How to compare [32]byte with []byte in golang?

You can trivially convert any array ([size]T) to a slice ([]T) by slicing it:

x := [32]byte{}
slice := x[:] // shorthand for x[0:len(x)]

From there you can compare it to your slice like you would compare any other two slices, e.g.

func Equal(slice1, slice2 []byte) bool {
    if len(slice1) != len(slice2) {
        return false
    }

    for i := range slice1 {
        if slice1[i] != slice2[i] {
            return false
        }
    }

    return true
}

Edit: As Dave mentions in the comments, there's also an Equal method in the bytes package, bytes.Equal(x[:], y[:])