Receiving 401 Unauthorized error on OAuth 1.0 using HMAC-SHA1 signature(ABAP)

Hi,

I have a requirement to call a REST API using HMAC-SHA1 signature algorithm.

I have created API key on the server side and have below information to do the Auth request to retrieve data.

• App key
• Secret
• Access token
• Access token secret

I have implemented it in ABAP using the link https://wiki.scn.sap.com/wiki/pages/viewpage.action?pageId=248709473 and followed OAuth guidelines per https://oauth.net/core/1.0/#signing_process . When I do the HTTP call from SAP, I get 401 Unauthorized from the server.

I know it is a bit hard to find the root cause but anybody faced this issue in the past?

Thanks,

Sarat