mirror of
https://github.com/apernet/OpenGFW.git
synced 2024-11-14 14:29:22 +08:00
518 lines
9.6 KiB
Go
518 lines
9.6 KiB
Go
package tcp
|
|
|
|
import (
|
|
"bytes"
|
|
|
|
"github.com/apernet/OpenGFW/analyzer"
|
|
)
|
|
|
|
var _ analyzer.TCPAnalyzer = (*TrojanAnalyzer)(nil)
|
|
|
|
// CCS stands for "Change Cipher Spec"
|
|
var ccsPattern = []byte{20, 3, 3, 0, 1, 1}
|
|
|
|
// TrojanAnalyzer uses length-based heuristics to detect Trojan traffic based on
|
|
// its "TLS-in-TLS" nature. The heuristics are trained using a decision tree with
|
|
// about 20k Trojan samples and 30k non-Trojan samples. The tree is then converted
|
|
// to code using a custom tool and inlined here (isTrojanSeq function).
|
|
// Accuracy: 1% false positive rate, 10% false negative rate.
|
|
// We do NOT recommend directly blocking all positive connections, as this may
|
|
// break legitimate TLS connections.
|
|
type TrojanAnalyzer struct{}
|
|
|
|
func (a *TrojanAnalyzer) Name() string {
|
|
return "trojan"
|
|
}
|
|
|
|
func (a *TrojanAnalyzer) Limit() int {
|
|
return 512000
|
|
}
|
|
|
|
func (a *TrojanAnalyzer) NewTCP(info analyzer.TCPInfo, logger analyzer.Logger) analyzer.TCPStream {
|
|
return newTrojanStream(logger)
|
|
}
|
|
|
|
type trojanStream struct {
|
|
logger analyzer.Logger
|
|
first bool
|
|
count bool
|
|
rev bool
|
|
seq [4]int
|
|
seqIndex int
|
|
}
|
|
|
|
func newTrojanStream(logger analyzer.Logger) *trojanStream {
|
|
return &trojanStream{logger: logger}
|
|
}
|
|
|
|
func (s *trojanStream) Feed(rev, start, end bool, skip int, data []byte) (u *analyzer.PropUpdate, done bool) {
|
|
if skip != 0 {
|
|
return nil, true
|
|
}
|
|
if len(data) == 0 {
|
|
return nil, false
|
|
}
|
|
|
|
if s.first {
|
|
s.first = false
|
|
// Stop if it's not a valid TLS connection
|
|
if !(!rev && len(data) >= 3 && data[0] >= 0x16 && data[0] <= 0x17 &&
|
|
data[1] == 0x03 && data[2] <= 0x09) {
|
|
return nil, true
|
|
}
|
|
}
|
|
|
|
if !rev && !s.count && len(data) >= 6 && bytes.Equal(data[:6], ccsPattern) {
|
|
// Client Change Cipher Spec encountered, start counting
|
|
s.count = true
|
|
}
|
|
|
|
if s.count {
|
|
if rev == s.rev {
|
|
// Same direction as last time, just update the number
|
|
s.seq[s.seqIndex] += len(data)
|
|
} else {
|
|
// Different direction, bump the index
|
|
s.seqIndex += 1
|
|
if s.seqIndex == 4 {
|
|
return &analyzer.PropUpdate{
|
|
Type: analyzer.PropUpdateReplace,
|
|
M: analyzer.PropMap{
|
|
"seq": s.seq,
|
|
"yes": isTrojanSeq(s.seq),
|
|
},
|
|
}, true
|
|
}
|
|
s.seq[s.seqIndex] += len(data)
|
|
s.rev = rev
|
|
}
|
|
}
|
|
|
|
return nil, false
|
|
}
|
|
|
|
func (s *trojanStream) Close(limited bool) *analyzer.PropUpdate {
|
|
return nil
|
|
}
|
|
|
|
func isTrojanSeq(seq [4]int) bool {
|
|
length1 := seq[0]
|
|
length2 := seq[1]
|
|
length3 := seq[2]
|
|
length4 := seq[3]
|
|
|
|
if length2 <= 2431 {
|
|
if length2 <= 157 {
|
|
if length1 <= 156 {
|
|
if length3 <= 108 {
|
|
return false
|
|
} else {
|
|
return false
|
|
}
|
|
} else {
|
|
if length1 <= 892 {
