('%02x'):format(Number) in Node Js

Question

Trying to convert lua encryption to Node.JS, just need this in it. ("%02x"):format(c) Once, I got that I'll have it in node.js, so I tried buffer and it didn't work. Tried a few other things, and they also didn't work.

Orginal post for this encryption: Low impact encryption formula for ROBLOX Lua Lua Code:

local Key53 = 8186484168865098
local Key14 = 4887
local inv256

    function encode(str)
        if not inv256 then
            inv256 = {}
            for M = 0, 127 do
                local inv = -1

                repeat 
                    inv = inv + 2
                until inv * (2*M + 1) % 256 == 1
                inv256[M] = inv
            end
        end

        local K, F = Key53, 16384 + Key14
        return (str:gsub('.',
            function(m)
                local L = K % 274877906944  -- 2^38
                local H = (K - L) / 274877906944
                local M = H % 128
                m = m:byte()

                local c = (m * inv256[M] - (H - M) / 128) % 256
                K = L * F + H + c + m
                
                --print("lol ".. c)
                --print(('%02x'):format(c))
                return ('%02x'):format(c)
            end
        ))
    end

    function decode(str)
        local K, F = Key53, 16384 + Key14
        return (str:gsub('%x%x',
            function(c)
                local L = K % 274877906944  -- 2^38
                local H = (K - L) / 274877906944
                local M = H % 128
                c = tonumber(c, 16)

                local m = (c + (H - M) / 128) * (2*M + 1) % 256
                K = L * F + H + c + m

                return string.char(m)
            end
        ))
    end

Does this answer your question? [JavaScript equivalent to printf/String.Format](https://stackoverflow.com/questions/610406/javascript-equivalent-to-printf-string-format) — Piglet, Oct 25 '21 at 08:35

score 1 · Answer 1 · answered Oct 24 '21 at 04:26

The %02x just convert a decimal to hex. In JS it could be done that way:

function toHex(value) {
    let hex = value.toString(16);
    if ((hex.length % 2) > 0) {
        hex = "0" + hex;
    }
    return hex;
}

Outputs:

toHex(120) // 78
('%02x'):format(120) -- 78

('%02x'):format(Number) in Node Js

1 Answers1