(Delphi DLL) Verify a .p7m and get Algorithm Information

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

Chilkat for Delphi Downloads Chilkat non-ActiveX DLL for Delphi Chilkat ActiveX DLL for Delphi * The examples here use the non-ActiveX DLL.

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Crypt2, JsonObject;

...

procedure TForm1.Button1Click(Sender: TObject);
var
crypt: HCkCrypt2;
inFile: PWideChar;
outFile: PWideChar;
success: Boolean;
json: HCkJsonObject;
i: Integer;
count_i: Integer;
strVal: PWideChar;
certSerialNumber: PWideChar;
certIssuerCN: PWideChar;
certIssuerDN: PWideChar;
certDigestAlgOid: PWideChar;
certDigestAlgName: PWideChar;
contentType: PWideChar;
signingTime: PWideChar;
messageDigest: PWideChar;
signingAlgOid: PWideChar;
signerDigest: PWideChar;
j: Integer;
count_j: Integer;
oid: PWideChar;
oidName: PWideChar;
der: PWideChar;

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

crypt := CkCrypt2_Create();

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

// Verify and extract the signed data.
success := CkCrypt2_VerifyP7M(crypt,inFile,outFile);
if (success = False) then
  begin
    Memo1.Lines.Add(CkCrypt2__lastErrorText(crypt));
    Exit;
  end;

// Examine details about the signature(s)
json := CkCrypt2_LastJsonData(crypt);
CkJsonObject_putEmitCompact(json,False);
Memo1.Lines.Add(CkJsonObject__emit(json));

// 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 := CkJsonObject_SizeOfArray(json,'pkcs7.verify.digestAlgorithms');
while i < count_i do
  begin
    CkJsonObject_putI(json,i);
    strVal := CkJsonObject__stringOf(json,'pkcs7.verify.digestAlgorithms[i]');
    i := i + 1;
  end;

i := 0;
count_i := CkJsonObject_SizeOfArray(json,'pkcs7.verify.signerInfo');
while i < count_i do
  begin
    CkJsonObject_putI(json,i);
    certSerialNumber := CkJsonObject__stringOf(json,'pkcs7.verify.signerInfo[i].cert.serialNumber');
    certIssuerCN := CkJsonObject__stringOf(json,'pkcs7.verify.signerInfo[i].cert.issuerCN');
    certIssuerDN := CkJsonObject__stringOf(json,'pkcs7.verify.signerInfo[i].cert.issuerDN');
    certDigestAlgOid := CkJsonObject__stringOf(json,'pkcs7.verify.signerInfo[i].cert.digestAlgOid');
    certDigestAlgName := CkJsonObject__stringOf(json,'pkcs7.verify.signerInfo[i].cert.digestAlgName');
    contentType := CkJsonObject__stringOf(json,'pkcs7.verify.signerInfo[i].contentType');
    signingTime := CkJsonObject__stringOf(json,'pkcs7.verify.signerInfo[i].signingTime');
    messageDigest := CkJsonObject__stringOf(json,'pkcs7.verify.signerInfo[i].messageDigest');
    signingAlgOid := CkJsonObject__stringOf(json,'pkcs7.verify.signerInfo[i].signingAlgOid');
    signerDigest := CkJsonObject__stringOf(json,'pkcs7.verify.signerInfo[i].signerDigest');
    j := 0;
    count_j := CkJsonObject_SizeOfArray(json,'pkcs7.verify.signerInfo[i].authAttr');
    while j < count_j do
      begin
        CkJsonObject_putJ(json,j);
        oid := CkJsonObject__stringOf(json,'pkcs7.verify.signerInfo[i].authAttr[j].oid');
        oidName := CkJsonObject__stringOf(json,'pkcs7.verify.signerInfo[i].authAttr[j].oidName');
        der := CkJsonObject__stringOf(json,'pkcs7.verify.signerInfo[i].authAttr[j].der');
        j := j + 1;
      end;

    i := i + 1;
  end;

CkJsonObject_Dispose(json);

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

CkCrypt2_Dispose(crypt);

end;