// Creates metadata in the following manner:
// - the snapshot has bad checksums for itself and for timestamp, to show that those aren't checked
// - snapshot has valid checksums for root, targets, and targets/other
// - snapshot doesn't have a checksum for targets/other/other, but targets/other/other is a valid
//   delegation role in targets/other and there is metadata for targets/other/other that is correctly
//   signed
func setupSnapshotChecksumming(t *testing.T, gun string) map[string][]byte {
	repo, _, err := testutils.EmptyRepo(gun, "targets/other", "targets/other/other")
	require.NoError(t, err)

	// add invalid checkums for all the other roles to timestamp too, and show that
	// cached items aren't checksummed against this
	fakeChecksum, err := data.NewFileMeta(bytes.NewBuffer([]byte("fake")), notary.SHA256, notary.SHA512)
	require.NoError(t, err)
	// fake the snapshot and timestamp checksums
	repo.Snapshot.Signed.Meta[data.CanonicalSnapshotRole] = fakeChecksum
	repo.Snapshot.Signed.Meta[data.CanonicalTimestampRole] = fakeChecksum

	meta, err := testutils.SignAndSerialize(repo)
	require.NoError(t, err)
	// ensure that the fake metadata for other roles wasn't destroyed by signing
	require.Len(t, repo.Snapshot.Signed.Meta, 5)

	// create delegation metadata that should not be in snapshot, but has a valid role and signature
	_, err = repo.InitTargets("targets/other/other")
	require.NoError(t, err)
	s, err := repo.SignTargets("targets/other/other", data.DefaultExpires(data.CanonicalTargetsRole))
	require.NoError(t, err)
	meta["targets/other/other"], err = json.Marshal(s)
	require.NoError(t, err)

	return meta
}

// If applying a change fails due to a prefix error, changeTargetMeta fails outright
func TestChangeTargetMetaFailsIfPrefixError(t *testing.T) {
	repo, cs, err := testutils.EmptyRepo("docker.com/notary")
	require.NoError(t, err)

	newKey, err := cs.Create("targets/level1", "docker.com/notary", data.ED25519Key)
	require.NoError(t, err)

	err = repo.UpdateDelegationKeys("targets/level1", []data.PublicKey{newKey}, []string{}, 1)
	require.NoError(t, err)
	err = repo.UpdateDelegationPaths("targets/level1", []string{"pathprefix"}, []string{}, false)
	require.NoError(t, err)

	hash := sha256.Sum256([]byte{})
	f := &data.FileMeta{
		Length: 1,
		Hashes: map[string][]byte{
			"sha256": hash[:],
		},
	}
	fjson, err := json.Marshal(f)
	require.NoError(t, err)

	err = changeTargetMeta(repo, &changelist.TUFChange{
		Actn:       changelist.ActionCreate,
		Role:       "targets/level1",
		ChangeType: "target",
		ChangePath: "notPathPrefix",
		Data:       fjson,
	})
	require.Error(t, err)

	// no target in targets or targets/latest
	require.Empty(t, repo.Targets[data.CanonicalTargetsRole].Signed.Targets)
	require.Empty(t, repo.Targets["targets/level1"].Signed.Targets)
}

// Applying a delegation whose parent doesn't exist fails.
func TestApplyTargetsDelegationParentDoesntExist(t *testing.T) {
	repo, cs, err := testutils.EmptyRepo("docker.com/notary")
	assert.NoError(t, err)

	// make sure a key exists for the previous level, so it's not a missing
	// key error, but we don't care about this key
	_, err = cs.Create("targets/level1", data.ED25519Key)
	assert.NoError(t, err)

	newKey, err := cs.Create("targets/level1/level2", data.ED25519Key)
	assert.NoError(t, err)

	// create delegation
	kl := data.KeyList{newKey}
	td := &changelist.TufDelegation{
		NewThreshold: 1,
		AddKeys:      kl,
	}

	tdJSON, err := json.Marshal(td)
	assert.NoError(t, err)

	ch := changelist.NewTufChange(
		changelist.ActionCreate,
		"targets/level1/level2",
		changelist.TypeTargetsDelegation,
		"",
		tdJSON,
	)

	err = applyTargetsChange(repo, ch)
	assert.Error(t, err)
	assert.IsType(t, data.ErrInvalidRole{}, err)
}

func TestApplyTargetsDelegationCreateInvalid(t *testing.T) {
	_, repo, cs := testutils.EmptyRepo()

	newKey, err := cs.Create("targets/level1", data.ED25519Key)
	assert.NoError(t, err)

