hex 2 base64

hex2base64.rb

input = "49276d206b696c6c696e6720796f757220627261696e206c696b65206120706f69736f6e6f7573206d757368726f6f6d"
expected_output = "SSdtIGtpbGxpbmcgeW91ciBicmFpbiBsaWtlIGEgcG9pc29ub3VzIG11c2hyb29t"

def six(string)
  string.scan(/\w{6}/)
end

def to_binary(hex_string)
  expected_length = (hex_string.length / 2) * 8
  "%0#{expected_length}d" % hex_string.to_i(16).to_s(2)
end

chunks = six(input)
characters = (("A".."Z").to_a + ("a".."z").to_a + (0..9).to_a + ["?"] + ["?"])

retval = chunks.map do |chunk|
  binary = to_binary(chunk)
  puts [chunk, binary].join(" => ")

  bits = six(binary)
  in64 = bits.map do |b|
    decimal = b.to_i(2)
    c = characters[decimal]
    puts [b, decimal, c].join(" => ")

    c
  end
end

puts retval.join