Support password encryption

[bangsun1234]

In the production environment, the configuration file cannot contain plaintext passwords. The password needs to be encrypted. We need to use an encryption algorithm 'PBEWithHmacSHA256AndAES_256'.

[wey-gu]

Thanks @bangsun1234 we need to provide a secured way to pass the credential with importer(and other tooling).

cc @MuYiYong

[veezhang]

@wey-gu Maybe env parameter is suitable? Configure it in config file is indeed less secure.
For example NG_PASSWORD or NEBULAGRAPH_PASSWORD.

And nebula-console have similar question.
@MuYiYong

[veezhang]

@bangsun1234 Thank you!
I think it may not be appropriate to use an encryption algorithm, because the encrypted string can still connect to the database, so encryption is meaningless?

[wey-gu]

Maybe env parameter is suitable? Configure it in config file is indeed less secure.
For example NG_PASSWORD or NEBULAGRAPH_PASSWORD.

Agreed 👍🏻 @veezhang