|
|
if length3 <= 40 {
|
|
return false
|
|
} else {
|
|
if length3 <= 788 {
|
|
if length4 <= 185 {
|
|
if length1 <= 411 {
|
|
return true
|
|
} else {
|
|
return false
|
|
}
|
|
} else {
|
|
if length2 <= 112 {
|
|
return false
|
|
} else {
|
|
return true
|
|
}
|
|
}
|
|
} else {
|
|
if length3 <= 1346 {
|
|
if length1 <= 418 {
|
|
return false
|
|
} else {
|
|
return true
|
|
}
|
|
} else {
|
|
return false
|
|
}
|
|
}
|
|
}
|
|
} else {
|
|
if length2 <= 120 {
|
|
if length2 <= 63 {
|
|
return false
|
|
} else {
|
|
if length4 <= 653 {
|
|
return false
|
|
} else {
|
|
return false
|
|
}
|
|
}
|
|
} else {
|
|
return false
|
|
}
|
|
}
|
|
}
|
|
} else {
|
|
if length1 <= 206 {
|
|
if length1 <= 185 {
|
|
if length1 <= 171 {
|
|
return false
|
|
} else {
|
|
if length4 <= 211 {
|
|
return false
|
|
} else {
|
|
return false
|
|
}
|
|
}
|
|
} else {
|
|
if length2 <= 251 {
|
|
return true
|
|
} else {
|
|
return false
|
|
}
|
|
}
|
|
} else {
|
|
if length2 <= 286 {
|
|
if length1 <= 1123 {
|
|
if length3 <= 70 {
|
|
return false
|
|
} else {
|
|
if length1 <= 659 {
|
|
if length3 <= 370 {
|
|
return true
|
|
} else {
|
|
return false
|
|
}
|
|
} else {
|
|
if length4 <= 272 {
|
|
return false
|
|
} else {
|
|
return true
|
|
}
|
|
}
|
|
}
|
|
} else {
|
|
if length4 <= 537 {
|
|
if length2 <= 276 {
|
|
if length3 <= 1877 {
|
|
return false
|
|
} else {
|
|
return false
|
|
}
|
|
} else {
|
|
return false
|
|
}
|
|
} else {
|
|
if length1 <= 1466 {
|
|
if length1 <= 1435 {
|
|
return false
|
|
} else {
|
|
return true
|
|
}
|
|
} else {
|
|
if length2 <= 193 {
|
|
return false
|
|
} else {
|
|
return false
|
|
}
|
|
}
|
|
}
|
|
}
|
|
} else {
|
|
if length1 <= 284 {
|
|
if length1 <= 277 {
|
|
if length2 <= 726 {
|
|
return false
|
|
} else {
|
|
if length2 <= 768 {
|
|
return true
|
|
} else {
|
|
return false
|
|
}
|
|
}
|
|
} else {
|
|
if length2 <= 782 {
|
|
if length4 <= 783 {
|
|
return true
|
|
} else {
|
|
return false
|
|
}
|
|
} else {
|
|
return false
|
|
}
|
|
}
|
|
} else {
|
|
if length2 <= 492 {
|
|
if length2 <= 396 {
|
|
if length2 <= 322 {
|
|
return false
|
|
} else {
|
|
return false
|
|
}
|
|
} else {
|
|
if length4 <= 971 {
|
|
return false
|
|
} else {
|
|
return true
|
|
}
|
|
}
|
|
} else {
|
|
if length2 <= 2128 {
|
|
if length2 <= 1418 {
|
|
return false
|
|
} else {
|
|
return false
|
|
}
|
|
} else {
|
|
if length3 <= 103 {
|
|
return false
|
|
} else {
|
|
return false
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
} else {
|
|
if length2 <= 6232 {
|
|
if length3 <= 85 {
|
|
if length2 <= 3599 {
|
|
return false
|
|
} else {
|
|
if length1 <= 613 {
|
|
return false
|
|
} else {
|
|
return false
|
|
}
|
|
}
|
|
} else {
|
|
if length3 <= 220 {
|
|
if length4 <= 1173 {
|
|
if length1 <= 874 {
|
|
if length4 <= 337 {
|
|
if length4 <= 68 {
|
|
return true
|
|
} else {
|
|
return true
|
|
}
|
|
} else {
|
|
if length1 <= 667 {
|
|
return true
|
|
} else {
|
|
return true
|
|
}
|
|
}
|
|
} else {
|
|
if length3 <= 108 {
|
