neo-go/pkg/smartcontract/manifest/permission.go

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package manifest
import (
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"crypto/elliptic"
"encoding/hex"
"encoding/json"
"errors"
"fmt"
"github.com/nspcc-dev/neo-go/pkg/crypto/keys"
"github.com/nspcc-dev/neo-go/pkg/util"
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"github.com/nspcc-dev/neo-go/pkg/vm/stackitem"
)
// PermissionType represents permission type.
type PermissionType uint8
const (
// PermissionWildcard allows everything.
PermissionWildcard PermissionType = 0
// PermissionHash restricts called contracts based on hash.
PermissionHash PermissionType = 1
// PermissionGroup restricts called contracts based on public key.
PermissionGroup PermissionType = 2
)
// PermissionDesc is a permission descriptor.
type PermissionDesc struct {
Type PermissionType
Value interface{}
}
// Permission describes which contracts may be invoked and which methods are called.
type Permission struct {
Contract PermissionDesc `json:"contract"`
Methods WildStrings `json:"methods"`
}
// Permissions is just an array of Permission.
type Permissions []Permission
type permissionAux struct {
Contract PermissionDesc `json:"contract"`
Methods WildStrings `json:"methods"`
}
// NewPermission returns a new permission of the given type.
func NewPermission(typ PermissionType, args ...interface{}) *Permission {
return &Permission{
Contract: *newPermissionDesc(typ, args...),
}
}
func newPermissionDesc(typ PermissionType, args ...interface{}) *PermissionDesc {
desc := &PermissionDesc{Type: typ}
switch typ {
case PermissionWildcard:
if len(args) != 0 {
panic("wildcard permission has no arguments")
}
case PermissionHash:
if len(args) == 0 {
panic("hash permission should have an argument")
} else if u, ok := args[0].(util.Uint160); !ok {
panic("hash permission should have util.Uint160 argument")
} else {
desc.Value = u
}
case PermissionGroup:
if len(args) == 0 {
panic("group permission should have an argument")
} else if pub, ok := args[0].(*keys.PublicKey); !ok {
panic("group permission should have a public key argument")
} else {
desc.Value = pub
}
}
return desc
}
// Hash returns hash for hash-permission.
func (d *PermissionDesc) Hash() util.Uint160 {
return d.Value.(util.Uint160)
}
// Group returns group's public key for group-permission.
func (d *PermissionDesc) Group() *keys.PublicKey {
return d.Value.(*keys.PublicKey)
}
// Less returns true if this value is less than the given PermissionDesc value.
func (d *PermissionDesc) Less(d1 PermissionDesc) bool {
if d.Type < d1.Type {
return true
}
if d.Type != d1.Type {
return false
}
switch d.Type {
case PermissionHash:
return d.Hash().Less(d1.Hash())
case PermissionGroup:
return d.Group().Cmp(d1.Group()) < 0
}
return false
}
// Equals returns true if both PermissionDesc values are the same.
func (d *PermissionDesc) Equals(v PermissionDesc) bool {
if d.Type != v.Type {
return false
}
switch d.Type {
case PermissionHash:
return d.Hash().Equals(v.Hash())
case PermissionGroup:
return d.Group().Cmp(v.Group()) == 0
}
return false
}
// IsValid checks if Permission is correct.
func (p *Permission) IsValid() error {
for i := range p.Methods.Value {
if p.Methods.Value[i] == "" {
return errors.New("empty method name")
}
}
if len(p.Methods.Value) < 2 {
return nil
}
names := make([]string, len(p.Methods.Value))
copy(names, p.Methods.Value)
if stringsHaveDups(names) {
return errors.New("duplicate method names")
}
return nil
}
// AreValid checks each Permission and ensures there are no duplicates.
func (ps Permissions) AreValid() error {
for i := range ps {
err := ps[i].IsValid()
if err != nil {
return err
}
}
if len(ps) < 2 {
return nil
}
contracts := make([]PermissionDesc, 0, len(ps))
for i := range ps {
contracts = append(contracts, ps[i].Contract)
}
if permissionDescsHaveDups(contracts) {
return errors.New("contracts have duplicates")
}
return nil
}
// IsAllowed checks if the method is allowed to be executed.
func (p *Permission) IsAllowed(hash util.Uint160, m *Manifest, method string) bool {
switch p.Contract.Type {
case PermissionWildcard:
case PermissionHash:
if !p.Contract.Hash().Equals(hash) {
return false
}
case PermissionGroup:
has := false
g := p.Contract.Group()
for i := range m.Groups {
if g.Equal(m.Groups[i].PublicKey) {
has = true
break
}
}
if !has {
return false
}
default:
panic(fmt.Sprintf("unexpected permission: %d", p.Contract.Type))
}
if p.Methods.IsWildcard() {
return true
}
return p.Methods.Contains(method)
}
// UnmarshalJSON implements the json.Unmarshaler interface.
