Category Archives: Experience

Unlock Bell’s Carrier Lock on iPhone

For “SIM Not Supported Error” when using a SIM card other than Bell/Virgin Mobile


Send you device purchase agreement to

[email protected]

Their process time is usually 10-60 minutes.


Customer service can’t really handle this.

Yes, there’s no lock after 2018, but the store usually lock their expensive iPhone models and unlock the carrier for you after the purchase. They do forget about the unlocking step quite often.

Disable mouse zooming in Firefox


The scroll wheel on my MX master 3 doesn’t really work well with MacOS. Zooming is triggered by mistake quite often.


  • about:config
  • mousewheel.with_control.action
  • change the value to 1



  • about:config
  • mousewheel.with_meta.action
  • change the value to 1

In MacOS, meta key is the Command key. (Source)

The value 0 means “Do nothing”, 1 means “Scroll contents”, 2 means “Go back or forward in the history”, 3 means “Zoom in or out the contents”

More Info about the config


Enable MySQL/MariaDB SSL for PDO/Laravel

Server side setup

Refer to this manual from MariaDB

require_secure_transport = ON could be added to the my.cnf file to enforece SSL for all connections (including those from localhost & unix socket)

One way SSL

Without CA verification


$pdo = new PDO(';dbname=image', 'laravel', 'laravel',array(

Laravel (config/database.php)

// under mysql => options
'options' => extension_loaded('pdo_mysql') ? [
 ] : []

PLEASE NOTE: array_filter in this original config file is REMOVED. Because entries with empty() value will be filtered, so that MYSQL_ATTR_SSL_VERIFY_SERVER_CERT will be removed.

MYSQL_ATTR_SSL_CA is set just to enable SSL (like mysql -h …. -u … -p –ssl)

With CA verification

PLEASE BE AWARE, the cert in this mode is domain validated. The MySQL server should use a cert with matched common name, ‘’ for example. the use of domain name for the host is preferred.

Same to without verification, but set MYSQL_ATTR_SSL_VERIFY_SERVER_CERT to true. (Or just remove the attribute, since it’s true by default)

Two way (mutual) SSL

PDO::MYSQL_ATTR_SSL_CA => "/path/to/ca-cert.pem",
PDO::MYSQL_ATTR_SSL_CERT => "/path/to/client-cert.pem",
PDO::MYSQL_ATTR_SSL_KEY => "/path/to/client-key.pem",

MYSQL_ATTR_SSL_VERIFY_SERVER_CERT could be true or false, it depends.

Common Errors

PHP ‘illegal hardware instruction’ on MacOS

I’m using MacOS 10.15 using PHP 7.4.11 from homebrew.
This error basically happens when PDO SSL setup/verification failed.
For example:

PDO::__construct(): SSL operation failed with code 1. OpenSSL Error messages

Or maybe

PDO::__construct(): Peer certificate CN=Common name' did not match expected CN= domain’

I believe it’s a platform specific issue.

PDO attribute not received by Laravel

Mentioned already.
array_filter will filter out all attributes with value of null/false/0/”” …
Remove it when you have to use those values.

Fixing a “Damaged App” from App Store


  • OSX (From Apple, or Hackintosh)
  • The App was purchased from the App Store with the current iCloud ID

The problem:

  • Unable to open a previously purchased App

The error:

“Magnet” is damaged and can’t be opened. Delete “Magnet” and download it again from the App Store.

It could be any paid app, in my case, ‘Magnet’.

There exist a similar but common error caused by unsigned/modified third party apps (blocked by Gatekeeper)

App Is Damaged and Can’t Be Opened. You Should Move It To The Trash

This is NOT what my guide is talking about.

The Cause

The error basically means Apple is unable to verify the App purchased on this machine.

The MAC address of your en0 is part of the verification. Because all Macs come with a built-in Wifi/Ethernet Adapter.

Run this in your terminal to list all network interfaces.

networksetup -listallhardwareports

What exactly happened to my is, my hackintosh motherboard comes with two built-in Ethernet adapters. I disabled one (en0) from the BIOS few days after the OSX is installed.

How to fix

If you encountered the same error message, try the following:

(Software issue, basically sync your current en0 MAC address with iCloud)

  • Follow this guide from 1Password (also work for other apps from the App Store)
  • If that doesn’t help, move on:

(Hardware issue. in most cases, en0 not found)

  • list all network interfaces, find en0
  • If en0 is not found, enable it from BIOS (if you disabled it before)
  • If you didn’t remove/disable any network hardware, rename your primary interface to en0, here are some useful resources
  • After that, follow the guide from 1Password again when necessary (when it’s still not working)

If none of those work:

Go to network settings > tiny gear icon > Set service order
Open a terminal and run:

cd /Library/Preferences/SystemConfiguration/
sudo rm NetworkInterfaces.plist
sudo rm preferences.plist
Restart machine

Credit for this: Jeremy Wininger

Getting started with eBay API Tokens (Oauth) with PHP

Official Guide:

I’ll also cover some mistakes I made.

