title: have trouble when use microsoft task api through OAuth2
body: <p>I want to use microsoft task api in here <code>https://docs.microsoft.com/zh-cn/previous-versions/office/office-365-api/api/version-2.0/task-rest-operations</code>. I understand if I want to request api I should use OAuth2. this is my OAuth steps:</p>
  
  <p>step 1: register application in azure and config redirect uri ,then I can get client_id and new a client secret.
  <a href="https://i.stack.imgur.com/kFuXB.png" rel="noreferrer"><img src="https://i.stack.imgur.com/kFuXB.png" alt="enter image description here"></a></p>
  
  <p>step 2: GET <code>https://login.microsoftonline.com/common/oauth2/v2.0/authorize?client_id=&lt;client_id&gt;&amp;redirect_uri=http://localhost:8080&amp;response_type=code&amp;scope=Tasks.Read</code>. now I can get code from redirect uri params: <a href="http://localhost:8080/?code=Mfcae1736-738e-3aff-2de6-7a6d72308feb#/login" rel="noreferrer">http://localhost:8080/?code=Mfcae1736-738e-3aff-2de6-7a6d72308feb#/login</a></p>
  
  <p>step 3: POST <code>https://login.microsoftonline.com/common/oauth2/v2.0/token</code> with params, like this:
  <a href="https://i.stack.imgur.com/9O8r0.png" rel="noreferrer"><img src="https://i.stack.imgur.com/9O8r0.png" alt="enter image description here"></a></p>
  
  <p>step 4: from step 3 I can get access_token,(but It's not a jwt token, why?),so I can get tasks through access_token.
  <a href="https://i.stack.imgur.com/wtQap.png" rel="noreferrer"><img src="https://i.stack.imgur.com/wtQap.png" alt="enter image description here"></a></p>
  
  <p>now there is a problem,the request return  wrong, but I don't know why, and don't where to find the correct doc and how to fix it .</p>
  
  <pre><code>{"error":{"code":"InvalidMsaTicket","message":"ErrorCode: 'PP_E_RPS_CERT_NOT_FOUND'. Message: ' Internal error:
  spRPSTicket-&gt;ProcessToken failed. Failed to call CRPSDataCryptImpl::UnpackData: Internal error: Failed to decrypt data.
  :Failed to get session key. RecipientId=293577. spCache-&gt;GetCacheItem returns error.:Cert Name: (null). SKI:
  3bd72187c709b1c40b994f8b496a5b9ebd2f9b0c...'","innerError":{"requestId":"c6cec9b3-091f-439d-8e01-5489eef2b776","date":"2019-09-24T03:27:02"}}}
  </code></pre>