WhitePages

Information

Points	Category	Level
250	Forensics	Medium

Challenge

I stopped using YellowPages and moved onto WhitePages… but the page they gave me is all blank!

Hint

Solution

I download the file, and opened it - There is nothing I can see in it, but when i press Ctrl + A to mark all, I can see that there is something! The name of the challenge make me think about whitespace characters Those characters are invisible but still are in the file. So after some searching in the web I saw a interpreter for those white-spaces, but nothing came out. So I go back to the file to check if all the chars are the same or there are different white-spaces in the file. I copy the first char and Ctrl+F in the file -

As you can see, there some holes so this is different white-spaces chars, I copy one of the “holes” and search too, I found that the file include only 2 diffrenet white-spaces. So after some time I thought about binary, maybe those chars signal 1 and 0s.

So I wrote this python script: There is much to scroll because the text of the file is just one line

# coding=utf8

text = '                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                '

firstType = ' '
secondType =  ' '
binaryString = ''

for char in text: #Foreach char
	if char == firstType: #Check if it is the first type
		binaryString += '0' #Mark it as 0
	else:
		binaryString += '1' #Mark it as 1

print(binaryString) #Print result

So it’s just move on each char and set it to 0 or 1. I tried it when the first type is 0 and the second one is 1, and the opposite, the opposite worked… run the script - So we got an binary number, used this site to convert it to a meaningful text - We got the flag!

Flag

picoCTF{not_all_spaces_are_created_equal_c167040c738e8bcae2109ef4be5960b1}

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