Support chat validation

This commit is contained in:
Tnze
2023-01-01 18:43:21 +08:00
parent fa83b762bf
commit bb98d90db3
9 changed files with 239 additions and 152 deletions

42
chat/sign/cache.go Normal file
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@ -0,0 +1,42 @@
package sign
import (
"errors"
)
type SignatureCache struct {
signatures [128]*Signature
signIndexes map[Signature]int
cachedBuffer []*Signature
}
func NewSignatureCache() SignatureCache {
return SignatureCache{
signIndexes: make(map[Signature]int),
}
}
func (s *SignatureCache) PopOrInsert(self *Signature, lastSeen []*Signature) {
var tmp *Signature
s.cachedBuffer = s.cachedBuffer[:0] // clear buffer
if self != nil {
s.cachedBuffer = append(s.cachedBuffer, self)
}
for _, v := range lastSeen {
s.cachedBuffer = append(s.cachedBuffer, v)
}
for i := 0; i < len(s.cachedBuffer) && i < len(s.signatures); i++ {
v := s.cachedBuffer[i]
if i, ok := s.signIndexes[*v]; ok {
s.signatures[i] = nil
}
tmp, s.signatures[i] = s.signatures[i], v
s.signIndexes[*v] = i
if tmp != nil {
s.cachedBuffer = append(s.cachedBuffer, tmp)
delete(s.signIndexes, *tmp)
}
}
}
var UncachedSignature = errors.New("uncached signature")

65
chat/sign/cache_test.go Normal file
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@ -0,0 +1,65 @@
package sign
import (
"crypto/rand"
"testing"
)
func TestSignatureCache(t *testing.T) {
cache := NewSignatureCache()
s1 := &Signature{1}
s2 := &Signature{2}
s3 := &Signature{3}
s4 := &Signature{4}
// t.Logf("%p, %p, %p, %p", s1, s2, s3, s4)
cache.PopOrInsert(nil, []*Signature{s1, s2, s3})
// cache: [s1, s2, s3, nil...]
if cache.signatures[0] != s1 || cache.signatures[1] != s2 || cache.signatures[2] != s3 {
t.Log(cache.signatures)
t.Fatal("insert s1~3 error")
}
cache.PopOrInsert(s4, []*Signature{s3})
// cache: [s4, s3, s1, s2, nil...]
if cache.signatures[0] != s4 {
t.Log(cache.signatures)
t.Fatal("insert s4 error")
}
if cache.signatures[1] != s3 {
t.Log(cache.signatures)
t.Fatal("pop s3 error")
}
if cache.signatures[2] != s1 || cache.signatures[3] != s2 {
t.Log(cache.signatures)
t.Fatal("s1~2 position error")
}
}
func TestSignatureCache_2(t *testing.T) {
cache := NewSignatureCache()
signs := make([]*Signature, len(cache.signatures)+5)
for i := range signs {
signs[i] = new(Signature)
_, _ = rand.Read(signs[i][:])
}
cache.PopOrInsert(nil, signs[:len(cache.signatures)])
if !signatureEquals(cache.signatures[:], signs[:len(cache.signatures)]) {
t.Fatal("insert error")
}
insert2 := signs[len(cache.signatures)-5:]
cache.PopOrInsert(nil, insert2)
if !signatureEquals(cache.signatures[:10], insert2) {
t.Fatal("insert and pop error")
}
}
func signatureEquals(a, b []*Signature) bool {
if len(a) != len(b) {
return false
}
for i := range a {
if a[i] != b[i] {
return false
}
}
return true
}

