Simon's Coding Journal

[simonbboettcher-blog]

Some James Bond Shit

Back from school holiday break and back with some more programming. I've been looking at how to encrypt data and strings in Visual Basic. some quick Google dearching brings up this Encrypting and Decrypting Strings Walkthrough on MSDN. Applying the code, I attempt to create a login interface that simply encrypts the users password with a built in key. I understand that the key should theoretically also be encrypted and not left as plain text in the program, but thats outside of the scope of this program at the moment.

I've currently run into repeated NullException errors and am having difficulty sotring the problem, though they seem to be caused by dynamic arrays. It also seems to be no assigning values to parts of arrays in the Global Variables Module. This code is in progress and poorly commented and unoptimised. It also doesn't work :P

Language: Visual Basic 2015

The task: Successfully create a securely encrypted login system.

Login Form

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Public Class Form1 ' FORM LOAD Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load ' UI Setup boxUsername.DropDownStyle = 2 If usercount = 0 Then MsgBox("Welcome, Please Create A User Account.") Form2.ShowDialog() End If For loops = 0 To usercount boxUsername.Items.Add(username(loops)) Next End Sub ' LOG IN BUTTON Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click End Sub ' CREATE ACCOUNT BUTTON Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click Form2.Show() End Sub End Class

Create Account Form

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Public Class Form2 Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click If txtPassword.Text = txtPasswordConfirm.Text Then username(usercount) = txtUsername.Text password(usercount) = txtPassword.Text usercount += 1 Else MsgBox("Passwords Do No Match, Please Try Again.") txtUsername.Text = "" : txtPassword.Text = "" : txtPasswordConfirm.Text = "" End If Dim exportfile As IO.StreamWriter exportfile = IO.File.AppendText("usersencrypted.txt") Dim wrapper As New Simple3Des(key) Dim cipherText(9999) As String Dim plaintext As String For loops = 0 To username.Length plaintext = password(loops) cipherText(loops) = wrapper.EncryptData(plaintext) exportfile.WriteLine(cipherText(loops)) loops += 1 Next MsgBox("User Acccount Created Successfully.") Form1.Show() End Sub Private Sub Form2_Load(sender As Object, e As EventArgs) Handles MyBase.Load End Sub Private Sub txtUsername_TextChanged(sender As Object, e As EventArgs) Handles txtUsername.TextChanged End Sub End Class

Variable Module

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Module Module2 Public username(9999) As String Public password(9999) As String Public key As String = "temporarykey" Public usercount As Integer = 0 End Module

Done for today, I'm getting an early night. I guess I'll tackle this pain tomorrow.

31.07.2016, 9:00PM (Australia)

[simonbboettcher-blog]

Feel Good

A quick status update on the Crunchbang virtual machine, I just installed Nautlius file manager on it for a more familiar working environment. Easiest job so far; sudo apt-get install nautilus and confirming the install of dependancies. Feels good man.

06.06.2016, 2:33PM (Australia)

[simonbboettcher-blog]

Float Away

A quick little post about something new I learnt while updating this website. How to align text to both the left and the right in a singular line. The issue came up when adding dates to the contents page. Initially I tried just using margins to realise that counts pixels from the last character. So, after a lot of tinkering around and extensive forum reading I found what was rather a simple solution (I found many other but they were all much too complicated for both my liking and my use case). Here's the code:

.boxed {width: auto; height:auto px; border: 1px solid black; overflow-x: scroll; overflow-y: hidden; white-space: nowrap; } [Show][Hide]

This is aligned on the left. <span style="float:right"> This is aligned on the right. </span>

So there we go, just a little thing I learnt today.

04.06.2016, 3:32PM (Australia)

[simonbboettcher-blog]

Hello World

So, eager to jump into some programming I began going through 'Learn C The Hard Way', here's a summary of my experience working my way through the first 5 exercises.

Language: C

The task: Learning the basics.

Exercise 1 As always, starting off with the good old Hello World programming, we covered how to compile the code and some basic error messages. It's noted that you need to import at the start of the file.

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#include <stdio.h> int main(int argc, char *argv[]) { puts("Hello world."); return 0; }

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Exercise 2 Having learnt the basic make function of how to compile, I learnt how to create a makefile to automatically check for errors and create a clean command. This program also uses a statement, which works exactly like print in Python, why we used put in the last exercise I am yet to discover. Extending my knowledge I researched the all section and learnt its functions and uses within a makefile.

