I'm attempting to write a simple app to upload files via the API. The enterprise admin requests that we use the OAuth 2.0 authentication scheme, and I've followed the directions to generate my enterprise key, public/private keypair and so on. I'm on a very lightweight platform that has openssl, perl and bash, so I've been attmepting this in either shell or perl. Unfortunately, while I can generate a token that validates on jwt.io, when I post it to api.box.com/oauth2/token, I receive this error:
{"error":"invalid_grant","error_description":"OpenSSL unable to verify data: error:0906D06C:PEM routines:PEM_read_bio:no start line"}
Other posts I've read suggest this happens when there are Windows line breaks, or when base64 encoding is used instead of base64url, but I don't have either of these problems.
Is it possible to create the JWT completely in bash using simple string concatenation, openssl commands and curl to send? I'd love to start with something simple like that and work my way up from there.
Thanks!