(MFC) Download Google OAuth2 Certs (JWK) and Load into Chilkat PublicKey Objects

Demonstrates how to download the JWK from https://www.googleapis.com/oauth2/v3/certs and load the public keys into Chilkat public key objects.

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

See Also: Using MFC CString in Chilkat

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

void ChilkatSample(void)
    {
    CkString strOut;

    // This example requires the Chilkat API to have been previously unlocked.
    // See Global Unlock Sample for sample code.

    CkHttp http;

    const char *jwkStr = http.quickGetStr("https://www.googleapis.com/oauth2/v3/certs");
    if (http.get_LastMethodSuccess() == false) {
        strOut.append(http.lastErrorText());
        strOut.append("\r\n");
        SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
        return;
    }

    // We have the following:

    //     {
    //       "keys": [
    // 	{
    // 	  "kid": "e8732db06287515556213b80acbcfd08cfb302a9",
    // 	  "n": "4RIrO30287Wsq3gqXCMkUYMVAeI3H8...w2mbMNEBQ",
    // 	  "kty": "RSA",
    // 	  "e": "AQAB",
    // 	  "alg": "RS256",
    // 	  "use": "sig"
    // 	},
    // 	{
    // 	  "kid": "8462a71da4f6d611fc0fecf0fc4ba9c37d65e6cd",
    // 	  "e": "AQAB",
    // 	  "n": "xT_ngLZNmT5GBtJZeTB...Ft4gK0eoFi0d3l8bcw",
    // 	  "alg": "RS256",
    // 	  "use": "sig",
    // 	  "kty": "RSA"
    // 	}
    //       ]
    //     }

    CkJsonObject json;
    bool success = json.Load(jwkStr);

    int numKeys = json.SizeOfArray("keys");
    int i = 0;
    while (i < numKeys) {
        json.put_I(i);
        CkJsonObject *jsonKey = json.ObjectOf("keys[i]");
        CkPublicKey pubKey;
        success = pubKey.LoadFromString(jsonKey->emit());
        if (success == false) {
            strOut.append(pubKey.lastErrorText());
            strOut.append("\r\n");
            SetDlgItemText(IDC_EDIT1,strOut.getUnicode());
            return;
        }

        strOut.appendInt(i);
        strOut.append("\r\n");
        strOut.append(pubKey.getPem(true));
        strOut.append("\r\n");
        delete jsonKey;
        i = i + 1;
    }

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

    // Sample output:

    // 0
    // -----BEGIN RSA PUBLIC KEY-----
    // MIIBCgKCAQEA4RIrO30287Wsq3gqXCMkUYMVAeI3H8LVE6IXR1krdFeGnZLiGUPw
    // cbkeVpXf3lmJdsStOg+jijces2DZCfPyIBiQuLYfxxmAZE6ErJ0QJFg1stwli2Pz
    // 9ncYhFoqi8pXr7kEzEJBTzX4thuw56ydbGsshSEznPXoerCJOc7UI2+n0wFCWQ4Y
    // LHbh/PrWt4vdadyUUUW/QpQHXQLdD8q/Qwqdj0O9zlJE7R6Elw2E9EqnHyIGu1hm
    // LxhqrTru1M18SUhONYbVskV/BCEdVKs//X96849HorWQDCAgVMWfGsdMVq55FAdJ
    // 680N5UmQDRynIZ4+PeNGN4S9iw2mbMNEBQIDAQAB
    // -----END RSA PUBLIC KEY-----
    // 
    // 1
    // -----BEGIN RSA PUBLIC KEY-----
    // MIIBCgKCAQEAxT/ngLZNmT5GBdkLtJZjNeTB+8B5yWgrq/e5eMZ1hrZhcmLK+dSn
    // IkpOPV8/OekV67EnQ7I4II2rcNJnHGrGKZziXO3XN2gtUHE+mBJC99oULSbX/QwB
    // Kz7gC/IBPq9EuxTt6Oq6fPkVQ9DbRIgWJSEGBF/KRaNl3kyAlIZfpY7XgHyJTTv8
    // E7yAcYKPR+36gzdl+ps0sDLKzUuAtZNq8llK0u80z6AtAUIYwWdkEhM9upy6keKI
    // TasIxcsO7M6kZPINUSbh6t5VAm8FuqRmxpgg+9c9/GQSGd89InVypoVzWLQ+wOGg
    // 5G4H6JqIgtj0TRFt4gK0eoFi2U0d3l8bcwIDAQAB
    // -----END RSA PUBLIC KEY-----
    // 
    // Success.


    SetDlgItemText(IDC_EDIT1,strOut.getUnicode());

    }