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CFLAGS=-Wall -g all: ex4 ex3 ex1 clean: rm -f ex4 ex3 ex1

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Exercise 3 Before I began on this exercise I did some quick googling on how to comment in C, I found /* */, I now know // works in C too, but at this stage I was not yet aware of that fact. The exercise itself covered basic variable decleration and use of escape sequences, namely /n. Through further research I found all the other escape sequences in C and added examples of them into my program, to gain some familiarity of them into my program. While attempting to build this file I realised that I'd forgotten to add semicolons at the end of each statement, rookie mistake.

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/* Header (Means: Using Standard I/O) */ #include <stdio.h> int main() { /* Declaring Variables (int = Integer?) */ int age = 10; int height = 72; /* printf, Works like Python's print */ /* \n = New Line */ printf("I am %d years old.\n", age); printf("I am %d inches tall.\n", height); /* \t = New Tab */ printf("I am inserting a tab. \t See, I did it.\n"); /* \a = Bell (Audio Beep) */ printf("This line cause a beep.\n"); /* \b = Backspace */ printf("What does\b this do?\n"); /* \r = Carriage Return (Out of use) */ printf("Carriage Return? No idea\r\n"); /* \t = Vertical Tab (Out of use, does not function?)*/ printf("There should be lots of spaces-ish\t\n"); /* \\ = Insert Backslash */ printf("This lets me insert a backslash, see: \\\n"); /* \? = Insert Questin Mark */ printf("This lets me insert a question mark, see: \?\n"); /* \' = Insert Single Quote */ printf("This lets me insert a single quote, see: \'\n"); /* \" = Insert Double Quote */ printf("This lets me insert a double quote, see: \"\n"); /* \x = Insert Character with Hexadecimal Code */ printf("This is a plus printed with a hexadecimal character code, see: \x2B\n"); /* \ = Insert Character with Octal Code */ printf("This is a plus printed with a octal character code, see: \053\n"); return 0; } /* NOTES: - Make sure to use ; at the end of each line. (Causes build error on last line). - dummies.com/how-to/content/c-language-escape-sequences.html - www.asciitable.com */

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Exercise 4 Here we were introduced to a more thorough diagnostics program for our programming, called Valgrind, the book encourages you to install the package manually. So, being somewhat shy of the Linux terminal, I decided to give it a bash. First thing I did was check the Valgrind website if there was an updated version, which there was. I used wget to obtain the file as curl brought up many scary results in practice. Installing the program worked like a charm, however, upon trying to use valgrind an error message came back. Intalling libc6-dbg fixed the problem. Having successfully compiled a .tar file I went to practice. I visited the WinRAR website and found the URL for the 64-Bit Linux download, I got the file and tried making magic twice, this one wasn't so easy. I learnt that -xjvf is exclusively for .bz2 files and -xzf works for .gz files. I also had to teach myself some basic terminal commands. However, I got there in the end and proceeded to download a sample .rar file to check if it worked fine and was very surprised when it did, indeed, run as expected. Having installed Valgrind I now tested it with a broken program. The errors were returned as expected.

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#include <stdio.h> /* WARNING: This Program Is Wrong on Purpse. */ int main() { int age = 10; int height; printf("I am %d yeard old.\n"); printf("I am %d inches tall.\n", height); return 0; }

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Exercise 5 This exercise was surprisigly simple, it just ran through the structure. Though I'm still lost as to the exact working of the main function and its parameters apparently its explained in later exercises. Therefore, the only thing I learned in this exercise was that you can comment using //, something that made my OCD much happier (as it looks a lot less horrific than /* */).

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#include <stdio.h> int main(int argc, char *argv[]) { int distance = 100; // This is also a comment. printf("You are %d miles away.\n", distance); return 0; }

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Terminal Commands Here are some terminal commands that I learnt along the way working myself through these five exercies:

1. cd - , cd followed by '-' goes to the prevously accessed directory.

2. rm removes files and directories, imoprtant additions are -f to force -d to delete a directory and * to delete all files within the directory.

3. md5sum checks that youve recieved the correct package.

4. ls lists all the contents of the directory you're in.

5. mkdir creates a new directory.

Now I've finally finished and it's nearly 2:30 in the morning and I'm beginning to regret some of my life choices; my butt is sore from this chair and my eyes are drooping from exhaustion. Man, my bed look lovely right now. More tomorrow (today).

03.06.2016, 2:24AM (Australia)

[simonbboettcher-blog]

Crunchbang

Since I'm having all the epiphanies lately and telling myself I should all sorts of weird organised things like starting this blog I thought I may as well start learning something new while I'm at it. Having started learning programming in python, being familiar with Visual Basic and having dabbled in other scripting and web based languages I thought it might be high time a bit the bullet and hit up some real languages. So, keeping this epiphany in mind, I decided to go to the roots and learn so C. Looking for some good ways to learn I stumbled upon the fact that Zed Shaw has a currently in development book, 'Learn C The Hard Way', having learnt Python assisted greatly by his Python book I was immediatley sold. Hitting up the first chapter I learnt something new; program in C on Linux, seems obvious when you think about it. So began this little adventure.

