(Delphi ActiveX) Extract PKCS7 from MIME and Decrypt

Extracts the base64-encoded PKCS7 body of a MIME message to a file, and then decrypts using Chilkat Crypt2.

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;
crypt: TChilkatCrypt2;
inPath: WideString;
outPath: WideString;

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

mime := TChilkatMime.Create(Self);

success := mime.LoadMimeFile('c:/aaworkarea/EmailInBytes.txt');
if (success <> 1) then
  begin
    Memo1.Lines.Add(mime.LastErrorText);
    Exit;
  end;

success := mime.SaveBody('c:/aaworkarea/smime.p7m');
if (success <> 1) then
  begin
    Memo1.Lines.Add(mime.LastErrorText);
    Exit;
  end;

crypt := TChilkatCrypt2.Create(Self);

success := crypt.AddPfxSourceFile('c:/aaworkarea/my.pfx','pfxPassword');
if (success = 0) then
  begin
    Memo1.Lines.Add(crypt.LastErrorText);
    Exit;
  end;

// Indicate the public-key (PKCS7) encryption/decryption should be used:
crypt.CryptAlgorithm := 'pki';

inPath := 'c:/aaworkarea/smime.p7m';
outPath := 'c:/aaworkarea/decrypted.dat';

success := crypt.CkDecryptFile(inPath,outPath);
if (success = 0) then
  begin
    Memo1.Lines.Add(crypt.LastErrorText);
    Exit;
  end;

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