Twitter OAuth 请求令牌返回未经授权

Question

我正在尝试从 Twitter OAuth 获取请求令牌，但我不断收到401 Unauthorized，但我不知道为什么。我尝试尽可能地遵循签名创建，并且挣扎了400 Bad Request一段时间，但最终破解了代码，获得了一个有效的请求，但只能由 401 来满足。

我觉得我错过了一些非常简单的东西，但我就是找不到什么。

这是我正在使用的代码：

using (HttpClient client = new HttpClient())
{
    client.BaseAddress = new Uri("https://api.twitter.com/");
    client.DefaultRequestHeaders.Accept.Clear();
    client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));

    TimeSpan ts = DateTime.UtcNow - new DateTime(1970, 1, 1, 0, 0, 0, 0, DateTimeKind.Utc);

    string oauth_nonce = Convert.ToBase64String(new ASCIIEncoding().GetBytes(DateTime.Now.Ticks.ToString()));
    string oauth_callback = Uri.EscapeUriString("oob");
    string oauth_signature_method = "HMAC-SHA1";
    string oauth_timestamp = Convert.ToInt64(ts.TotalSeconds).ToString();
    string oauth_consumer_key = OAUTH_KEY;
    string oauth_version = "1.0";

    // Generate signature
    string baseString = "POST&";
    baseString += Uri.EscapeDataString(client.BaseAddress + "oauth/request_token") + "&";
    // Each oauth value sorted alphabetically
    baseString += Uri.EscapeDataString("oauth_callback=" + oauth_callback + "&");
    baseString += Uri.EscapeDataString("oauth_consumer_key=" + oauth_consumer_key + "&");
    baseString += Uri.EscapeDataString("oauth_nonce=" + oauth_nonce + "&");
    baseString += Uri.EscapeDataString("oauth_signature_method=" + oauth_signature_method + "&");
    baseString += Uri.EscapeDataString("oauth_timestamp=" + oauth_timestamp + "&");
    baseString += Uri.EscapeDataString("oauth_version=" + oauth_version + "&");

    string signingKey = Uri.EscapeDataString(OAUTH_SECRET) + "&";
    HMACSHA1 hasher = new HMACSHA1(new ASCIIEncoding().GetBytes(signingKey));
    string oauth_signature = Convert.ToBase64String(hasher.ComputeHash(new ASCIIEncoding().GetBytes(baseString)));

    client.DefaultRequestHeaders.Add("Authorization", "OAuth " +
        "oauth_nonce=\"" + oauth_nonce + "\"," +
        "oauth_callback=\"" + oauth_callback + "\"," +
        "oauth_signature_method=\"" + oauth_signature_method + "\"," +
        "oauth_timestamp=\"" + oauth_timestamp + "\"," +
        "oauth_consumer_key=\"" + oauth_consumer_key + "\"," +
        "oauth_signature=\"" + Uri.EscapeDataString(oauth_signature) + "\"," +
        "oauth_version=\"" + oauth_version + "\""
    );

    HttpResponseMessage response = await client.PostAsJsonAsync("oauth/request_token", "");
    var responseString = await response.Content.ReadAsStringAsync();
}

我正在使用 .Net 4.5，因此Uri.EscapeDataString()应该给出正确的百分比编码字符串。

编辑

我注意到该oauth_nonce值有时包含非字母数字字符，因此我将变量计算更改为以下内容：

string nonce = Convert.ToBase64String(new ASCIIEncoding().GetBytes(DateTime.Now.Ticks.ToString()));
string oauth_nonce = new string(nonce.Where(c => Char.IsLetter(c) || Char.IsDigit(c)).ToArray());

不幸的是这没有帮助。

我还尝试了标头Uri.EscapeUriData()中的所有值Authorization，以及在每个逗号后添加一个空格（正如 Twitter 上的文档所说），但这也没有帮助。

Answer 1

我从头开始尝试了稍微不同的方法，但它应该产生相同的结果。然而，它并没有，而是按预期工作！

如果有人能指出此工作代码与原始问题中的代码之间的实际差异，我将非常感激，因为在我看来，它们产生相同的结果。

using (HttpClient client = new HttpClient())
{
    client.BaseAddress = new Uri("https://api.twitter.com/");
    client.DefaultRequestHeaders.Accept.Clear();
    client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));

    TimeSpan timestamp = DateTime.UtcNow - new DateTime(1970, 1, 1, 0, 0, 0, 0, DateTimeKind.Utc);
    string nonce = Convert.ToBase64String(new ASCIIEncoding().GetBytes(DateTime.Now.Ticks.ToString()));

    Dictionary<string, string> oauth = new Dictionary<string, string>
    {
        ["oauth_nonce"] = new string(nonce.Where(c => char.IsLetter(c) || char.IsDigit(c)).ToArray()),
        ["oauth_callback"] = "http://my.callback.url",
        ["oauth_signature_method"] = "HMAC-SHA1",
        ["oauth_timestamp"] = Convert.ToInt64(timestamp.TotalSeconds).ToString(),
        ["oauth_consumer_key"] = OAUTH_KEY,
        ["oauth_version"] = "1.0"
    };

    string[] parameterCollectionValues = oauth.Select(parameter =>
            Uri.EscapeDataString(parameter.Key) + "=" +
            Uri.EscapeDataString(parameter.Value))
        .OrderBy(kv => kv)
        .ToArray();
    string parameterCollection = string.Join("&", parameterCollectionValues);

    string baseString = "POST";
    baseString += "&";
    baseString += Uri.EscapeDataString(client.BaseAddress + "oauth/request_token");
    baseString += "&";
    baseString += Uri.EscapeDataString(parameterCollection);

    string signingKey = Uri.EscapeDataString(OAUTH_SECRET);
    signingKey += "&";
    HMACSHA1 hasher = new HMACSHA1(new ASCIIEncoding().GetBytes(signingKey));
    oauth["oauth_signature"] = Convert.ToBase64String(hasher.ComputeHash(new ASCIIEncoding().GetBytes(baseString)));

    string headerString = "OAuth ";
    string[] headerStringValues = oauth.Select(parameter =>
            Uri.EscapeDataString(parameter.Key) + "=" + "\"" +
            Uri.EscapeDataString(parameter.Value) + "\"")
        .ToArray();
    headerString += string.Join(", ", headerStringValues);

    client.DefaultRequestHeaders.Add("Authorization", headerString);

    HttpResponseMessage response = await client.PostAsJsonAsync("oauth/request_token", "");
    var responseString = await response.Content.ReadAsStringAsync();
}