	// create delegation
	kl := data.KeyList{newKey}
	td := &changelist.TufDelegation{
		NewThreshold:        1,
		AddKeys:             kl,
		AddPaths:            []string{"level1"},
		AddPathHashPrefixes: []string{"abc"},
	}

	tdJSON, err := json.Marshal(td)
	assert.NoError(t, err)

	ch := changelist.NewTufChange(
		changelist.ActionCreate,
		"targets/level1",
		changelist.TypeTargetsDelegation,
		"",
		tdJSON,
	)

	err = applyTargetsChange(repo, ch)
	assert.Error(t, err)
}

// Ensures that the httpstore can interpret the errors returned from the server
func TestValidationErrorFormat(t *testing.T) {
	ctx := context.WithValue(
		context.Background(), "metaStore", storage.NewMemStorage())
	ctx = context.WithValue(ctx, "keyAlgorithm", data.ED25519Key)

	handler := RootHandler(nil, ctx, signed.NewEd25519())
	server := httptest.NewServer(handler)
	defer server.Close()

	client, err := store.NewHTTPStore(
		fmt.Sprintf("%s/v2/gun/_trust/tuf/", server.URL),
		"",
		"json",
		"",
		"key",
		http.DefaultTransport,
	)

	_, repo, _ := testutils.EmptyRepo()
	r, tg, sn, ts, err := testutils.Sign(repo)
	assert.NoError(t, err)
	rs, _, _, _, err := testutils.Serialize(r, tg, sn, ts)
	assert.NoError(t, err)

	err = client.SetMultiMeta(map[string][]byte{data.CanonicalRootRole: rs})
	assert.Error(t, err)
	assert.IsType(t, validation.ErrBadRoot{}, err)
}

func TestValidateSnapshotGenerate(t *testing.T) {
	kdb, repo, cs := testutils.EmptyRepo()
	store := storage.NewMemStorage()
	snapRole := kdb.GetRole(data.CanonicalSnapshotRole)

	for _, id := range snapRole.KeyIDs {
		k := kdb.GetKey(id)
		assert.NotNil(t, k)
		err := store.SetKey("testGUN", data.CanonicalSnapshotRole, k.Algorithm(), k.Public())
		assert.NoError(t, err)
	}

	r, tg, sn, ts, err := testutils.Sign(repo)
	assert.NoError(t, err)
	root, targets, _, _, err := getUpdates(r, tg, sn, ts)
	assert.NoError(t, err)

	updates := []storage.MetaUpdate{targets}

	store.UpdateCurrent("testGUN", root)

	copyTimestampKey(t, kdb, store, "testGUN")
	updates, err = validateUpdate(cs, "testGUN", updates, store)
	assert.NoError(t, err)
}

func TestDownloadTargetChecksumMismatch(t *testing.T) {
	repo, _, err := testutils.EmptyRepo("docker.com/notary")
	assert.NoError(t, err)
	localStorage := store.NewMemoryStore(nil)
	remoteStorage := testutils.NewCorruptingMemoryStore(nil)
	client := NewClient(repo, remoteStorage, localStorage)

	// create and "upload" sample targets
	signedOrig, err := repo.SignTargets("targets", data.DefaultExpires("targets"))
	assert.NoError(t, err)
	orig, err := json.Marshal(signedOrig)
	assert.NoError(t, err)
	origSha256 := sha256.Sum256(orig)
	err = remoteStorage.SetMeta("targets", orig)
	assert.NoError(t, err)

