Should I use a blacklist/whitelist toggle?

I've been meaning to add a feature to my application's config files that allow you to blacklist or whitelist certain users. Which one is a better mechanic?

Mechanic 1

Block certain people

{
  "blacklist": [
    "these",
    "users",
    "are",
    "blocked"
  ],
  "whitelist": [
    "these",
    "users",
    "are",
    "always",
    "allowed"
  ]
}

(result: blocked is the only blocked user)

Block all except a few people

{
  "blacklist": [
    "*"
  ],
  "whitelist": [
    "these",
    "users",
    "are",
    "allowed"
  ]
}

(result: these, users, are, allowed are the only allowed users)

Mechanic 2

Block certain people

{
  "blacklist": [
    "these",
    "users",
    "are",
    "blocked"
  ],
  "isWhitelist": false
}

(result: these, users, are, blocked are blocked)

Block all except a few people

{
  "blacklist": [
    "these",
    "users",
    "are",
    "allowed"
  ],
  "isWhitelist": true
}

(result: these, users, are, allowed are the only allowed users)

Which one would work better and feel more intuitive?

Thanks.