Having dabbled in many different distros before I didn't just want to go with the boring old make it easy Ubuntu install for the virtual machine I was going to program in, so I set out on a hunt for a new distro. Initially, I found Elementary OS, a very pretty looking distro that's reportedly very stable. I downloaded it and tried running it in a virtual machine, all worked great but I couldn't get the VirtualBox Guest Additions installed properly, an issue that I spent many hours trying to fix but (admittedly probably due to my own inaptitude) was ultimately not able to.

So, what to do now? Give up. I gave up on a new distro and installed the latest version of an old favourite of mine, Crunchbang Linux, in which everything ran silky smooth and the latest build even has a wicked post install setup wizard.

Some initial setup I did included:

1. Installing Chrome, this was an easy do. Just downloaded the debian package and installed through package manager.

2. Installing Sublime Text 3, another easy job just installing the .deb file, just remember the command is 'subl' not the package name, 'sublime-text'.

3. Setting up the menu to my liking, the distro is based on OpenBox so the menu is as as such, just some easy tweaks to 'menu.xml'.

4. Time to install guest additions again, had some trouble trying to install 'linux-headers-general' but all ran fine when I ran 'linux-headers-$(uname -r)' instead, thanks garron.me. I also had to copy the .run file onto my the local drive of the machine, but everything installed fine.

Screenshots: A few flicks I took along the way.

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Now, happy with my Linux setup, I'm keen to get into some nitty gritty programming. Let's see how long that lasts...

02.06.2016, 10:57PM (Australia)

[simonbboettcher-blog]

The Irony

I didn’t quite think about the fact, undertaking this journal, that I would indeed most likely be doing some basic web coding along the way. Don’t worry though, this was made abundantly clear to me while trying to format that last post.

Here are some things I learned along the way:

1. This came very much in handy highlighting the code for easy readability in my post, and I will most definitely be using it in the future.

2. Tumblr's HTML editing system sucks. Constantly breaks code when auto reformatting it after editing. Stick to coding on a program of choice and pasting it in. I use Sublime Text 3, it's highly recommended.

3. I found some handy code to show and hide text, simpler than a button and easy to use with this blogging interface. Credit to Provoltion, check it out:

Language: HTML

Notes: Some Hide/Show Spoiler Code

.boxed { width: auto; height:auto px; border: 1px solid black; overflow-x: scroll; overflow-y: hidden; white-space: nowrap; margin: 40 px; } [Show][Hide]

<a id="show_id" onclick="document.getElementById('spoiler_id').style.display=''; document.getElementById('show_id').style.display='none';" class="link">[Show]</a><span id="spoiler_id" style="display: none"><a onclick="document.getElementById('spoiler_id').style.display='none'; document.getElementById('show_id').style.display='';" class="link">[Hide]</a><br>spoiler_content</span>

4. See that horizontal scrolling box up there? That's also something new for me. I used this post on stackoverflow for reference.

Long story short; I think I'm going to need to scratch up on some HTML.

01.06.2016, 1:04PM (Australia)

[simonbboettcher-blog]

In The Beginning

Today I found this project of mine. This was the first proper programming project I undertook, in which I was given an objective and was told to go figure it out. It was done quite a few years ago, and looking back I've come a long way, but the finding of this is what brought to me to create this journal. Language: Python 2.7 The task: Create an attendance program for a class. Write results externally and open previous logs of attenance. Notes: Designed to be setup and then allow students to log themselves as present as they enter the classroom.

