From 3cbaca666ec471f8e366c22bddf064459f8ccc7e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=E4=B8=96=E7=95=8C?= <i@sekai.icu>
Date: Mon, 2 Jan 2023 14:09:40 +0800
Subject: [PATCH] Add JA3 fingerprint rule item

---
 option/dns.go                 |  1 +
 option/route.go               |  1 +
 route/rule.go                 |  5 ++++
 route/rule_dns.go             |  5 ++++
 route/rule_ja3_fingerprint.go | 43 +++++++++++++++++++++++++++++++++++
 5 files changed, 55 insertions(+)
 create mode 100644 route/rule_ja3_fingerprint.go

diff --git a/option/dns.go b/option/dns.go
index b232baea..1a8a7af5 100644
--- a/option/dns.go
+++ b/option/dns.go
@@ -98,6 +98,7 @@ type DefaultDNSRule struct {
 	PackageName     Listable[string] `json:"package_name,omitempty"`
 	User            Listable[string] `json:"user,omitempty"`
 	UserID          Listable[int32]  `json:"user_id,omitempty"`
+	JA3Fingerprint  Listable[string] `json:"ja3_fingerprint,omitempty"`
 	Outbound        Listable[string] `json:"outbound,omitempty"`
 	ClashMode       string           `json:"clash_mode,omitempty"`
 	Invert          bool             `json:"invert,omitempty"`
diff --git a/option/route.go b/option/route.go
index 308c4802..f37ecfcc 100644
--- a/option/route.go
+++ b/option/route.go
@@ -101,6 +101,7 @@ type DefaultRule struct {
 	PackageName     Listable[string] `json:"package_name,omitempty"`
 	User            Listable[string] `json:"user,omitempty"`
 	UserID          Listable[int32]  `json:"user_id,omitempty"`
+	JA3Fingerprint  Listable[string] `json:"ja3_fingerprint,omitempty"`
 	ClashMode       string           `json:"clash_mode,omitempty"`
 	Invert          bool             `json:"invert,omitempty"`
 	Outbound        string           `json:"outbound,omitempty"`
diff --git a/route/rule.go b/route/rule.go
index 6f2f3baa..0acff56b 100644
--- a/route/rule.go
+++ b/route/rule.go
@@ -194,6 +194,11 @@ func NewDefaultRule(router adapter.Router, logger log.ContextLogger, options opt
 		rule.items = append(rule.items, item)
 		rule.allItems = append(rule.allItems, item)
 	}
+	if len(options.JA3Fingerprint) > 0 {
+		item := NewJA3FingerprintItem(options.JA3Fingerprint)
+		rule.items = append(rule.items, item)
+		rule.allItems = append(rule.allItems, item)
+	}
 	if options.ClashMode != "" {
 		item := NewClashModeItem(router, options.ClashMode)
 		rule.items = append(rule.items, item)
diff --git a/route/rule_dns.go b/route/rule_dns.go
index 0f072750..550352fa 100644
--- a/route/rule_dns.go
+++ b/route/rule_dns.go
@@ -178,6 +178,11 @@ func NewDefaultDNSRule(router adapter.Router, logger log.ContextLogger, options
 		rule.items = append(rule.items, item)
 		rule.allItems = append(rule.allItems, item)
 	}
+	if len(options.JA3Fingerprint) > 0 {
+		item := NewJA3FingerprintItem(options.JA3Fingerprint)
+		rule.items = append(rule.items, item)
+		rule.allItems = append(rule.allItems, item)
+	}
 	if len(options.Outbound) > 0 {
 		item := NewOutboundRule(options.Outbound)
 		rule.items = append(rule.items, item)
diff --git a/route/rule_ja3_fingerprint.go b/route/rule_ja3_fingerprint.go
new file mode 100644
index 00000000..3ac3e763
--- /dev/null
+++ b/route/rule_ja3_fingerprint.go
@@ -0,0 +1,43 @@
+package route
+
+import (
+	"strings"
+
+	"github.com/sagernet/sing-box/adapter"
+)
+
+var _ RuleItem = (*JA3FingerprintItem)(nil)
+
+type JA3FingerprintItem struct {
+	fingerprints   []string
+	fingerprintMap map[string]bool
+}
+
+func NewJA3FingerprintItem(hashList []string) *JA3FingerprintItem {
+	rule := &JA3FingerprintItem{
+		fingerprints:   hashList,
+		fingerprintMap: make(map[string]bool),
+	}
+	for _, hash := range hashList {
+		rule.fingerprintMap[strings.ToLower(hash)] = true
+	}
+	return rule
+}
+
+func (r *JA3FingerprintItem) Match(metadata *adapter.InboundContext) bool {
+	if metadata.JA3Fingerprint == "" {
+		return false
+	}
+	return r.fingerprintMap[metadata.JA3Fingerprint]
+}
+
+func (r *JA3FingerprintItem) String() string {
+	var description string
+	pLen := len(r.fingerprints)
+	if pLen == 1 {
+		description = "ja3_fingerprint=" + r.fingerprints[0]
+	} else {
+		description = "ja3_fingerprint=[" + strings.Join(r.fingerprints, " ") + "]"
+	}
+	return description
+}