fix(order): prevent duplicate subscriptions and repair invite gifts

internal/logic/auth/trialEmailWhitelist.go

@@ -2,6 +2,7 @@ package auth
 
 import (
 	"context"
+	"net/mail"
 	"strings"
 
 	"github.com/perfect-panel/server/internal/config"
@@ -15,11 +16,10 @@ func IsEmailDomainWhitelisted(email, whitelistCSV string) bool {
 	if whitelistCSV == "" {
 		return false
 	}
-	parts := strings.SplitN(email, "@", 2)
-	if len(parts) != 2 {
+	_, domain, ok := parseStrictEmail(email)
+	if !ok {
 		return false
 	}
-	domain := strings.ToLower(strings.TrimSpace(parts[1]))
 	for _, d := range strings.Split(whitelistCSV, ",") {
 		if strings.ToLower(strings.TrimSpace(d)) == domain {
 			return true
@@ -32,10 +32,16 @@ func ShouldGrantTrialForEmail(register config.RegisterConfig, email string) bool
 	if !register.EnableTrial {
 		return false
 	}
+	if !IsValidTrialEmail(email) {
+		return false
+	}
 	// 无论白名单是否启用，泛域名邮箱（含 + 别名或 Gmail 点号）始终拒绝赠送
 	if IsDisposableAlias(email) {
 		return false
 	}
+	if isConfusableGmailDomain(emailDomain(email)) {
+		return false
+	}
 	if !register.EnableTrialEmailWhitelist {
 		return true
 	}
@@ -52,11 +58,10 @@ func ShouldGrantTrialForEmail(register config.RegisterConfig, email string) bool
 // For Gmail-like domains, local part containing "." or "+" is rejected.
 // For all other domains, only "+" alias is rejected.
 func IsDisposableAlias(email string) bool {
-	parts := strings.SplitN(strings.ToLower(strings.TrimSpace(email)), "@", 2)
-	if len(parts) != 2 {
+	local, domain, ok := parseStrictEmail(email)
+	if !ok {
 		return false
 	}
-	local, domain := parts[0], parts[1]
 
 	// All domains: reject + alias
 	if strings.ContainsRune(local, '+') {
@@ -74,11 +79,10 @@ func IsDisposableAlias(email string) bool {
 // Removes dots from local part for Gmail-like providers (gmail.com, googlemail.com).
 func NormalizeEmail(email string) string {
 	email = strings.ToLower(strings.TrimSpace(email))
-	parts := strings.SplitN(email, "@", 2)
-	if len(parts) != 2 {
+	local, domain, ok := parseStrictEmail(email)
+	if !ok {
 		return email
 	}
-	local, domain := parts[0], parts[1]
 
 	// Strip + alias
 	if idx := strings.IndexByte(local, '+'); idx != -1 {
@@ -101,6 +105,51 @@ func isGmailLikeDomain(domain string) bool {
 	return false
 }
 
+func IsValidTrialEmail(email string) bool {
+	local, domain, ok := parseStrictEmail(email)
+	if !ok {
+		return false
+	}
+	return local != "" && domain != ""
+}
+
+func parseStrictEmail(email string) (local, domain string, ok bool) {
+	email = strings.ToLower(strings.TrimSpace(email))
+	if email == "" || strings.ContainsAny(email, " \t\r\n") {
+		return "", "", false
+	}
+	addr, err := mail.ParseAddress(email)
+	if err != nil || addr.Address != email || addr.Name != "" {
+		return "", "", false
+	}
+	parts := strings.Split(addr.Address, "@")
+	if len(parts) != 2 {
+		return "", "", false
+	}
+	local = strings.TrimSpace(parts[0])
+	domain = strings.Trim(strings.TrimSpace(parts[1]), ".")
+	if local == "" || domain == "" || strings.Contains(domain, "..") || !strings.Contains(domain, ".") {
+		return "", "", false
+	}
+	return local, domain, true
+}
+
+func emailDomain(email string) string {
+	_, domain, ok := parseStrictEmail(email)
+	if !ok {
+		return ""
+	}
+	return domain
+}
+
+func isConfusableGmailDomain(domain string) bool {
+	switch strings.ToLower(strings.TrimSpace(domain)) {
+	case "gmaial.com", "gmial.com", "gmai.com", "gamil.com", "gmal.com", "gmail.co", "gmail.con":
+		return true
+	}
+	return false
+}
+
 // NormalizedEmailHasTrial returns true if any user with the same normalized email
 // already holds a trial subscription. Only performs the cross-user DB check when
 // normalization actually changes the email (i.e., dots removed or + alias stripped).

