(MFC) Get PDF Signer Certs

See more PDF Signatures Examples

This example demonstrates how to validate the signatures in a PDF and also shows how to get each signature's signer certificate.

Note: This example requires Chilkat v9.5.0.87 or greater.

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

See Also: Using MFC CString in Chilkat

#include <CkPdf.h>
#include <CkJsonObject.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.

    CkPdf pdf;

    // Load a PDF that has cryptographic signatures to be validated
    bool success = pdf.LoadFile("qa_data/pdf/sign_testing_1/helloSigned2.pdf");
    if (success == false) {
        strOut.append(pdf.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    // Each time we verify a signature, information about the signature is written into
    // sigInfo (replacing whatever sigInfo previously contained).
    CkJsonObject sigInfo;

    // Iterate over each signature and validate each.
    int numSignatures = pdf.get_NumSignatures();
    bool validated = false;
    CkCert cert;
    int i = 0;
    while (i < numSignatures) {
        validated = pdf.VerifySignature(i,sigInfo);
        strOut.append("Signature ");
        strOut.appendInt(i);
        strOut.append(" validated: ");
        strOut.appendInt(validated);
        strOut.append("\r\n");

        // The GetSignerCert method was added in Chilkat v9.5.0.87
        // After calling VerifySignature, you can get the signer certificate by calling
        // GetSignerCert with the same index. 
        success = pdf.GetSignerCert(i,cert);
        if (success != false) {
            strOut.append("PDF signer certificate: ");
            strOut.append(cert.subjectDN());
            strOut.append("\r\n");
        }

        i = i + 1;
    }

    strOut.append("Finished.");
    strOut.append("\r\n");


    SetDlgItemText(IDC_EDIT1,strOut.getUnicode());

    }