No way to access generated OAuth token except through logs

[anonymouse64]

Currently the only place that the OAuth bearer token is output when generated by edgexproxy is in the log using an LoggingClient.Info call. This has 2 problems:

1. Info log level should not output sensitive data like the OAuth token (I think outputting it with Debug level is okay though)
2. There should also be a different way to access the token, i.e. using vault or a file on the filesystem so that after generating the token, there is an easy way to access the token for automatic usage by scripts and such.

[tingyuz]

Currently we have most information output as Info level in the log for debugging purpose, and this indeed could be a security concern. Switching them to debug level or export the token into a file on the file system still expose potential security threat. Utilizing secret store service could be a good idea, and we will explore the approach in the next release.

[anonymouse64]

While I agree that putting the token onto a file exposes a security threat, in some circumstances it's an acceptable compromise. I think it should be at least be configurable to either use the security secret store or use a file. For reference, the kong token is also still saved as a file, so saving the oauth token to a file isn't any less secure than the general case where we don't have hardware root of trust.

[tingyuz]

one approach is to write the token into a file as well as print out on console. I would propose to write to a file "accessToken.json" that includes user name and token in the current directory. The format will be something like:

{
"User": "tom",
"Token": "yIPD6phz1zhFiF7PwRa7gDV4GP0YVSAe"
}

[tingyuz]

Fixed in #66. The token will be written to accessToken.json file.

[anonymouse64]

@tingyuz please do not close issues until the issue is actually merged and fixed in master, i.e. your linked PR may eventually resolve the issue but it is not yet resolved because that PR hasn't been merged.

[tingyuz]

ok reopen the issue to track.