# PicoCTF - WhitePages ###### tags: `PicoCTF` `CTF` `Misc` Challenge: [WhitePages](https://play.picoctf.org/practice/challenge/51?category=4&page=3) ## Source code :::spoiler source text ```text!                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                       ``` ::: ## Exploit - Binary Encoding If you use sublime editor to observe the file, then you may see the result as below. ![](https://i.imgur.com/ME4F3hm.png) In unicode, `<0x2003>` is a kind of white space, then some gap between `<0x2003>` is a normal white space. Obviously, this is a binary encoding(`<0x2003>` is 0 and normal white space is 1) $\to$ ```binary! 00001010000010010000100101110000011010010110001101101111010000110101010001000110000010100000101000001001000010010101001101000101010001010010000001010000010101010100001001001100010010010100001100100000010100100100010101000011010011110101001001000100010100110010000000100110001000000100001001000001010000110100101101000111010100100100111101010101010011100100010000100000010100100100010101010000010011110101001001010100000010100000100100001001001101010011000000110000001100000010000001000110011011110111001001100010011001010111001100100000010000010111011001100101001011000010000001010000011010010111010001110100011100110110001001110101011100100110011101101000001011000010000001010000010000010010000000110001001101010011001000110001001100110000101000001001000010010111000001101001011000110110111101000011010101000100011001111011011011100110111101110100010111110110000101101100011011000101111101110011011100000110000101100011011001010111001101011111011000010111001001100101010111110110001101110010011001010110000101110100011001010110010001011111011001010111000101110101011000010110110001011111001101110011000100110000001100000011100000110110001100000110001000110000011001100110000100110111001101110011100101100001001101010110001001100100001110000110001101100101001100100011100101100110001100100011010001100110001101010011100000110110011001000110001101111101000010100000100100001001 ``` ![](https://i.imgur.com/fJc4IZD.png) * Note that, must choose `ASCII` mode