Delphi ActiveX

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. Delphi ActiveX

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Chilkat_TLB;

...

procedure TForm1.Button1Click(Sender: TObject);
var
success: Integer;
crypt: TChilkatCrypt2;
inFile: WideString;
outFile: WideString;
json: TChilkatJsonObject;
i: Integer;
count_i: Integer;
strVal: WideString;
certSerialNumber: WideString;
certIssuerCN: WideString;
certIssuerDN: WideString;
certDigestAlgOid: WideString;
certDigestAlgName: WideString;
contentType: WideString;
signingTime: WideString;
messageDigest: WideString;
signingAlgOid: WideString;
signerDigest: WideString;
j: Integer;
count_j: Integer;
oid: WideString;
oidName: WideString;
der: WideString;

begin
success := 0;

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

crypt := TChilkatCrypt2.Create(Self);

inFile := 'qa_data/p7m/brainpoolP256r1.p7m';
outFile := 'qa_output/something.dat';

// Verify and extract the signed data.
success := crypt.VerifyP7M(inFile,outFile);
if (success = 0) then
  begin
    Memo1.Lines.Add(crypt.LastErrorText);
    Exit;
  end;

// Examine details about the signature(s)
json := TChilkatJsonObject.Create(Self);
crypt.GetLastJsonData(json.ControlInterface);
json.EmitCompact := 0;
Memo1.Lines.Add(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...

i := 0;
count_i := json.SizeOfArray('pkcs7.verify.digestAlgorithms');
while i < count_i do
  begin
    json.I := i;
    strVal := json.StringOf('pkcs7.verify.digestAlgorithms[i]');
    i := i + 1;
  end;

i := 0;
count_i := json.SizeOfArray('pkcs7.verify.signerInfo');
while i < count_i do
  begin
    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 do
      begin
        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;
      end;

    i := i + 1;
  end;

Memo1.Lines.Add('Success!');
end;