f = (f << 1) | (f >> 31)

				feistelBox[s][t] = uint32(f)
			}
		}
	}
}

// permuteInitialBlock is equivalent to the permutation defined
// by initialPermutation.
func permuteInitialBlock(block uint64) uint64 {
	// block = b7 b6 b5 b4 b3 b2 b1 b0 (8 bytes)
	b1 := block >> 48
	b2 := block << 48
	block ^= b1 ^ b2 ^ b1<<48 ^ b2>>48

// license that can be found in the LICENSE file.

package des

import "testing"

func TestInitialPermute(t *testing.T) {
	for i := uint(0); i < 64; i++ {
		bit := uint64(1) << i
		got := permuteInitialBlock(bit)
		want := uint64(1) << finalPermutation[63-i]
		if got != want {
			t.Errorf("permute(%x) = %x, want %x", bit, got, want)
		}
	}
}

func TestFinalPermute(t *testing.T) {

		panic("crypto/des: output not full block")
	}
	if alias.InexactOverlap(dst[:BlockSize], src[:BlockSize]) {
		panic("crypto/des: invalid buffer overlap")
	}

	b := byteorder.BeUint64(src)
	b = permuteInitialBlock(b)
	left, right := uint32(b>>32), uint32(b)

	left = (left << 1) | (left >> 31)
	right = (right << 1) | (right >> 31)

	for i := 0; i < 8; i++ {