(Delphi ActiveX) Verify and Unwrap S/MIME, and get Information about CMS Signature

Demonstrates calling the Verify method to verify and unwrap S/MIME. The MIME is restored to the original structure that it would have originally had prior to signing. The Verify method works with both detached signatures, as well as opaque/attached signatures.

Calls LastJsonData to get information about the signature(s) that were verified.

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

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
mime: TChilkatMime;
success: Integer;
verified: Integer;
json: IChilkatJsonObject;
signingTime: TDtObj;
authAttrSigningTimeUtctime: TDtObj;
issuerCN: WideString;
serial: WideString;
strVal: WideString;
certSerialNumber: WideString;
certIssuerCN: WideString;
certDigestAlgOid: WideString;
certDigestAlgName: WideString;
contentType: WideString;
messageDigest: WideString;
signingAlgOid: WideString;
signingAlgName: WideString;
authAttrContentTypeName: WideString;
authAttrContentTypeOid: WideString;
authAttrSigningTimeName: WideString;
authAttrMessageDigestName: WideString;
authAttrMessageDigestDigest: WideString;
authAttr1_2_840_113549_1_9_15Der: WideString;
authAttr1_3_6_1_4_1_311_16_4Der: WideString;
i: Integer;
count_i: Integer;

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

mime := TChilkatMime.Create(Self);

// Load the signed MIME from a file...
success := mime.LoadMimeFile('qa_data/mime/detached_sig.eml');
if (success = 0) then
  begin
    Memo1.Lines.Add(mime.LastErrorText);
    Exit;
  end;

// Verify the S/MIME and restore the MIME
// to the structure/content it had prior to signing.
verified := mime.Verify();
if (verified = 0) then
  begin
    Memo1.Lines.Add(mime.LastErrorText);
    Exit;
  end;

// Examine the details of what was verified.
json := mime.LastJsonData();
json.EmitCompact := 0;
Memo1.Lines.Add(json.Emit());

// The code to parse the following JSON (i.e. extract desired information) is shown below..

// {
//   "pkcs7": {
//     "verify": {
//       "certs": [
//         {
//           "issuerCN": "VeriSign Class 1 Public Primary Certification Authority - G3",
//           "serial": "0702A21A85B84B659E180A6EE6F5A365"
//         },
//         {
//           "issuerCN": "VeriSign Class 1 Public Primary Certification Authority - G3",
//           "serial": "008B5B75568454850B00CFAF3848CEB1A4"
//         },
//         {
//           "issuerCN": "Symantec Class 1 Individual Subscriber CA - G5",
//           "serial": "619C55C32FF6BD1A7B7E0330D21C8F3C"
//         }
//       ],
//       "digestAlgorithms": [
//         "sha1"
//       ],
//       "signerInfo": [
//         {
//           "cert": {
//             "serialNumber": "619C55C32FF6BD1A7B7E0330D21C8F3C",
//             "issuerCN": "Symantec Class 1 Individual Subscriber CA - G5",
//             "digestAlgOid": "1.3.14.3.2.26",
//             "digestAlgName": "SHA1"
//           },
//           "contentType": "1.2.840.113549.1.7.1",
//           "signingTime": "160428055000Z",
//           "messageDigest": "2hJJVmO/jtaJV5uCKMFzIkRRvtY=",
//           "signingAlgOid": "1.2.840.113549.1.1.1",
//           "signingAlgName": "RSA-PKCSV-1_5",
//           "authAttr": {
//             "1.2.840.113549.1.9.3": {
//               "name": "contentType",
//               "oid": "1.2.840.113549.1.7.1"
//             },
//             "1.2.840.113549.1.9.5": {
//               "name": "signingTime",
//               "utctime": "160428055000Z"
//             },
//             "1.2.840.113549.1.9.4": {
//               "name": "messageDigest",
//               "digest": "2hJJVmO/jtaJV5uCKMFzIkRRvtY="
//             },
//             "1.2.840.113549.1.9.15": {
//               "der": "MFAwCwYJYIZIAWUDBAECMAoGCCqGSIb3DQMHMA4GCCqGSIb3DQMCAgIAgDANBggqhkiG9w0DAgIBQDAHBgUrDgMCBzANBggqhkiG9w0DAgIBKA=="
//             },
//             "1.3.6.1.4.1.311.16.4": {
//               "der": "MIG7MIG...7fgMw0hyPPA=="
//             }
//           }
//         }
//       ]
//     }
//   }
// }

// Use this online tool to generate parsing code from sample JSON: 
// Generate Parsing Code from JSON

signingTime := TDtObj.Create(Self);
authAttrSigningTimeUtctime := TDtObj.Create(Self);

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

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');
    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');
    json.DtOf('pkcs7.verify.signerInfo[i].signingTime',0,signingTime.ControlInterface);
    messageDigest := json.StringOf('pkcs7.verify.signerInfo[i].messageDigest');
    signingAlgOid := json.StringOf('pkcs7.verify.signerInfo[i].signingAlgOid');
    signingAlgName := json.StringOf('pkcs7.verify.signerInfo[i].signingAlgName');
    authAttrContentTypeName := json.StringOf('pkcs7.verify.signerInfo[i].authAttr."1.2.840.113549.1.9.3".name');
    authAttrContentTypeOid := json.StringOf('pkcs7.verify.signerInfo[i].authAttr."1.2.840.113549.1.9.3".oid');
    authAttrSigningTimeName := json.StringOf('pkcs7.verify.signerInfo[i].authAttr."1.2.840.113549.1.9.5".name');
    json.DtOf('pkcs7.verify.signerInfo[i].authAttr."1.2.840.113549.1.9.5".utctime',0,authAttrSigningTimeUtctime.ControlInterface);
    authAttrMessageDigestName := json.StringOf('pkcs7.verify.signerInfo[i].authAttr."1.2.840.113549.1.9.4".name');
    authAttrMessageDigestDigest := json.StringOf('pkcs7.verify.signerInfo[i].authAttr."1.2.840.113549.1.9.4".digest');
    authAttr1_2_840_113549_1_9_15Der := json.StringOf('pkcs7.verify.signerInfo[i].authAttr."1.2.840.113549.1.9.15".der');
    authAttr1_3_6_1_4_1_311_16_4Der := json.StringOf('pkcs7.verify.signerInfo[i].authAttr."1.3.6.1.4.1.311.16.4".der');
    i := i + 1;
  end;
end;