fix: 登录验证已有密码并保留新密码规则 (#2)

server/app/lexgo/integration_test.go

@@ -100,6 +100,38 @@ func randomName(prefix string) string {
 	return prefix + hex.EncodeToString(b)
 }
 
+func TestMySQLLoginUsesStoredPasswordWithoutChangingCreationPolicy(t *testing.T) {
+	db := testDB(t)
+	// Fictional legacy credential: login verifies the stored hash independently
+	// of the policy applied when creating accounts or setting new passwords.
+	legacyPassword := strings.Repeat("z", 6)
+	u := admin.SysUser{Username: randomName("legacy"), Password: legacyPassword, RoleId: 1, Status: "2"}
+	if err := db.Create(&u).Error; err != nil {
+		t.Fatal("fixture creation failed")
+	}
+	r := Router(db, time.Now)
+	token := loginToken(t, r, u.Username, legacyPassword)
+	for _, password := range []string{strings.Repeat("y", 6), strings.Repeat("z", 5)} {
+		code, _ := callAPI(t, r, "POST", "/api/v1/login", "", map[string]string{"username": u.Username, "password": password})
+		if code != 401 {
+			t.Fatalf("incorrect stored password status %d, want 401", code)
+		}
+	}
+	code, _ := callAPI(t, r, "POST", "/api/v1/accounts", token, map[string]string{"username": randomName("new"), "password": legacyPassword})
+	if code != 400 {
+		t.Fatalf("short new password status %d, want 400", code)
+	}
+	learner, err := createAccount(db, randomName("reset"), fixturePassword, 2, u.UserId)
+	if err != nil {
+		t.Fatal(err)
+	}
+	code, _ = callAPI(t, r, "PATCH", fmt.Sprintf("/api/v1/accounts/%d", learner.ID), token, map[string]string{"password": legacyPassword})
+	if code != 400 {
+		t.Fatalf("short reset password status %d, want 400", code)
+	}
+	loginToken(t, r, learner.Username, fixturePassword)
+}
+
 func TestMySQLAccountIsolationAndRevocation(t *testing.T) {
 	db := testDB(t)
 	if err := Migrate(db); err != nil {

server/app/lexgo/router.go

@@ -42,7 +42,7 @@ func Router(db *gorm.DB, now func() time.Time) *gin.Engine {
 			respond(c, 400, nil, err)
 			return
 		}
-		name, err := credentials(input.Username, input.Password)
+		name, err := loginCredentials(input.Username, input.Password)
 		if err != nil {
 			respond(c, 400, nil, err)
 			return

server/app/lexgo/router_test.go

@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"net/http"
 	"net/http/httptest"
+	"strings"
 	"testing"
 	"time"
 )
@@ -13,7 +14,7 @@ func TestLoginRejectsEmailAndMissingPasswordBeforeDatabase(t *testing.T) {
 	for _, payload := range []string{
 		`{"username":"person@example.test","password":"example-password"}`,
 		`{"username":"learner","password":""}`,
-		`{"username":"learner","password":"short"}`,
+		`{"username":"learner","password":"` + strings.Repeat("x", 73) + `"}`,
 	} {
 		w := httptest.NewRecorder()
 		q := httptest.NewRequest(http.MethodPost, "/api/v1/login", bytes.NewBufferString(payload))

server/app/lexgo/service.go

@@ -62,12 +62,25 @@ func failure(code int, msg string) error { return &apiError{code, msg} }
 var usernamePattern = regexp.MustCompile(`^[a-z][a-z0-9_.-]{2,31}$`)
 
 func credentials(username, password string) (string, error) {
+	name, err := loginCredentials(username, password)
+	if err != nil {
+		return "", err
+	}
+	if len(password) < 10 {
+		return "", failure(400, "密码须为 10～72 字节")
+	}
+	return name, nil
+}
+
+// Login verifies an existing hash; account creation and normal password resets
+// separately enforce the current minimum password length.
+func loginCredentials(username, password string) (string, error) {
 	username = strings.ToLower(strings.TrimSpace(username))
 	if !usernamePattern.MatchString(username) {
 		return "", failure(400, "账号须为字母开头的 3～32 位字母、数字、点、下划线或连字符")
 	}
-	if len(password) < 10 || len(password) > 72 {
-		return "", failure(400, "密码须为 10～72 字节")
+	if len(password) == 0 || len(password) > 72 {
+		return "", failure(400, "密码不能为空且不能超过 72 字节")
 	}
 	return username, nil
 }