(Objective-C) Refresh Expiring OAuth2 Access Token for Azure Registered App

See more OAuth2 Examples

Chilkat Objective-C Library Downloads MAC OS X (Cocoa) Libs iOS Libs

#import <CkoJsonObject.h>
#import <CkoDateTime.h>
#import <CkoOAuth2.h>
#import <CkoFileAccess.h>

// 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.

CkoJsonObject *json = [[CkoJsonObject alloc] init];
BOOL success = [json LoadFile: @"qa_data/tokens/_myAzureApp.json"];
if (success != YES) {
    NSLog(@"%@",@"Failed to load the access token.");
    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.
CkoDateTime *dtExpire = [[CkoDateTime alloc] init];
[dtExpire SetFromUnixTime: NO t: [[json IntOf: @"expires_on"] intValue]];

// If this date/time expires within 10 minutes of the current system time, refresh the token.
if ([dtExpire ExpiresWithin: [NSNumber numberWithInt: 10] units: @"minutes"] != YES) {
    NSLog(@"%@",@"No need to refresh, the access token won't expire within the next 10 minutes.");
    return;
}

// OK, we need to refresh the access token..
CkoOAuth2 *oauth2 = [[CkoOAuth2 alloc] init];

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

// Use your client ID.
oauth2.ClientId = @"CLIENT_ID";

// Get the existing refresh token.
oauth2.RefreshToken = [json StringOf: @"refresh_token"];

// Send the HTTP POST to refresh the access token.
success = [oauth2 RefreshAccessToken];
if (success == NO) {
    NSLog(@"%@",oauth2.LastErrorText);
    return;
}

NSLog(@"%@",@"OAuth2 authorization granted!");
NSLog(@"%@%@",@"Access Token = ",oauth2.AccessToken);

// Get the full JSON response:
[json Load: oauth2.AccessTokenResponse];
json.EmitCompact = NO;

// 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 ([json HasMember: @"expires_on"] != YES) {
    [dtExpire SetFromCurrentSystemTime];
    [dtExpire AddSeconds: [json IntOf: @"expires_in"]];
    [json AppendString: @"expires_on" value: [dtExpire GetAsUnixTimeStr: NO]];
}

NSLog(@"%@",[json Emit]);

// Save the new access token JSON to a file for future requests.
CkoFileAccess *fac = [[CkoFileAccess alloc] init];
[fac WriteEntireTextFile: @"qa_data/tokens/_myAzureApp.json" fileData: [json Emit] charset: @"utf-8" includePreamble: NO];