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C++

Decrypt S/MIME using a Certificate with Private Key Access

See more MIME Examples

Loads a CMS/PKCS #7 encrypted S/MIME message and decrypts it back to the original MIME content.

DecryptUsingCert takes a single certificate that already has access to its associated private key, for example a certificate loaded from a PFX.

The file paths are relative to the application's current working directory. Absolute paths may also be used. Supply the paths appropriate to your own environment.

Background. A public-only certificate is insufficient for decryption. The certificate passed to DecryptUsingCert must be linked to its private key, as happens when it is loaded from a PFX/P12 file.

Chilkat C++ Downloads

C++
#include <CkMime.h>
#include <CkCert.h>

void ChilkatSample(void)
    {
    bool success = false;

    CkMime mime;
    success = mime.LoadMimeFile("qa_data/encrypted.eml");
    if (success == false) {
        std::cout << mime.lastErrorText() << "\r\n";
        return;
    }

    //  Decrypt using a certificate that already provides access to its private key (for example loaded
    //  from a PFX).  The only argument is the certificate.
    const char *pfxPassword = "myPfxPassword";
    CkCert cert;
    success = cert.LoadPfxFile("qa_data/recipient.pfx",pfxPassword);
    if (success == false) {
        std::cout << cert.lastErrorText() << "\r\n";
        return;
    }

    success = mime.DecryptUsingCert(cert);
    if (success == false) {
        std::cout << mime.lastErrorText() << "\r\n";
        return;
    }

    const char *body = mime.getBodyDecoded();
    if (mime.get_LastMethodSuccess() == false) {
        std::cout << mime.lastErrorText() << "\r\n";
        return;
    }

    std::cout << body << "\r\n";
    }