我有身份验证问题，我正在执行以下步骤：
1. First time I get the oauth_signature by using this site url with following details: http://7digital.github.io/oauth-reference-page/
url: https://api.7digital.com/1.2/oauth/requesttoken
consumer key: MY_KEY
consumer secret: MY_SECRET_KEY
nonce: 814629426
- *timestamp: 1383291284
正文编码：** application / json
并发送请求以获取7digital API的oauth_token：https://api.7digital.com/1.2/oauth/requesttoken?oauth_consumer_key=MY_KEY&oauth_nonce=184615245&oauth_signature_method=HMAC-SHA1&oauth_timestamp=1383144733&oauth_version=1.0&oauth_signature=sJ%2B%2BPq2i9LfC1xGG1EHx2DrTBxg%3D
此请求获取oauth_token和oauth_token_secret .
2. I need to authorize the oauth_token with the client key:
https://account.7digital.com/7dysvzdxkkmf/oauth/authorise?oauth_token=7EP6KGD如果我有一个7digital帐户，请求会将页面注册到注册或登录 .
3. I need to access token:
但在第3步我收到错误消息：OAuth身份验证错误：签名无效 .
我的代码有什么问题？