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@ -1,6 +1,8 @@
package sign
import (
"crypto/sha256"
"encoding/binary"
"io"
"github.com/google/uuid"
@ -11,40 +13,81 @@ import (
)
type Message struct {
Link struct {
Index int
Sender uuid.UUID
Session uuid.UUID
}
Signature []byte
PackedMessageBody
Prev Prev
Signature *Signature
*MessageBody
Unsigned *chat.Message
FilterMask
}
type Prev struct {
Index int
Sender uuid.UUID
Session uuid.UUID
}
type Session struct {
sessionID uuid.UUID
publicKey user.PublicKey
SessionID uuid.UUID
PublicKey user.PublicKey
valid bool
lastMsg *Message
}
func (s Session) WriteTo(w io.Writer) (n int64, err error) {
n1, err := pk.UUID(s.sessionID).WriteTo(w)
n1, err := pk.UUID(s.SessionID).WriteTo(w)
if err != nil {
return n1, err
}
n2, err := s.publicKey.WriteTo(w)
n2, err := s.PublicKey.WriteTo(w)
return n1 + n2, err
}
func (s *Session) ReadFrom(r io.Reader) (n int64, err error) {
n1, err := ((*pk.UUID)(&s.sessionID)).ReadFrom(r)
n1, err := ((*pk.UUID)(&s.SessionID)).ReadFrom(r)
if err != nil {
return n1, err
}
n2, err := s.publicKey.ReadFrom(r)
n2, err := s.PublicKey.ReadFrom(r)
return n1 + n2, err
}
func (s *Session) Update(msg Message) bool {
panic("todo")
func (s *Session) InitValidate() {
s.valid = true
s.lastMsg = nil
}
func (s *Session) VerifyAndUpdate(msg *Message) bool {
s.valid = s.valid && s.verifyHash(msg) && s.verifyChain(msg)
if s.valid {
s.lastMsg = msg
return true
}
return false
}
func (s *Session) verifyHash(msg *Message) bool {
h := sha256.New()
// 1
_ = binary.Write(h, binary.BigEndian, int32(1))
// Prev
_, _ = h.Write(msg.Prev.Sender[:])
_, _ = h.Write(msg.Prev.Session[:])
_ = binary.Write(h, binary.BigEndian, msg.Prev.Index)
// Body
_ = binary.Write(h, binary.BigEndian, msg.Salt)
_ = binary.Write(h, binary.BigEndian, msg.Timestamp.Unix())
content := []byte(msg.PlainMsg)
_ = binary.Write(h, binary.BigEndian, int32(len(content)))
_, _ = h.Write(content)
// Body.LastSeen
_ = binary.Write(h, binary.BigEndian, int32(len(msg.LastSeen)))
for _, v := range msg.LastSeen {
_, _ = h.Write((*v)[:])
}
return s.PublicKey.VerifyMessage(h.Sum(nil), msg.Signature[:]) == nil
}
func (s *Session) verifyChain(msg *Message) bool {
return s.lastMsg != nil && (msg.Prev.Index < s.lastMsg.Prev.Index || msg.Prev.Sender != s.lastMsg.Prev.Sender || msg.Prev.Session != s.lastMsg.Prev.Session)
}

View File

@ -9,6 +9,13 @@ import (
pk "github.com/Tnze/go-mc/net/packet"
)
type MessageBody struct {
PlainMsg string
Timestamp time.Time
Salt int64
LastSeen []*Signature
}
type PackedMessageBody struct {
PlainMsg string
Timestamp time.Time
@ -37,6 +44,25 @@ func (m *PackedMessageBody) ReadFrom(r io.Reader) (n int64, err error) {
return
}
func (m *PackedMessageBody) Unpack(cache *SignatureCache) (*MessageBody, error) {
LastSeen := make([]*Signature, len(m.LastSeen))
for i, v := range m.LastSeen {
if v.Signature != nil {
LastSeen[i] = v.Signature
} else if v.ID >= 0 && int(v.ID) < len(cache.signatures) {
LastSeen[i] = cache.signatures[v.ID]
} else {
return nil, UncachedSignature
}
}
return &MessageBody{
PlainMsg: m.PlainMsg,
Timestamp: m.Timestamp,
Salt: m.Salt,
LastSeen: LastSeen,
}, nil
}
type HistoryMessage struct {
Sender uuid.UUID
Signature []byte