rotr.rb

# -----------
# Shift Right
# -----------
def rotr(n, x)
  mask = 2**32 - 1
  right = (x >> n) & mask
  left  = (x << 32-n) & mask
  result = right | left
  return result
end

# -----
# Input
# -----
# defaults
x = 0b11111111000000001111111100000000 #0b11101001101101011101101110100101
n = 32
# arguments passed
x = ARGV[0].to_i(2) if ARGV[0] # binary
n = ARGV[1].to_i    if ARGV[1] # integer
# check arguments
if ARGV[0] && ARGV[0].size > 32
	puts "We only operate on 32-bit words in SHA-256. Your x is #{ARGV[0].size} bits."; exit
end

# ---------
# Animation
# ---------
s = n.to_s.ljust(2, " ")
n.times do |i|
  system "clear"
  i += 1

  puts "      x: #{"%032b" % x}"
  puts "ROTR #{s}: #{"%032b" % rotr(i, x)}"

  sleep 0.10
end
sleep 0.5