C++

Save a Private Key as a Traditional DER File

Demonstrates the Chilkat PrivateKey.SavePkcs1File method, which saves the key using the traditional/preferred unencrypted DER representation. The only argument is the destination path.

Note: 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: This writes the older, algorithm-specific DER structure — useful for compatibility with tools that predate or do not accept PKCS #8. For new work, PKCS #8 (SavePkcs8File) is more interoperable. The output is unencrypted, so protect the file accordingly.

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C++

#include <CkPrivateKey.h>

void ChilkatSample(void)
    {
    bool success = false;

    //  Load a private key to export.
    CkPrivateKey privKey;
    success = privKey.LoadPemFile("qa_data/private.pem");
    if (success == false) {
        std::cout << privKey.lastErrorText() << "\r\n";
        return;
    }

    //  Save using the traditional/preferred unencrypted DER representation.
    success = privKey.SavePkcs1File("qa_output/private_pkcs1.der");
    if (success == false) {
        std::cout << privKey.lastErrorText() << "\r\n";
        return;
    }

    std::cout << "Saved." << "\r\n";
    }