iOS Push Notification Tutorial:-

Note:- Start following steps and dont do anything else. There are so many Gotchas while creating certificates but dont get confuse and follow these steps.

Step 1:- Generating the Certificate Signing Request (CSR)

Open Keychain Access on your Mac (it is in Applications/Utilities) and choose the menu option Request a Certificate from a Certificate Authority.

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Please ensure that Let me specify key pair information is available. Check Saved to disk and click Continue. Save the file as PushChat.certSigningRequest.

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Step 2:- If you go to the Keys section of Keychain Access, you will see that a new private key has appeared in your keychain. Right click it and choose Export.

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Save the private key as PushChatKey.p12 and enter a passphrase.

Step 3:

Login to apple developer account

Go to Identifiers section select AppId.

Scroll down to the Push Notifications section and select the Create Certificate button in the Development SSL Certificate section.

Choose the CSR file that you generated earlier and click Generate. Click Continue when its done. Now click Download to get the certificate it is named aps_development.cer.

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Now we have three things in hand:-

The CSR
The private key as a p12 file (PushChatKey.p12)
The SSL certificate, aps_development.cer

Note: Please dont think about any other .p12 or any other certificate other than these three which you have created just now. Keep all files altogether in a same folder or on Desktop.

Step 4:-
Now open Terminal window and type the following commands.
Command 1 - cd ~/Desktop/

Convert the .cer file into a .pem file:
Command 2 - openssl x509 -in aps_development.cer -inform der -out PushChatCert.pem

Convert the private keys .p12 file into a .pem file:

Command 3 - openssl pkcs12 -nocerts -out PushChatKey.pem -in PushChatKey.p12
Enter Import Password:
MAC verified OK
Enter PEM pass phrase:
Verifying - Enter PEM pass phrase:

Combine the certificate and key into a single .pem file:
Command 4 - cat PushChatCert.pem PushChatKey.pem > ck.pem

Test whether the certificate works.
Command 5 - telnet gateway.sandbox.push.apple.com 2195
Trying 17.172.232.226...
Connected to gateway.sandbox.push-apple.com.akadns.net.
Escape character is '^]'.

Now press ctrl+C.

This time using our SSL certificate and private key to set up a secure connection:
Command 6 - openssl s_client -connect gateway.sandbox.push.apple.com:2195
-cert PushChatCert.pem -key PushChatKey.pem
Enter pass phrase for PushChatKey.pem:

Open AppDelegate file of your project in XCode

   - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions { 

// Let the device know we want to receive push notifications 

[[UIApplication sharedApplication] registerForRemoteNotificationTypes:(UIRemoteNotificationTypeBadge | UIRemoteNotificationTypeSound | UIRemoteNotificationTypeAlert)]; 

    return YES; 
}

Get device token using:-

    - (void)application:(UIApplication*)application didRegisterForRemoteNotificationsWithDeviceToken:(NSData*)deviceToken
{
    NSLog(@"My token is: %@", deviceToken);
}

- (void)application:(UIApplication*)application didFailToRegisterForRemoteNotificationsWithError:(NSError*)error
{
    NSLog(@"Failed to get token, error: %@", error);
}

For testing purpose download samplePush.php file and edit the following info in it...

// Put your device token here (without spaces): $deviceToken = '0f744707bebcf74f9b7c25d48e3358945f6aa01da5ddb387462c7eaf61bbad78';

// Put your private key's passphrase here: $passphrase = 'pushchat';

// Put your alert message here: $message = 'My first sample push notification!';

*Final Step* Open terminal and type Command :- php samplePush.php

Result :- you'll get "message successfully delivered".

Happy Coding :)