package crypto_test import ( "bytes" "crypto/rand" "io" "testing" "github.com/restic/restic/internal/crypto" rtest "github.com/restic/restic/internal/test" "github.com/restic/chunker" ) const testLargeCrypto = false func TestEncryptDecrypt(t *testing.T) { k := crypto.NewRandomKey() tests := []int{5, 23, 2<<18 + 23, 1 << 20} if testLargeCrypto { tests = append(tests, 7<<20+123) } for _, size := range tests { data := rtest.Random(42, size) buf := make([]byte, 0, size+crypto.Extension) nonce := crypto.NewRandomNonce() ciphertext := k.Seal(buf[:0], nonce, data, nil) rtest.Assert(t, len(ciphertext) == len(data)+k.Overhead(), "ciphertext length does not match: want %d, got %d", len(data)+crypto.Extension, len(ciphertext)) plaintext := make([]byte, 0, len(ciphertext)) plaintext, err := k.Open(plaintext[:0], nonce, ciphertext, nil) rtest.OK(t, err) rtest.Assert(t, len(plaintext) == len(data), "plaintext length does not match: want %d, got %d", len(data), len(plaintext)) rtest.Equals(t, plaintext, data) } } func TestSmallBuffer(t *testing.T) { k := crypto.NewRandomKey() size := 600 data := make([]byte, size) _, err := io.ReadFull(rand.Reader, data) rtest.OK(t, err) ciphertext := make([]byte, 0, size/2) nonce := crypto.NewRandomNonce() ciphertext = k.Seal(ciphertext[:0], nonce, data, nil) // this must extend the slice rtest.Assert(t, cap(ciphertext) > size/2, "expected extended slice, but capacity is only %d bytes", cap(ciphertext)) // check for the correct plaintext plaintext := make([]byte, len(ciphertext)) plaintext, err = k.Open(plaintext[:0], nonce, ciphertext, nil) rtest.OK(t, err) rtest.Assert(t, bytes.Equal(plaintext, data), "wrong plaintext returned") } func TestSameBuffer(t *testing.T) { k := crypto.NewRandomKey() size := 600 data := make([]byte, size) _, err := io.ReadFull(rand.Reader, data) rtest.OK(t, err) ciphertext := make([]byte, 0, size+crypto.Extension) nonce := crypto.NewRandomNonce() ciphertext = k.Seal(ciphertext, nonce, data, nil) // use the same buffer for decryption ciphertext, err = k.Open(ciphertext[:0], nonce, ciphertext, nil) rtest.OK(t, err) rtest.Assert(t, bytes.Equal(ciphertext, data), "wrong plaintext returned") } func encrypt(t testing.TB, k *crypto.Key, data, ciphertext, nonce []byte) []byte { prefixlen := len(ciphertext) ciphertext = k.Seal(ciphertext, nonce, data, nil) if len(ciphertext) != len(data)+k.Overhead()+prefixlen { t.Fatalf("destination slice has wrong length, want %d, got %d", len(data)+k.Overhead(), len(ciphertext)) } return ciphertext } func decryptNewSliceAndCompare(t testing.TB, k *crypto.Key, data, ciphertext, nonce []byte) { plaintext := make([]byte, 0, len(ciphertext)) decryptAndCompare(t, k, data, ciphertext, nonce, plaintext) } func decryptAndCompare(t testing.TB, k *crypto.Key, data, ciphertext, nonce, dst []byte) { prefix := make([]byte, len(dst)) copy(prefix, dst) plaintext, err := k.Open(dst, nonce, ciphertext, nil) if err != nil { t.Fatalf("unable to decrypt ciphertext: %v", err) } if len(data)+len(prefix) != len(plaintext) { t.Fatalf("wrong plaintext returned, want %d bytes, got %d", len(data)+len(prefix), len(plaintext)) } if !bytes.Equal(plaintext[:len(prefix)], prefix) { t.Fatal("prefix is wrong") } if !bytes.Equal(plaintext[len(prefix):], data) { t.Fatal("wrong plaintext returned") } } func TestAppendOpen(t *testing.T) { k := crypto.NewRandomKey() nonce := crypto.NewRandomNonce() data := make([]byte, 600) _, err := io.ReadFull(rand.Reader, data) rtest.OK(t, err) ciphertext := encrypt(t, k, data, nil, nonce) // we need to test several different cases: // * destination slice is nil // * destination slice is empty and has enough capacity // * destination slice is empty and does not have enough capacity // * destination slice contains data and has enough capacity // * destination slice contains data and does not have enough capacity // destination slice is nil t.Run("nil", func(t *testing.T) { var plaintext []byte decryptAndCompare(t, k, data, ciphertext, nonce, plaintext) }) // destination slice is empty and has enough capacity t.Run("empty-large", func(t *testing.T) { plaintext := make([]byte, 