mirror of
https://github.com/v2fly/v2ray-core.git
synced 2024-11-05 09:47:56 -05:00
97 lines
2.2 KiB
Go
97 lines
2.2 KiB
Go
package shadowsocks
|
|
|
|
import (
|
|
"crypto/hmac"
|
|
"crypto/sha1"
|
|
"io"
|
|
|
|
"github.com/v2ray/v2ray-core/common/alloc"
|
|
"github.com/v2ray/v2ray-core/common/log"
|
|
"github.com/v2ray/v2ray-core/common/serial"
|
|
"github.com/v2ray/v2ray-core/transport"
|
|
)
|
|
|
|
const (
|
|
AuthSize = 10
|
|
)
|
|
|
|
type KeyGenerator func() []byte
|
|
|
|
type Authenticator struct {
|
|
key KeyGenerator
|
|
}
|
|
|
|
func NewAuthenticator(keygen KeyGenerator) *Authenticator {
|
|
return &Authenticator{
|
|
key: keygen,
|
|
}
|
|
}
|
|
|
|
func (this *Authenticator) Authenticate(auth []byte, data []byte) []byte {
|
|
hasher := hmac.New(sha1.New, this.key())
|
|
hasher.Write(data)
|
|
res := hasher.Sum(nil)
|
|
return append(auth, res[:AuthSize]...)
|
|
}
|
|
|
|
func HeaderKeyGenerator(key []byte, iv []byte) func() []byte {
|
|
return func() []byte {
|
|
newKey := make([]byte, 0, len(key)+len(iv))
|
|
newKey = append(newKey, key...)
|
|
newKey = append(newKey, iv...)
|
|
return newKey
|
|
}
|
|
}
|
|
|
|
func ChunkKeyGenerator(iv []byte) func() []byte {
|
|
chunkId := 0
|
|
return func() []byte {
|
|
newKey := make([]byte, 0, len(iv)+4)
|
|
newKey = append(newKey, iv...)
|
|
newKey = append(newKey, serial.IntLiteral(chunkId).Bytes()...)
|
|
chunkId++
|
|
return newKey
|
|
}
|
|
}
|
|
|
|
type ChunkReader struct {
|
|
reader io.Reader
|
|
auth *Authenticator
|
|
}
|
|
|
|
func NewChunkReader(reader io.Reader, auth *Authenticator) *ChunkReader {
|
|
return &ChunkReader{
|
|
reader: reader,
|
|
auth: auth,
|
|
}
|
|
}
|
|
|
|
func (this *ChunkReader) Read() (*alloc.Buffer, error) {
|
|
buffer := alloc.NewLargeBuffer()
|
|
if _, err := io.ReadFull(this.reader, buffer.Value[:2]); err != nil {
|
|
buffer.Release()
|
|
return nil, err
|
|
}
|
|
// There is a potential buffer overflow here. Large buffer is 64K bytes,
|
|
// while uin16 + 10 will be more than that
|
|
length := serial.BytesLiteral(buffer.Value[:2]).Uint16Value() + AuthSize
|
|
if _, err := io.ReadFull(this.reader, buffer.Value[:length]); err != nil {
|
|
buffer.Release()
|
|
return nil, err
|
|
}
|
|
buffer.Slice(0, int(length))
|
|
|
|
authBytes := buffer.Value[:AuthSize]
|
|
payload := buffer.Value[AuthSize:]
|
|
|
|
actualAuthBytes := this.auth.Authenticate(nil, payload)
|
|
if !serial.BytesLiteral(authBytes).Equals(serial.BytesLiteral(actualAuthBytes)) {
|
|
buffer.Release()
|
|
log.Debug("AuthenticationReader: Unexpected auth: ", authBytes)
|
|
return nil, transport.ErrorCorruptedPacket
|
|
}
|
|
buffer.Value = payload
|
|
|
|
return buffer, nil
|
|
}
|