func (p *Permission) UnmarshalJSON(data []byte) error {
aux := new(permissionAux)
if err := json.Unmarshal(data, aux); err != nil {
return err
}
p.Contract = aux.Contract
p.Methods = aux.Methods
return nil
}
// MarshalJSON implements the json.Marshaler interface.
func (d *PermissionDesc) MarshalJSON() ([]byte, error) {
switch d.Type {
case PermissionHash:
return json.Marshal("0x" + d.Hash().StringLE())
case PermissionGroup:
return json.Marshal(hex.EncodeToString(d.Group().Bytes()))
default:
return []byte(`"*"`), nil
}
}
// UnmarshalJSON implements the json.Unmarshaler interface.
func (d *PermissionDesc) UnmarshalJSON(data []byte) error {
var s string
if err := json.Unmarshal(data, &s); err != nil {
return err
}
const uint160HexSize = 2 * util.Uint160Size
switch len(s) {
case 2 + uint160HexSize:
// allow to unmarshal both hex and 0xhex forms
if s[0] != '0' || s[1] != 'x' {
return errors.New("invalid uint160")
}
s = s[2:]
fallthrough
case uint160HexSize:
u, err := util.Uint160DecodeStringLE(s)
if err != nil {
return err
}
d.Type = PermissionHash
d.Value = u
return nil
case 66:
pub, err := keys.NewPublicKeyFromString(s)
if err != nil {
return err
}
d.Type = PermissionGroup
d.Value = pub
return nil
case 1:
if s == "*" {
d.Type = PermissionWildcard
return nil
}
}
return errors.New("unknown permission")
}
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// ToStackItem converts PermissionDesc to stackitem.Item.
func (d *PermissionDesc) ToStackItem() stackitem.Item {
switch d.Type {
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case PermissionWildcard:
return stackitem.Null{}
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case PermissionHash:
return stackitem.NewByteArray(d.Hash().BytesBE())
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case PermissionGroup:
return stackitem.NewByteArray(d.Group().Bytes())
default:
panic("unsupported PermissionDesc type")
}
}
// FromStackItem converts stackitem.Item to PermissionDesc.
func (d *PermissionDesc) FromStackItem(item stackitem.Item) error {
if _, ok := item.(stackitem.Null); ok {
d.Type = PermissionWildcard
return nil
}
if item.Type() != stackitem.ByteArrayT {
return fmt.Errorf("unsupported permission descriptor type: %s", item.Type())
}
byteArr, err := item.TryBytes()
if err != nil {
return err
}
switch len(byteArr) {
case util.Uint160Size:
hash, _ := util.Uint160DecodeBytesBE(byteArr)
d.Type = PermissionHash
d.Value = hash
case 33:
pKey, err := keys.NewPublicKeyFromBytes(byteArr, elliptic.P256())
if err != nil {
return err
}
d.Type = PermissionGroup
d.Value = pKey
default:
return errors.New("invalid ByteArray length")
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}
return nil
}
// ToStackItem converts Permission to stackitem.Item.
func (p *Permission) ToStackItem() stackitem.Item {
var methods stackitem.Item
contract := p.Contract.ToStackItem()
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if p.Methods.IsWildcard() {
methods = stackitem.Null{}
} else {
m := make([]stackitem.Item, len(p.Methods.Value))
for i := range p.Methods.Value {
m[i] = stackitem.Make(p.Methods.Value[i])
}
methods = stackitem.Make(m)
}
return stackitem.NewStruct([]stackitem.Item{
contract,
methods,
})
}
// FromStackItem converts stackitem.Item to Permission.
func (p *Permission) FromStackItem(item stackitem.Item) error {
var err error
if item.Type() != stackitem.StructT {
return errors.New("invalid Permission stackitem type")
}
str := item.Value().([]stackitem.Item)
if len(str) != 2 {
return errors.New("invalid Permission stackitem length")
}
desc := new(PermissionDesc)
err = desc.FromStackItem(str[0])
if err != nil {
return fmt.Errorf("invalid Contract stackitem: %w", err)
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}
p.Contract = *desc
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if _, ok := str[1].(stackitem.Null); ok {
p.Methods = WildStrings{Value: nil}
} else {
if str[1].Type() != stackitem.ArrayT {
return errors.New("invalid Methods stackitem type")
}
methods := str[1].Value().([]stackitem.Item)
p.Methods = WildStrings{
Value: make([]string, len(methods)),
}
for i := range methods {
p.Methods.Value[i], err = stackitem.ToString(methods[i])
if err != nil {
return err
}
}
}
return nil
}