(MFC) Load ECC Private Key from JWK Format (JSON Web Key)

Demonstrates how to load an ECC private key from JWK (JSON Web Key) format.

Note: This example requires Chilkat v9.5.0.66 or later.

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

See Also: Using MFC CString in Chilkat

#include <CkJsonObject.h>
#include <CkPrivateKey.h>

void ChilkatSample(void)
    {
    CkString strOut;

    // Note: This example requires Chilkat v9.5.0.66 or later.
    bool success;

    // First build a JWK sample to load..
    CkJsonObject json;
    json.UpdateString("kty","EC");
    json.UpdateString("crv","P-256");
    json.UpdateString("x","oBUyo8CQAFPeYPvv78ylh5MwFZjTCLQeb042TjiMJxE");
    json.UpdateString("y","vvQyxZkUjJQUPU_0bCy3Pj5qQdfu8jwEfqEeYGZ95CU");
    json.UpdateString("d","EbVzfPnZPxfAyxqEZV05laAoJAl-_6Xt2O4mOB611sM");

    // The JSON contains the following:
    // { 
    //   "kty": "EC",
    //   "crv": "P-256",
    //   "x": "oBUyo8CQAFPeYPvv78ylh5MwFZjTCLQeb042TjiMJxE",
    //   "y": "vvQyxZkUjJQUPU_0bCy3Pj5qQdfu8jwEfqEeYGZ95CU",
    //   "d": "EbVzfPnZPxfAyxqEZV05laAoJAl-_6Xt2O4mOB611sM"
    // }

    // Note: The JSON can contain other members, such as "use", "kid", or anything else.  These will be ignored.
    json.put_EmitCompact(false);

    // Show the JWK string to be loaded:
    const char *jwkStr = json.emit();

    CkPrivateKey privKey;
    success = privKey.LoadJwk(jwkStr);
    if (success != true) {
        strOut.append(privKey.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    // OK.. the JWK is loaded.  It can be used in whatever way desired...

    // The key can be retrieved in any other format, such as XML or PEM..
    strOut.append(privKey.getXml());
    strOut.append("\r\n");

    // XML output:
    // <ECCKeyValue curve="secp256r1">MHcCAQEEIBG1c3z52T8XwMsahGVdOZWgKCQJfv+l7djuJjgetdbDoAoGCCqGSM49AwEHoEQDQgAEoBUyo8CQAFPeYPvv78ylh5MwFZjTCLQeb042TjiMJxG+9DLFmRSMlBQ9T/RsLLc+PmpB1+7yPAR+oR5gZn3kJQ==</ECCKeyValue>

    strOut.append(privKey.getPkcs8EncryptedPem("secret"));
    strOut.append("\r\n");

    // PEM output
    // 
    // -----BEGIN ENCRYPTED PRIVATE KEY-----
    // MIHFMEAGCSqGSIb3DQEFDTAzMBsGCSqGSIb3DQEFDDAOBAiku9rUjavLQQICCAAw
    // FAYIKoZIhvcNAwcECGsl/5nLai+JBIGAVIqKAdfcRQNLl1t3x+n8OZ92d1H+qgjS
    // Hs83wn2joJK4nlqy+rzosZxQ3e8NTJQyUEWZWcjqMj/N0phS3QWtcD/qbda5oEcv
    // QgtU60cZ4ql3truefAmlZz2PdpOfqtYhxlvjJQxnyojn4ntj69OwLOt9SZbaBQQi
    // KUL8KXT4Pq8=
    // -----END ENCRYPTED PRIVATE KEY-----


    SetDlgItemText(IDC_EDIT1,strOut.getUnicode());

    }