	// create local snapshot with targets file
	snap := data.SignedSnapshot{
		Signed: data.Snapshot{
			Meta: data.Files{
				"targets": data.FileMeta{
					Length: int64(len(orig)),
					Hashes: data.Hashes{
						"sha256": origSha256[:],
					},
				},
			},
		},
	}

	repo.Snapshot = &snap

	err = client.downloadTargets("targets")
	assert.IsType(t, ErrChecksumMismatch{}, err)
}

func TestValidateSnapshotGeneratePrevCorrupt(t *testing.T) {
	gun := "docker.com/notary"
	repo, cs, err := testutils.EmptyRepo(gun)
	require.NoError(t, err)
	store := storage.NewMemStorage()
	snapRole, err := repo.GetBaseRole(data.CanonicalSnapshotRole)
	require.NoError(t, err)

	for _, k := range snapRole.Keys {
		err := store.SetKey(gun, data.CanonicalSnapshotRole, k.Algorithm(), k.Public())
		require.NoError(t, err)
	}

	r, tg, sn, ts, err := testutils.Sign(repo)
	require.NoError(t, err)
	root, targets, snapshot, _, err := getUpdates(r, tg, sn, ts)
	require.NoError(t, err)

	updates := []storage.MetaUpdate{root, targets}

	// corrupt the JSON structure of prev snapshot
	snapshot.Data = snapshot.Data[1:]
	// set the current snapshot in the store manually so we find it when generating
	// the next version
	store.UpdateCurrent(gun, snapshot)

	serverCrypto := testutils.CopyKeys(t, cs, data.CanonicalTimestampRole, data.CanonicalSnapshotRole)
	_, err = validateUpdate(serverCrypto, gun, updates, store)
	require.Error(t, err)
	require.IsType(t, &json.SyntaxError{}, err)
}

// Store is broken when getting the current snapshot
func TestValidateSnapshotGenerateStoreGetCurrentSnapshotBroken(t *testing.T) {
	gun := "docker.com/notary"
	repo, cs, err := testutils.EmptyRepo(gun)
	require.NoError(t, err)
	store := getFailStore{
		MetaStore:    storage.NewMemStorage(),
		errsToReturn: map[string]error{data.CanonicalSnapshotRole: data.ErrNoSuchRole{}},
	}
	snapRole, err := repo.GetBaseRole(data.CanonicalSnapshotRole)
	require.NoError(t, err)

	for _, k := range snapRole.Keys {
		err := store.SetKey(gun, data.CanonicalSnapshotRole, k.Algorithm(), k.Public())
		require.NoError(t, err)
	}

	r, tg, sn, ts, err := testutils.Sign(repo)
	require.NoError(t, err)
	root, targets, _, _, err := getUpdates(r, tg, sn, ts)
	require.NoError(t, err)

	updates := []storage.MetaUpdate{root, targets}

	serverCrypto := testutils.CopyKeys(t, cs, data.CanonicalTimestampRole, data.CanonicalSnapshotRole)
	_, err = validateUpdate(serverCrypto, gun, updates, store)
	require.Error(t, err)
	require.IsType(t, data.ErrNoSuchRole{}, err)
}

func TestValidatePrevTimestamp(t *testing.T) {
	gun := "docker.com/notary"
	repo, cs, err := testutils.EmptyRepo(gun)
	require.NoError(t, err)

	r, tg, sn, ts, err := testutils.Sign(repo)
	require.NoError(t, err)
	root, targets, snapshot, timestamp, err := getUpdates(r, tg, sn, ts)
	require.NoError(t, err)

	updates := []storage.MetaUpdate{root, targets, snapshot}

	store := storage.NewMemStorage()
	store.UpdateCurrent(gun, timestamp)

	serverCrypto := testutils.CopyKeys(t, cs, data.CanonicalTimestampRole)
	updates, err = validateUpdate(serverCrypto, gun, updates, store)
	require.NoError(t, err)

	// we generated our own timestamp, and did not take the other timestamp,
	// but all other metadata should come from updates
	var foundTimestamp bool
	for _, update := range updates {
		if update.Role == data.CanonicalTimestampRole {
			foundTimestamp = true
			oldTimestamp, newTimestamp := &data.SignedTimestamp{}, &data.SignedTimestamp{}
			require.NoError(t, json.Unmarshal(timestamp.Data, oldTimestamp))
			require.NoError(t, json.Unmarshal(update.Data, newTimestamp))
			require.Equal(t, oldTimestamp.Signed.Version+1, newTimestamp.Signed.Version)
		}
	}
	require.True(t, foundTimestamp)
}

// We cannot validate a new root if the old root is corrupt, because there might
// have been a root key rotation.
func TestValidateOldRootCorruptRootRole(t *testing.T) {
	gun := "docker.com/notary"
	repo, cs, err := testutils.EmptyRepo(gun)
	require.NoError(t, err)
	store := storage.NewMemStorage()

	r, tg, sn, ts, err := testutils.Sign(repo)
	require.NoError(t, err)
	root, targets, snapshot, timestamp, err := getUpdates(r, tg, sn, ts)
	require.NoError(t, err)

	// so a valid root, but missing the root role
	signedRoot, err := data.RootFromSigned(r)
	require.NoError(t, err)
	delete(signedRoot.Signed.Roles, data.CanonicalRootRole)
	badRootJSON, err := json.Marshal(signedRoot)
	require.NoError(t, err)
	badRoot := storage.MetaUpdate{
		Version: root.Version,
		Role:    root.Role,
		Data:    badRootJSON,
	}
	store.UpdateCurrent(gun, badRoot)
	updates := []storage.MetaUpdate{root, targets, snapshot, timestamp}

	serverCrypto := testutils.CopyKeys(t, cs, data.CanonicalTimestampRole)
	_, err = validateUpdate(serverCrypto, gun, updates, store)
	require.Error(t, err)
	require.IsType(t, data.ErrInvalidMetadata{}, err)
}

func TestValidateTargetsModifiedHash(t *testing.T) {
	gun := "docker.com/notary"
	repo, cs, err := testutils.EmptyRepo(gun)
	require.NoError(t, err)
	store := storage.NewMemStorage()

	r, tg, sn, ts, err := testutils.Sign(repo)
	require.NoError(t, err)

	snap, err := data.SnapshotFromSigned(sn)
	require.NoError(t, err)
	snap.Signed.Meta["targets"].Hashes["sha256"][0] = snap.Signed.Meta["targets"].Hashes["sha256"][0] ^ 0xff

	sn, err = snap.ToSigned()
	require.NoError(t, err)

	root, targets, snapshot, timestamp, err := getUpdates(r, tg, sn, ts)
	require.NoError(t, err)

	updates := []storage.MetaUpdate{root, targets, snapshot, timestamp}

	serverCrypto := testutils.CopyKeys(t, cs, data.CanonicalTimestampRole)
	_, err = validateUpdate(serverCrypto, gun, updates, store)
	require.Error(t, err)
	require.IsType(t, validation.ErrBadSnapshot{}, err)
}

func TestValidateRootCanContainOnlyx509KeysWithRightGun(t *testing.T) {
	gun := "docker.com/notary"
	repo, cs, err := testutils.EmptyRepo("wrong/gun")
	require.NoError(t, err)
	serverCrypto := testutils.CopyKeys(t, cs, data.CanonicalTimestampRole)

	// if the root has the wrong gun, the server will fail to validate
	r, tg, sn, ts, err := testutils.Sign(repo)
	require.NoError(t, err)
	root, targets, snapshot, timestamp, err := getUpdates(r, tg, sn, ts)
	require.NoError(t, err)

	_, err = validateUpdate(serverCrypto, gun,
		[]storage.MetaUpdate{root, targets, snapshot, timestamp},
		storage.NewMemStorage())
	require.Error(t, err)
	require.IsType(t, validation.ErrBadRoot{}, err)

	// create regular non-x509 keys - change the root keys to one that is not
	// an x509 key - it should also fail to validate
	newRootKey, err := cs.Create(data.CanonicalRootRole, gun, data.ECDSAKey)
	require.NoError(t, err)
	require.NoError(t, repo.ReplaceBaseKeys(data.CanonicalRootRole, newRootKey))

	r, tg, sn, ts, err = testutils.Sign(repo)
	require.NoError(t, err)
	root, targets, snapshot, timestamp, err = getUpdates(r, tg, sn, ts)
	require.NoError(t, err)

	_, err = validateUpdate(serverCrypto, gun,
		[]storage.MetaUpdate{root, targets, snapshot, timestamp},
		storage.NewMemStorage())
	require.Error(t, err)
	require.IsType(t, validation.ErrBadRoot{}, err)
}

