[#1] chain: Add binary marshal/unmarshal

Signed-off-by: Dmitrii Stepanov <d.stepanov@yadro.com>

go.mod

@@ -4,6 +4,7 @@ go 1.20
 
 require (
 	git.frostfs.info/TrueCloudLab/frostfs-contract v0.18.1-0.20231129062201-a1b61d394958
+	github.com/google/uuid v1.3.0
 	github.com/nspcc-dev/neo-go v0.103.0
 	github.com/stretchr/testify v1.8.4
 	golang.org/x/exp v0.0.0-20230817173708-d852ddb80c63
@@ -12,7 +13,6 @@ require (
 require (
 	github.com/davecgh/go-spew v1.1.1 // indirect
 	github.com/decred/dcrd/dcrec/secp256k1/v4 v4.0.1 // indirect
-	github.com/google/uuid v1.3.0 // indirect
 	github.com/hashicorp/golang-lru v0.6.0 // indirect
 	github.com/mr-tron/base58 v1.2.0 // indirect
 	github.com/nspcc-dev/go-ordered-json v0.0.0-20220111165707-25110be27d22 // indirect

pkg/chain/chain.go

@@ -45,7 +45,7 @@ func (id *ID) UnmarshalJSON(data []byte) error {
 }
 
 func (c *Chain) Bytes() []byte {
-	data, err := json.Marshal(c)
+	data, err := c.MarshalBinary()
 	if err != nil {
 		panic(err)
 	}
@@ -53,7 +53,7 @@ func (c *Chain) Bytes() []byte {
 }
 
 func (c *Chain) DecodeBytes(b []byte) error {
-	return json.Unmarshal(b, c)
+	return c.UnmarshalBinary(b)
 }
 
