Xojo Plugin

Verify a .p7m and get Algorithm Information

See more Digital Signatures Examples

Demonstrates how to verify a .p7m and then examine the algorithms used by the signature. Xojo Plugin

Dim success As Boolean
success = False

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

Dim crypt As New Chilkat.Crypt2

Dim inFile As String
inFile = "qa_data/p7m/brainpoolP256r1.p7m"
Dim outFile As String
outFile = "qa_output/something.dat"

// Verify and extract the signed data.
success = crypt.VerifyP7M(inFile,outFile)
If (success = False) Then
    System.DebugLog(crypt.LastErrorText)
    Return
End If

// Examine details about the signature(s)
Dim json As New Chilkat.JsonObject
crypt.GetLastJsonData json
json.EmitCompact = False
System.DebugLog(json.Emit())

// Sample output

// {
//   "pkcs7": {
//     "verify": {
//       "digestAlgorithms": [
//         "sha256"
//       ],
//       "signerInfo": [
//         {
//           "cert": {
//             "serialNumber": "FFFFE552B302FFFFFF1E34C3ACEB2FFFF",
//             "issuerCN": "The common name of the cert...",
//             "issuerDN": "",
//             "digestAlgOid": "2.16.840.1.101.3.4.2.1",
//             "digestAlgName": "SHA256"
//           },
//           "contentType": "1.2.840.113549.1.7.1",
//           "signingTime": "190409140500Z",
//           "messageDigest": "lQe9If7vZKFf/NlSYu5Esmlw3phVK/RFsbbb1uH73t8=",
//           "signingAlgOid": "1.2.840.10045.4.3.2",
//           "signerDigest": "lQe9If7vZKFf/NlSYu5Esmlw3phVK/RFsbbb1uH73t8=",
//           "authAttr": [
//             {
//               "oid": "1.2.840.113549.1.9.3",
//               "oidName": "contentType"
//             },
//             {
//               "oid": "1.2.840.113549.1.9.5",
//               "oidName": "signingTime"
//             },
//             {
//               "oid": "1.2.840.113549.1.9.52",
//               "oidName": "1.2.840.113549.1.9.52",
//               "der": "MBs ... AwI="
//             },
//             {
//               "oid": "1.2.840.113549.1.9.4",
//               "oidName": "messageDigest"
//             },
//             {
//               "oid": "1.2.840.113549.1.9.16.2.47",
//               "oidName": "signingCertificateV2",
//               "der": "MCYw .. 7PlQ=="
//             },
//             {
//               "oid": "1.2.840.113549.1.9.20",
//               "oidName": "1.2.840.113549.1.9.20"
//             }
//           ]
//         }
//       ]
//     }
//   }
// }

// Code for parsing the above JSON...
Dim i As Int32
Dim count_i As Int32
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 j As Int32
Dim count_j As Int32
Dim oid As String
Dim oidName As String
Dim der As String

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
Wend
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")
    messageDigest = json.StringOf("pkcs7.verify.signerInfo[i].messageDigest")
    signingAlgOid = json.StringOf("pkcs7.verify.signerInfo[i].signingAlgOid")
    signerDigest = json.StringOf("pkcs7.verify.signerInfo[i].signerDigest")
    j = 0
    count_j = json.SizeOfArray("pkcs7.verify.signerInfo[i].authAttr")
    While j < count_j
        json.J = j
        oid = json.StringOf("pkcs7.verify.signerInfo[i].authAttr[j].oid")
        oidName = json.StringOf("pkcs7.verify.signerInfo[i].authAttr[j].oidName")
        der = json.StringOf("pkcs7.verify.signerInfo[i].authAttr[j].der")
        j = j + 1
    Wend
    i = i + 1
Wend

System.DebugLog("Success!")