frostfs-contract/audit/audit_contract.go
Alex Vanin e6fc97810b [#28] audit: Add version offset in AuditResult binary
Signed-off-by: Alex Vanin <alexey@nspcc.ru>
2020-12-29 14:24:52 +03:00

190 lines
4 KiB
Go

package auditcontract
import (
"github.com/nspcc-dev/neo-go/pkg/interop"
"github.com/nspcc-dev/neo-go/pkg/interop/contract"
"github.com/nspcc-dev/neo-go/pkg/interop/crypto"
"github.com/nspcc-dev/neo-go/pkg/interop/iterator"
"github.com/nspcc-dev/neo-go/pkg/interop/runtime"
"github.com/nspcc-dev/neo-go/pkg/interop/storage"
"github.com/nspcc-dev/neo-go/pkg/interop/util"
)
type (
irNode struct {
key interop.PublicKey
}
auditHeader struct {
epoch int
cid []byte
from interop.PublicKey
}
)
// Audit key is a combination of epoch, container ID and public key of node that
// executed audit. Together it should be no more than 64 bytes. We can't shrink
// epoch and container ID since we iterate over these values. But we can shrink
// public key by using first bytes of the hashed value.
const maxKeySize = 24 // 24 + 32 (container ID length) + 8 (epoch length) = 64
func (a auditHeader) ID() []byte {
var buf interface{} = a.epoch
hashedKey := crypto.SHA256(a.from)
shortedKey := hashedKey[:maxKeySize]
return append(buf.([]byte), append(a.cid, shortedKey...)...)
}
const (
version = 1
netmapContractKey = "netmapScriptHash"
netmapContractKeyLn = len(netmapContractKey)
)
var ctx storage.Context
func init() {
if runtime.GetTrigger() != runtime.Application {
panic("contract has not been called in application node")
}
ctx = storage.GetContext()
}
func Init(addrNetmap interop.Hash160) {
if storage.Get(ctx, netmapContractKey) != nil {
panic("init: contract already deployed")
}
if len(addrNetmap) != 20 {
panic("init: incorrect length of contract script hash")
}
storage.Put(ctx, netmapContractKey, addrNetmap)
runtime.Log("audit contract initialized")
}
func Put(rawAuditResult []byte) bool {
netmapContractAddr := storage.Get(ctx, netmapContractKey).([]byte)
innerRing := contract.Call(netmapContractAddr, "innerRingList").([]irNode)
hdr := newAuditHeader(rawAuditResult)
presented := false
for i := range innerRing {
ir := innerRing[i]
if bytesEqual(ir.key, hdr.from) {
presented = true
break
}
}
if !runtime.CheckWitness(hdr.from) || !presented {
panic("audit: put access denied")
}
storage.Put(ctx, hdr.ID(), rawAuditResult)
runtime.Log("audit: result has been saved")
return true
}
func Get(id []byte) []byte {
return storage.Get(ctx, id).([]byte)
}
func List() [][]byte {
it := storage.Find(ctx, []byte{})
return list(it)
}
func ListByEpoch(epoch int) [][]byte {
it := storage.Find(ctx, epoch)
return list(it)
}
func ListByCID(epoch int, cid []byte) [][]byte {
var buf interface{} = epoch
prefix := append(buf.([]byte), cid...)
it := storage.Find(ctx, prefix)
return list(it)
}
func ListByNode(epoch int, cid []byte, key interop.PublicKey) [][]byte {
hdr := auditHeader{
epoch: epoch,
cid: cid,
from: key,
}
it := storage.Find(ctx, hdr.ID())
return list(it)
}
func list(it iterator.Iterator) [][]byte {
var result [][]byte
for iterator.Next(it) {
key := iterator.Key(it).([]byte)
if len(key) == netmapContractKeyLn {
continue
}
result = append(result, key)
}
return result
}
func Version() int {
return version
}
// readNext reads length from first byte and then reads data (max 127 bytes).
func readNext(input []byte) ([]byte, int) {
var buf interface{} = input[0]
ln := buf.(int)
return input[1 : 1+ln], 1 + ln
}
func newAuditHeader(input []byte) auditHeader {
offset := int(input[1])
offset = 2 + offset + 1 // version prefix + version len + epoch prefix
var buf interface{} = input[offset : offset+8] // [ 8 integer bytes ]
epoch := buf.(int)
offset = offset + 8
// cid is a nested structure with raw bytes
// [ cid struct prefix (wireType + len = 2 bytes), cid value wireType (1 byte), ... ]
cid, cidOffset := readNext(input[offset+2+1:])
// key is a raw byte
// [ public key wireType (1 byte), ... ]
key, _ := readNext(input[offset+2+1+cidOffset+1:])
return auditHeader{
epoch,
cid,
key,
}
}
// neo-go#1176
func bytesEqual(a []byte, b []byte) bool {
return util.Equals(string(a), string(b))
}