 type Rule struct {

pkg/chain/marshal.go

@@ -0,0 +1,257 @@
+package chain
+
+import (
+	"encoding"
+	"fmt"
+
+	"git.frostfs.info/TrueCloudLab/policy-engine/pkg/marshal"
+)
+
+const (
+	ChainMarshalVersion uint8 = 0 // increase if breaking change
+)
+
+var (
+	_ encoding.BinaryMarshaler   = (*Chain)(nil)
+	_ encoding.BinaryUnmarshaler = (*Chain)(nil)
+)
+
+func (c *Chain) MarshalBinary() ([]byte, error) {
+	s := marshal.UInt8Size // Marshaller version
+	s += marshal.UInt8Size // Chain version
+	s += marshal.StringSize(string(c.ID))
+	s += marshal.SliceSize(c.Rules, ruleSize)
+	s += marshal.UInt8Size // MatchType
+
+	buf := make([]byte, s)
+	var offset int
+	var err error
+	offset, err = marshal.UInt8Marshal(buf, offset, marshal.Version)
+	if err != nil {
+		return nil, err
+	}
+	offset, err = marshal.UInt8Marshal(buf, offset, ChainMarshalVersion)
+	if err != nil {
+		return nil, err
+	}
+	offset, err = marshal.StringMarshal(buf, offset, string(c.ID))
+	if err != nil {
+		return nil, err
+	}
+	offset, err = marshal.SliceMarshal(buf, offset, c.Rules, marshalRule)
+	if err != nil {
+		return nil, err
+	}
+	offset, err = marshal.UInt8Marshal(buf, offset, uint8(c.MatchType))
+	if err != nil {
+		return nil, err
+	}
+
+	if err := marshal.VerifyMarshal(buf, offset); err != nil {
+		return nil, err
+	}
+	return buf, nil
+}
+
+func (c *Chain) UnmarshalBinary(data []byte) error {
+	var offset int
+
+	marshallerVersion, offset, err := marshal.UInt8Unmarshal(data, offset)
+	if err != nil {
+		return err
+	}
+	if marshallerVersion != marshal.Version {
+		return fmt.Errorf("unsupported marshaller version %d", marshallerVersion)
+	}
+
+	chainVersion, offset, err := marshal.UInt8Unmarshal(data, offset)
+	if err != nil {
+		return err
+	}
+	if chainVersion != ChainMarshalVersion {
+		return fmt.Errorf("unsupported chain version %d", chainVersion)
+	}
+
+	idStr, offset, err := marshal.StringUnmarshal(data, offset)
+	if err != nil {
+		return err
+	}
+	c.ID = ID(idStr)
+
+	c.Rules, offset, err = marshal.SliceUnmarshal(data, offset, unmarshalRule)
+	if err != nil {
+		return err
+	}
+
+	matchTypeV, offset, err := marshal.UInt8Unmarshal(data, offset)
+	if err != nil {
+		return err
+	}
+	c.MatchType = MatchType(matchTypeV)
+
+	return marshal.VerifyUnmarshal(data, offset)
+}
+
+func ruleSize(r Rule) int {
+	s := marshal.ByteSize // Status
+	s += actionsSize(r.Actions)
+	s += resourcesSize(r.Resources)
+	s += marshal.BoolSize // Any
+	s += marshal.SliceSize(r.Condition, conditionSize)
+	return s
+}
+
+func marshalRule(buf []byte, offset int, r Rule) (int, error) {
+	offset, err := marshal.ByteMarshal(buf, offset, byte(r.Status))
+	if err != nil {
+		return 0, err
+	}
+	offset, err = marshalActions(buf, offset, r.Actions)
+	if err != nil {
+		return 0, err
+	}
+	offset, err = marshalResources(buf, offset, r.Resources)
+	if err != nil {
+		return 0, err
+	}
+	offset, err = marshal.BoolMarshal(buf, offset, r.Any)
+	if err != nil {
+		return 0, err
+	}
+	return marshal.SliceMarshal(buf, offset, r.Condition, marshalCondition)
+}
+
+func unmarshalRule(buf []byte, offset int) (Rule, int, error) {
+	var r Rule
+	statusV, offset, err := marshal.ByteUnmarshal(buf, offset)
+	if err != nil {
+		return Rule{}, 0, err
+	}
+	r.Status = Status(statusV)
