I created an LTI application with .Net. I have tried different libraries to create OAuth 1.0 signature, but it never matches with the one comes from Canvas. I checked it with this tool: http://lti.tools/oauth/ and it matches with the OAuth signature I generated, however not with the "signature" parameter comes from Canvas.
Consumer Key: orhun-123
Shared Secret: orhun-123
Signature comes from Canvas: z2tzUWURgkf6m56L7wrUyqe50wE=
Currently, I am using this code to generate the OAuth signature: