Merge pull request #2251 from nspcc-dev/rules-witness-scope

transaction: add new Rules witness scope

pkg/core/interop/runtime/witness.go

@@ -9,6 +9,7 @@ import (
 	"github.com/nspcc-dev/neo-go/pkg/core/transaction"
 	"github.com/nspcc-dev/neo-go/pkg/crypto/keys"
 	"github.com/nspcc-dev/neo-go/pkg/smartcontract/callflag"
+	"github.com/nspcc-dev/neo-go/pkg/smartcontract/manifest"
 	"github.com/nspcc-dev/neo-go/pkg/util"
 	"github.com/nspcc-dev/neo-go/pkg/vm"
 	"github.com/nspcc-dev/neo-go/pkg/vm/stackitem"
@@ -28,6 +29,38 @@ func CheckHashedWitness(ic *interop.Context, hash util.Uint160) (bool, error) {
 	return false, errors.New("script container is not a transaction")
 }
 
+type scopeContext struct {
+	*vm.VM
+	ic *interop.Context
+}
+
+func getContractGroups(v *vm.VM, ic *interop.Context, h util.Uint160) (manifest.Groups, error) {
+	if !v.Context().GetCallFlags().Has(callflag.ReadStates) {
+		return nil, errors.New("missing ReadStates call flag")
+	}
+	cs, err := ic.GetContract(h)
+	if err != nil {
+		return nil, nil // It's OK to not have the contract.
+	}
+	return manifest.Groups(cs.Manifest.Groups), nil
+}
+
+func (sc scopeContext) checkScriptGroups(h util.Uint160, k *keys.PublicKey) (bool, error) {
+	groups, err := getContractGroups(sc.VM, sc.ic, h)
+	if err != nil {
+		return false, err
+	}
+	return groups.Contains(k), nil
+}
+
+func (sc scopeContext) CallingScriptHasGroup(k *keys.PublicKey) (bool, error) {
+	return sc.checkScriptGroups(sc.GetCallingScriptHash(), k)
+}
+
+func (sc scopeContext) CurrentScriptHasGroup(k *keys.PublicKey) (bool, error) {
+	return sc.checkScriptGroups(sc.GetCurrentScriptHash(), k)
+}
+
 func checkScope(ic *interop.Context, tx *transaction.Transaction, v *vm.VM, hash util.Uint160) (bool, error) {
 	for _, c := range tx.Signers {
 		if c.Account == hash {
@@ -50,19 +83,26 @@ func checkScope(ic *interop.Context, tx *transaction.Transaction, v *vm.VM, hash
 				}
 			}
 			if c.Scopes&transaction.CustomGroups != 0 {
-				if !v.Context().GetCallFlags().Has(callflag.ReadStates) {
-					return false, errors.New("missing ReadStates call flag")
-				}
-				cs, err := ic.GetContract(v.GetCurrentScriptHash())
+				groups, err := getContractGroups(v, ic, v.GetCurrentScriptHash())
 				if err != nil {
-					return false, nil
+					return false, err
 				}
 				// check if the current group is the required one
 				for _, allowedGroup := range c.AllowedGroups {
-					for _, group := range cs.Manifest.Groups {
-						if group.PublicKey.Equal(allowedGroup) {
-							return true, nil
-						}
+					if groups.Contains(allowedGroup) {
+						return true, nil
+					}
+				}
+			}
+			if c.Scopes&transaction.Rules != 0 {
+				ctx := scopeContext{v, ic}
+				for _, r := range c.Rules {
+					res, err := r.Condition.Match(ctx)
+					if err != nil {
+						return false, err
+					}
+					if res {
+						return r.Action == transaction.WitnessAllow, nil
 					}
 				}
 			}

pkg/core/interop_system_test.go

@@ -1189,6 +1189,28 @@ func TestRuntimeCheckWitness(t *testing.T) {
 				ic.VM.LoadScriptWithHash([]byte{0x1}, random.Uint160(), callflag.AllowCall)
 				check(t, ic, hash.BytesBE(), true)
 			})
+			t.Run("Rules, missing ReadStates flag", func(t *testing.T) {
+				hash := random.Uint160()
+				pk, err := keys.NewPrivateKey()
+				require.NoError(t, err)
+				tx := &transaction.Transaction{
+					Signers: []transaction.Signer{
+						{
+							Account: hash,
+							Scopes:  transaction.Rules,
+							Rules: []transaction.WitnessRule{{
+								Action:    transaction.WitnessAllow,
+								Condition: (*transaction.ConditionGroup)(pk.PublicKey()),
+							}},
+						},
+					},
+				}
+				ic.Container = tx
+				callingScriptHash := scriptHash
+				loadScriptWithHashAndFlags(ic, script, callingScriptHash, callflag.All)
+				ic.VM.LoadScriptWithHash([]byte{0x1}, random.Uint160(), callflag.AllowCall)
+				check(t, ic, hash.BytesBE(), true)
+			})
 		})
 	})
 	t.Run("positive", func(t *testing.T) {
@@ -1301,6 +1323,64 @@ func TestRuntimeCheckWitness(t *testing.T) {
 					check(t, ic, targetHash.BytesBE(), false, true)
 				})
 			})
+			t.Run("Rules", func(t *testing.T) {
+				t.Run("no match", func(t *testing.T) {
+					hash := random.Uint160()
+					tx := &transaction.Transaction{
+						Signers: []transaction.Signer{
+							{
+								Account: hash,
+								Scopes:  transaction.Rules,
+								Rules: []transaction.WitnessRule{{
+									Action:    transaction.WitnessAllow,
+									Condition: (*transaction.ConditionScriptHash)(&hash),
+								}},
+							},
+						},
+					}
+					loadScriptWithHashAndFlags(ic, script, scriptHash, callflag.ReadStates)
+					ic.Container = tx
+					check(t, ic, hash.BytesBE(), false, false)
+				})
+				t.Run("allow", func(t *testing.T) {
+					hash := random.Uint160()
+					var cond = true
+					tx := &transaction.Transaction{
+						Signers: []transaction.Signer{
+							{
+								Account: hash,
+								Scopes:  transaction.Rules,
+								Rules: []transaction.WitnessRule{{
+									Action:    transaction.WitnessAllow,
+									Condition: (*transaction.ConditionBoolean)(&cond),
+								}},
+							},
+						},
+					}
+					loadScriptWithHashAndFlags(ic, script, scriptHash, callflag.ReadStates)
+					ic.Container = tx
+					check(t, ic, hash.BytesBE(), false, true)
+				})
+				t.Run("deny", func(t *testing.T) {
+					hash := random.Uint160()
+					var cond = true
+					tx := &transaction.Transaction{
+						Signers: []transaction.Signer{
+							{
+								Account: hash,
+								Scopes:  transaction.Rules,
+								Rules: []transaction.WitnessRule{{
+									Action:    transaction.WitnessDeny,
+									Condition: (*transaction.ConditionBoolean)(&cond),
+								}},
+							},
+						},
+					}
+					loadScriptWithHashAndFlags(ic, script, scriptHash, callflag.ReadStates)
+					ic.Container = tx
+					check(t, ic, hash.BytesBE(), false, false)
+				})
+			})
 			t.Run("bad scope", func(t *testing.T) {
 				hash := random.Uint160()
 				tx := &transaction.Transaction{

pkg/core/transaction/signer.go

@@ -17,6 +17,7 @@ type Signer struct {
 	Scopes           WitnessScope      `json:"scopes"`
 	AllowedContracts []util.Uint160    `json:"allowedcontracts,omitempty"`
 	AllowedGroups    []*keys.PublicKey `json:"allowedgroups,omitempty"`
+	Rules            []WitnessRule     `json:"rules,omitempty"`
 }
 
 // EncodeBinary implements Serializable interface.
@@ -29,6 +30,9 @@ func (c *Signer) EncodeBinary(bw *io.BinWriter) {
 	if c.Scopes&CustomGroups != 0 {
 		bw.WriteArray(c.AllowedGroups)
 	}
+	if c.Scopes&Rules != 0 {
+		bw.WriteArray(c.Rules)
+	}
 }
 
 // DecodeBinary implements Serializable interface.
@@ -49,4 +53,7 @@ func (c *Signer) DecodeBinary(br *io.BinReader) {
 	if c.Scopes&CustomGroups != 0 {
 		br.ReadArray(&c.AllowedGroups, maxSubitems)
 	}
+	if c.Scopes&Rules != 0 {
+		br.ReadArray(&c.Rules, maxSubitems)
+	}
 }

pkg/core/transaction/witness_condition.go

@@ -0,0 +1,575 @@
+package transaction
+
+import (
+	"encoding/json"
+	"errors"
+
+	"github.com/nspcc-dev/neo-go/pkg/crypto/keys"
+	"github.com/nspcc-dev/neo-go/pkg/io"
+	"github.com/nspcc-dev/neo-go/pkg/util"
+)
+
+//go:generate stringer -type=WitnessConditionType -linecomment
+
+// WitnessConditionType encodes a type of witness condition.
+type WitnessConditionType byte
+
+const (
+	// WitnessBoolean is a generic boolean condition.
+	WitnessBoolean WitnessConditionType = 0x00 // Boolean
+	// WitnessNot reverses another condition.
+	WitnessNot WitnessConditionType = 0x01 // Not
+	// WitnessAnd means that all conditions must be met.
+	WitnessAnd WitnessConditionType = 0x02 // And
+	// WitnessOr means that any of conditions must be met.
+	WitnessOr WitnessConditionType = 0x03 // Or
+	// WitnessScriptHash matches executing contract's script hash.
+	WitnessScriptHash WitnessConditionType = 0x18 // ScriptHash
+	// WitnessGroup matches executing contract's group key.
+	WitnessGroup WitnessConditionType = 0x19 // Group
+	// WitnessCalledByEntry matches when current script is an entry script or is called by an entry script.
+	WitnessCalledByEntry WitnessConditionType = 0x20 // CalledByEntry
+	// WitnessCalledByContract matches when current script is called by the specified contract.
+	WitnessCalledByContract WitnessConditionType = 0x28 // CalledByContract
+	// WitnessCalledByGroup matches when current script is called by contract belonging to the specified group.
+	WitnessCalledByGroup WitnessConditionType = 0x29 // CalledByGroup
+
+	// MaxConditionNesting limits the maximum allowed level of condition nesting.
+	MaxConditionNesting = 2
+)
+
+// WitnessCondition is a condition of WitnessRule.
+type WitnessCondition interface {
+	// Type returns a type of this condition.
+	Type() WitnessConditionType
+	// Match checks whether this condition matches current context.
+	Match(MatchContext) (bool, error)
+	// EncodeBinary allows to serialize condition to its binary
+	// representation (including type data).
+	EncodeBinary(*io.BinWriter)
+	// DecodeBinarySpecific decodes type-specific binary data from the given
+	// reader (not including type data).
+	DecodeBinarySpecific(*io.BinReader, int)
+
+	json.Marshaler
+}
+
+// MatchContext is a set of methods from execution engine needed to perform the
+// witness check.
+type MatchContext interface {
+	GetCallingScriptHash() util.Uint160
+	GetCurrentScriptHash() util.Uint160
+	GetEntryScriptHash() util.Uint160
+	CallingScriptHasGroup(*keys.PublicKey) (bool, error)
+	CurrentScriptHasGroup(*keys.PublicKey) (bool, error)
+}
+
+type (
+	// ConditionBoolean is a boolean condition type.
+	ConditionBoolean bool
+	// ConditionNot inverses the meaning of contained condition.
+	ConditionNot struct {
+		Condition WitnessCondition
+	}
+	// ConditionAnd is a set of conditions required to match.
+	ConditionAnd []WitnessCondition
+	// ConditionOr is a set of conditions one of which is required to match.
+	ConditionOr []WitnessCondition
+	// ConditionScriptHash is a condition matching executing script hash.
+	ConditionScriptHash util.Uint160
+	// ConditionGroup is a condition matching executing script group.
+	ConditionGroup keys.PublicKey
+	// ConditionCalledByEntry is a condition matching entry script or one directly called by it.
+	ConditionCalledByEntry struct{}
+	// ConditionCalledByContract is a condition matching calling script hash.
+	ConditionCalledByContract util.Uint160
+	// ConditionCalledByGroup is a condition matching calling script group.
+	ConditionCalledByGroup keys.PublicKey
+)
+
+// conditionAux is used for JSON marshaling/unmarshaling.
+type conditionAux struct {
+	Expression  json.RawMessage   `json:"expression,omitempty"` // Can be either boolean or conditionAux.
+	Expressions []json.RawMessage `json:"expressions,omitempty"`
+	Group       *keys.PublicKey   `json:"group,omitempty"`
+	Hash        *util.Uint160     `json:"hash,omitempty"`
+	Type        string            `json:"type"`
+}
+
+// Type implements WitnessCondition interface and returns condition type.
+func (c *ConditionBoolean) Type() WitnessConditionType {
+	return WitnessBoolean
+}
+
+// Match implements WitnessCondition interface checking whether this condition
+// matches given context.
+func (c *ConditionBoolean) Match(_ MatchContext) (bool, error) {
+	return bool(*c), nil
+}
+
+// EncodeBinary implements WitnessCondition interface allowing to serialize condition.
+func (c *ConditionBoolean) EncodeBinary(w *io.BinWriter) {
+	w.WriteB(byte(c.Type()))
+	w.WriteBool(bool(*c))
+}
+
+// DecodeBinarySpecific implements WitnessCondition interface allowing to
+// deserialize condition-specific data.
+func (c *ConditionBoolean) DecodeBinarySpecific(r *io.BinReader, maxDepth int) {
+	*c = ConditionBoolean(r.ReadBool())
+}
+
+// MarshalJSON implements json.Marshaler interface.
+func (c *ConditionBoolean) MarshalJSON() ([]byte, error) {
+	boolJSON, _ := json.Marshal(bool(*c)) // Simple boolean can't fail.
+	aux := conditionAux{
+		Type:       c.Type().String(),
+		Expression: json.RawMessage(boolJSON),
+	}
+	return json.Marshal(aux)
+}
+
+// Type implements WitnessCondition interface and returns condition type.
+func (c *ConditionNot) Type() WitnessConditionType {
+	return WitnessNot
+}
+
+// Match implements WitnessCondition interface checking whether this condition
+// matches given context.
+func (c *ConditionNot) Match(ctx MatchContext) (bool, error) {
+	res, err := c.Condition.Match(ctx)
+	return ((err == nil) && !res), err
+}
+
+// EncodeBinary implements WitnessCondition interface allowing to serialize condition.
+func (c *ConditionNot) EncodeBinary(w *io.BinWriter) {
+	w.WriteB(byte(c.Type()))
+	c.Condition.EncodeBinary(w)
+}
+
+// DecodeBinarySpecific implements WitnessCondition interface allowing to
+// deserialize condition-specific data.
+func (c *ConditionNot) DecodeBinarySpecific(r *io.BinReader, maxDepth int) {
+	c.Condition = decodeBinaryCondition(r, maxDepth-1)
+}
+
+// MarshalJSON implements json.Marshaler interface.
+func (c *ConditionNot) MarshalJSON() ([]byte, error) {
+	condJSON, err := json.Marshal(c.Condition)
+	if err != nil {
+		return nil, err
+	}
+	aux := conditionAux{
+		Type:       c.Type().String(),
+		Expression: json.RawMessage(condJSON),
+	}
+	return json.Marshal(aux)
+}
+
+// Type implements WitnessCondition interface and returns condition type.
+func (c *ConditionAnd) Type() WitnessConditionType {
+	return WitnessAnd
+}
+
+// Match implements WitnessCondition interface checking whether this condition
+// matches given context.
+func (c *ConditionAnd) Match(ctx MatchContext) (bool, error) {
+	for _, cond := range *c {
+		res, err := cond.Match(ctx)
+		if err != nil {
+			return false, err
+		}
+		if !res {
+			return false, nil
+		}
+	}
+	return true, nil
+}
+
+// EncodeBinary implements WitnessCondition interface allowing to serialize condition.
+func (c *ConditionAnd) EncodeBinary(w *io.BinWriter) {
+	w.WriteB(byte(c.Type()))
+	w.WriteArray([]WitnessCondition(*c))
+}
+
+func readArrayOfConditions(r *io.BinReader, maxDepth int) []WitnessCondition {
+	l := r.ReadVarUint()
+	if l == 0 {
+		r.Err = errors.New("empty array of conditions")
+		return nil
+	}
+	if l > maxSubitems {
+		r.Err = errors.New("too many elements")
+		return nil
+	}
+	a := make([]WitnessCondition, l)
+	for i := 0; i < int(l); i++ {
+		a[i] = decodeBinaryCondition(r, maxDepth-1)
+	}
+	if r.Err != nil {
+		return nil
+	}
+	return a
+}
+
+// DecodeBinarySpecific implements WitnessCondition interface allowing to
+// deserialize condition-specific data.
+func (c *ConditionAnd) DecodeBinarySpecific(r *io.BinReader, maxDepth int) {
+	a := readArrayOfConditions(r, maxDepth)
+	if r.Err == nil {
+		*c = a
+	}
+}
+
+func arrayToJSON(c WitnessCondition, a []WitnessCondition) ([]byte, error) {
+	exprs := make([]json.RawMessage, len(a))
+	for i := 0; i < len(a); i++ {
+		b, err := a[i].MarshalJSON()
+		if err != nil {
+			return nil, err
+		}
+		exprs[i] = json.RawMessage(b)
+	}
+	aux := conditionAux{
+		Type:        c.Type().String(),
+		Expressions: exprs,
+	}
+	return json.Marshal(aux)
+}
+
+// MarshalJSON implements json.Marshaler interface.
+func (c *ConditionAnd) MarshalJSON() ([]byte, error) {
+	return arrayToJSON(c, []WitnessCondition(*c))
+}
+
+// Type implements WitnessCondition interface and returns condition type.
+func (c *ConditionOr) Type() WitnessConditionType {
+	return WitnessOr
+}
+
+// Match implements WitnessCondition interface checking whether this condition
+// matches given context.
+func (c *ConditionOr) Match(ctx MatchContext) (bool, error) {
+	for _, cond := range *c {
+		res, err := cond.Match(ctx)
+		if err != nil {
+			return false, err
+		}
+		if res {
+			return true, nil
+		}
+	}
+	return false, nil
+}
+
+// EncodeBinary implements WitnessCondition interface allowing to serialize condition.
+func (c *ConditionOr) EncodeBinary(w *io.BinWriter) {
+	w.WriteB(byte(c.Type()))
+	w.WriteArray([]WitnessCondition(*c))
+}
+
+// DecodeBinarySpecific implements WitnessCondition interface allowing to
+// deserialize condition-specific data.
+func (c *ConditionOr) DecodeBinarySpecific(r *io.BinReader, maxDepth int) {
+	a := readArrayOfConditions(r, maxDepth)
+	if r.Err == nil {
+		*c = a
+	}
+}
+
+// MarshalJSON implements json.Marshaler interface.
+func (c *ConditionOr) MarshalJSON() ([]byte, error) {
+	return arrayToJSON(c, []WitnessCondition(*c))
+}
+
+// Type implements WitnessCondition interface and returns condition type.
+func (c *ConditionScriptHash) Type() WitnessConditionType {
+	return WitnessScriptHash
+}
+
+// Match implements WitnessCondition interface checking whether this condition
+// matches given context.
+func (c *ConditionScriptHash) Match(ctx MatchContext) (bool, error) {
+	return util.Uint160(*c).Equals(ctx.GetCurrentScriptHash()), nil
+}
+
+// EncodeBinary implements WitnessCondition interface allowing to serialize condition.
+func (c *ConditionScriptHash) EncodeBinary(w *io.BinWriter) {
+	w.WriteB(byte(c.Type()))
+	w.WriteBytes(c[:])
+}
+
+// DecodeBinarySpecific implements WitnessCondition interface allowing to
+// deserialize condition-specific data.
+func (c *ConditionScriptHash) DecodeBinarySpecific(r *io.BinReader, _ int) {
+	r.ReadBytes(c[:])
+}
+
+// MarshalJSON implements json.Marshaler interface.
+func (c *ConditionScriptHash) MarshalJSON() ([]byte, error) {
+	aux := conditionAux{
+		Type: c.Type().String(),
+		Hash: (*util.Uint160)(c),
+	}
+	return json.Marshal(aux)
+}
+
+// Type implements WitnessCondition interface and returns condition type.
+func (c *ConditionGroup) Type() WitnessConditionType {
+	return WitnessGroup
+}
+
+// Match implements WitnessCondition interface checking whether this condition
+// matches given context.
+func (c *ConditionGroup) Match(ctx MatchContext) (bool, error) {
+	return ctx.CurrentScriptHasGroup((*keys.PublicKey)(c))
+}
+
+// EncodeBinary implements WitnessCondition interface allowing to serialize condition.
+func (c *ConditionGroup) EncodeBinary(w *io.BinWriter) {
+	w.WriteB(byte(c.Type()))
+	(*keys.PublicKey)(c).EncodeBinary(w)
+}
+
+// DecodeBinarySpecific implements WitnessCondition interface allowing to
+// deserialize condition-specific data.
+func (c *ConditionGroup) DecodeBinarySpecific(r *io.BinReader, _ int) {
+	(*keys.PublicKey)(c).DecodeBinary(r)
+}
+
+// MarshalJSON implements json.Marshaler interface.
+func (c *ConditionGroup) MarshalJSON() ([]byte, error) {
+	aux := conditionAux{
+		Type:  c.Type().String(),
+		Group: (*keys.PublicKey)(c),
+	}
+	return json.Marshal(aux)
+}
+
+// Type implements WitnessCondition interface and returns condition type.
+func (c ConditionCalledByEntry) Type() WitnessConditionType {
+	return WitnessCalledByEntry
+}
+
+// Match implements WitnessCondition interface checking whether this condition
+// matches given context.
+func (c ConditionCalledByEntry) Match(ctx MatchContext) (bool, error) {
+	entry := ctx.GetEntryScriptHash()
+	return entry.Equals(ctx.GetCallingScriptHash()) || entry.Equals(ctx.GetCurrentScriptHash()), nil
+}
+
+// EncodeBinary implements WitnessCondition interface allowing to serialize condition.
+func (c ConditionCalledByEntry) EncodeBinary(w *io.BinWriter) {
+	w.WriteB(byte(c.Type()))
+}
+
+// DecodeBinarySpecific implements WitnessCondition interface allowing to
+// deserialize condition-specific data.
+func (c ConditionCalledByEntry) DecodeBinarySpecific(_ *io.BinReader, _ int) {
+}
+
+// MarshalJSON implements json.Marshaler interface.
+func (c ConditionCalledByEntry) MarshalJSON() ([]byte, error) {
+	aux := conditionAux{
+		Type: c.Type().String(),
+	}
+	return json.Marshal(aux)
+}
+
+// Type implements WitnessCondition interface and returns condition type.
+func (c *ConditionCalledByContract) Type() WitnessConditionType {
+	return WitnessCalledByContract
+}
+
+// Match implements WitnessCondition interface checking whether this condition
+// matches given context.
+func (c *ConditionCalledByContract) Match(ctx MatchContext) (bool, error) {
+	return util.Uint160(*c).Equals(ctx.GetCallingScriptHash()), nil
+}
+
+// EncodeBinary implements WitnessCondition interface allowing to serialize condition.
+func (c *ConditionCalledByContract) EncodeBinary(w *io.BinWriter) {
+	w.WriteB(byte(c.Type()))
+	w.WriteBytes(c[:])
+}
+
+// DecodeBinarySpecific implements WitnessCondition interface allowing to
+// deserialize condition-specific data.
+func (c *ConditionCalledByContract) DecodeBinarySpecific(r *io.BinReader, _ int) {
+	r.ReadBytes(c[:])
+}
+
+// MarshalJSON implements json.Marshaler interface.
+func (c *ConditionCalledByContract) MarshalJSON() ([]byte, error) {
+	aux := conditionAux{
+		Type: c.Type().String(),
+		Hash: (*util.Uint160)(c),
+	}
+	return json.Marshal(aux)
+}
+
+// Type implements WitnessCondition interface and returns condition type.
+func (c *ConditionCalledByGroup) Type() WitnessConditionType {
+	return WitnessCalledByGroup
+}
+
+// Match implements WitnessCondition interface checking whether this condition
+// matches given context.
+func (c *ConditionCalledByGroup) Match(ctx MatchContext) (bool, error) {
+	return ctx.CallingScriptHasGroup((*keys.PublicKey)(c))
+}
+
+// EncodeBinary implements WitnessCondition interface allowing to serialize condition.
+func (c *ConditionCalledByGroup) EncodeBinary(w *io.BinWriter) {
+	w.WriteB(byte(c.Type()))
+	(*keys.PublicKey)(c).EncodeBinary(w)
+}
+
+// DecodeBinarySpecific implements WitnessCondition interface allowing to
+// deserialize condition-specific data.
+func (c *ConditionCalledByGroup) DecodeBinarySpecific(r *io.BinReader, _ int) {
+	(*keys.PublicKey)(c).DecodeBinary(r)
+}
+
+// MarshalJSON implements json.Marshaler interface.
+func (c *ConditionCalledByGroup) MarshalJSON() ([]byte, error) {
+	aux := conditionAux{
+		Type:  c.Type().String(),
+		Group: (*keys.PublicKey)(c),
+	}
+	return json.Marshal(aux)
+}
+
+// DecodeBinaryCondition decodes and returns condition from the given binary stream.
+func DecodeBinaryCondition(r *io.BinReader) WitnessCondition {
+	return decodeBinaryCondition(r, MaxConditionNesting)
+}
+
+func decodeBinaryCondition(r *io.BinReader, maxDepth int) WitnessCondition {
+	if maxDepth <= 0 {
+		r.Err = errors.New("too many nesting levels")
+		return nil
+	}
+	t := WitnessConditionType(r.ReadB())
+	if r.Err != nil {
+		return nil
+	}
+	var res WitnessCondition
+	switch t {
+	case WitnessBoolean:
+		var v ConditionBoolean
+		res = &v
+	case WitnessNot:
+		res = &ConditionNot{}
+	case WitnessAnd:
+		res = &ConditionAnd{}
+	case WitnessOr:
+		res = &ConditionOr{}
+	case WitnessScriptHash:
+		res = &ConditionScriptHash{}
+	case WitnessGroup:
+		res = &ConditionGroup{}
+	case WitnessCalledByEntry:
+		res = ConditionCalledByEntry{}
+	case WitnessCalledByContract:
+		res = &ConditionCalledByContract{}
+	case WitnessCalledByGroup:
+		res = &ConditionCalledByGroup{}
+	default:
+		r.Err = errors.New("invalid condition type")
+		return nil
+	}
+	res.DecodeBinarySpecific(r, maxDepth)
+	if r.Err != nil {
+		return nil
+	}
+	return res
+}
+
+func unmarshalArrayOfConditionJSONs(arr []json.RawMessage, maxDepth int) ([]WitnessCondition, error) {
+	l := len(arr)
+	if l == 0 {
+		return nil, errors.New("empty array of conditions")
+	}
+	if l >= maxSubitems {
+		return nil, errors.New("too many elements")
+	}
+	res := make([]WitnessCondition, l)
+	for i := range arr {
+		v, err := unmarshalConditionJSON(arr[i], maxDepth-1)
+		if err != nil {
+			return nil, err
+		}
+		res[i] = v
+	}
+	return res, nil
+}
+
+// UnmarshalConditionJSON unmarshalls condition from the given JSON data.
+func UnmarshalConditionJSON(data []byte) (WitnessCondition, error) {
+	return unmarshalConditionJSON(data, MaxConditionNesting)
+}
+
+func unmarshalConditionJSON(data []byte, maxDepth int) (WitnessCondition, error) {
+	if maxDepth <= 0 {
+		return nil, errors.New("too many nesting levels")
+	}
+	aux := &conditionAux{}
+	err := json.Unmarshal(data, aux)
+	if err != nil {
+		return nil, err
+	}
+	var res WitnessCondition
+	switch aux.Type {
+	case WitnessBoolean.String():
+		var v bool
+		err = json.Unmarshal(aux.Expression, &v)
+		if err != nil {
+			return nil, err
+		}
+		res = (*ConditionBoolean)(&v)
+	case WitnessNot.String():
+		v, err := unmarshalConditionJSON(aux.Expression, maxDepth-1)
+		if err != nil {
+			return nil, err
+		}
+		res = &ConditionNot{Condition: v}
+	case WitnessAnd.String():
+		v, err := unmarshalArrayOfConditionJSONs(aux.Expressions, maxDepth)
+		if err != nil {
+			return nil, err
+		}
+		res = (*ConditionAnd)(&v)
+	case WitnessOr.String():
+		v, err := unmarshalArrayOfConditionJSONs(aux.Expressions, maxDepth)
+		if err != nil {
+			return nil, err
+		}
+		res = (*ConditionOr)(&v)
+	case WitnessScriptHash.String():
+		if aux.Hash == nil {
+			return nil, errors.New("no hash specified")
+		}
+		res = (*ConditionScriptHash)(aux.Hash)
+	case WitnessGroup.String():
+		if aux.Group == nil {
+			return nil, errors.New("no group specified")
+		}
+		res = (*ConditionGroup)(aux.Group)
+	case WitnessCalledByEntry.String():
+		res = ConditionCalledByEntry{}
+	case WitnessCalledByContract.String():
+		if aux.Hash == nil {
+			return nil, errors.New("no hash specified")
+		}
+		res = (*ConditionCalledByContract)(aux.Hash)
+	case WitnessCalledByGroup.String():
+		if aux.Group == nil {
+			return nil, errors.New("no group specified")
+		}
+		res = (*ConditionCalledByGroup)(aux.Group)
+	default:
+		return nil, errors.New("invalid condition type")
+	}
+	return res, nil
+}

pkg/core/transaction/witness_condition_test.go

@@ -0,0 +1,325 @@
+package transaction
+
+import (
+	"encoding/json"
+	"errors"
+	"testing"
+
+	"github.com/nspcc-dev/neo-go/pkg/crypto/keys"
+	"github.com/nspcc-dev/neo-go/pkg/io"
+	"github.com/nspcc-dev/neo-go/pkg/util"
+	"github.com/stretchr/testify/require"
+)
+
+type InvalidCondition struct{}
+
+func (c InvalidCondition) Type() WitnessConditionType {
+	return 0xff
+}
+func (c InvalidCondition) Match(_ MatchContext) (bool, error) {
+	return true, nil
+}
+func (c InvalidCondition) EncodeBinary(w *io.BinWriter) {
+	w.WriteB(byte(c.Type()))
+}
+func (c InvalidCondition) DecodeBinarySpecific(r *io.BinReader, _ int) {
+}
+func (c InvalidCondition) MarshalJSON() ([]byte, error) {
+	aux := conditionAux{
+		Type: c.Type().String(),
+	}
+	return json.Marshal(aux)
+}
+
+type condCase struct {
+	condition WitnessCondition
+	success   bool
+}
+
+func TestWitnessConditionSerDes(t *testing.T) {
+	var someBool bool
+	pk, err := keys.NewPrivateKey()
+	require.NoError(t, err)
+	var cases = []condCase{
+		{(*ConditionBoolean)(&someBool), true},
+		{&ConditionNot{(*ConditionBoolean)(&someBool)}, true},
+		{&ConditionAnd{(*ConditionBoolean)(&someBool), (*ConditionBoolean)(&someBool)}, true},
+		{&ConditionOr{(*ConditionBoolean)(&someBool), (*ConditionBoolean)(&someBool)}, true},
+		{&ConditionScriptHash{1, 2, 3}, true},
+		{(*ConditionGroup)(pk.PublicKey()), true},
+		{ConditionCalledByEntry{}, true},
+		{&ConditionCalledByContract{1, 2, 3}, true},
+		{(*ConditionCalledByGroup)(pk.PublicKey()), true},
+		{InvalidCondition{}, false},
+		{&ConditionAnd{}, false},
+		{&ConditionOr{}, false},
+		{&ConditionNot{&ConditionNot{&ConditionNot{(*ConditionBoolean)(&someBool)}}}, false},
+	}
+	var maxSubCondAnd = &ConditionAnd{}
+	var maxSubCondOr = &ConditionAnd{}
+	for i := 0; i < maxSubitems+1; i++ {
+		*maxSubCondAnd = append(*maxSubCondAnd, (*ConditionBoolean)(&someBool))
+		*maxSubCondOr = append(*maxSubCondOr, (*ConditionBoolean)(&someBool))
+	}
+	cases = append(cases, condCase{maxSubCondAnd, false})
+	cases = append(cases, condCase{maxSubCondOr, false})
+	t.Run("binary", func(t *testing.T) {
+		for i, c := range cases {
+			w := io.NewBufBinWriter()
+			c.condition.EncodeBinary(w.BinWriter)
+			require.NoError(t, w.Err)
+			b := w.Bytes()
+
+			r := io.NewBinReaderFromBuf(b)
+			res := DecodeBinaryCondition(r)
+			if !c.success {
+				require.Nil(t, res)
+				require.Errorf(t, r.Err, "case %d", i)
+				continue
+			}
+			require.NoErrorf(t, r.Err, "case %d", i)
+			require.Equal(t, c.condition, res)
+		}
+	})
+	t.Run("json", func(t *testing.T) {
+		for i, c := range cases {
+			jj, err := c.condition.MarshalJSON()
+			require.NoError(t, err)
+			res, err := UnmarshalConditionJSON(jj)
+			if !c.success {
+				require.Errorf(t, err, "case %d, json %s", i, jj)
+				continue
+			}
+			require.NoErrorf(t, err, "case %d, json %s", i, jj)
+			require.Equal(t, c.condition, res)
+		}
+	})
+}
+
+func TestWitnessConditionZeroDeser(t *testing.T) {
+	r := io.NewBinReaderFromBuf([]byte{})
+	res := DecodeBinaryCondition(r)
+	require.Nil(t, res)
+	require.Error(t, r.Err)
+}
+
+func TestWitnessConditionJSONErrors(t *testing.T) {
+	var cases = []string{
+		`[]`,
+		`{}`,
+		`{"type":"Boolean"}`,
+		`{"type":"Not"}`,
+		`{"type":"And"}`,
+		`{"type":"Or"}`,
+		`{"type":"ScriptHash"}`,
+		`{"type":"Group"}`,
+		`{"type":"CalledByContract"}`,
+		`{"type":"CalledByGroup"}`,
+		`{"type":"Boolean", "expression":42}`,
+		`{"type":"Not", "expression":true}`,
+		`{"type":"And", "expressions":[{"type":"CalledByGroup"},{"type":"Not", "expression":true}]}`,
+		`{"type":"Or", "expressions":{"type":"CalledByGroup"}}`,
+		`{"type":"Or", "expressions":[{"type":"CalledByGroup"},{"type":"Not", "expression":false}]}`,
+		`{"type":"ScriptHash", "hash":"1122"}`,
+		`{"type":"Group", "group":"032211"}`,
+		`{"type":"CalledByContract", "hash":"1122"}`,
+		`{"type":"CalledByGroup", "group":"032211"}`,
+	}
+	for i := range cases {
+		res, err := UnmarshalConditionJSON([]byte(cases[i]))
+		require.Errorf(t, err, "case %d, json %s", i, cases[i])
+		require.Nil(t, res)
+	}
+}
+
+type TestMC struct {
+	calling util.Uint160
+	current util.Uint160
+	entry   util.Uint160
+	goodKey *keys.PublicKey
+	badKey  *keys.PublicKey
+}
+
+func (t *TestMC) GetCallingScriptHash() util.Uint160 {
+	return t.calling
+}
+func (t *TestMC) GetCurrentScriptHash() util.Uint160 {
+	return t.current
+}
+func (t *TestMC) GetEntryScriptHash() util.Uint160 {
+	return t.entry
+}
+func (t *TestMC) CallingScriptHasGroup(k *keys.PublicKey) (bool, error) {
+	res, err := t.CurrentScriptHasGroup(k)
+	return !res, err // To differentiate from current we invert the logic value.
+}
+func (t *TestMC) CurrentScriptHasGroup(k *keys.PublicKey) (bool, error) {
+	if k.Equal(t.goodKey) {
+		return true, nil
+	}
+	if k.Equal(t.badKey) {
+		return false, errors.New("baaad key")
+	}
+	return false, nil
+}
+
+func TestWitnessConditionMatch(t *testing.T) {
+	pkGood, err := keys.NewPrivateKey()
+	require.NoError(t, err)
+	pkBad, err := keys.NewPrivateKey()
+	require.NoError(t, err)
+	pkNeutral, err := keys.NewPrivateKey()
+	require.NoError(t, err)
+	entrySC := util.Uint160{1, 2, 3}
+	currentSC := util.Uint160{4, 5, 6}
+	tmc := &TestMC{
+		calling: entrySC,
+		entry:   entrySC,
+		current: currentSC,
+		goodKey: pkGood.PublicKey(),
+		badKey:  pkBad.PublicKey(),
+	}
+
+	t.Run("boolean", func(t *testing.T) {
+		var b bool
+		var c = (*ConditionBoolean)(&b)
+		res, err := c.Match(tmc)
+		require.NoError(t, err)
+		require.False(t, res)
+		b = true
+		res, err = c.Match(tmc)
+		require.NoError(t, err)
+		require.True(t, res)
+	})
+	t.Run("not", func(t *testing.T) {
+		var b bool
+		var cInner = (*ConditionBoolean)(&b)
+		var cInner2 = (*ConditionGroup)(pkBad.PublicKey())
+		var c = &ConditionNot{cInner}
+		var c2 = &ConditionNot{cInner2}
+
+		res, err := c.Match(tmc)
+		require.NoError(t, err)
+		require.True(t, res)
+		b = true
+		res, err = c.Match(tmc)
+		require.NoError(t, err)
+		require.False(t, res)
+		_, err = c2.Match(tmc)
+		require.Error(t, err)
+	})
+	t.Run("and", func(t *testing.T) {
+		var bFalse, bTrue bool
+		var cInnerFalse = (*ConditionBoolean)(&bFalse)
+		var cInnerTrue = (*ConditionBoolean)(&bTrue)
+		var cInnerBad = (*ConditionGroup)(pkBad.PublicKey())
+		var c = &ConditionAnd{cInnerTrue, cInnerFalse, cInnerFalse}
+		var cBad = &ConditionAnd{cInnerTrue, cInnerBad}
+
+		bTrue = true
+		res, err := c.Match(tmc)
+		require.NoError(t, err)
+		require.False(t, res)
+		bFalse = true
+		res, err = c.Match(tmc)
+		require.NoError(t, err)
+		require.True(t, res)
+
+		_, err = cBad.Match(tmc)
+		require.Error(t, err)
+	})
+	t.Run("or", func(t *testing.T) {
+		var bFalse, bTrue bool
+		var cInnerFalse = (*ConditionBoolean)(&bFalse)
+		var cInnerTrue = (*ConditionBoolean)(&bTrue)
+		var cInnerBad = (*ConditionGroup)(pkBad.PublicKey())
+		var c = &ConditionOr{cInnerTrue, cInnerFalse, cInnerFalse}
+		var cBad = &ConditionOr{cInnerTrue, cInnerBad}
+
+		bTrue = true
+		res, err := c.Match(tmc)
+		require.NoError(t, err)
+		require.True(t, res)
+		bTrue = false
+		res, err = c.Match(tmc)
+		require.NoError(t, err)
+		require.False(t, res)
+
+		_, err = cBad.Match(tmc)
+		require.Error(t, err)
+	})
+	t.Run("script hash", func(t *testing.T) {
+		var cEntry = (*ConditionScriptHash)(&entrySC)
+		var cCurrent = (*ConditionScriptHash)(&currentSC)
+
+		res, err := cEntry.Match(tmc)
+		require.NoError(t, err)
+		require.False(t, res)
+		res, err = cCurrent.Match(tmc)
+		require.NoError(t, err)
+		require.True(t, res)
+	})
+	t.Run("group", func(t *testing.T) {
+		var cBad = (*ConditionGroup)(pkBad.PublicKey())
+		var cGood = (*ConditionGroup)(pkGood.PublicKey())
+		var cNeutral = (*ConditionGroup)(pkNeutral.PublicKey())
+
+		res, err := cGood.Match(tmc)
+		require.NoError(t, err)
+		require.True(t, res)
+
+		res, err = cNeutral.Match(tmc)
+		require.NoError(t, err)
+		require.False(t, res)
+
+		_, err = cBad.Match(tmc)
+		require.Error(t, err)
+	})
+	t.Run("called by entry", func(t *testing.T) {
+		var c = ConditionCalledByEntry{}
+
+		res, err := c.Match(tmc)
+		require.NoError(t, err)
+		require.True(t, res)
+
+		tmc2 := *tmc
+		tmc2.entry = util.Uint160{0, 9, 8}
+		res, err = c.Match(&tmc2)
+		require.NoError(t, err)
+		require.False(t, res)
+
+		tmc3 := *tmc
+		tmc3.calling = util.Uint160{}
+		tmc3.current = tmc3.entry
+		res, err = c.Match(&tmc3)
+		require.NoError(t, err)
+		require.True(t, res)
+	})
+	t.Run("called by contract", func(t *testing.T) {
+		var cEntry = (*ConditionCalledByContract)(&entrySC)
+		var cCurrent = (*ConditionCalledByContract)(&currentSC)
+
+		res, err := cEntry.Match(tmc)
+		require.NoError(t, err)
+		require.True(t, res)
+		res, err = cCurrent.Match(tmc)
+		require.NoError(t, err)
+		require.False(t, res)
+	})
+	t.Run("called by group", func(t *testing.T) {
+		var cBad = (*ConditionCalledByGroup)(pkBad.PublicKey())
+		var cGood = (*ConditionCalledByGroup)(pkGood.PublicKey())
+		var cNeutral = (*ConditionCalledByGroup)(pkNeutral.PublicKey())
+
+		res, err := cGood.Match(tmc)
+		require.NoError(t, err)
+		require.False(t, res)
+
+		res, err = cNeutral.Match(tmc)
+		require.NoError(t, err)
+		require.True(t, res)
+
+		_, err = cBad.Match(tmc)
+		require.Error(t, err)
+	})
+}