+
+	r.Actions, offset, err = unmarshalActions(buf, offset)
+	if err != nil {
+		return Rule{}, 0, err
+	}
+
+	r.Resources, offset, err = unmarshalResources(buf, offset)
+	if err != nil {
+		return Rule{}, 0, err
+	}
+
+	r.Any, offset, err = marshal.BoolUnmarshal(buf, offset)
+	if err != nil {
+		return Rule{}, 0, err
+	}
+
+	r.Condition, offset, err = marshal.SliceUnmarshal(buf, offset, unmarshalCondition)
+	if err != nil {
+		return Rule{}, 0, err
+	}
+
+	return r, offset, nil
+}
+
+func actionsSize(a Actions) int {
+	return marshal.BoolSize + // Inverted
+		marshal.SliceSize(a.Names, marshal.StringSize)
+}
+
+func marshalActions(buf []byte, offset int, a Actions) (int, error) {
+	offset, err := marshal.BoolMarshal(buf, offset, a.Inverted)
+	if err != nil {
+		return 0, err
+	}
+	return marshal.SliceMarshal(buf, offset, a.Names, marshal.StringMarshal)
+}
+
+func unmarshalActions(buf []byte, offset int) (Actions, int, error) {
+	var a Actions
+	var err error
+	a.Inverted, offset, err = marshal.BoolUnmarshal(buf, offset)
+	if err != nil {
+		return Actions{}, 0, err
+	}
+	a.Names, offset, err = marshal.SliceUnmarshal(buf, offset, marshal.StringUnmarshal)
+	if err != nil {
+		return Actions{}, 0, err
+	}
+	return a, offset, nil
+}
+
+func resourcesSize(r Resources) int {
+	return marshal.BoolSize + // Inverted
+		marshal.SliceSize(r.Names, marshal.StringSize)
+}
+
+func marshalResources(buf []byte, offset int, r Resources) (int, error) {
+	offset, err := marshal.BoolMarshal(buf, offset, r.Inverted)
+	if err != nil {
+		return 0, err
+	}
+	return marshal.SliceMarshal(buf, offset, r.Names, marshal.StringMarshal)
+}
+
+func unmarshalResources(buf []byte, offset int) (Resources, int, error) {
+	var r Resources
+	var err error
+	r.Inverted, offset, err = marshal.BoolUnmarshal(buf, offset)
+	if err != nil {
+		return Resources{}, 0, err
+	}
+	r.Names, offset, err = marshal.SliceUnmarshal(buf, offset, marshal.StringUnmarshal)
+	if err != nil {
+		return Resources{}, 0, err
+	}
+	return r, offset, nil
+}
+
+func conditionSize(c Condition) int {
+	return marshal.ByteSize + // Op
+		marshal.ByteSize + // Object
+		marshal.StringSize(c.Key) +
+		marshal.StringSize(c.Value)
+}
+
+func marshalCondition(buf []byte, offset int, c Condition) (int, error) {
+	offset, err := marshal.ByteMarshal(buf, offset, byte(c.Op))
+	if err != nil {
+		return 0, err
+	}
+	offset, err = marshal.ByteMarshal(buf, offset, byte(c.Object))
+	if err != nil {
+		return 0, err
+	}
+	offset, err = marshal.StringMarshal(buf, offset, c.Key)
+	if err != nil {
+		return 0, err
+	}
+	return marshal.StringMarshal(buf, offset, c.Value)
+}
+
+func unmarshalCondition(buf []byte, offset int) (Condition, int, error) {
+	var c Condition
+	opV, offset, err := marshal.ByteUnmarshal(buf, offset)
+	if err != nil {
+		return Condition{}, 0, err
+	}
+	c.Op = ConditionType(opV)
+
+	obV, offset, err := marshal.ByteUnmarshal(buf, offset)
+	if err != nil {
+		return Condition{}, 0, err
+	}
+	c.Object = ObjectType(obV)
+
+	c.Key, offset, err = marshal.StringUnmarshal(buf, offset)
+	if err != nil {
+		return Condition{}, 0, err
+	}
+
+	c.Value, offset, err = marshal.StringUnmarshal(buf, offset)
+	if err != nil {
+		return Condition{}, 0, err
+	}
+
+	return c, offset, nil
+}

