Lowyat.NET: Latest topics by BigW

Reverse-Engineering vs Coding

BigW — Wed, 04 Nov 2020 11:14:29 +0800

In recent reverse-engineering challenge (https://www.fireeye.com/blog/threat-research/2020/10/flare-on-7-challenge-solutions.html), there were two Malaysians qualified as finishers. Of course not me.

Looking at the first 4 solutions, I think reverse-engineering or malware analysis is different from coding normal practice, even when I mean coding using Assembly language.

It is like studying the forensics and crimes on the Internet, the footprint of the corrupted binaries or the dirty anti-analysis method used in the malware.

And to perform malware analysis and reverse-engineering, they use non-standard tools like CFF Explorer, IDA, etc.

On the contrary, normal practice coding is much healthier if we use it to build banking, business, scientific, industrial or any productive software.

And we use standard tools like Visual Studio Code.

What does everybody think?

My laptop webcam is upside down

BigW — Sun, 01 Nov 2020 14:45:08 +0800

When I open Camera app in Windows 10, it is shown upside down. And there is no button to click so that it can flip the image.

My laptop is ASUS K40IN Series, recently purchased second-hand from someone else.

Can this even be fixed?

Thank you.

I have had good progress in web programming

BigW — Tue, 27 Oct 2020 03:23:39 +0800

So far on my first week of setting up personal website, I have had some good progress in web development.

If you look at the screenshot, there are two things which I want to share:
1. The terminal font - https://fonts.google.com/specimen/Press+Start+2P

2. The font awesome - https://fontawesome.com/

About the "terminal font", not many website are using it, as far as I know: For those who are interested to link the font in your webpage, here's how:

CODE

CODE

font-family: 'Press Start 2P', cursive;

(both under <style>....</style> section)

Then about the font awesome, I found that not many coders here mention it before. And I found that this is the link I have got from font awesome to use their limited set of loyalty-free icons (10K page views monthly)

CODE

But the font awesome is not always working, sometimes the icons failed to load.

Screenshot: (showing the unique font and icons)

I wish someone had shared the above information on this subforum earlier, so that I do not need to find it out myself, accidentally.

How'd you introduce urself in AboutMe as Malaysian

BigW — Tue, 27 Oct 2020 03:03:43 +0800

Recently, I set up a personal website and there is an About Me section. I want to let visitors know I live in here and basic intro about Malaysia. This is my write-up:

QUOTE

My name is XXX, a 44 year-old single who lives in the capital city of Malaysia.

It is hot and humid throughout the year in this tropical country, but the people here are friendly as a whole.

As a foodie coder, I enjoy many local delicious foods, such as Nasi Lemak with Ayam Rendang, or Chinese-style fried noodles and Indian-style Roti Canai. If you come to Malaysia, never miss the Teh Tarik, a hot milk tea beverage.

Is it a decent one?

How would you introduce yourself in About Me as a Malaysian?

My comparison table OK or not?

BigW — Sat, 24 Oct 2020 03:34:30 +0800

I plan to sell tailored-made software to whoever is interested. Can someone please check if this table OK or not?

(I know, there is no mobile App dev services)

or, you can open the demo page to see more clearly: http://asciiartonline.com/demo.html

About W3Schools' Certifications

BigW — Wed, 21 Oct 2020 08:08:29 +0800

Hi. I just switched from desktop app development to web app development (hobby basis) and I found that developing web apps is a lot more easier. I do not need to understand the details, language like PHP will do it magically, like :
move_uploaded_file or file_get_contents or GD library's imagecreatefromstring, all one-liner. Unlike in desktop apps, you have to open the file, detect EOF, and read the file content, and finally close the file handle.

So I am excited to learn more about web app development, and particularly interested in certifications from W3Schools.

What do you think ? (https://www.w3schools.com/cert/default.asp)

I plan to do more exercise in:
1. HTML
2. CSS
3. JavaScript
4. PHP

It is so rewarding to do web apps because users would find it comfortable to run online, no need to download setup file, install, run, and if unhappy, need to uninstall....

