module ZSteg::Checker::SteganographyPNG
Constants
- URL
Public Class Methods
check_image(image, _params = {})
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# File lib/zsteg/checker/steganography_png.rb, line 24 def self.check_image image, _params = {} ls = image.scanlines.last data = ls.decoded_bytes secret_type_length = data[-1].ord return nil if secret_type_length > data.size - 8 data = data[ -secret_type_length-8 .. -2 ] # data.size to prevent "want 8 bytes, got 7" IOStruct warning when secret_type_length == 0 r = Result.read(data, data.size) r.valid? && [r, URL] end