feat(backend): bcrypt+jwt auth package and admin seeding

backend/internal/auth/auth_test.go

@@ -0,0 +1,40 @@
+package auth
+
+import (
+	"strings"
+	"testing"
+	"time"
+)
+
+func TestHashCheck(t *testing.T) {
+	h, err := HashPassword("hunter2")
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !strings.HasPrefix(h, "$2a$") || !CheckPassword(h, "hunter2") || CheckPassword(h, "wrong") {
+		t.Fatal("bcrypt wrong")
+	}
+}
+
+func TestSignParse(t *testing.T) {
+	secret := []byte("k")
+	tok, err := Sign(secret, 7, "admin")
+	if err != nil {
+		t.Fatal(err)
+	}
+	c, err := Parse(secret, tok)
+	if err != nil || c.UID != 7 || c.Role != "admin" {
+		t.Fatalf("parse: %v %+v", err, c)
+	}
+	if _, err := Parse([]byte("other"), tok); err == nil {
+		t.Fatal("must reject wrong secret")
+	}
+	expired, _ := SignWithTTL(secret, 1, "member", -time.Hour)
+	if _, err := Parse(secret, expired); err == nil {
+		t.Fatal("must reject expired")
+	}
+	// alg 混淆攻击:none 必须拒
+	if _, err := Parse(secret, "eyJhbGciOiJub25lIiwidHlwIjoiSldUIn0.eyJ1aWQiOjF9."); err == nil {
+		t.Fatal("must reject alg=none")
+	}
+}