# Functions
ConstantTimeByteEq returns 1 if x == y and 0 otherwise.
ConstantTimeCompare returns 1 if the two slices, x and y, have equal contents and 0 otherwise.
ConstantTimeCopy copies the contents of y into x (a slice of equal length) if v == 1.
ConstantTimeEq returns 1 if x == y and 0 otherwise.
ConstantTimeLessOrEq returns 1 if x <= y and 0 otherwise.
ConstantTimeSelect returns x if v == 1 and y if v == 0.