Firebase Distribution API OAuth2授权失败：401认证错误求助

核心问题：AccessToken请求的Scope错误 #

你调用GetAccessTokenForRequestAsync时传入的是授权端点URL，而非Firebase Distribution API所需的权限范围（Scope），这会导致获取的Token没有访问该API的权限。

修正步骤： #

1. 替换正确的Scope
   将获取Token的代码改为传入Firebase Distribution API专属Scope：

   var token = await credential.UnderlyingCredential.GetAccessTokenForRequestAsync("https://www.googleapis.com/auth/firebase.distribution");
   

   该Scope是访问Firebase Distribution API必须的权限标识。

2. 验证API请求URL的正确性
   确认apps后的参数是你的应用包名/ID（比如com.yourcompany.yourapp），而非项目ID。正确的URL格式应为：

   https://firebaseappdistribution.googleapis.com/v1/projects/myApp/apps/com.yourcompany.yourapp/releases
   

3. 确认服务账户权限
   确保你的服务账户已被授予Firebase App Distribution Admin或Firebase Admin角色：

   • 进入Google Cloud控制台的IAM页面
   • 找到对应的服务账户，添加上述角色并保存

修正后的完整代码示例： #

var credential = GoogleCredential.FromJsonParameters(new JsonCredentialParameters()
{
    Type = "service_account",
    ProjectId = "myApp",
    PrivateKeyId = "************",
    PrivateKey = "-----BEGIN PRIVATE KEY-----key-----END PRIVATE KEY-----\n",
    ClientEmail = "firebase-adminsdk-fbsvc@*******.iam.gserviceaccount.com",
    ClientId = "**************",
    TokenUri = "https://oauth2.googleapis.com/token",
    UniverseDomain = "googleapis.com"
});

// 使用正确的Scope获取Token
var token = await credential.UnderlyingCredential.GetAccessTokenForRequestAsync("https://www.googleapis.com/auth/firebase.distribution");

try
{
    using (HttpClient client = new HttpClient())
    {
        client.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", token);
        // 替换为正确的应用ID
        string url = "https://firebaseappdistribution.googleapis.com/v1/projects/myApp/apps/com.yourcompany.yourapp/releases";
        HttpResponseMessage response = await client.GetAsync(url);
        string result = await response.Content.ReadAsStringAsync();
        Console.WriteLine("Response: " + result);
    }
}
catch(Exception e)
{
    Console.WriteLine("Error: " + e.Message);
}

内容的提问来源于stack exchange，提问作者DOCZIC