Sample code for 30+ languages & platforms
Delphi DLL

Create PKCS7 Signed File (.p7m)

See more Encryption Examples

Demonstrates how to sign a file to create a .p7m that contains both the file contents and the signature.

Chilkat Delphi DLL Downloads

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

...

procedure TForm1.Button1Click(Sender: TObject);
var
success: Boolean;
crypt: HCkCrypt2;
certStore: HCkCertStore;
jsonCN: HCkJsonObject;
cert: HCkCert;
inFile: PWideChar;
outFile: PWideChar;

begin
success := False;

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

crypt := CkCrypt2_Create();

certStore := CkCertStore_Create();

// Load a PFX file into a certificate store object.
success := CkCertStore_LoadPfxFile(certStore,'myPfx.pfx','pfxPassword');
if (success <> True) then
  begin
    Memo1.Lines.Add(CkCertStore__lastErrorText(certStore));
    Exit;
  end;

// Get the certificate by subject common name.
// This should be the cert within the PFX that also
// has a private key (also stored within the PFX).
jsonCN := CkJsonObject_Create();
CkJsonObject_UpdateString(jsonCN,'CN','myCert');
cert := CkCert_Create();
success := CkCertStore_FindCert(certStore,jsonCN,cert);
if (success = False) then
  begin
    Memo1.Lines.Add(CkCertStore__lastErrorText(certStore));
    Exit;
  end;

// Tell the crypt object to use the certificate for signing:
success := CkCrypt2_SetSigningCert(crypt,cert);

// Sign a file, producing a .p7m as output.
// The input file is unchanged, the test.p7m contains the 
// contents of the input file and the signature.
inFile := 'test.txt';
outFile := 'testp7m';
success := CkCrypt2_CreateP7M(crypt,inFile,outFile);
if (success <> True) then
  begin
    Memo1.Lines.Add(CkCrypt2__lastErrorText(crypt));
    Exit;
  end;

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

CkCrypt2_Dispose(crypt);
CkCertStore_Dispose(certStore);
CkJsonObject_Dispose(jsonCN);
CkCert_Dispose(cert);

end;