81 lines
No EOL
1.4 KiB
Ruby
81 lines
No EOL
1.4 KiB
Ruby
require "./pixel_image.rb"
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require "digest"
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class ImageUtils
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@@magickImg = nil
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@@pixelImg = nil
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@@password = ""
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@@message = ""
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@@hash = nil
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def initialize(pass, msg, i)
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@@password = pass
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@@message = msg
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if msg.length > 400 then
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puts "Maximum length exceeded. Exiting."
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exit
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end
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@@magickImg = i
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@@pixelImg = PixelImage.new(@@magickImg)
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self.generateHash
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end
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def getImage
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return @@pixelImg
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end
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def generateHash
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h = Digest::SHA512.hexdigest(@@password)
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s = @@pixelImg.getSalt
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merge_to_i = h + s
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@@hash = Digest::SHA512.hexdigest(h+s)
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end
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def generateLookupTable
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tbl = []
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hash_bits = @@pixelImg.getBits(@@hash)
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msg_bits = @@pixelImg.getBits(@@message)
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# gross, but pad in the 24 bits that will become the msg length
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# and padding bits...
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msg_bits = msg_bits << 24
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while msg_bits > 0 do
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loc = nil
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loop do
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x = (hash_bits.to_i % @@pixelImg.getSize[:width])
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y = (hash_bits.to_i % @@pixelImg.getSize[:height])
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loc = {"x": x, "y": y}
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break if !tbl.include?(loc)
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hash_bits = hash_bits >> 1
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if hash_bits <= 0 then
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puts
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puts "wow too much data"
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puts "leftover bits: " + msg_bits.to_s(36)
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exit
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end
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end
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hash_bits = hash_bits >> 1
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tbl.push(loc)
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msg_bits = msg_bits >> 6
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end
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return tbl
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end
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end |