// ### Snapshot size mismatch negative tests ###
func TestValidateRootModifiedSize(t *testing.T) {
	gun := "docker.com/notary"
	repo, cs, err := testutils.EmptyRepo(gun)
	require.NoError(t, err)
	store := storage.NewMemStorage()

	r, tg, sn, ts, err := testutils.Sign(repo)
	require.NoError(t, err)

	// add another copy of the signature so the hash is different
	r.Signatures = append(r.Signatures, r.Signatures[0])

	root, targets, snapshot, timestamp, err := getUpdates(r, tg, sn, ts)
	require.NoError(t, err)

	// flip all the bits in the first byte
	root.Data[0] = root.Data[0] ^ 0xff

	updates := []storage.MetaUpdate{root, targets, snapshot, timestamp}

	serverCrypto := testutils.CopyKeys(t, cs, data.CanonicalTimestampRole)
	_, err = validateUpdate(serverCrypto, gun, updates, store)
	require.Error(t, err)
	require.IsType(t, validation.ErrBadRoot{}, err)
}

func TestCreateSnapshotNoKeyInCrypto(t *testing.T) {
	store := storage.NewMemStorage()
	repo, _, err := testutils.EmptyRepo("gun")
	require.NoError(t, err)

	sgnd, err := repo.SignRoot(data.DefaultExpires(data.CanonicalRootRole))
	require.NoError(t, err)
	rootJSON, err := json.Marshal(sgnd)
	require.NoError(t, err)

	// create an expired snapshot
	sgnd, err = repo.SignSnapshot(time.Now().AddDate(-1, -1, -1))
	require.True(t, repo.Snapshot.Signed.Expires.Before(time.Now()))
	require.NoError(t, err)
	snapshotJSON, err := json.Marshal(sgnd)
	require.NoError(t, err)

	// set all the metadata so we know the failure to sign is just because of the key
	require.NoError(t, store.UpdateCurrent("gun",
		storage.MetaUpdate{Role: data.CanonicalRootRole, Version: 0, Data: rootJSON}))
	require.NoError(t, store.UpdateCurrent("gun",
		storage.MetaUpdate{Role: data.CanonicalSnapshotRole, Version: 0, Data: snapshotJSON}))

	hashBytes := sha256.Sum256(snapshotJSON)
	hashHex := hex.EncodeToString(hashBytes[:])

	// pass it a new cryptoservice without the key
	_, _, err = GetOrCreateSnapshot("gun", hashHex, store, signed.NewEd25519())
	require.Error(t, err)
	require.IsType(t, signed.ErrInsufficientSignatures{}, err)
}

func TestValidateSnapshotGenerate(t *testing.T) {
	gun := "docker.com/notary"
	repo, cs, err := testutils.EmptyRepo(gun)
	require.NoError(t, err)
	store := storage.NewMemStorage()
	snapRole, err := repo.GetBaseRole(data.CanonicalSnapshotRole)
	require.NoError(t, err)

	for _, k := range snapRole.Keys {
		err := store.SetKey(gun, data.CanonicalSnapshotRole, k.Algorithm(), k.Public())
		require.NoError(t, err)
	}

	r, tg, sn, ts, err := testutils.Sign(repo)
	require.NoError(t, err)
	root, targets, _, _, err := getUpdates(r, tg, sn, ts)
	require.NoError(t, err)

	updates := []storage.MetaUpdate{targets}

	store.UpdateCurrent(gun, root)

	serverCrypto := testutils.CopyKeys(t, cs, data.CanonicalTimestampRole, data.CanonicalSnapshotRole)
	_, err = validateUpdate(serverCrypto, gun, updates, store)
	require.NoError(t, err)
}

func TestValidateSnapshotGeneratePrevCorrupt(t *testing.T) {
	kdb, repo, cs := testutils.EmptyRepo()
	store := storage.NewMemStorage()
	snapRole := kdb.GetRole(data.CanonicalSnapshotRole)

	for _, id := range snapRole.KeyIDs {
		k := kdb.GetKey(id)
		assert.NotNil(t, k)
		err := store.SetKey("testGUN", data.CanonicalSnapshotRole, k.Algorithm(), k.Public())
		assert.NoError(t, err)
	}