pkg/core/transaction/witness_rule.go

@@ -0,0 +1,86 @@
+package transaction
+
+import (
+	"encoding/json"
+	"errors"
+
+	"github.com/nspcc-dev/neo-go/pkg/io"
+)
+
+//go:generate stringer -type=WitnessAction -linecomment
+
+// WitnessAction represents an action to perform in WitnessRule if
+// WitnessCondition matches.
+type WitnessAction byte
+
+const (
+	// WitnessDeny rejects current witness if condition is met.
+	WitnessDeny WitnessAction = 0 // Deny
+	// WitnessAllow approves current witness if condition is met.
+	WitnessAllow WitnessAction = 1 // Allow
+)
+
+// WitnessRule represents a single rule for Rules witness scope.
+type WitnessRule struct {
+	Action    WitnessAction    `json:"action"`
+	Condition WitnessCondition `json:"condition"`
+}
+
+type witnessRuleAux struct {
+	Action    string          `json:"action"`
+	Condition json.RawMessage `json:"condition"`
+}
+
+// EncodeBinary implements Serializable interface.
+func (w *WitnessRule) EncodeBinary(bw *io.BinWriter) {
+	bw.WriteB(byte(w.Action))
+	w.Condition.EncodeBinary(bw)
+}
+
+// DecodeBinary implements Serializable interface.
+func (w *WitnessRule) DecodeBinary(br *io.BinReader) {
+	w.Action = WitnessAction(br.ReadB())
+	if br.Err == nil && w.Action != WitnessDeny && w.Action != WitnessAllow {
+		br.Err = errors.New("unknown witness rule action")
+		return
+	}
+	w.Condition = DecodeBinaryCondition(br)
+}
+
+// UnmarshalJSON implements json.Unmarshaler interface.
+func (w *WitnessRule) MarshalJSON() ([]byte, error) {
+	cond, err := w.Condition.MarshalJSON()
+	if err != nil {
+		return nil, err
+	}
+	aux := &witnessRuleAux{
+		Action:    w.Action.String(),
+		Condition: cond,
+	}
+	return json.Marshal(aux)
+}
+
+// UnmarshalJSON implements json.Unmarshaler interface.
+func (w *WitnessRule) UnmarshalJSON(data []byte) error {
+	aux := &witnessRuleAux{}
+	err := json.Unmarshal(data, aux)
+	if err != nil {
+		return err
+	}
+	var action WitnessAction
+	switch aux.Action {
+	case WitnessDeny.String():
+		action = WitnessDeny
+	case WitnessAllow.String():
+		action = WitnessAllow
+	default:
+		return errors.New("unknown witness rule action")
+	}
+	cond, err := UnmarshalConditionJSON(aux.Condition)
+	if err != nil {
+		return err
+	}
+	w.Action = action
+	w.Condition = cond
+	return nil
+}

pkg/core/transaction/witness_rule_test.go

@@ -0,0 +1,56 @@
+package transaction
+
+import (
+	"encoding/json"
+	"testing"
+
+	"github.com/nspcc-dev/neo-go/internal/testserdes"
+	"github.com/stretchr/testify/require"
+)
+
+func TestWitnessRuleSerDes(t *testing.T) {
+	var b bool
+	expected := &WitnessRule{
+		Action:    WitnessAllow,
+		Condition: (*ConditionBoolean)(&b),
+	}
+	actual := &WitnessRule{}
+	testserdes.EncodeDecodeBinary(t, expected, actual)
+}
+
+func TestWitnessRuleSerDesBad(t *testing.T) {
+	var b bool
+	bad := &WitnessRule{
+		Action:    0xff,
+		Condition: (*ConditionBoolean)(&b),
+	}
+	badB, err := testserdes.EncodeBinary(bad)
+	require.NoError(t, err)
+	err = testserdes.DecodeBinary(badB, &WitnessRule{})
+	require.Error(t, err)
+}
+
+func TestWitnessRuleJSON(t *testing.T) {
+	var b bool
+	expected := &WitnessRule{
+		Action:    WitnessDeny,
+		Condition: (*ConditionBoolean)(&b),
+	}
+	actual := &WitnessRule{}
+	testserdes.MarshalUnmarshalJSON(t, expected, actual)
+}
+
+func TestWitnessRuleBadJSON(t *testing.T) {
+	var cases = []string{
+		`{}`,
+		`[]`,
+		`{"action":"Allow"}`,
+		`{"action":"Unknown","condition":{"type":"Boolean", "expression":true}}`,
+		`{"action":"Allow","condition":{"type":"Boolean", "expression":42}}`,
+	}
+	for i := range cases {
+		actual := &WitnessRule{}
+		err := json.Unmarshal([]byte(cases[i]), actual)
+		require.Errorf(t, err, "case %d, json %s", i, cases[i])
+	}
+}

pkg/core/transaction/witness_scope.go

@@ -22,6 +22,8 @@ const (
 	CustomContracts WitnessScope = 0x10
 	// CustomGroups define custom pubkey for group members.
 	CustomGroups WitnessScope = 0x20
+	// Rules is a set of conditions with boolean operators.
+	Rules WitnessScope = 0x40
 	// Global allows this witness in all contexts (default Neo2 behavior).
 	// This cannot be combined with other flags.
 	Global WitnessScope = 0x80
@@ -42,6 +44,7 @@ func ScopesFromString(s string) (WitnessScope, error) {
 		CalledByEntry.String():   CalledByEntry,
 		CustomContracts.String(): CustomContracts,
 		CustomGroups.String():    CustomGroups,
+		Rules.String():           Rules,
 		None.String():            None,
 	}
 	var isGlobal bool
@@ -61,6 +64,16 @@ func ScopesFromString(s string) (WitnessScope, error) {
 	return result, nil
 }
 
