Force restic to ask the password when adding a key.

[middelink]

As restic key add uses the same ReadPasswordTwice() as the
rest of restic, it is sensitive to the environment variable
RESTIC_PASSWORD or --password-file= override.

When asking for the new key, temporary remove these 2 overrides, forcing
the password to be asked.

Closes #1132

[codecov-io]

Codecov Report

Merging #1133 into master will decrease coverage by 3.34%.
The diff coverage is 18.18%.

@@            Coverage Diff            @@
##           master   #1133      +/-   ##
=========================================
- Coverage   52.84%   49.5%   -3.35%     
=========================================
  Files         121     121              
  Lines       11397   11406       +9     
=========================================
- Hits         6023    5646     -377     
- Misses       4667    5078     +411     
+ Partials      707     682      -25

Impacted Files	Coverage Δ
cmd/restic/main.go	7.54% <0%> (-1.15%)	⬇️
cmd/restic/cmd_backup.go	25.89% <0%> (ø)	⬆️
cmd/restic/cmd_key.go	53.78% <0%> (-1.4%)	⬇️
cmd/restic/global.go	23.05% <21.42%> (+2.59%)	⬆️
cmd/restic/cmd_init.go	53.12% <60%> (+10.7%)	⬆️
internal/backend/b2/b2.go	0% <0%> (-79.32%)	⬇️
internal/backend/swift/swift.go	0% <0%> (-73.9%)	⬇️
internal/backend/swift/config.go	34.37% <0%> (-56.25%)	⬇️
internal/archiver/archiver.go	64.9% <0%> (+0.16%)	⬆️
... and 1 more

---

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[pvgoran]

Sounds like this solution will not allow non-interactive invocation of this subcommand.

Possibly a more universal solution would be to use a different environment variable and a different command line option for password that is added by restic key add. Like RESTIC_NEW_PASSWORD and --new-password-file. Moreover, these new environment variable/command line option could be also used by restic init; this way, a password to open the repository will be always RESTIC_PASSWORD/--password-file, and a "new" password (for new repository or new key) will be always RESTIC_NEW_PASSWORD/--new-password-file.

[middelink]

Can you please file a new feature request for this? I'm just trying to fix the broken existing behavior (==bug) here and would be happy to discuss (and share my concerns ^^) on your feature request.

[fd0]

Great, thanks!