(MFC) Load EC Public Key from X,Y Values

Demonstrates how to load an EC public key from X and Y values.

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

See Also: Using MFC CString in Chilkat

#include <CkJsonObject.h>
#include <CkPublicKey.h>

void ChilkatSample(void)
    {
    CkString strOut;

    bool success;

    // We have the following x and y values in base64 (for an EC point on the P-256 curve).
    const char *x = "Dn7uB1O7kgk74G6qfQwFJESeDnxO6lLjGZFWZJE16tw";
    const char *y = "iOWA5DInzK6nuUGvHJbMVq1Dpj248FqSV2teN3HzmhU";

    // Build a JWK that looks like this:

    // {
    //   "kty": "EC",
    //   "crv": "P-256",
    //   "x": "Dn7uB1O7kgk74G6qfQwFJESeDnxO6lLjGZFWZJE16tw",
    //   "y": "iOWA5DInzK6nuUGvHJbMVq1Dpj248FqSV2teN3HzmhU"
    // }

    CkJsonObject json;
    json.UpdateString("kty","EC");
    json.UpdateString("crv","P-256");
    json.UpdateString("x",x);
    json.UpdateString("y",y);

    // Load from the JWK.
    CkPublicKey pubkey;
    success = pubkey.LoadFromString(json.emit());
    if (success == false) {
        strOut.append(pubkey.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

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


    SetDlgItemText(IDC_EDIT1,strOut.getUnicode());

    }