C

Refresh Expiring OAuth2 Access Token for Azure Registered App

See more OAuth2 Examples

Shows how to renew an Azure App's access token using the refresh token when it's near expiration. C

#include <C_CkJsonObject.h>
#include <C_CkDateTime.h>
#include <C_CkOAuth2.h>
#include <C_CkFileAccess.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkJsonObject json;
    HCkDateTime dtExpire;
    HCkOAuth2 oauth2;
    HCkFileAccess fac;

    success = FALSE;

    // We previously obtained an access token and saved the JSON to a file using this example:
    // Get OAuth2 Access Token for Azure Registered App

    // This example will examine the JSON and expiration date, and if near expiration will
    // refresh the access token.

    json = CkJsonObject_Create();
    success = CkJsonObject_LoadFile(json,"qa_data/tokens/_myAzureApp.json");
    if (success != TRUE) {
        printf("Failed to load the access token.\n");
        CkJsonObject_Dispose(json);
        return;
    }

    // The contents of the JSON look like this:
    // {
    //   "token_type": "Bearer",
    //   "scope": "User.Read Mail.ReadWrite Mail.Send",
    //   "expires_in": 3600,
    //   "ext_expires_in": 0,
    //   "access_token": "EwBAA8l6B...",
    //   "refresh_token": "MCRMdbe6Cd...",
    //   "id_token": "eyJ0eXAiOiJ...",
    //   "expires_on": "1494112119"
    // }

    // The "expires_on" value is a Unix time.
    dtExpire = CkDateTime_Create();
    CkDateTime_SetFromUnixTime(dtExpire,FALSE,CkJsonObject_IntOf(json,"expires_on"));

    // If this date/time expires within 10 minutes of the current system time, refresh the token.
    if (CkDateTime_ExpiresWithin(dtExpire,10,"minutes") != TRUE) {
        printf("No need to refresh, the access token won't expire within the next 10 minutes.\n");
        CkJsonObject_Dispose(json);
        CkDateTime_Dispose(dtExpire);
        return;
    }

    // OK, we need to refresh the access token..
    oauth2 = CkOAuth2_Create();

    // Note: The endpoint depends on the Azure App Registration.
    // See How to Choose the Correct Endpoints for your Azure App Registration
    CkOAuth2_putTokenEndpoint(oauth2,"https://login.microsoftonline.com/common/oauth2/v2.0/token");

    // Use your client ID.
    CkOAuth2_putClientId(oauth2,"CLIENT_ID");

    // Get the existing refresh token.
    CkOAuth2_putRefreshToken(oauth2,CkJsonObject_stringOf(json,"refresh_token"));

    // Send the HTTP POST to refresh the access token.
    success = CkOAuth2_RefreshAccessToken(oauth2);
    if (success == FALSE) {
        printf("%s\n",CkOAuth2_lastErrorText(oauth2));
        CkJsonObject_Dispose(json);
        CkDateTime_Dispose(dtExpire);
        CkOAuth2_Dispose(oauth2);
        return;
    }

    printf("OAuth2 authorization granted!\n");
    printf("Access Token = %s\n",CkOAuth2_accessToken(oauth2));

    // Get the full JSON response:
    CkJsonObject_Load(json,CkOAuth2_accessTokenResponse(oauth2));
    CkJsonObject_putEmitCompact(json,FALSE);

    // If an "expires_on" member does not exist, then add the JSON member by
    // getting the current system date/time and adding the "expires_in" seconds.
    // This way we'll know when the token expires.
    if (CkJsonObject_HasMember(json,"expires_on") != TRUE) {
        CkDateTime_SetFromCurrentSystemTime(dtExpire);
        CkDateTime_AddSeconds(dtExpire,CkJsonObject_IntOf(json,"expires_in"));
        CkJsonObject_AppendString(json,"expires_on",CkDateTime_getAsUnixTimeStr(dtExpire,FALSE));
    }

    printf("%s\n",CkJsonObject_emit(json));

    // Save the new access token JSON to a file for future requests.
    fac = CkFileAccess_Create();
    CkFileAccess_WriteEntireTextFile(fac,"qa_data/tokens/_myAzureApp.json",CkJsonObject_emit(json),"utf-8",FALSE);


    CkJsonObject_Dispose(json);
    CkDateTime_Dispose(dtExpire);
    CkOAuth2_Dispose(oauth2);
    CkFileAccess_Dispose(fac);

    }