feat: enhance GenerateMachineID to include auth0|user_ prefix

- Updated the GenerateMachineID function to generate a machine ID with the prefix "auth0|user_".
- The random part of the ID is now 25 bytes, producing a 50-character hexadecimal string.
- This change improves the uniqueness and format of generated machine IDs, aligning with authentication standards.

pkg/idgen/generator.go

@@ -35,10 +35,25 @@ func (g *Generator) generateRandomHex(length int) (string, error) {
 // Public methods
 // -------------
 
-// GenerateMachineID generates a new 32-byte machine ID
+// GenerateMachineID generates a new machine ID with auth0|user_ prefix
 func (g *Generator) GenerateMachineID() (string, error) {
 	g.simulateWork()
-	return g.generateRandomHex(32)
+
+	// 生成随机部分 (25字节，将产生50个十六进制字符)
+	randomPart, err := g.generateRandomHex(25)
+	if err != nil {
+		return "", err
+	}
+
+	// 构建完整的ID: "auth0|user_" + random
+	prefix := "auth0|user_"
+	fullID := fmt.Sprintf("%x%x%s",
+		[]byte(prefix), // 转换前缀为十六进制
+		[]byte("0"),    // 添加一个字符
+		randomPart,     // 随机部分
+	)
+
+	return fullID, nil
 }
 
 // GenerateMacMachineID generates a new 64-byte MAC machine ID

pkg/idgen/generator_test.go

@@ -0,0 +1,47 @@
+package idgen
+
+import (
+	"fmt"
+	"strings"
+	"testing"
+)
+
+func TestGenerateMachineID(t *testing.T) {
+	g := NewGenerator()
+
+	fmt.Println("\n=== 开始测试 MachineID 生成 ===")
+
+	// 运行多次测试以确保一致性
+	for i := 0; i < 10; i++ {
+		id, err := g.GenerateMachineID()
+		if err != nil {
+			t.Fatalf("生成ID时发生错误: %v", err)
+		}
+
+		fmt.Printf("\n第 %d 次测试:\n", i+1)
+		fmt.Printf("生成的 ID: %s\n", id)
+		fmt.Printf("ID 长度: %d\n", len(id))
+		fmt.Printf("前缀部分: %s\n", id[:20])
+		fmt.Printf("随机部分: %s\n", id[20:])
+
+		// 测试1: 验证总长度
+		if len(id) != 74 {
+			t.Errorf("ID长度不正确. 期望: 74, 实际: %d", len(id))
+		}
+
+		// 测试2: 验证前缀
+		expectedPrefix := "61757468307c757365725f" // "auth0|user_" 的十六进制
+		if !strings.HasPrefix(id, expectedPrefix) {
+			t.Errorf("ID前缀不正确.\n期望前缀: %s\n实际ID: %s", expectedPrefix, id)
+		}
+
+		// 测试3: 验证十六进制格式
+		for _, c := range id {
+			if !strings.ContainsRune("0123456789abcdef", c) {
+				t.Errorf("ID包含非十六进制字符: %c", c)
+			}
+		}
+	}
+
+	fmt.Println("\n=== 测试完成 ===")
+}