neoneo-go/pkg/core/interop/runtime/witness.go

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package runtime
import (
"crypto/elliptic"
"errors"
"fmt"
"github.com/nspcc-dev/neo-go/pkg/core/interop"
"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"
)
// CheckHashedWitness checks the given hash against the current list of script hashes
// for verifying in the interop context.
func CheckHashedWitness(ic *interop.Context, hash util.Uint160) (bool, error) {
callingSH := ic.VM.GetCallingScriptHash()
if !callingSH.Equals(util.Uint160{}) && hash.Equals(callingSH) {
return true, nil
}
return checkScope(ic, hash)
}
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) IsCalledByEntry() bool {
return sc.VM.Context().IsCalledByEntry()
}
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, hash util.Uint160) (bool, error) {
signers := ic.Signers()
if len(signers) == 0 {
return false, errors.New("no valid signers")
}
for i := range signers {
c := &signers[i]
if c.Account == hash {
if c.Scopes == transaction.Global {
return true, nil
}
if c.Scopes&transaction.CalledByEntry != 0 {
if ic.VM.Context().IsCalledByEntry() {
return true, nil
}
}
if c.Scopes&transaction.CustomContracts != 0 {
currentScriptHash := ic.VM.GetCurrentScriptHash()
for _, allowedContract := range c.AllowedContracts {
if allowedContract == currentScriptHash {
return true, nil
}
}
}
if c.Scopes&transaction.CustomGroups != 0 {
groups, err := getContractGroups(ic.VM, ic, ic.VM.GetCurrentScriptHash())
if err != nil {
return false, err
}
// check if the current group is the required one
for _, allowedGroup := range c.AllowedGroups {
if groups.Contains(allowedGroup) {
return true, nil
}
}
}
if c.Scopes&transaction.Rules != 0 {
ctx := scopeContext{ic.VM, 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
}
}
}
return false, nil
}
}
return false, nil
}
// CheckKeyedWitness checks the hash of the signature check contract with the given public
// key against the current list of script hashes for verifying in the interop context.
func CheckKeyedWitness(ic *interop.Context, key *keys.PublicKey) (bool, error) {
return CheckHashedWitness(ic, key.GetScriptHash())
}
// CheckWitness checks witnesses.
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func CheckWitness(ic *interop.Context) error {
var res bool
var err error
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hashOrKey := ic.VM.Estack().Pop().Bytes()
hash, err := util.Uint160DecodeBytesBE(hashOrKey)
if err != nil {
var key *keys.PublicKey
key, err = keys.NewPublicKeyFromBytes(hashOrKey, elliptic.P256())
if err != nil {
return errors.New("parameter given is neither a key nor a hash")
}
res, err = CheckKeyedWitness(ic, key)
} else {
res, err = CheckHashedWitness(ic, hash)
}
if err != nil {
return fmt.Errorf("failed to check witness: %w", err)
}
ic.VM.Estack().PushItem(stackitem.Bool(res))
return nil
}