(MFC) Create PKCS7 Signed File (.p7m)

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

Chilkat C/C++ Library Downloads MS Visual C/C++ Libs

See Also: Using MFC CString in Chilkat

#include <CkCrypt2.h>
#include <CkCertStore.h>
#include <CkCert.h>

void ChilkatSample(void)
    {
    CkString strOut;

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

    CkCrypt2 crypt;

    CkCertStore certStore;

    // Load a PFX file into a certificate store object.
    bool success = certStore.LoadPfxFile("myPfx.pfx","pfxPassword");
    if (success != true) {
        strOut.append(certStore.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    // 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).
    CkCert *cert = certStore.FindCertBySubjectCN("myCert");
    if (certStore.get_LastMethodSuccess() == false) {
        strOut.append(certStore.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    // Tell the crypt object to use the certificate for signing:
    success = crypt.SetSigningCert(*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.
    const char *inFile = "test.txt";
    const char *outFile = "testp7m";
    success = crypt.CreateP7M(inFile,outFile);
    if (success != true) {
        strOut.append(crypt.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    strOut.append("Success!");
    strOut.append("\r\n");


    SetDlgItemText(IDC_EDIT1,strOut.getUnicode());

    }