	r, tg, sn, ts, err := testutils.Sign(repo)
	assert.NoError(t, err)
	root, targets, snapshot, _, err := getUpdates(r, tg, sn, ts)
	assert.NoError(t, err)

	updates := []storage.MetaUpdate{root, targets}

	// corrupt the JSON structure of prev snapshot
	snapshot.Data = snapshot.Data[1:]
	// set the current snapshot in the store manually so we find it when generating
	// the next version
	store.UpdateCurrent("testGUN", snapshot)

	copyTimestampKey(t, kdb, store, "testGUN")
	updates, err = validateUpdate(cs, "testGUN", updates, store)
	assert.Error(t, err)
}

// If the timestamp role has a threshold > 1, validation fails.
func TestValidateRootInvalidTimestampThreshold(t *testing.T) {
	gun := "docker.com/notary"
	oldRepo, cs, err := testutils.EmptyRepo(gun)
	require.NoError(t, err)

	tsKey2, err := testutils.CreateKey(cs, gun, "timestamp2", data.ECDSAKey)
	require.NoError(t, err)
	oldRepo.AddBaseKeys(data.CanonicalTimestampRole, tsKey2)
	tsRole, ok := oldRepo.Root.Signed.Roles[data.CanonicalTimestampRole]
	require.True(t, ok)
	tsRole.Threshold = 2

	r, tg, sn, ts, err := testutils.Sign(oldRepo)
	require.NoError(t, err)
	root, targets, snapshot, _, err := getUpdates(r, tg, sn, ts)
	require.NoError(t, err)

	store := storage.NewMemStorage()
	updates := []storage.MetaUpdate{root, targets, snapshot}

	serverCrypto := testutils.CopyKeys(t, cs, data.CanonicalTimestampRole)
	_, err = validateUpdate(serverCrypto, gun, updates, store)
	require.Error(t, err)
	require.IsType(t, validation.ErrBadRoot{}, err)
}

// If there is no timestamp key in the store, validation fails.  This could
// happen if pushing an existing repository from one server to another that
// does not have the repo.
func TestValidateRootNoTimestampKey(t *testing.T) {
	_, oldRepo, cs := testutils.EmptyRepo()

	r, tg, sn, ts, err := testutils.Sign(oldRepo)
	assert.NoError(t, err)
	root, targets, snapshot, _, err := getUpdates(r, tg, sn, ts)
	assert.NoError(t, err)

	store := storage.NewMemStorage()
	updates := []storage.MetaUpdate{root, targets, snapshot}

	// sanity check - no timestamp keys for the GUN
	_, _, err = store.GetKey("testGUN", data.CanonicalTimestampRole)
	assert.Error(t, err)
	assert.IsType(t, &storage.ErrNoKey{}, err)

	// do not copy the targets key to the storage, and try to update the root
	_, err = validateUpdate(cs, "testGUN", updates, store)
	assert.Error(t, err)
	assert.IsType(t, validation.ErrBadRoot{}, err)

	// there should still be no timestamp keys - one should not have been
	// created
	_, _, err = store.GetKey("testGUN", data.CanonicalTimestampRole)
	assert.Error(t, err)
}

func TestValidateSnapshotGenerate(t *testing.T) {
	repo, cs, err := testutils.EmptyRepo("docker.com/notary")
	assert.NoError(t, err)
	store := storage.NewMemStorage()
	snapRole, err := repo.GetBaseRole(data.CanonicalSnapshotRole)
	assert.NoError(t, err)

	for _, k := range snapRole.Keys {
		err := store.SetKey("testGUN", data.CanonicalSnapshotRole, k.Algorithm(), k.Public())
		assert.NoError(t, err)
	}

	r, tg, sn, ts, err := testutils.Sign(repo)
	assert.NoError(t, err)
	root, targets, _, _, err := getUpdates(r, tg, sn, ts)
	assert.NoError(t, err)

	updates := []storage.MetaUpdate{targets}

	store.UpdateCurrent("testGUN", root)

	copyTimestampKey(t, repo, store, "testGUN")
	updates, err = validateUpdate(cs, "testGUN", updates, store)
	assert.NoError(t, err)
}