1.2.840.113549.1.1.11",
#           "signerDigest": "trzyxXbZ96z2M4mncyZ7BNMV4yIT92+5sS27Fu64iG8="
#         }
#       ]
#     }
#   }
# }
# 

$dt = New-Object Chilkat.CkDateTime

$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
    $certSerialNumber = $json.StringOf("pkcs7.verify.signerInfo[i].cert.serialNumber")
    $certIssuerCN = $json.StringOf("pkcs7.verify.signerInfo[i].cert.issuerCN")
    $certIssuerDN = $json.StringOf("pkcs7.verify.signerInfo[i].cert.issuerDN")
    $certDigestAlgOid = $json.StringOf("pkcs7.verify.signerInfo[i].cert.digestAlgOid")
    $certDigestAlgName = $json.StringOf("pkcs7.verify.signerInfo[i].cert.digestAlgName")
    $contentType = $json.StringOf("pkcs7.verify.signerInfo[i].contentType")
    $signingTime = $json.StringOf("pkcs7.verify.signerInfo[i].signingTime")

    # The signingTime isin UTCTime format.
    # UTCTime values take the form of either "YYMMDDhhmm[ss]Z" or "YYMMDDhhmm[ss](+|-)hhmm"
    # Starting in Chilkat v9.5.0.77, the SetFromTimestamp method auto-recognizes the UTCTime format and parses it correctly.
    $success = $dt.SetFromTimestamp($signingTime)
    # To get the signingTime in other date/time formats, look at the online reference documentation for CkDateTime.
    # There are numerous methods such as GetAsDateTime, GetAsIso8601, GetAsUnixTime, GetAsRfc822, etc.

    $messageDigest = $json.StringOf("pkcs7.verify.signerInfo[i].messageDigest")
    $signingAlgOid = $json.StringOf("pkcs7.verify.signerInfo[i].signingAlgOid")
    $signerDigest = $json.StringOf("pkcs7.verify.signerInfo[i].signerDigest")
    $i = $i + 1
}

# println crypt.LastErrorText;
$("Success.")