def is_acceptable(p, q): '''Returns True iff p and q are acceptable: - p and q differ - (p * q) has the right nr of bits (when accurate=True) ''' if p == q: return False if not accurate: return True # Make sure we have just the right amount of bits found_size = common.bit_size(p * q) return total_bits == found_size
def randint(maxvalue): '''Returns a random integer x with 1 <= x <= maxvalue May take a very long time in specific situations. If maxvalue needs N bits to store, the closer maxvalue is to (2 ** N) - 1, the faster this function is. ''' bit_size = common.bit_size(maxvalue) tries = 0 while True: value = read_random_int(bit_size) if value <= maxvalue: break if tries and tries % 10 == 0: # After a lot of tries to get the right number of bits but still # smaller than maxvalue, decrease the number of bits by 1. That'll # dramatically increase the chances to get a large enough number. bit_size -= 1 tries += 1 return value