|
if length1 <= 1930 {
|
|
return true
|
|
} else {
|
|
return true
|
|
}
|
|
} else {
|
|
if length2 <= 5383 {
|
|
return false
|
|
} else {
|
|
return true
|
|
}
|
|
}
|
|
}
|
|
} else {
|
|
return false
|
|
}
|
|
} else {
|
|
if length1 <= 664 {
|
|
if length3 <= 411 {
|
|
if length3 <= 383 {
|
|
if length4 <= 346 {
|
|
return true
|
|
} else {
|
|
return false
|
|
}
|
|
} else {
|
|
if length1 <= 445 {
|
|
return true
|
|
} else {
|
|
return false
|
|
}
|
|
}
|
|
} else {
|
|
if length2 <= 3708 {
|
|
if length4 <= 307 {
|
|
return true
|
|
} else {
|
|
return false
|
|
}
|
|
} else {
|
|
if length2 <= 4656 {
|
|
return false
|
|
} else {
|
|
return false
|
|
}
|
|
}
|
|
}
|
|
} else {
|
|
if length1 <= 1055 {
|
|
if length3 <= 580 {
|
|
if length1 <= 724 {
|
|
return true
|
|
} else {
|
|
return false
|
|
}
|
|
} else {
|
|
if length1 <= 678 {
|
|
return false
|
|
} else {
|
|
return true
|
|
}
|
|
}
|
|
} else {
|
|
if length2 <= 5352 {
|
|
if length3 <= 1586 {
|
|
return false
|
|
} else {
|
|
return false
|
|
}
|
|
} else {
|
|
if length4 <= 2173 {
|
|
return true
|
|
} else {
|
|
return false
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
} else {
|
|
if length2 <= 9408 {
|
|
if length1 <= 670 {
|
|
if length4 <= 76 {
|
|
if length3 <= 175 {
|
|
return true
|
|
} else {
|
|
return true
|
|
}
|
|
} else {
|
|
if length2 <= 9072 {
|
|
if length3 <= 314 {
|
|
if length3 <= 179 {
|
|
return false
|
|
} else {
|
|
return false
|
|
}
|
|
} else {
|
|
if length4 <= 708 {
|
|
return false
|
|
} else {
|
|
return false
|
|
}
|
|
}
|
|
} else {
|
|
return true
|
|
}
|
|
}
|
|
} else {
|
|
if length1 <= 795 {
|
|
if length2 <= 6334 {
|
|
if length2 <= 6288 {
|
|
return true
|
|
} else {
|
|
return false
|
|
}
|
|
} else {
|
|
if length4 <= 6404 {
|
|
if length2 <= 8194 {
|
|
return true
|
|
} else {
|
|
return true
|
|
}
|
|
} else {
|
|
if length2 <= 8924 {
|
|
return false
|
|
} else {
|
|
return true
|
|
}
|
|
}
|
|
}
|
|
} else {
|
|
if length3 <= 732 {
|
|
if length1 <= 1397 {
|
|
if length3 <= 179 {
|
|
return false
|
|
} else {
|
|
return false
|
|
}
|
|
} else {
|
|
if length1 <= 1976 {
|
|
return false
|
|
} else {
|
|
return false
|
|
}
|
|
}
|
|
} else {
|
|
if length1 <= 2840 {
|
|
if length1 <= 2591 {
|
|
return false
|
|
} else {
|
|
return true
|
|
}
|
|
} else {
|
|
return false
|
|
}
|
|
}
|
|
}
|
|
}
|
|
} else {
|
|
if length4 <= 30 {
|
|
return false
|
|
} else {
|
|
if length2 <= 13314 {
|
|
if length4 <= 1786 {
|
|
if length2 <= 13018 {
|
|
if length4 <= 869 {
|
|
return false
|
|
} else {
|
|
return false
|
|
}
|
|
} else {
|
|
return true
|
|
}
|
|
} else {
|
|
if length3 <= 775 {
|
|
return false
|
|
} else {
|
|
return false
|
|
}
|
|
}
|
|
} else {
|
|
if length4 <= 73 {
|
|
return false
|
|
} else {
|
|
if length3 <= 640 {
|
|
if length3 <= 237 {
|
|
return false
|
|
} else {
|
|
return false
|
|
}
|
|
} else {
|
|
if length2 <= 43804 {
|
|
return false
|
|
} else {
|
|
return false
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|