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# This is a small Python 2.7 attendance roll program. # Author: Simon Boettcher # Thanks: Morris Bernstein, Zed Shaw # Date created: 15/05/2013 # Last updated: 22/05/2013 # Times updated: 7 # Assignations a = True # This makes 'a' true. x = True # This makes 'x' true. y = True # This makes 'y' true. # Program intro. print "\n" print "Roll Initiated" # Teacher Startup Wizard, asking for prerequisite information from teacher or staff. print "\n" print "Teacher, Please enter the current date in DD.MM.YYYY format." while a == True: date = raw_input ("Date: ") #Checks whether user input is higher or lower than 10 characters, if so prints 'invalid statement'. if len(date) < 10 or len(date) > 10: print "Invalid date, try again." print "\n" continue # Checks whether the date format is correct. try: with open(date + '.dat', 'w'): pass a = False except IOError: print "Date invalid format, please try again." print "\n" a = True # Writes attendance roll intro into file. target = open(date + '.dat', 'w') # This assigns 'date'.dat as the writable target. target.write("Class Attendance Roll") target.write("\n") target.write("\n") target.write("Date: ") target.write(date) target.write("\n") target.write("\n") target.write("Students: ") target.write("\n") print "Startup Wizard complete." print "\n" print "NOTE: Please type the 'help' command for functions." # Student Wizard, asking for student code or command. while x == True: print "\n" print "Please enter your student code or a command." response = raw_input ("Student Code/Command: ") # Checking if response is a quit command and then exiting if it is. if response == "exit": x = False else: # Checks whether user input is higher or lower than 6 characters. if len(response) < 7 or len(response) > 7: # Checks if reponse is a command. if response == "open" or response == "read" or response == "help" or response == "clear" or response == "absent" or response == "delete" or response == "remove": # or response == "restart" if response == "delete" or response == "remove": print "Which file date's file file would you like to delete (DD.MM.YYYY)?" remove = raw_input("Date: ") print "Are you sure you want to delete %d from database?" % remove remove_sure = raw_input("y/n: ") if remove_sure == "y" or remove_sure == "yes": import os os.remove(remove + '.dat') print "File %s was deleted from database." % remove else: continue # Checks if response is a 'restart' command. if response == "restart": # Asks user if they're certain they want to restart the program. print "Are you should you would like to restart the program?" restart = raw_input("y/n: ") if restart == "y" or restart == "yes": # Opens second copy of program. import os os.startfile(open_date + '.dat') # Exits current copy of program. print "Restarting..." x = False else: print "Restart cancelled." continue # Checking if response is an 'absent' command. if response == "absent": print "\n" print "Which student is absent?" absent = raw_input("Student Code: ") print "Are you sure that %s is absent (y/n)?" % absent absent_check = raw_input("y/n:") print "Why is %s absent?" % absent absent_reason = raw_input("Reason: ") if absent_check == "y" or absent_check == "yes": target.write("\n") target.write("NOTE: ") target.write("\n") target.write(absent + " = absent") target.write("\n") target.write("Reason: " + absent_reason) target.write("\n") target.write("\n") print "%s has been marked absent." % absent else: continue # Checking if response is a clear command. if response == "clear": print "\n" print "What date's roll would you like to clear (DD.MM.YYYY)?" clear_date = raw_input ("Date: ") # Checks whether file exists. try: with open(clear_date + '.dat'): pass except IOError: print "File does not exist." continue # Prompts user whether they're sure they wish to clear file. print "Are you sure you want to clear %s's file (y/n)?" % clear_date clear_sure = raw_input("y/n:") # If user is sure clear specified date's file. if clear_sure == "y": clear = open(clear_date + '.dat', 'w') clear.truncate() print "%s's roll cleared." % clear_date else: continue # Checking if response is a read command. if response == "read": # Asks which file user would wish to view. print "\n" print "What date's roll would you like to view (DD.MM.YYYY)?" print "NOTE: To view the current date you must restart the program." read_date = raw_input ("Date: ") # Checks whether file exists. try: with open(read_date + '.dat'): pass except IOError: print "File does not exist." continue # Displays contents of selected '.dat' file from sys import argv f = open(read_date + '.dat') print "\n" print f.read() # Checking if response is an open command. if response == "open": print "\n" print "What date's roll would you like to manually edit (DD.MM.YYYY)?" open_date = raw_input ("Date: ") # Checks whether file exists. try: with open(open_date + '.dat'): pass except IOError: print "File does not exist." continue # Opens specified date's file. import os os.startfile(open_date + '.dat') print "Now editing %s." % open_date # Checks whether response is help, if so displays help. if response == "help": print "\n" print "Commands:" print "Mark student as absent = absent" print "View/read previous date's file = read" print "Open previous date's file for editing = open" print "Deletes/removes the specified date's file = delete" print "Clear the contents of a date's file = clear" print "Exit/close the program = exit" # print "Restart/reboot the program = restart" continue # Prints 'invalid statment' after user input if applicable. else: print "Invalid student code or command." continue # Writes student code to target '.dat' file. else: student_code = response target.write(student_code + " = present") target.write("\n") # Tells user data is saved before program exits. print "\n" print "Data saved."

In fact, reading this makes me rather keen to try out some Python again.

01.06.2016, 12:36PM (Australia)

[simonbboettcher-blog]

Genesis

Today I decided to start a coding journal. Some sort of a log or archive of past projects and what I’m currently working on, let’s see where it takes us.

01.06.2016, 11:55AM (Australia)