| 1 | package seal |
| 2 | |
| 3 | import ( |
| 4 | "bytes" |
| 5 | "testing" |
| 6 | ) |
| 7 | |
| 8 | func testDEK() []byte { |
| 9 | d := make([]byte, 32) |
| 10 | for i := range d { |
| 11 | d[i] = byte(i) |
| 12 | } |
| 13 | return d |
| 14 | } |
| 15 | |
| 16 | func TestRoundTrip(t *testing.T) { |
| 17 | s, err := New(testDEK()) |
| 18 | if err != nil { |
| 19 | t.Fatal(err) |
| 20 | } |
| 21 | want := []byte("June revenue was 1,350,000") |
| 22 | ct, err := s.Seal(PurposeChunk, want) |
| 23 | if err != nil { |
| 24 | t.Fatal(err) |
| 25 | } |
| 26 | if bytes.Contains(ct, want) { |
| 27 | t.Fatal("ciphertext contains the plaintext") |
| 28 | } |
| 29 | got, err := s.Open(PurposeChunk, ct) |
| 30 | if err != nil { |
| 31 | t.Fatal(err) |
| 32 | } |
| 33 | if !bytes.Equal(got, want) { |
| 34 | t.Fatalf("round trip: got %q want %q", got, want) |
| 35 | } |
| 36 | } |
| 37 | |
| 38 | // A chunk must not open as a title. The two are adjacent columns of |
| 39 | // related rows; without HKDF purpose separation a swap would decrypt |
| 40 | // cleanly and nothing would notice. |
| 41 | func TestPurposesDoNotInterchange(t *testing.T) { |
| 42 | s, _ := New(testDEK()) |
| 43 | ct, err := s.Seal(PurposeChunk, []byte("secret passage")) |
| 44 | if err != nil { |
| 45 | t.Fatal(err) |
| 46 | } |
| 47 | if _, err := s.Open(PurposeTitle, ct); err == nil { |
| 48 | t.Fatal("a chunk opened as a title; purpose separation is not working") |
| 49 | } |
| 50 | } |
| 51 | |
| 52 | func TestRejectsWrongKeyLength(t *testing.T) { |
| 53 | for _, n := range []int{0, 16, 31, 33, 64} { |
| 54 | if _, err := New(make([]byte, n)); err == nil { |
| 55 | t.Errorf("accepted a %d-byte DEK", n) |
| 56 | } |
| 57 | } |
| 58 | } |
| 59 | |
| 60 | // Two seals of the same plaintext must differ, or the store leaks |
| 61 | // equality between passages — which over a corpus leaks structure. |
| 62 | func TestNonceIsFresh(t *testing.T) { |
| 63 | s, _ := New(testDEK()) |
| 64 | a, _ := s.Seal(PurposeChunk, []byte("same")) |
| 65 | b, _ := s.Seal(PurposeChunk, []byte("same")) |
| 66 | if bytes.Equal(a, b) { |
| 67 | t.Fatal("two seals of the same plaintext are identical") |
| 68 | } |
| 69 | } |
| 70 | |
amadan