Sign a File to Create a .p7m File (using a PFX)

Delphi example to sign a file creating a .p7m file as output. 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,
    CHILKATCERTIFICATELib_TLB,
    OleCtrls;

...

procedure TForm1.Button1Click(Sender: TObject);
var
crypt: TChilkatCrypt2;
success: Integer;
signingCertSubject: String;
pfxFilename: String;
pfxPassword: String;
certStore: CHILKATCERTIFICATELib_TLB.IChilkatCertStore;
cert: CHILKATCRYPT2Lib_TLB.IChilkatCert;
inFile: String;
outFile: 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;

//  Use a digital certificate and private key from a PFX file (.pfx or .p12).
signingCertSubject := 'Acme Inc';
pfxFilename := '/Users/chilkat/testData/pfx/acme.pfx';
pfxPassword := 'test123';

certStore := CoChilkatCertStore.Create();
success := certStore.LoadPfxFile(pfxFilename,pfxPassword);
if (success <> 1) then
  begin
    Memo1.Lines.Add(certStore.LastErrorText);
    Exit;
  end;

cert := certStore.FindCertBySubjectCN(signingCertSubject) As CHILKATCRYPT2Lib_TLB.IChilkatCert;
if (cert = nil ) then
  begin
    Memo1.Lines.Add('Failed to find certificate by subject common name.');
    Exit;
  end;

//  Tell the crypt component to use this cert.
crypt.SetSigningCert(cert As CHILKATCRYPT2Lib_TLB.IChilkatCert);

//  We can sign any type of file, creating a .p7m as output:
inFile := '/Users/chilkat/testData/pdf/sample.pdf';
outFile := '/Users/chilkat/testData/p7m/sample.pdf.p7m';
success := crypt.CreateP7M(inFile,outFile);
if (success = 0) then
  begin
    Memo1.Lines.Add(crypt.LastErrorText);

    Exit;
  end;

//  Verify and restore the original file:
crypt.SetVerifyCert(cert As CHILKATCRYPT2Lib_TLB.IChilkatCert);

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

success := crypt.VerifyP7M(inFile,outFile);
if (success = 0) then
  begin
    Memo1.Lines.Add(crypt.LastErrorText);

    Exit;
  end;

ShowMessage('Success!');
end;