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vm: move JNumbers parsing precision under HFBasilisk

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Signed-off-by: Anna Shaleva <shaleva.ann@nspcc.ru>
This commit is contained in:
Anna Shaleva 2023-08-08 18:52:14 +03:00
parent d90608ddbf
commit 624f193f94
5 changed files with 64 additions and 25 deletions
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32
pkg/vm/stackitem/json.go
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@ -18,6 +18,11 @@ type decoder struct {
count int
depth int
// bestIntPrecision denotes whether maximum allowed integer precision should
// be used to parse big.Int items. If false, then default NeoC# value will be
// used which doesn't allow to precisely parse big values. This behaviour is
// managed by the config.HFBasilisk.
bestIntPrecision bool
}
// MaxAllowedInteger is the maximum integer allowed to be encoded.
@ -26,10 +31,16 @@ const MaxAllowedInteger = 2<<53 - 1
// MaxJSONDepth is the maximum allowed nesting level of an encoded/decoded JSON.
const MaxJSONDepth = 10
// MaxIntegerPrec is the maximum precision allowed for big.Integer parsing.
// It allows to properly parse integer numbers that our 256-bit VM is able to
// handle.
const MaxIntegerPrec = 1<<8 + 1
const (
// MaxIntegerPrec is the maximum precision allowed for big.Integer parsing.
// It allows to properly parse integer numbers that our 256-bit VM is able to
// handle.
MaxIntegerPrec = 1<<8 + 1
// CompatIntegerPrec is the maximum precision allowed for big.Integer parsing
// by the C# node before the Basilisk hardfork. It doesn't allow to precisely
// parse big numbers, see the https://github.com/neo-project/neo/issues/2879.
CompatIntegerPrec = 53
)
// ErrInvalidValue is returned when an item value doesn't fit some constraints
// during serialization or deserialization.
@ -166,10 +177,11 @@ func itemToJSONString(it Item) ([]byte, error) {
// null -> Null
// array -> Array
// map -> Map, keys are UTF-8
func FromJSON(data []byte, maxCount int) (Item, error) {
func FromJSON(data []byte, maxCount int, bestIntPrecision bool) (Item, error) {
d := decoder{
Decoder: *json.NewDecoder(bytes.NewReader(data)),
count: maxCount,
Decoder: *json.NewDecoder(bytes.NewReader(data)),
count: maxCount,
bestIntPrecision: bestIntPrecision,
}
d.UseNumber()
if item, err := d.decode(); err != nil {
@ -226,7 +238,11 @@ func (d *decoder) decode() (Item, error) {
if isScientific {
// As a special case numbers like 2.8e+22 are allowed (SetString rejects them).
// That's the way how C# code works.
f, _, err := big.ParseFloat(ts, 10, MaxIntegerPrec, big.ToNearestEven)
var prec uint = CompatIntegerPrec
if d.bestIntPrecision {
prec = MaxIntegerPrec
}
f, _, err := big.ParseFloat(ts, 10, prec, big.ToNearestEven)
if err != nil {
return nil, fmt.Errorf("%w (malformed exp value for int)", ErrInvalidValue)
}