+func appendScopeString(str string, scopes WitnessScope, scope WitnessScope) string {
+	if scopes&scope != 0 {
+		if len(str) != 0 {
+			str += ", "
+		}
+		str += scope.String()
+	}
+	return str
+}
+
 // scopesToString converts witness scope to it's string representation. It uses
 // `, ` to separate scope names.
 func scopesToString(scopes WitnessScope) string {
@@ -68,21 +81,10 @@ func scopesToString(scopes WitnessScope) string {
 		return scopes.String()
 	}
 	var res string
-	if scopes&CalledByEntry != 0 {
-		res = CalledByEntry.String()
-	}
-	if scopes&CustomContracts != 0 {
-		if len(res) != 0 {
-			res += ", "
-		}
-		res += CustomContracts.String()
-	}
-	if scopes&CustomGroups != 0 {
-		if len(res) != 0 {
-			res += ", "
-		}
-		res += CustomGroups.String()
-	}
+	res = appendScopeString(res, scopes, CalledByEntry)
+	res = appendScopeString(res, scopes, CustomContracts)
+	res = appendScopeString(res, scopes, CustomGroups)
+	res = appendScopeString(res, scopes, Rules)
 	return res
 }
 

pkg/core/transaction/witness_scope_string.go

@@ -12,6 +12,7 @@ func _() {
 	_ = x[CalledByEntry-1]
 	_ = x[CustomContracts-16]
 	_ = x[CustomGroups-32]
+	_ = x[Rules-64]
 	_ = x[Global-128]
 }
 
@@ -19,7 +20,8 @@ const (
 	_WitnessScope_name_0 = "NoneCalledByEntry"
 	_WitnessScope_name_1 = "CustomContracts"
 	_WitnessScope_name_2 = "CustomGroups"
-	_WitnessScope_name_3 = "Global"
+	_WitnessScope_name_3 = "Rules"
+	_WitnessScope_name_4 = "Global"
 )
 
 var (
@@ -28,14 +30,16 @@ var (
 
 func (i WitnessScope) String() string {
 	switch {
-	case i <= 1:
+	case 0 <= i && i <= 1:
 		return _WitnessScope_name_0[_WitnessScope_index_0[i]:_WitnessScope_index_0[i+1]]
 	case i == 16:
 		return _WitnessScope_name_1
 	case i == 32:
 		return _WitnessScope_name_2
-	case i == 128:
+	case i == 64:
 		return _WitnessScope_name_3
+	case i == 128:
+		return _WitnessScope_name_4
 	default:
 		return "WitnessScope(" + strconv.FormatInt(int64(i), 10) + ")"
 	}

pkg/core/transaction/witnessaction_string.go

@@ -0,0 +1,24 @@
+// Code generated by "stringer -type=WitnessAction -linecomment"; DO NOT EDIT.
+
+package transaction
+
+import "strconv"
+
+func _() {
+	// An "invalid array index" compiler error signifies that the constant values have changed.
+	// Re-run the stringer command to generate them again.
+	var x [1]struct{}
+	_ = x[WitnessDeny-0]
+	_ = x[WitnessAllow-1]
+}
+
+const _WitnessAction_name = "DenyAllow"
+
+var _WitnessAction_index = [...]uint8{0, 4, 9}
+
+func (i WitnessAction) String() string {
+	if i >= WitnessAction(len(_WitnessAction_index)-1) {
+		return "WitnessAction(" + strconv.FormatInt(int64(i), 10) + ")"
+	}
+	return _WitnessAction_name[_WitnessAction_index[i]:_WitnessAction_index[i+1]]
+}

pkg/core/transaction/witnessconditiontype_string.go

@@ -0,0 +1,50 @@
+// Code generated by "stringer -type=WitnessConditionType -linecomment"; DO NOT EDIT.
+
+package transaction
+
+import "strconv"
+
+func _() {
+	// An "invalid array index" compiler error signifies that the constant values have changed.
+	// Re-run the stringer command to generate them again.
+	var x [1]struct{}
+	_ = x[WitnessBoolean-0]
+	_ = x[WitnessNot-1]
+	_ = x[WitnessAnd-2]
+	_ = x[WitnessOr-3]
+	_ = x[WitnessScriptHash-24]
+	_ = x[WitnessGroup-25]
+	_ = x[WitnessCalledByEntry-32]
+	_ = x[WitnessCalledByContract-40]
+	_ = x[WitnessCalledByGroup-41]
+}
+
+const (
+	_WitnessConditionType_name_0 = "BooleanNotAndOr"
+	_WitnessConditionType_name_1 = "ScriptHashGroup"
+	_WitnessConditionType_name_2 = "CalledByEntry"
+	_WitnessConditionType_name_3 = "CalledByContractCalledByGroup"
+)
+
+var (
+	_WitnessConditionType_index_0 = [...]uint8{0, 7, 10, 13, 15}
+	_WitnessConditionType_index_1 = [...]uint8{0, 10, 15}
+	_WitnessConditionType_index_3 = [...]uint8{0, 16, 29}
+)
+
+func (i WitnessConditionType) String() string {
+	switch {
+	case 0 <= i && i <= 3:
+		return _WitnessConditionType_name_0[_WitnessConditionType_index_0[i]:_WitnessConditionType_index_0[i+1]]
+	case 24 <= i && i <= 25:
+		i -= 24
+		return _WitnessConditionType_name_1[_WitnessConditionType_index_1[i]:_WitnessConditionType_index_1[i+1]]
+	case i == 32:
+		return _WitnessConditionType_name_2
+	case 40 <= i && i <= 41:
+		i -= 40
+		return _WitnessConditionType_name_3[_WitnessConditionType_index_3[i]:_WitnessConditionType_index_3[i+1]]
+	default:
+		return "WitnessConditionType(" + strconv.FormatInt(int64(i), 10) + ")"
+	}
+}

pkg/smartcontract/manifest/group.go

@@ -64,6 +64,15 @@ func (g Groups) AreValid(h util.Uint160) error {
 	return nil
 }
 
+func (g Groups) Contains(k *keys.PublicKey) bool {
+	for i := range g {
+		if k.Equal(g[i].PublicKey) {
+			return true
+		}
+	}
+	return false
+}
+
 // MarshalJSON implements json.Marshaler interface.
 func (g *Group) MarshalJSON() ([]byte, error) {
 	aux := &groupAux{

pkg/smartcontract/manifest/group_test.go

@@ -41,3 +41,17 @@ func TestGroupsAreValid(t *testing.T) {
 	gps = Groups{gcorrect, gcorrect}
 	require.Error(t, gps.AreValid(h))
 }
+
+func TestGroupsContains(t *testing.T) {
+	priv, err := keys.NewPrivateKey()
+	require.NoError(t, err)
+	priv2, err := keys.NewPrivateKey()
+	require.NoError(t, err)
+	priv3, err := keys.NewPrivateKey()
+	require.NoError(t, err)
+	g1 := Group{priv.PublicKey(), nil}
+	g2 := Group{priv2.PublicKey(), nil}
+	gps := Groups{g1, g2}
+	require.True(t, gps.Contains(priv2.PublicKey()))
+	require.False(t, gps.Contains(priv3.PublicKey()))
+}