0, len(data)+100) decryptAndCompare(t, k, data, ciphertext, nonce, plaintext) }) // destination slice is empty and does not have enough capacity t.Run("empty-small", func(t *testing.T) { plaintext := make([]byte, 0, len(data)/2) decryptAndCompare(t, k, data, ciphertext, nonce, plaintext) }) // destination slice contains data and has enough capacity t.Run("prefix-large", func(t *testing.T) { plaintext := make([]byte, 0, len(data)+100) plaintext = append(plaintext, []byte("foobar")...) decryptAndCompare(t, k, data, ciphertext, nonce, plaintext) }) // destination slice contains data and does not have enough capacity t.Run("prefix-small", func(t *testing.T) { plaintext := make([]byte, 0, len(data)/2) plaintext = append(plaintext, []byte("foobar")...) decryptAndCompare(t, k, data, ciphertext, nonce, plaintext) }) } func TestAppendSeal(t *testing.T) { k := crypto.NewRandomKey() data := make([]byte, 600) _, err := io.ReadFull(rand.Reader, data) rtest.OK(t, err) // we need to test several different cases: // * destination slice is nil // * destination slice is empty and has enough capacity // * destination slice is empty and does not have enough capacity // * destination slice contains data and has enough capacity // * destination slice contains data and does not have enough capacity // destination slice is nil t.Run("nil", func(t *testing.T) { nonce := crypto.NewRandomNonce() var ciphertext []byte ciphertext = encrypt(t, k, data, ciphertext, nonce) decryptNewSliceAndCompare(t, k, data, ciphertext, nonce) }) // destination slice is empty and has enough capacity t.Run("empty-large", func(t *testing.T) { nonce := crypto.NewRandomNonce() ciphertext := make([]byte, 0, len(data)+100) ciphertext = encrypt(t, k, data, ciphertext, nonce) decryptNewSliceAndCompare(t, k, data, ciphertext, nonce) }) // destination slice is empty and does not have enough capacity t.Run("empty-small", func(t *testing.T) { nonce := crypto.NewRandomNonce() ciphertext := make([]byte, 0, len(data)/2) ciphertext = encrypt(t, k, data, ciphertext, nonce) decryptNewSliceAndCompare(t, k, data, ciphertext, nonce) }) // destination slice contains data and has enough capacity t.Run("prefix-large", func(t *testing.T) { nonce := crypto.NewRandomNonce() ciphertext := make([]byte, 0, len(data)+100) ciphertext = append(ciphertext, []byte("foobar")...) ciphertext = encrypt(t, k, data, ciphertext, nonce) if string(ciphertext[:6]) != "foobar" { t.Errorf("prefix is missing") } decryptNewSliceAndCompare(t, k, data, ciphertext[6:], nonce) }) // destination slice contains data and does not have enough capacity t.Run("prefix-small", func(t *testing.T) { nonce := crypto.NewRandomNonce() ciphertext := make([]byte, 0, len(data)/2) ciphertext = append(ciphertext, []byte("foobar")...) ciphertext = encrypt(t, k, data, ciphertext, nonce) if string(ciphertext[:6]) != "foobar" { t.Errorf("prefix is missing") } decryptNewSliceAndCompare(t, k, data, ciphertext[6:], nonce) }) } func TestLargeEncrypt(t *testing.T) { if !testLargeCrypto { t.SkipNow() } k := crypto.NewRandomKey() for _, size := range []int{chunker.MaxSize, chunker.MaxSize + 1, chunker.MaxSize + 1<<20} { data := make([]byte, size) _, err := io.ReadFull(rand.Reader, data) rtest.OK(t, err) nonce := crypto.NewRandomNonce() ciphertext := k.Seal(make([]byte, size+k.Overhead()), nonce, data, nil) plaintext, err := k.Open([]byte{}, nonce, ciphertext, nil) rtest.OK(t, err) rtest.Equals(t, plaintext, data) } } func BenchmarkEncrypt(b *testing.B) { size := 8 << 20 // 8MiB data := make([]byte, size) k := crypto.NewRandomKey() buf := make([]byte, len(data)+crypto.Extension) nonce := crypto.NewRandomNonce() b.ResetTimer() b.SetBytes(int64(size)) for i := 0; i < b.N; i++ { _ = k.Seal(buf, nonce, data, nil) } } func BenchmarkDecrypt(b *testing.B) { size := 8 << 20 // 8MiB data := make([]byte, size) k := crypto.NewRandomKey() plaintext := make([]byte, 0, size) ciphertext := make([]byte, 0, size+crypto.Extension) nonce := crypto.NewRandomNonce() ciphertext = k.Seal(ciphertext, nonce, data, nil) var err error b.ResetTimer() b.SetBytes(int64(size)) for i := 0; i < b.N; i++ { _, err = k.Open(plaintext, nonce, ciphertext, nil) rtest.OK(b, err) } }