Function ocrypto_constant_time_is_zero 

pub unsafe extern "C" fn ocrypto_constant_time_is_zero(
    x: *const c_void,
    length: usize,
) -> c_int

Variable length compare to zero.

• x - Memory region that will be compared.
• length - Number of bytes to compare, * length - > 0.

Returns 1 If * x - is equal to a zero memory region. Returns 0 Otherwise.