pkg/chain/marshal_test.go

@@ -0,0 +1,272 @@
+package chain
+
+import (
+	"fmt"
+	"testing"
+
+	"git.frostfs.info/TrueCloudLab/policy-engine/schema/native"
+	"github.com/google/uuid"
+	"github.com/stretchr/testify/require"
+)
+
+func TestChainMarshalling(t *testing.T) {
+	t.Parallel()
+	for _, id := range generateTestIDs() {
+		for _, rules := range generateTestRules() {
+			for _, matchType := range generateTestMatchTypes() {
+				performMarshalTest(t, id, rules, matchType)
+			}
+		}
+	}
+}
+
+func TestInvalidChainData(t *testing.T) {
+	var ch Chain
+	require.Error(t, ch.UnmarshalBinary(nil))
+	require.Error(t, ch.UnmarshalBinary([]byte{}))
+	require.Error(t, ch.UnmarshalBinary([]byte{1, 2, 3}))
+	require.Error(t, ch.UnmarshalBinary([]byte("\x00\x00:aws:iam::namespace:group/so\x82\x82\x82\x82\x82\x82u\x82")))
+}
+
+func FuzzUnmarshal(f *testing.F) {
+	for _, id := range generateTestIDs() {
+		for _, rules := range generateTestRules() {
+			for _, matchType := range generateTestMatchTypes() {
+
+				chain := Chain{
+					ID:        id,
+					Rules:     rules,
+					MatchType: matchType,
+				}
+				data, err := chain.MarshalBinary()
+				require.NoError(f, err)
+				f.Add(data)
+			}
+		}
+	}
+
+	f.Fuzz(func(t *testing.T, data []byte) {
+		var ch Chain
+		require.NotPanics(t, func() {
+			_ = ch.UnmarshalBinary(data)
+		})
+	})
+}
+
+func performMarshalTest(t *testing.T, id ID, r []Rule, mt MatchType) {
+	chain := Chain{
+		ID:        id,
+		Rules:     r,
+		MatchType: mt,
+	}
+	data, err := chain.MarshalBinary()
+	require.NoError(t, err)
+
+	var unmarshalledChain Chain
+	require.NoError(t, unmarshalledChain.UnmarshalBinary(data))
+
+	require.Equal(t, chain, unmarshalledChain)
+}
+
+func generateTestIDs() []ID {
+	return []ID{
+		ID(""),
+		ID(uuid.New().String()),
+		ID("*::/"),
+		ID("avada kedavra"),
+		ID("arn:aws:iam::namespace:group/some_group"),
+		ID("$Object:homomorphicHash"),
+		ID("native:container/ns/9LPLUFZpEmfidG4n44vi2cjXKXSqWT492tCvLJiJ8W1J"),
+	}
+}
+
+func generateTestRules() [][]Rule {
+	result := [][]Rule{
+		nil,
+		{},
+		{},
+	}
+
+	for _, st := range generateTestStatuses() {
+		for _, act := range generateTestActions() {
+			for _, res := range generateTestResources() {
+				for _, cond := range generateTestConditions() {
+					result[2] = append(result[2], Rule{
+						Status:    st,
+						Actions:   act,
+						Resources: res,
+						Condition: cond,
+						Any:       true,
+					})
+					result[2] = append(result[2], Rule{
+						Status:    st,
+						Actions:   act,
+						Resources: res,
+						Condition: cond,
+					})
+				}
+			}
+		}
+	}
+
+	return result
+}
+
+func generateTestStatuses() []Status {
+	return []Status{
+		Allow,
+		NoRuleFound,
+		AccessDenied,
+		QuotaLimitReached,
+	}
+}
+
+func generateTestActions() []Actions {
+	return []Actions{
+		{
+			Inverted: true,
+			Names:    nil,
+		},
+		{
+			Names: nil,
+		},
+		{
+			Inverted: true,
+			Names:    []string{},
+		},
+		{
+			Names: []string{},
+		},
+		{
+			Inverted: true,
+			Names:    []string{native.MethodPutObject},
+		},
+		{
+			Names: []string{native.MethodPutObject},
+		},
+		{
+			Inverted: true,
+			Names:    []string{native.MethodPutObject, native.MethodDeleteContainer, native.MethodDeleteObject},
+		},
+		{
+			Names: []string{native.MethodPutObject, native.MethodDeleteContainer, native.MethodDeleteObject},
+		},
+	}
+}
+
+func generateTestResources() []Resources {
+	return []Resources{
+		{
+			Inverted: true,
+			Names:    nil,
+		},
+		{
+			Names: nil,
+		},
+		{
+			Inverted: true,
+			Names:    []string{},
+		},
+		{
+			Names: []string{},
+		},
+		{
+			Inverted: true,
+			Names:    []string{native.ResourceFormatAllObjects},
+		},
+		{
+			Names: []string{native.ResourceFormatAllObjects},
+		},
+		{
+			Inverted: true,
+			Names: []string{
+				native.ResourceFormatAllObjects,
+				fmt.Sprintf(native.ResourceFormatRootContainer, "9LPLUFZpEmfidG4n44vi2cjXKXSqWT492tCvLJiJ8W1J"),
+			},
+		},
+		{
+			Names: []string{
+				native.ResourceFormatAllObjects,
+				fmt.Sprintf(native.ResourceFormatRootContainer, "9LPLUFZpEmfidG4n44vi2cjXKXSqWT492tCvLJiJ8W1J"),
+			},
+		},
+	}
+}
+
+func generateTestConditions() [][]Condition {
+	result := [][]Condition{
+		nil,
+		{},
+		{},
+	}
+
+	for _, ct := range generateTestConditionTypes() {
+		for _, ot := range generateObjectTypes() {
+			result[2] = append(result[2], Condition{
+				Op:     ct,
+				Object: ot,
+				Key:    "",
+				Value:  "",
+			})
+
+			result[2] = append(result[2], Condition{
+				Op:     ct,
+				Object: ot,
+				Key:    "key",
+				Value:  "",
+			})
+
+			result[2] = append(result[2], Condition{
+				Op:     ct,
+				Object: ot,
+				Key:    "",
+				Value:  "value",
+			})
+
+			result[2] = append(result[2], Condition{
+				Op:     ct,
+				Object: ot,
+				Key:    "key",
+				Value:  "value",
+			})
+		}
+	}
+
+	return result
+}
+
+func generateTestConditionTypes() []ConditionType {
+	return []ConditionType{
+		CondStringEquals,
+		CondStringNotEquals,
+		CondStringEqualsIgnoreCase,
+		CondStringNotEqualsIgnoreCase,
+		CondStringLike,
+		CondStringNotLike,
+		CondStringLessThan,
+		CondStringLessThanEquals,
+		CondStringGreaterThan,
+		CondStringGreaterThanEquals,
+		CondNumericEquals,
+		CondNumericNotEquals,
+		CondNumericLessThan,
+		CondNumericLessThanEquals,
+		CondNumericGreaterThan,
+		CondNumericGreaterThanEquals,
+		CondSliceContains,
+	}
+}
+
+func generateObjectTypes() []ObjectType {
+	return []ObjectType{
+		ObjectResource,
+		ObjectRequest,
+	}
+}
+
+func generateTestMatchTypes() []MatchType {
+	return []MatchType{
+		MatchTypeDenyPriority,
+		MatchTypeFirstMatch,
+	}
+}

