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Unicode C

Get Access Token using a Pre-Created JSON Web Token

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Demonstrates how to get an access token using a pre-created JSON Web Token (JWT).

Chilkat Unicode C Downloads

Unicode C
#include <C_CkPrivateKeyW.h>
#include <C_CkJwtW.h>
#include <C_CkJsonObjectW.h>
#include <C_CkHttpW.h>
#include <C_CkHttpRequestW.h>
#include <C_CkHttpResponseW.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkPrivateKeyW privkey;
    HCkJwtW jwt;
    HCkJsonObjectW jsonHeader;
    HCkJsonObjectW jsonPayload;
    int curDateTime;
    const wchar_t *jwtStr;
    HCkHttpW http;
    HCkHttpRequestW req;
    HCkHttpResponseW resp;
    HCkJsonObjectW json;

    success = FALSE;

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

    // We're going to duplicate this CURL statement:
    // curl -X POST https://api-sandbox.abnamro.com/v1/oauth/token \
    // -H "Content-Type: application/x-www-form-urlencoded" \
    // -H "API-Key: xxxxxx" \
    // -d 'client_assertion_type=urn:ietf:params:oauth:client-assertion-type:jwt-bearer&grant_type=client_credentials&client_assertion=eyJhbGciOiJSUzI1NiIsInR5cCI6IkpXVCJ9.eyJzdWIiOiJ4eHh4eHgiLCJleHAiOiIxNDk5OTQ3NjY4IiwiaXNzIjoibWUiLCJhdWQiOiJodHRwczovL2F1dGgtc2FuZGJveC5hYm5hbXJvLmNvbS9vYXV0aC90b2tlbiJ9.jGwHKG_YjgKpR8NPpaLu6nJ97obeP2vcxg6fOWBKdJ0&scope=tikkie'

    // Load our pre-creaed private key PEM file.
    // Note: Please share your public key along with your app name and developer email id at api.support@nl.abnamro.com. 
    // Token generation will not work unless public key is associated with your app.
    privkey = CkPrivateKeyW_Create();

    success = CkPrivateKeyW_LoadPemFile(privkey,L"qa_data/pem/abnAmroPrivateKey.pem");
    if (success == FALSE) {
        wprintf(L"%s\n",CkPrivateKeyW_lastErrorText(privkey));
        CkPrivateKeyW_Dispose(privkey);
        return;
    }

    // Create the JWT.
    jwt = CkJwtW_Create();

    // Create the header:
    // {
    //     "typ": "JWT",
    //     "alg": "RS256"
    // }
    jsonHeader = CkJsonObjectW_Create();
    CkJsonObjectW_UpdateString(jsonHeader,L"typ",L"JWT");
    CkJsonObjectW_UpdateString(jsonHeader,L"alg",L"RS256");

    // Create the payload:
    // {
    //     "nbf": 1499947668,
    //     "exp": 1499948668,
    //     "iss": "me",
    //     "sub": "anApiKey",
    //     "aud": "https://auth-sandbox.abnamro.com/oauth/token"
    // }
    jsonPayload = CkJsonObjectW_Create();

    curDateTime = CkJwtW_GenNumericDate(jwt,0);

    // Set the "not process before" timestamp to now.
    success = CkJsonObjectW_AddIntAt(jsonPayload,-1,L"nbf",curDateTime);

    // Set the timestamp defining an expiration time (end time) for the token
    // to be now + 1 hour (3600 seconds)
    success = CkJsonObjectW_AddIntAt(jsonPayload,-1,L"exp",curDateTime + 3600);

    CkJsonObjectW_UpdateString(jsonPayload,L"iss",L"me");
    CkJsonObjectW_UpdateString(jsonPayload,L"sub",L"anApiKey");
    CkJsonObjectW_UpdateString(jsonPayload,L"aud",L"https://auth-sandbox.abnamro.com/oauth/token");

    // Produce the smallest possible JWT:
    CkJwtW_putAutoCompact(jwt,TRUE);

    jwtStr = CkJwtW_createJwtPk(jwt,CkJsonObjectW_emit(jsonHeader),CkJsonObjectW_emit(jsonPayload),privkey);
    if (CkJwtW_getLastMethodSuccess(jwt) == FALSE) {
        wprintf(L"%s\n",CkJwtW_lastErrorText(jwt));
        CkPrivateKeyW_Dispose(privkey);
        CkJwtW_Dispose(jwt);
        CkJsonObjectW_Dispose(jsonHeader);
        CkJsonObjectW_Dispose(jsonPayload);
        return;
    }

    http = CkHttpW_Create();

    req = CkHttpRequestW_Create();
    CkHttpRequestW_AddParam(req,L"client_assertion_type",L"urn:ietf:params:oauth:client-assertion-type:jwt-bearer");
    CkHttpRequestW_AddParam(req,L"grant_type",L"client_credentials");
    CkHttpRequestW_AddParam(req,L"client_assertion",jwtStr);
    CkHttpRequestW_AddParam(req,L"scope",L"tikkie");

    CkHttpRequestW_putHttpVerb(req,L"POST");
    CkHttpRequestW_putContentType(req,L"application/x-www-form-urlencoded");

    resp = CkHttpResponseW_Create();
    success = CkHttpW_HttpReq(http,L"https://api-sandbox.abnamro.com/v1/oauth/token",req,resp);
    if (success == FALSE) {
        wprintf(L"%s\n",CkHttpW_lastErrorText(http));
        CkPrivateKeyW_Dispose(privkey);
        CkJwtW_Dispose(jwt);
        CkJsonObjectW_Dispose(jsonHeader);
        CkJsonObjectW_Dispose(jsonPayload);
        CkHttpW_Dispose(http);
        CkHttpRequestW_Dispose(req);
        CkHttpResponseW_Dispose(resp);
        return;
    }

    if (CkHttpResponseW_getStatusCode(resp) != 200) {
        wprintf(L"%s\n",CkHttpResponseW_bodyStr(resp));
        CkPrivateKeyW_Dispose(privkey);
        CkJwtW_Dispose(jwt);
        CkJsonObjectW_Dispose(jsonHeader);
        CkJsonObjectW_Dispose(jsonPayload);
        CkHttpW_Dispose(http);
        CkHttpRequestW_Dispose(req);
        CkHttpResponseW_Dispose(resp);
        return;
    }

    // Get the JSON result:
    // {
    //     "access_token": "{your access token}",
    //     "expires_in": "{duration of validity in seconds}",
    //     "scope": "{scope(s) for which the access token is valid}",
    //     "token_type": "{it is always Bearer}"
    // }
    json = CkJsonObjectW_Create();
    CkJsonObjectW_Load(json,CkHttpResponseW_bodyStr(resp));
    wprintf(L"access_token: %s\n",CkJsonObjectW_stringOf(json,L"access_token"));
    wprintf(L"token_type: %s\n",CkJsonObjectW_stringOf(json,L"token_type"));
    wprintf(L"expires_in: %s\n",CkJsonObjectW_stringOf(json,L"expires_in"));
    wprintf(L"scope: %s\n",CkJsonObjectW_stringOf(json,L"scope"));


    CkPrivateKeyW_Dispose(privkey);
    CkJwtW_Dispose(jwt);
    CkJsonObjectW_Dispose(jsonHeader);
    CkJsonObjectW_Dispose(jsonPayload);
    CkHttpW_Dispose(http);
    CkHttpRequestW_Dispose(req);
    CkHttpResponseW_Dispose(resp);
    CkJsonObjectW_Dispose(json);

    }