oauth2 error AADSTS90014: The request body must contain the following parameter: 'grant_type'

Question

From the development in Windev I use Oauth 2.0 for authorization to get access to the outlook mail from a user.

The application is registered at https://apps.dev.microsoft.com without the Implicit workflow. After the user enters the credentials, an Authorization Code is returned. With the new code the Bearer Token is requested with a HTTP Post command.

So far, so good.

Only that the response gives an error message that makes no sense to me.

In code:

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m_sHTTPUrl = "client_id=" + m_sClientID + "&client_secret=" ...     + m_sClientSecret ...     + "&redirect_uri=" + m_sRedirectURL + "&code=" + m_sAuthToken ...     + "&grant_type=authorization_code" m_sHTTPres = "" LogLocalFile("GetAccessToken - " + m_sTokenURL + " // " + m_sHTTPUrl)   cMyRequest is httpRequest cMyRequest..Method = httpPost cMyRequest..URL = m_sTokenURL cMyRequest..ContentType = "application/x-www-form-urlencoded" cMyRequest..Header["grant_type"] = "authorization_code" cMyRequest..Header["code"] = m_sAuthToken cMyRequest..Header["client_id"] = m_sClientID cMyRequest..Header["client_secret"] = m_sClientSecret cMyRequest..Header["scope"] = m_sScope cMyRequest..Header["redirect_uri"] = m_sRedirectURL //cMyRequest..Content = m_sHTTPUrl cMyResponse is httpResponse = HTTPSend(cMyRequest) m_sHTTPres = cMyResponse.Content 

In a logfile I requested the used parameters and the content of the httpResponse:

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GetAccessToken - https://login.microsoftonline.com/common/oauth2/v2.0/token // grant_type=authorization_code &code=xxxxxxx &scope=openid+offline_access+User.Read+Email+Mail.Read+Contacts.Read &redirect_uri=http://localhost/ &client_id=xxxxxxx &client_secret=xxxxxxx  GetAccessToken - error = invalid_request GetAccessToken - error_description = AADSTS90014: The request body must contain the following parameter: 'grant_type'. 

The grant_type is in the header as it is supposed to be.

Does anybody have any clue of what is needed to get the OAUTH2 working ?

Answer 1

You shouldn't send grant_type neither in params nor in headers. Those should be sent in body params then only it will work.

Url: https://login.microsoftonline.com/common/oauth2/v2.0/token client_id, scope and redirect_uri params can be sent as query params. where as grant_type, code and client_secret should sent in body params.

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grant_type:authorization_code,  code: {code you got from the authorization step},  client_secret: ****