First Hop app released !

First Hop Free app has been approved in the AppStore. By the way the review process took 6 days. Now you can download for free here.

Use the free FirstHop app to easily get access to important networking information about your iOS device. The main information panel displays the public IP address, the location of your ISP, and the name and network of your ISP.

Understanding Apple's SSL/TLS bug

Yesterday, an entry about a serious Apple's bug reached the top of Hacker News The  bug was related with SSL/TTL connections.

Any time you have a bug that affects SSL/TLS you should pay close attention. As a quick refresher, SSL/TLS refers to encryption protocols that are widely and commonly used to encrypt the transmission of sensitive data. Any bug affecting SSL/TLS has the ability to undermine many, if not all, of the secure transmissions made from your devices.

Fortunately the code is open sourced, and the culprit was quickly spotted, here is the Apple bug:

static OSStatus
SSLVerifySignedServerKeyExchange(SSLContext *ctx, bool isRsa, SSLBuffer signedParams,
                                 uint8_t *signature, UInt16 signatureLen)
{
 OSStatus        err;
 ...

 if ((err = SSLHashSHA1.update(&hashCtx, &serverRandom)) != 0)
  goto fail;
 if ((err = SSLHashSHA1.update(&hashCtx, &signedParams)) != 0)
  goto fail;
  goto fail;
 if ((err = SSLHashSHA1.final(&hashCtx, &hashOut)) != 0)
  goto fail;
 ...

fail:
 SSLFreeBuffer(&signedHashes);
 SSLFreeBuffer(&hashCtx);
 return err;
}

Wow, note the two goto fail lines in a row.The first one is correctly bound to the if statement but the second, despite the indentation, isn't conditional at all. The code will always jump to the end from that second goto, err will contain a successful value because the SHA1 update operation was successful and so the signature verification will never fail.

UPDATE 1. More information here 

UPDATE 2. Apple promises fix 'very soon' for Macs with failed encryption

Checking network availability

In order to check the network availability of your device you can use the Apple Reachability class.  You can even hook up to be notified of network status changes through the ReachabilityCallback. 

But if you prefer a  a quick and dirty solution use this:
Write the following C code and save on a file named Goodies.h:

#include<unistd.h>

#include<netdb.h>

#include <stdbool.h>

#include <sys/types.h>

#include <sys/socket.h>

extern bool is_NetworkAvailable();

The matching implementation is Goodies.m

#include <stdio.h>

#include "Goodies.h"

bool is_NetworkAvailable()

{

    char *hostname;

    hostname = "google.com";

    

    struct addrinfo *res = NULL;

    int s = getaddrinfo(hostname, "http", NULL, &res);

    bool network_ok = (s == 0 && res != NULL);

    freeaddrinfo(res);

    if (network_ok ) {

        return 1;

    }

    else {

        return 0;

    }

    

}

And that's all. Now import Goodies.h an you can use the function is_NetworkAvailable() everywhre.

 



boolean _isNetworkAvailable = is_NetworkAvailable();

if (_isNetworkAvailable) {

          // Network related tasks

} else {

       UIAlertView *message = [[UIAlertView alloc]                                initWithTitle:@"Alert"
                 message:@"Nointernet connectivity." delegate:nil
                 cancelButtonTitle:@"OK"
                 otherButtonTitles:nil];

      [message show];

}

Apple releases Secure Coding Guide

You can download the document here (apple.com).

How to download Facebook Paper if you don't live in the US

Thanks to TUAW reporter John Michael Bond for this trick!

1. First thing, go to the App Store.
2. Go to Apple ID (Store- View Account)
3. Log in with your password as you normally would
4. Once you've logged in, go to your settings, find "country," then "change country or region" and change your country to "United States."
5. Click "none" when it asks you for payment information.
6. Search for Paper, download it, then change your country back to wherever you're from.

Voila! You've got Paper, at least until Facebook updates the app with a region lock.

GraphSketcher is now open source

GraphSketcher is a simple, elegant tool for quickly sketching graphs and plotting data — but you don’t even need data to get started. It’s perfect for reports, presentations, and problem sets where you need to produce sharp-looking graphs on the fly.

The OmniGroup stated on his blog that they will stop selling OmniGraphSketcher. Now is open source. You can download the source code from GitHub. I f you prefer to download the binary you can also do. Enjoy !

NFC standart: Why Apple does not like it?

As you know Apple does not support NFC. Also Apple does not like NFC and promotes iBeacons, based on Bluetooth LE.

There are some reasons for this. NFC has a number of disadvantages:

• Another radio? No way Smartphones have to accommodate a number of radios. An iPhone5 must include radios for LTE (or GSM), WIFI and Bluetooth.

• Serial interaction. NFC works well in a one-to-one interaction. But what happens when 10 smartphones want to interact with an NFC tag? the tenth will have to wait until the first nine have had a go.

Bluetooth LE does not have this limitations, but it also have some disadvantages over NFC: is more expensive and the server part has shorter battery life. But overall Bluetooth LE is in a better position to prevail in the battle for short-range peer-to-peer transactions.