neo-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/util"
"github.com/nspcc-dev/neo-go/pkg/vm"
)
// CheckHashedWitness checks given hash against 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
}
if tx, ok := ic.Container.(*transaction.Transaction); ok {
return checkScope(ic, tx, ic.VM, hash)
}
return false, errors.New("script container is not a transaction")
}
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 {
if c.Scopes == transaction.Global {
return true, nil
}
if c.Scopes&transaction.CalledByEntry != 0 {
callingScriptHash := v.GetCallingScriptHash()
entryScriptHash := v.GetEntryScriptHash()
if callingScriptHash.Equals(util.Uint160{}) || callingScriptHash == entryScriptHash {
return true, nil
}
}
if c.Scopes&transaction.CustomContracts != 0 {
currentScriptHash := v.GetCurrentScriptHash()
for _, allowedContract := range c.AllowedContracts {
if allowedContract == currentScriptHash {
return true, nil
}
}
}
if c.Scopes&transaction.CustomGroups != 0 {
callingScriptHash := v.GetCallingScriptHash()
if callingScriptHash.Equals(util.Uint160{}) {
return false, nil
}
if !v.Context().GetCallFlags().Has(callflag.ReadStates) {
return false, errors.New("missing ReadStates call flag")
}
cs, err := ic.GetContract(callingScriptHash)
if err != nil {
return false, fmt.Errorf("unable to find calling script: %w", 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
}
}
}
}
return false, nil
}
}
return false, nil
}
// CheckKeyedWitness checks hash of signature check contract with a given public
// key against 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)
}
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ic.VM.Estack().PushVal(res)
return nil
}