pkg/marshal/marshal.go

@@ -0,0 +1,267 @@
+package marshal
+
+import (
+	"encoding/binary"
+	"fmt"
+)
+
+const (
+	Version byte = 0 // increase if breaking change
+
+	ByteSize  int = 1
+	UInt8Size int = ByteSize
+	BoolSize  int = ByteSize
+
+	nilSlice     int64 = -1
+	nilSliceSize int   = 1
+
+	byteTrue  uint8 = 1
+	byteFalse uint8 = 0
+
+	// maxSliceLen taken from https://github.com/neo-project/neo/blob/38218bbee5bbe8b33cd8f9453465a19381c9a547/src/Neo/IO/Helper.cs#L77
+	maxSliceLen = 0x1000000
+)
+
+type MarshallerError struct {
+	errMsg string
+	offset int
+}
+
+func (e *MarshallerError) Error() string {
+	if e == nil {
+		return ""
+	}
+	if e.offset < 0 {
+		return e.errMsg
+	}
+	return fmt.Sprintf("%s (offset: %d)", e.errMsg, e.offset)
+}
+
+func errBufTooSmall(t string, marshal bool, offset int) error {
+	action := "unmarshal"
+	if marshal {
+		action = "marshal"
+	}
+	return &MarshallerError{
+		errMsg: fmt.Sprintf("not enough bytes left to %s value of type '%s'", action, t),
+		offset: offset,
+	}
+}
+
+func VerifyMarshal(buf []byte, lastOffset int) error {
+	if len(buf) != lastOffset {
+		return &MarshallerError{
+			errMsg: "actual data size differs from expected",
+			offset: -1,
+		}
+	}
+	return nil
+}
+
+func VerifyUnmarshal(buf []byte, lastOffset int) error {
+	if len(buf) != lastOffset {
+		return &MarshallerError{
+			errMsg: "unmarshalled bytes left",
+		}
+	}
+	return nil
+}
+
+func SliceSize[T any](slice []T, sizeOf func(T) int) int {
+	if slice == nil {
+		return nilSliceSize
+	}
+	s := Int64Size(int64(len(slice)))
+	for _, v := range slice {
+		s += sizeOf(v)
+	}
+	return s
+}
+
+func SliceMarshal[T any](buf []byte, offset int, slice []T, marshalT func([]byte, int, T) (int, error)) (int, error) {
+	if slice == nil {
+		return Int64Marshal(buf, offset, nilSlice)
+	}
+	if len(slice) > maxSliceLen {
+		return 0, &MarshallerError{
+			errMsg: fmt.Sprintf("slice size if too big: '%d'", len(slice)),
+			offset: offset,
+		}
+	}
+	offset, err := Int64Marshal(buf, offset, int64(len(slice)))
+	if err != nil {
+		return 0, err
+	}
+	for _, v := range slice {
+		offset, err = marshalT(buf, offset, v)
+		if err != nil {
+			return 0, err
+		}
+	}
+	return offset, nil
+}
+
+func SliceUnmarshal[T any](buf []byte, offset int, unmarshalT func(buf []byte, offset int) (T, int, error)) ([]T, int, error) {
+	size, offset, err := Int64Unmarshal(buf, offset)
+	if err != nil {
+		return nil, 0, err
+	}
+	if size == nilSlice {
+		return nil, offset, nil
+	}
+	if size > maxSliceLen {
+		return nil, 0, &MarshallerError{
+			errMsg: fmt.Sprintf("slice size if too big: '%d'", size),
+			offset: offset,
+		}
+	}
+	if size < 0 {
+		return nil, 0, &MarshallerError{
+			errMsg: fmt.Sprintf("invalid slice size: '%d'", size),
+			offset: offset,
+		}
+	}
+	result := make([]T, size)
+	for idx := 0; idx < len(result); idx++ {
+		result[idx], offset, err = unmarshalT(buf, offset)
+		if err != nil {
+			return nil, 0, err
+		}
+	}
+	return result, offset, nil
+}
+
+func Int64Size(v int64) int {
+	// https://cs.opensource.google/go/go/+/master:src/encoding/binary/varint.go;l=92;drc=dac9b9ddbd5160c5f4552410f5f8281bd5eed38c
+	// and
+	// https://cs.opensource.google/go/go/+/master:src/encoding/binary/varint.go;l=41;drc=dac9b9ddbd5160c5f4552410f5f8281bd5eed38c
