IBM Watson语音对带有IAM API密钥的WebSocket授权文本

我正在尝试使用新帐户（仅具有IAM授权）将IBM Watson的讲话连接到文本WebSocket。

我的WS端点是，wss://stream-fra.watsonplatform.net/text-to-speech/api/v1/recognize并且我通过获得了访问令牌https://iam.bluemix.net/identity/token。现在，当我打开带有Authorization标头的套接字连接时，Bearer token会得到一个不好的握手响应：websocket: bad handshake, Unauthorized 401。语言就是去。

我是在做错什么，还是没有用户名/密码身份验证即不赞成使用Watson的语音连接到文本WebSocket watson-token？

编辑：

打开WebSocket的代码：

headers := http.Header{}
headers.Set("Authorization", "Bearer " + access_token)
conn, resp, err := websocket.DefaultDialer.Dial("wss://stream-fra.watsonplatform.net/text-to-speech/api/v1/recognize", headers)

我还尝试了基本授权，apikey:**api_key**结果是相同的：401。

编辑2：

获取访问令牌（基于Watson Swift和Python SDK）的代码，该令牌成功并返回访问和刷新令牌：

func getWatsonToken(apiKey string) (string, error) {
    // Base on the Watson Swift and Python SDKs
    // https://github.com/watson-developer-cloud/restkit/blob/master/Sources/RestKit/Authentication.swift
    // https://github.com/watson-developer-cloud/python-sdk/blob/master/watson_developer_cloud/iam_token_manager.py

    const tokenUrl = "https://iam.bluemix.net/identity/token"

    form := url.Values{}
    form.Set("grant_type", "urn:ibm:params:oauth:grant-type:apikey")
    form.Set("apikey", apiKey)
    form.Set("response_type", "cloud_iam")

    // Token from simple "http.PostForm" does not work either
    //resp, err := http.PostForm(tokenUrl, form)

    req, err := http.NewRequest(http.MethodPost, tokenUrl, nil)
    if err != nil {
        log.Printf("could not create HTTP request to get Watson token: %+v", err)
        return "", nil
    }

    header := http.Header{}
    header.Set("Content-Type", "application/x-www-form-urlencoded")
    header.Set("Accept", "application/json")
    // "Yng6Yng=" is "bx:bx"
    header.Set("Authorization", "Basic Yng6Yng=")
    req.Header = header

    req.Body = ioutil.NopCloser(bytes.NewReader([]byte(form.Encode())))

    resp, err := http.DefaultClient.Do(req)
    if err != nil {
        log.Printf("problem executing HTTP request to get Watson token: %+v", err)
        return "", err
    }

    defer resp.Body.Close()

    if resp.StatusCode != 200 {
        return "", errors.New(fmt.Sprintf("failed to get Watson token: %d", resp.StatusCode))
    }

    jsonBody, err := ioutil.ReadAll(resp.Body)
    if err != nil {
        log.Printf("problem reading Watson token from response body: %+v", err)
    }

    tokenResponse := &struct {
        AccessToken  string `json:"access_token"`
        RefreshToken string `json:"refresh_token"`
        TokenType    string `json:"token_type"`
        ExpiresIn    int64  `json:"expires_in"`
        Expiration   int64  `json:"expiration"`
    }{}

    err = json.Unmarshal(jsonBody, tokenResponse)
    if err != nil {
        log.Printf("could not parse Watson token response: %+v", err)
        return "", err
    }

    return tokenResponse.AccessToken, err
}