  1.  Signup at
  2. Create an App and get the App ID (Client ID) and Cert ID (Client Secret)
  3. Click ‘User Tokens‘ (either from sandbox or production, depend on you)
  4. Click “Get a Token from eBay via Your Application” then “Add eBay Redirect URL
  5. Fill in the form, the only important thing is the “Your auth accepted URL“, it should be under your domain. (You should able to extract the auth code from the call back later, for example $_GET[‘code’] in PHP),  let’s assume this
  6. Take down the value of “RuName (eBay Redirect URL name)” and “Your branded eBay Production Sign In (OAuth)

So far, we’ve done our preparation at

Then, on you local developing environment or you production server,:

  1. Set user login you own website
  2. put a hyperlink pointing to the URL of “Your branded eBay Production Sign In (OAuth)
  3. visitor click on that link, and login with their ebay account.
  4. ebay will make a callback redirect to “Your auth accepted URL” if success.

On the “Your auth accepted URL“, prepare a PHP script that get the value of $_GET[‘code’] and save it in sessions. It starts with ‘v%5E1’. this is called “Authorization Code

Next, get an “Access Token” with this “Authorization Code” 

Craft a HTTP Request with whatever you like with PHP.

HTTP headers:
Content-Type = application/x-www-form-urlencoded
Authorization = Basic <B64-encoded-oauth-credentials>

HTTP method: POST


Request body (wrapped for readability):

We have three ‘Variables’ here.

<B64-encoded-oauth-credentials>: Use a Chrome Browser, Right click, Inspect, Console
Then type: btoa(‘APP_ID:CERT_ID‘);
We did take down these two values earlier. and there is a : between.
Hit ENTER, the value inside the double quotes is <B64-encoded-oauth-credentials>

<authorization-code>: the ‘Authorization Code‘ we got in the callback redirect.

<redirect_URI>: This is the tricky part. This can’t be ignored or filled with random things, it’s the value of “RuName (eBay Redirect URL name)

Send the request, and you’ll get the access token and the refresh token.
Follow the official guide to refresh the token if expired.

We are basically finished here, If you wanna call an API, ‘List orders as a seller’ for instance:


Authorization: Bearer <YOUR_ACCESS_TOKEN>
It’s Bearer this time :), don’t use Basic by mistake.

Remove the Loop Icon for VOX

VOX is the best music players on OSX I’ve ever used.

The Loop becomes one of it’s features to store unlimited music on it’s platform. It’s a good feature, and the only way for the developer to get some pay back for the wonderful applet.

I just don’t need it, and try to save some space for my menu bar.

On the VOX’s preference page, uncheck “Keep Loop Agent Running when” just doesn’t make any sense. Neither for “launchctl remove com.coppertino.VOXCloud” as the developer mentioned.

My way to close that:

Finder – Application – VOX – right click – Show package contents – Contents – Library – LoginItems

You can find the here, but things like deleting/renaming/[removing permission] will all prevent VOX from launching. – Show package contents – Contents – Resources – Base.lproj

Then rename “MainMenu.nib” to something else for example: “MainMenu.nib.bye”

Quit Loop and restart VOX, Done.

Note on sshd_config Setup

What’s sshd_config?

It’s “OpenSSH SSH daemon configuration file”

Simply means the config file for OpenSSH Server.

Located at /etc/ssh/sshd_config

My reference

ListenAddress and Port

By default, OpenSSH will listen on port 22 for all address( and ::)

There can be multiple Port defined, for example:

Port 22
Port 622

OpenSSH will listen on both ports

ListenAddress specify the address to listen, the address can be hostname, ipv4 or ipv6

You may also add an optional port number, for example:


OpenSSH will listen on and at port 22, plus port 922

If there are multiple “Port” specified:

Port 22
Port 622

Then are listened


If port is not specified, sshd will listen on the address and all prior Port options specified.

Access Control:

Process order: DenyUsers, AllowUsers, DenyGroups, and finally AllowGroups.

If none of the four is defined, login is allowed fro all users.

If Allow* is defined, login is only allowed to declared users and groups.

Only username and groupname are accepted, UID and GID are NOT.

In the following example, only ‘root’ and ‘user’ are allowed

PermitRootLogin yes
AllowUsers root user

In the following example, only ‘user2’ is denied.

DenyUsers user2

Limit user to specified destination address and port

Supposed the OpenSSH server is listening to multiple IPs ( and

At the end of sshd_config file: add:

# Only user'git' can access to server address
Match LocalAddress
AllowUsers git

You may also specify port

# Only user'git' can access to server at port 622
Match LocalPort 622
AllowUsers git

You may also specify address and port

# Only user'git' can access to server
Match LocalAddress LocalPort 622
AllowUsers git


Match Introduces a conditional block. If all of the criteria on the Match line are satisfied, the keywords on the following lines override those set in the global section of the config file, until either another Match line or the end of the file. If a keyword appears in multiple Match blocks that are satisfied, only the first instance of the keyword is applied.


Limit user from specified source address

# Allow root only from and Allow 'user from'
# Allow user2 from any host 
AllowUsers [email protected].* user2

More details on HOST:

Host: Restricts the following declarations (up to the next Host or Match keyword) to be only for those hosts that match one of the patterns given after the keyword. If more than one pattern is provided, they should be separated by whitespace. A single *' as a pattern can be used to provide global defaults for all hosts. The host is the hostname argument given on the command line (i.e. the name is not converted to a canonicalized host name before matching). A pattern entry may be negated by prefixing it with an exclama- tion mark (!’). If a negated entry is matched, then the Host entry is ignored, regardless of whether any other patterns on the line match. Negated matches are therefore useful to provide exceptions for wildcard matches.

Here is another approach using Match:

At the end of sshd_config file: add:

# Only user'git' can access to server address
Match Address User user
AllowUsers user