+	ux := uint64(v) << 1
+	if v < 0 {
+		ux = ^ux
+	}
+	s := 0
+	for ux >= 0x80 {
+		s++
+		ux >>= 7
+	}
+	return s + 1
+}
+
+func Int64Marshal(buf []byte, offset int, v int64) (int, error) {
+	if len(buf)-offset < Int64Size(v) {
+		return 0, errBufTooSmall("int64", true, offset)
+	}
+	return offset + binary.PutVarint(buf[offset:], v), nil
+}
+
+func Int64Unmarshal(buf []byte, offset int) (int64, int, error) {
+	v, read := binary.Varint(buf[offset:])
+	if read == 0 {
+		return 0, 0, errBufTooSmall("int64", false, offset)
+	}
+	if read < 0 {
+		return 0, 0, &MarshallerError{
+			errMsg: "int64 unmarshal overflow",
+			offset: offset,
+		}
+	}
+	return v, offset + read, nil
+}
+
+func StringSize(s string) int {
+	return Int64Size(int64(len(s))) + len(s)
+}
+
+func StringMarshal(buf []byte, offset int, s string) (int, error) {
+	if len(s) > maxSliceLen {
+		return 0, &MarshallerError{
+			errMsg: fmt.Sprintf("string is too long: '%d'", len(s)),
+			offset: offset,
+		}
+	}
+	if len(buf)-offset < Int64Size(int64(len(s)))+len(s) {
+		return 0, errBufTooSmall("string", true, offset)
+	}
+
+	offset, err := Int64Marshal(buf, offset, int64(len(s)))
+	if err != nil {
+		return 0, err
+	}
+	if s == "" {
+		return offset, nil
+	}
+	return offset + copy(buf[offset:], s), nil
+}
+
+func StringUnmarshal(buf []byte, offset int) (string, int, error) {
+	size, offset, err := Int64Unmarshal(buf, offset)
+	if err != nil {
+		return "", 0, err
+	}
+	if size == 0 {
+		return "", offset, nil
+	}
+	if size > maxSliceLen {
+		return "", 0, &MarshallerError{
+			errMsg: fmt.Sprintf("string is too long: '%d'", size),
+			offset: offset,
+		}
+	}
+	if size < 0 {
+		return "", 0, &MarshallerError{
+			errMsg: fmt.Sprintf("invalid string size: '%d'", size),
+			offset: offset,
+		}
+	}
+	if len(buf)-offset < int(size) {
+		return "", 0, errBufTooSmall("string", false, offset)
+	}
+	return string(buf[offset : offset+int(size)]), offset + int(size), nil
+}
+
+func UInt8Marshal(buf []byte, offset int, value uint8) (int, error) {
+	if len(buf)-offset < 1 {
+		return 0, errBufTooSmall("uint8", true, offset)
+	}
+	buf[offset] = value
+	return offset + 1, nil
+}
+
+func UInt8Unmarshal(buf []byte, offset int) (uint8, int, error) {
+	if len(buf)-offset < 1 {
+		return 0, 0, errBufTooSmall("uint8", false, offset)
+	}
+	return buf[offset], offset + 1, nil
+}
+
+func ByteMarshal(buf []byte, offset int, value byte) (int, error) {
+	return UInt8Marshal(buf, offset, value)
+}
+
+func ByteUnmarshal(buf []byte, offset int) (byte, int, error) {
+	return UInt8Unmarshal(buf, offset)
+}
+
+func BoolMarshal(buf []byte, offset int, value bool) (int, error) {
+	if value {
+		return UInt8Marshal(buf, offset, byteTrue)
+	}
+	return UInt8Marshal(buf, offset, byteFalse)
+}
+
+func BoolUnmarshal(buf []byte, offset int) (bool, int, error) {
+	v, offset, err := UInt8Unmarshal(buf, offset)
+	if err != nil {
+		return false, 0, err
+	}
+	if v == byteTrue {
+		return true, offset, nil
+	}
+	if v == byteFalse {
+		return false, offset, nil
+	}
+	return false, 0, &MarshallerError{
+		errMsg: fmt.Sprintf("invalid marshalled value for bool: %d", v),
+		offset: offset - BoolSize,
+	}
+}

