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C

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

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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 Downloads

C
#include <C_CkHttp.h>
#include <C_CkJsonObject.h>
#include <C_CkPublicKey.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkHttp http;
    const char *jwkStr;
    HCkJsonObject json;
    HCkJsonObject jsonKey;
    HCkPublicKey pubKey;
    int numKeys;
    int i;

    success = FALSE;

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

    http = CkHttp_Create();

    jwkStr = CkHttp_quickGetStr(http,"https://www.googleapis.com/oauth2/v3/certs");
    if (CkHttp_getLastMethodSuccess(http) == FALSE) {
        printf("%s\n",CkHttp_lastErrorText(http));
        CkHttp_Dispose(http);
        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"
    // 	}
    //       ]
    //     }

    json = CkJsonObject_Create();
    success = CkJsonObject_Load(json,jwkStr);

    jsonKey = CkJsonObject_Create();
    pubKey = CkPublicKey_Create();
    numKeys = CkJsonObject_SizeOfArray(json,"keys");
    i = 0;
    while (i < numKeys) {
        CkJsonObject_putI(json,i);

        CkJsonObject_ObjectOf2(json,"keys[i]",jsonKey);

        success = CkPublicKey_LoadFromString(pubKey,CkJsonObject_emit(jsonKey));
        if (success == FALSE) {
            printf("%s\n",CkPublicKey_lastErrorText(pubKey));
            CkHttp_Dispose(http);
            CkJsonObject_Dispose(json);
            CkJsonObject_Dispose(jsonKey);
            CkPublicKey_Dispose(pubKey);
            return;
        }

        printf("%d\n",i);
        printf("%s\n",CkPublicKey_getPem(pubKey,TRUE));
        i = i + 1;
    }

    printf("Success.\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.


    CkHttp_Dispose(http);
    CkJsonObject_Dispose(json);
    CkJsonObject_Dispose(jsonKey);
    CkPublicKey_Dispose(pubKey);

    }