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

Examine a PKCS7 signature (.p7s) and get information about it. Note: This example requires Chilkat v9.5.0.75 or greater.

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' 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..
Dim bd As Chilkat.BinData
Set bd = Chilkat.NewBinData

success = bd.LoadFile("qa_data/p7s/sample.p7s")
If (success <> True) Then
    Debug.Print "Failed to load .p7s file."
    Exit Sub
End If

' IMPORTANT:  This example requires Chilkat v9.5.0.75 or greater.
Dim crypt As Chilkat.Crypt2
Set crypt = Chilkat.NewCrypt2

' Assuming this is a signature that contains the original data that was signed..
success = crypt.OpaqueVerifyBd(bd)
If (success <> True) Then
    Debug.Print crypt.LastErrorText
    Exit Sub
End If

' Examine the LastJsonData after signature verification..

Set json = crypt.LastJsonData()
json.EmitCompact = False
Debug.Print json.Emit()

' --
' IMPORTANT:  This example requires Chilkat v9.5.0.75 or greater.
' --

' 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="
'         }
'       ]
'     }
'   }
' }
' 

Dim dt As Chilkat.CkDateTime
Set dt = Chilkat.NewCkDateTime

i = 0
count_i = json.SizeOfArray("pkcs7.verify.digestAlgorithms")
Do While i < count_i
    json.I = i
    strVal = json.StringOf("pkcs7.verify.digestAlgorithms[i]")
    i = i + 1
Loop
i = 0
count_i = json.SizeOfArray("pkcs7.verify.signerInfo")
Do While i < 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
Loop

' println crypt.LastErrorText;
Debug.Print "Success."