(Delphi) Extract a File from a .p7m (PKCS7 Signed-Data)

Delphi example to extract the original file from a .p7m (Signed-Data PKCS7 Format) The .p7m contains the signed contents of the original file. It can be verified and restored by calling VerifyP7M.

Download Chilkat Crypt ActiveX

uses
    Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
    Dialogs, StdCtrls,
    CHILKATCRYPT2Lib_TLB,
    OleCtrls;

...

procedure TForm1.Button1Click(Sender: TObject);
var
crypt: TChilkatCrypt2;
success: Integer;
outFile: String;
inFile: String;

begin
crypt := TChilkatCrypt2.Create(Self);

//  Any string argument automatically begins the 30-day trial.
success := crypt.UnlockComponent('30-day trial');
if (success <> 1) then
  begin
    Memo1.Lines.Add(crypt.LastErrorText);
    Exit;
  end;

outFile := '/Users/chilkat/testData/pdf/sample.pdf';
inFile := '/Users/chilkat/testData/p7m/sample.pdf.p7m';

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

ShowMessage('Success!');
end;