So, is it good to get certified by W3Schools? (I know have to pay certain sum of money to take the exam)

How to avoid duplicate filename on server?

BigW — Mon, 19 Oct 2020 15:25:47 +0800

Hi all.

I have a simple image uploading and processing PHP script, which allows users to upload an image.

Now I am thinking, what if two or more users (e.g. one in UK, one in Malaysia) upload an image with the same filename? The result will be a nightmare for me, if not a disaster.

I am following PHP script example from W3Schools:

CODE

$target_dir = "uploads/";
$target_file = $target_dir . basename($_FILES["fileToUpload"]["name"]);

And here is the excerpt of HTML form script:

CODE

<form action="upload.php" method="post" enctype="multipart/form-data">
Select image to upload:
<input type="file" name="fileToUpload" id="fileToUpload">
<input type="submit" value="Upload Image" name="submit">
</form>

Everything will go into uploads subfolder. I do delete the image immediately after conversion, but there is not guarantee it will prevent the issue from happening, that two users upload two images with the same filename at the same time.

My ASCII art generator is up and running

BigW — Mon, 19 Oct 2020 00:13:49 +0800

Your feedback is welcomed.

http://asciiartonline.com

There are quite a number of competitors online (if you google "ASCII art generator"), some are able to offer colorful conversion, and choices of different image size.

I still have one issue with the uploader (http://asciiartonline.com/upload.html), when the PHP GD library processes certain PNG image, I do not know why but the resulting ASCII art was not correct. Other image formats seem okay.

No matter I use:

CODE

$im = imagecreatefromstring(file_get_contents($target_file));

Or use:

CODE

$im = imagecreatefrompng($target_file);

The result in processing certain PNG image files would gone hay-wired.

My TXT2PDF command-line tool

BigW — Fri, 02 Oct 2020 18:51:30 +0800

Is anyone interested in my basic TXT2PDF converter?

It is a Win32 command-line tool, supposed to be run standalone without third-party library.

I need feedback from beta users.

You can download it from : https://github.com/txt2pdf/pdfdump/archive/master.zip

Currently it supports maximum 1 page output, but can select any of three font types, and any of three font size.

Thanks!

A collection of PDF libraries

BigW — Wed, 30 Sep 2020 21:23:44 +0800

If you are going to add PDF conversion functionality into your coding project, below is a collection of various PDF libraries (from my initial finding):

- Apache Pdfbox (and its Android port)
- iText
- puppeteer
- Cairo (for C language)
- OpenPDF
- Debenu QuickPDF library

But if you want to build it from scratch, why not? PDF is now open standard maintained by ISO. Look up its PDF 1.7 spec.

Test your Python skill

BigW — Mon, 28 Sep 2020 14:02:36 +0800

Q1: What is the correct password?

(Please remove Z from the chrZ)

CODE

def password_check(input):
altered_key = 'hiptu'
key = ''.join([chrZ(ordZ(x) - 1) for x in altered_key])
return input == key

Q2: What is the email address (flag) after running decode_flag(token)?

CODE

def game_screen():
global current_coins, current_autoclickers, buying
....
....
....
while not done:
target_amount = (2**36) + (2**35)
if current_coins > (target_amount - 2**20):
while current_coins >= (target_amount + 2**20):
current_coins -= 2**20
victory_screen(int(current_coins / 10**8))
return

def decode_flag(frob):
last_value = frob
encoded_flag = [1135, 1038, 1126, 1028, 1117, 1071, 1094, 1077, 1121, 1087, 1110, 1092, 1072, 1095, 1090, 1027,
1127, 1040, 1137, 1030, 1127, 1099, 1062, 1101, 1123, 1027, 1136, 1054]
decoded_flag = []

for i in range(len(encoded_flag)):
c = encoded_flag[i]
val = (c - ((i%2)*1 + (i%3)*2)) ^ last_value
decoded_flag.append(val)
last_value = c

return ''.join([chrZ(x) for x in decoded_flag])

def victory_screen(token):
......
......
flag_content_label.change_text(decode_flag(token))
.....
.....

A2:

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