# itfx PrefixScript 示例库

> 仅为模式参考；生成脚本时**以用户描述的文档规则为准**，不要生搬硬套。

- 参数名 **`obj`**，无 `using`，类型全限定名

---

## 模式 1：HMAC + urlPath + 排序 keyvalue → Query

适用：开放平台 `signatureWithParamsAndUrlPath` 一类（如阿里国际站 notifyBizEvent）。

```csharp
string secret = obj.GetAccountFieldValueOrNull("appSecret");
string appKey = obj.GetAccountFieldValueOrNull("appKey");
string urlPath = "param2/1/vendor.namespace/api.name/" + appKey;

string dto = null;
for (int i = 0; i < obj.QueryFieldList.Count; i++) {
    if (obj.QueryFieldList[i].Name == "bizPayload") {
        dto = obj.QueryFieldList[i].Value;
        break;
    }
}
if (string.IsNullOrEmpty(dto) || dto == "$FromMappingBody") {
    dto = Newtonsoft.Json.JsonConvert.SerializeObject(obj.OriginalInterfaceMappedInput);
}

var parts = new System.Collections.Generic.List<string>();
parts.Add("bizPayload" + dto);
parts.Sort(System.StringComparer.Ordinal);
var sb = new System.Text.StringBuilder();
sb.Append(urlPath);
for (int i = 0; i < parts.Count; i++) sb.Append(parts[i]);

using (var hmac = new System.Security.Cryptography.HMACSHA1(System.Text.Encoding.UTF8.GetBytes(secret))) {
    byte[] hash = hmac.ComputeHash(System.Text.Encoding.UTF8.GetBytes(sb.ToString()));
    string sign = System.BitConverter.ToString(hash).Replace("-", "").ToLowerInvariant();
    for (int i = 0; i < obj.QueryFieldList.Count; i++) {
        if (obj.QueryFieldList[i].Name == "_aop_signature") {
            obj.QueryFieldList[i].Value = sign;
            break;
        }
    }
}
```

---

## 模式 2：MD5(secret + params + secret) → Header

```csharp
string secret = obj.GetAccountFieldValueOrNull("apiSecret") ?? "";
string body = Newtonsoft.Json.JsonConvert.SerializeObject(obj.OriginalInterfaceMappedInput);
string signStr = secret + "body" + body + secret;
var md5 = System.Security.Cryptography.MD5.Create();
byte[] hash = md5.ComputeHash(System.Text.Encoding.UTF8.GetBytes(signStr));
string sign = System.BitConverter.ToString(hash).Replace("-", "").ToUpperInvariant();
for (int i = 0; i < obj.HeaderFieldList.Count; i++) {
    if (obj.HeaderFieldList[i].Name == "sign") {
        obj.HeaderFieldList[i].Value = sign;
        break;
    }
}
```

---

## 模式 3：HMAC-SHA256 + JSON Body 字段

```csharp
string secret = obj.GetAccountFieldValueOrNull("appSecret") ?? "";
string payload = Newtonsoft.Json.JsonConvert.SerializeObject(obj.OriginalInterfaceMappedInput);
using (var hmac = new System.Security.Cryptography.HMACSHA256(System.Text.Encoding.UTF8.GetBytes(secret))) {
    byte[] hash = hmac.ComputeHash(System.Text.Encoding.UTF8.GetBytes(payload));
    string sign = System.Convert.ToBase64String(hash);
    obj.OriginalInterfaceMappedInput["signature"] = sign;
}
```

---

## 模式 4：Form 表单字段签名

```csharp
string sign = "..."; // 按文档计算
for (int i = 0; i < obj.FormFieldList.Count; i++) {
    if (obj.FormFieldList[i].Name == "sign") {
        obj.FormFieldList[i].Value = sign;
        break;
    }
}
```