Oauth 2.0 : facing issue to get authorization code

Thanks rajpi

I'm using the same redirect-uri as I do to obtain the authorization code.  When I tweak it intentionally to something invalid I receive (leading me to believe unchanged it may be valid):

"response":{"httpCode":400,"message":"Bad Request","status":"client_id + client_secret + redirect_uri is NOT not valid"}}

I've checked/tried encoding/decoding the authorization code and other values with the same result (and generated new fresh authorization codes) and get this response: 

{"response":{"httpCode":401,"message":"Unauthorized","status":"Authorization code is NOT authorized"}}

Double checking permissions again.

I'm testing from curl and python/urrlib2 with the same result.

Thanks for the help

Does this work with SSO?

I'm also trying to authorize a back-end API following the directions here, under the heading "Using the authorization grant flow via a back-end API call":

https://community.lithium.com/t5/Developer-Documentation/bd-p/dev-doc-portal?section=oauth2

We use SSO for access to our community. I can't figure out how to get the authorization code. And, as previous replies have shown, the /auth/v1/accessToken request only returns a "400 Bad Request" with this body:

{
    "response": {
        "httpCode":400,
        "message":"Bad Request",
        "status":"client_id + client_secret + redirect_uri is NOT not valid"
    }
}

I've been struggling with this error for a couple of weeks. I was finally able to get a code. The trick was making sure that the Client ID was URL encoded. The redirect_uri must NOT be encoded. Once I did that, the response has the code I was looking for in the URL. This conflicts with the developer documentation which shows an un-encoded client ID and an encoded return_uri.

https://community.lithium.com/t5/Developer-Documentation/bd-p/dev-doc-portal?section=oauth2