internal/logic/auth/trialEmailWhitelist_test.go

@@ -0,0 +1,188 @@
+package auth
+
+import (
+	"testing"
+
+	"github.com/perfect-panel/server/internal/config"
+)
+
+func TestNormalizeEmail(t *testing.T) {
+	tests := []struct {
+		input string
+		want  string
+	}{
+		// Gmail dot trick
+		{"a.v.x.xx@gmail.com", "avxxx@gmail.com"},
+		{"john.doe@gmail.com", "johndoe@gmail.com"},
+		{"a.b.c.d.e@gmail.com", "abcde@gmail.com"},
+		// Gmail + alias
+		{"user+tag@gmail.com", "user@gmail.com"},
+		{"a.b+tag@gmail.com", "ab@gmail.com"},
+		// Googlemail
+		{"a.b@googlemail.com", "ab@googlemail.com"},
+		// Non-Gmail: dots preserved
+		{"john.doe@outlook.com", "john.doe@outlook.com"},
+		{"john.doe@qq.com", "john.doe@qq.com"},
+		// + alias stripped for all providers
+		{"user+spam@outlook.com", "user@outlook.com"},
+		{"user+spam@qq.com", "user@qq.com"},
+		// Case insensitive
+		{"User@Gmail.COM", "user@gmail.com"},
+		{"A.B@Gmail.com", "ab@gmail.com"},
+		// No change for normal non-gmail email
+		{"abc@163.com", "abc@163.com"},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.input, func(t *testing.T) {
+			got := NormalizeEmail(tt.input)
+			if got != tt.want {
+				t.Errorf("NormalizeEmail(%q) = %q, want %q", tt.input, got, tt.want)
+			}
+		})
+	}
+}
+
+func TestNormalizeEmail_NoChangeSkipsCheck(t *testing.T) {
+	// These emails should NOT trigger cross-user check (normalized == original)
+	noChangeCases := []string{
+		"abc@163.com",
+		"john.doe@outlook.com",
+		"user@qq.com",
+	}
+	for _, email := range noChangeCases {
+		normalized := NormalizeEmail(email)
+		lower := email
+		if normalized == lower {
+			// correct: no normalization change, NormalizedEmailHasTrial would return false early
+		}
+	}
+}
+
+func TestShouldGrantTrialForEmail(t *testing.T) {
+	// 模拟线上配置：白名单开启，gmail.com 也在名单里
+	rcWithGmail := config.RegisterConfig{
+		EnableTrial:               true,
+		EnableTrialEmailWhitelist: true,
+		TrialEmailDomainWhitelist: "hifastapp.com,hifastvpn.com,126.com,139.com,163.com,gmail.com",
+	}
+	// 白名单关闭
+	rcNoWhitelist := config.RegisterConfig{
+		EnableTrial:               true,
+		EnableTrialEmailWhitelist: false,
+	}
+
+	tests := []struct {
+		name   string
+		rc     config.RegisterConfig
+		email  string
+		want   bool
+		reason string
+	}{
+		{
+			name:   "gmail dot trick - blocked even if gmail.com in whitelist",
+			rc:     rcWithGmail,
+			email:  "s.m.s.n.fsmbt.d.ndny@gmail.com",
+			want:   false,
+			reason: "gmail 泛域名（含点号）应拒绝",
+		},
+		{
+			name:   "gmail plus alias - blocked",
+			rc:     rcWithGmail,
+			email:  "user+tag@gmail.com",
+			want:   false,
+			reason: "gmail +别名应拒绝",
+		},
+		{
+			name:   "clean gmail - allowed",
+			rc:     rcWithGmail,
+			email:  "normaluser@gmail.com",
+			want:   true,
+			reason: "干净的 gmail 应放行",
+		},
+		{
+			name:   "163 with dot - allowed (non-gmail dot is ok)",
+			rc:     rcWithGmail,
+			email:  "s.m.s.n@163.com",
+			want:   true,
+			reason: "非 gmail 域点号不拦截",
+		},
+		{
+			name:   "163 plus alias - blocked",
+			rc:     rcWithGmail,
+			email:  "user+spam@163.com",
+			want:   false,
+			reason: "所有域名的 +别名都拦截",
+		},
+		{
+			name:   "gmail typo squatting domain - blocked even if accidentally whitelisted",
+			rc:     config.RegisterConfig{EnableTrial: true, EnableTrialEmailWhitelist: true, TrialEmailDomainWhitelist: "gmail.com,gmaial.com"},
+			email:  "1.2.3.4xxx@gmaial.com",
+			want:   false,
+			reason: "易混淆 Gmail 域名不应发放试用",
+		},
+		{
+			name:   "invalid empty local - blocked",
+			rc:     rcWithGmail,
+			email:  "@gmail.com",
+			want:   false,
+			reason: "邮箱 local 为空应拒绝",
+		},
+		{
+			name:   "subdomain spoof - blocked",
+			rc:     rcWithGmail,
+			email:  "user@fake.gmail.com",
+			want:   false,
+			reason: "白名单必须精确匹配域名，不匹配子域",
+		},
+		{
+			name:   "whitelist disabled - gmail dot trick still blocked",
+			rc:     rcNoWhitelist,
+			email:  "s.m.s.n.fsmbt.d.ndny@gmail.com",
+			want:   false,
+			reason: "白名单未启用，但泛域名仍应拒绝",
+		},
+		{
+			name:   "trial disabled - always blocked",
+			rc:     config.RegisterConfig{EnableTrial: false},
+			email:  "user@163.com",
+			want:   false,
+			reason: "试用未开启",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := ShouldGrantTrialForEmail(tt.rc, tt.email)
+			if got != tt.want {
+				t.Errorf("ShouldGrantTrialForEmail(%q) = %v, want %v | reason: %s",
+					tt.email, got, tt.want, tt.reason)
+			}
+		})
+	}
+}
+
+func TestIsEmailDomainWhitelisted(t *testing.T) {
+	whitelist := "gmail.com,edu.cn,outlook.com"
+	tests := []struct {
+		email string
+		want  bool
+	}{
+		{"user@gmail.com", true},
+		{"user@edu.cn", true},
+		{"User@Gmail.COM", true},
+		{"user@yahoo.com", false},
+		{"user@fake.gmail.com", false}, // subdomain not matched
+		{"user@", false},
+		{"notanemail", false},
+		{"@gmail.com", false},
+	}
+	for _, tt := range tests {
+		t.Run(tt.email, func(t *testing.T) {
+			got := IsEmailDomainWhitelisted(tt.email, whitelist)
+			if got != tt.want {
+				t.Errorf("IsEmailDomainWhitelisted(%q) = %v, want %v", tt.email, got, tt.want)
+			}
+		})
+	}
+}