pkg/marshal/marshal_test.go

@@ -0,0 +1,313 @@
+package marshal
+
+import (
+	"encoding/binary"
+	"math"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestMarshalling(t *testing.T) {
+	t.Parallel()
+	t.Run("slice", func(t *testing.T) {
+		t.Parallel()
+		t.Run("nil slice", func(t *testing.T) {
+			t.Parallel()
+
+			var int64s []int64
+			expectedSize := SliceSize(int64s, Int64Size)
+			require.Equal(t, 1, expectedSize)
+			buf := make([]byte, expectedSize)
+			offset, err := SliceMarshal(buf, 0, int64s, Int64Marshal)
+			require.NoError(t, err)
+			require.NoError(t, VerifyMarshal(buf, offset))
+
+			result, offset, err := SliceUnmarshal(buf, 0, Int64Unmarshal)
+			require.NoError(t, err)
+			require.NoError(t, VerifyUnmarshal(buf, offset))
+			require.Nil(t, result)
+		})
+
+		t.Run("empty slice", func(t *testing.T) {
+			t.Parallel()
+
+			int64s := make([]int64, 0)
+			expectedSize := SliceSize(int64s, Int64Size)
+			require.Equal(t, 1, expectedSize)
+			buf := make([]byte, expectedSize)
+			offset, err := SliceMarshal(buf, 0, int64s, Int64Marshal)
+			require.NoError(t, err)
+			require.NoError(t, VerifyMarshal(buf, offset))
+
+			result, offset, err := SliceUnmarshal(buf, 0, Int64Unmarshal)
+			require.NoError(t, err)
+			require.NoError(t, VerifyUnmarshal(buf, offset))
+			require.NotNil(t, result)
+			require.Len(t, result, 0)
+		})
+
+		t.Run("non empty slice", func(t *testing.T) {
+			t.Parallel()
+
+			int64s := make([]int64, 100)
+			for i := range int64s {
+				int64s[i] = int64(i)
+			}
+			expectedSize := SliceSize(int64s, Int64Size)
+			buf := make([]byte, expectedSize)
+			offset, err := SliceMarshal(buf, 0, int64s, Int64Marshal)
+			require.NoError(t, err)
+			require.NoError(t, VerifyMarshal(buf, offset))
+
+			result, offset, err := SliceUnmarshal(buf, 0, Int64Unmarshal)
+			require.NoError(t, err)
+			require.NoError(t, VerifyUnmarshal(buf, offset))
+			require.Equal(t, int64s, result)
+		})
+
+		t.Run("corrupted slice size", func(t *testing.T) {
+			t.Parallel()
+
+			int64s := make([]int64, 100)
+			for i := range int64s {
+				int64s[i] = int64(i)
+			}
+			expectedSize := SliceSize(int64s, Int64Size)
+			buf := make([]byte, expectedSize)
+			offset, err := SliceMarshal(buf, 0, int64s, Int64Marshal)
+			require.NoError(t, err)
+			require.NoError(t, VerifyMarshal(buf, offset))
+
+			for i := 0; i < binary.MaxVarintLen64; i++ {
+				buf[i] = 129
+			}
+
+			_, _, err = SliceUnmarshal(buf, 0, Int64Unmarshal)
+			var mErr *MarshallerError
+			require.ErrorAs(t, err, &mErr)
+
+			for i := 0; i < binary.MaxVarintLen64; i++ {
+				buf[i] = 127
+			}
+			_, _, err = SliceUnmarshal(buf, 0, Int64Unmarshal)
+			require.ErrorAs(t, err, &mErr)
+		})
+
+		t.Run("corrupted slice item", func(t *testing.T) {
+			t.Parallel()
+
+			int64s := make([]int64, 100)
+			for i := range int64s {
+				int64s[i] = int64(i)
+			}
+			expectedSize := SliceSize(int64s, Int64Size)
+			buf := make([]byte, expectedSize)
+			offset, err := SliceMarshal(buf, 0, int64s, Int64Marshal)
+			require.NoError(t, err)
+			require.NoError(t, VerifyMarshal(buf, offset))
+
+			for i := 2; i < binary.MaxVarintLen64+2; i++ {
+				buf[i] = 129
+			}
+
+			_, _, err = SliceUnmarshal(buf, 0, Int64Unmarshal)
+			var mErr *MarshallerError
+			require.ErrorAs(t, err, &mErr)
+		})
+
+		t.Run("small buffer", func(t *testing.T) {
+			t.Parallel()
+
+			int64s := make([]int64, 100)
+			for i := range int64s {
+				int64s[i] = int64(i)
+			}
+			buf := make([]byte, 1)
+			_, err := SliceMarshal(buf, 0, int64s, Int64Marshal)
+			var mErr *MarshallerError
+			require.ErrorAs(t, err, &mErr)
+
+			buf = make([]byte, 10)
+			_, err = SliceMarshal(buf, 0, int64s, Int64Marshal)
+			require.ErrorAs(t, err, &mErr)
+		})
+	})
+
+	t.Run("int64", func(t *testing.T) {
+		t.Parallel()
+
+		t.Run("success", func(t *testing.T) {
+			t.Parallel()
+
+			require.Equal(t, 1, Int64Size(0))
+			require.Equal(t, binary.MaxVarintLen64, Int64Size(math.MaxInt64))
+			require.Equal(t, binary.MaxVarintLen64, Int64Size(math.MinInt64))
+
+			for _, v := range []int64{0, math.MinInt64, math.MaxInt64} {
+				size := Int64Size(v)
+				buf := make([]byte, size)
+				offset, err := Int64Marshal(buf, 0, v)
+				require.NoError(t, err)
