VB.NET

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

See more Digital Signatures Examples

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

Dim success As Boolean = 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..
Dim bd As New Chilkat.BinData
success = bd.LoadFile("qa_data/p7s/sample.p7s")
If (success <> True) Then
    Debug.WriteLine("Failed to load .p7s file.")
    Exit Sub
End If


Dim crypt As New Chilkat.Crypt2

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


' Examine the last JSON data after signature verification..
Dim json As New Chilkat.JsonObject
crypt.GetLastJsonData(json)

json.EmitCompact = False
Debug.WriteLine(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="
'         }
'       ]
'     }
'   }
' }
' 

Dim i As Integer
Dim count_i As Integer
Dim strVal As String
Dim certSerialNumber As String
Dim certIssuerCN As String
Dim certIssuerDN As String
Dim certDigestAlgOid As String
Dim certDigestAlgName As String
Dim contentType As String
Dim signingTime As String
Dim messageDigest As String
Dim signingAlgOid As String
Dim signerDigest As String
Dim dt As New Chilkat.CkDateTime

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

' println crypt.LastErrorText;
Debug.WriteLine("Success.")