+				require.NoError(t, VerifyMarshal(buf, offset))
+
+				uv, offset, err := Int64Unmarshal(buf, 0)
+				require.NoError(t, err)
+				require.NoError(t, VerifyUnmarshal(buf, offset))
+				require.Equal(t, v, uv)
+			}
+		})
+
+		t.Run("invalid buffer", func(t *testing.T) {
+			t.Parallel()
+
+			var mErr *MarshallerError
+
+			_, err := Int64Marshal([]byte{}, 0, 100500)
+			require.ErrorAs(t, err, &mErr)
+
+			_, _, err = Int64Unmarshal(nil, 0)
+			require.ErrorAs(t, err, &mErr)
+		})
+
+		t.Run("overflow", func(t *testing.T) {
+			t.Parallel()
+
+			var mErr *MarshallerError
+
+			var v int64 = math.MaxInt64
+			buf := make([]byte, Int64Size(v))
+			_, err := Int64Marshal(buf, 0, v)
+			require.NoError(t, err)
+
+			buf[9] = 2
+
+			_, _, err = Int64Unmarshal(buf, 0)
+			require.ErrorAs(t, err, &mErr)
+		})
+	})
+
+	t.Run("string", func(t *testing.T) {
+		t.Parallel()
+
+		t.Run("success", func(t *testing.T) {
+			t.Parallel()
+			for _, v := range []string{
+				"", "arn:aws:iam::namespace:group/some_group", "$Object:homomorphicHash",
+				"native:container/ns/9LPLUFZpEmfidG4n44vi2cjXKXSqWT492tCvLJiJ8W1J",
+			} {
+				size := StringSize(v)
+				buf := make([]byte, size)
+				offset, err := StringMarshal(buf, 0, v)
+				require.NoError(t, err)
+				require.NoError(t, VerifyMarshal(buf, offset))
+
+				uv, offset, err := StringUnmarshal(buf, 0)
+				require.NoError(t, err)
+				require.NoError(t, VerifyUnmarshal(buf, offset))
+				require.Equal(t, v, uv)
+			}
+		})
+
+		t.Run("invalid buffer", func(t *testing.T) {
+			t.Parallel()
+
+			str := "avada kedavra"
+
+			var mErr *MarshallerError
+			_, err := StringMarshal(nil, 0, str)
+			require.ErrorAs(t, err, &mErr)
+
+			_, _, err = StringUnmarshal(nil, 0)
+			require.ErrorAs(t, err, &mErr)
+
+			buf := make([]byte, StringSize(str))
+			offset, err := StringMarshal(buf, 0, str)
+			require.NoError(t, err)
+			require.NoError(t, VerifyMarshal(buf, offset))
+			buf = buf[:len(buf)-1]
+			_, _, err = StringUnmarshal(buf, 0)
+			require.ErrorAs(t, err, &mErr)
+		})
+	})
+
+	t.Run("uint8, byte", func(t *testing.T) {
+		t.Parallel()
+
+		for _, v := range []byte{0, 8, 16, 32, 64, 128, 255} {
+			buf := make([]byte, ByteSize)
+			offset, err := ByteMarshal(buf, 0, v)
+			require.NoError(t, err)
+			require.NoError(t, VerifyMarshal(buf, offset))
+
+			ub, offset, err := ByteUnmarshal(buf, 0)
+			require.NoError(t, err)
+			require.NoError(t, VerifyUnmarshal(buf, offset))
+			require.Equal(t, v, ub)
+
+			buf = make([]byte, UInt8Size)
+			offset, err = UInt8Marshal(buf, 0, v)
+			require.NoError(t, err)
+			require.NoError(t, VerifyMarshal(buf, offset))
+
+			uu, offset, err := UInt8Unmarshal(buf, 0)
+			require.NoError(t, err)
+			require.NoError(t, VerifyUnmarshal(buf, offset))
+			require.Equal(t, v, uu)
+		}
+	})
+
+	t.Run("bool", func(t *testing.T) {
+		t.Parallel()
+
+		t.Run("success", func(t *testing.T) {
+			t.Parallel()
+			for _, v := range []bool{false, true} {
+				buf := make([]byte, BoolSize)
+				offset, err := BoolMarshal(buf, 0, v)
+				require.NoError(t, err)
+				require.NoError(t, VerifyMarshal(buf, offset))
+
+				ub, offset, err := BoolUnmarshal(buf, 0)
+				require.NoError(t, err)
+				require.NoError(t, VerifyUnmarshal(buf, offset))
+				require.Equal(t, v, ub)
+			}
+		})
+
+		t.Run("invalid value", func(t *testing.T) {
+			t.Parallel()
+			buf := make([]byte, BoolSize)
+			offset, err := BoolMarshal(buf, 0, true)
+			require.NoError(t, err)
+			require.NoError(t, VerifyMarshal(buf, offset))
+
+			buf[0] = 2
+
+			_, _, err = BoolUnmarshal(buf, 0)
+			var mErr *MarshallerError
+			require.ErrorAs(t, err, &mErr)
+		})
+
+		t.Run("invalid buffer", func(t *testing.T) {
+			t.Parallel()
+			var mErr *MarshallerError
+
+			_, err := BoolMarshal(nil, 0, true)
+			require.ErrorAs(t, err, &mErr)
+
+			buf := append(make([]byte, BoolSize), 100)
+			offset, err := BoolMarshal(buf, 0, true)
+			require.NoError(t, err)
+			require.ErrorAs(t, VerifyMarshal(buf, offset), &mErr)
+
+			v, offset, err := BoolUnmarshal(buf, 0)
+			require.NoError(t, err)
+			require.True(t, v)
+			require.ErrorAs(t, VerifyUnmarshal(buf, offset), &mErr)
+
+			_, _, err = BoolUnmarshal(nil, 0)
+			require.ErrorAs(t, err, &mErr)
+		})
+	})
+}