Safe Rotate and Drain

This takes an account rotest owned by key 2993f795d133fa5d0fd877a641cabc8b28cd36147f666988cacbaa4379d1ff93, rotates it to key dea647009295dc015ba6e6359b85bafe09d2ce935a03c3bf83f775442d539025, and transfers the whole balance to another account croesus. The croesus account pays the gas which makes it easy to drain the rotest account balance to exactly zero. The transfer out of rotest happens after the key is rotated which means that this transaction MUST be signed by the key you are rotating to and is therefore "safe"...i.e. it is impossible to accidentally rotate to an incorrect key and lose control of the rotest account.

Signing

This transaction must be signed by both the key that owns rotest at the beginning and the key that owns rotest at the end.

Transaction Template

code: |-
  (use coin)
  (let* ((acct:string "rotest")
         (bal:decimal (coin.get-balance acct))
        )
    (coin.rotate acct (read-keyset "ks"))
    (coin.transfer acct
      "croesus"
      bal)
  )
data:
  ks:
    keys: [dea647009295dc015ba6e6359b85bafe09d2ce935a03c3bf83f775442d539025]
    pred: "keys-all"
publicMeta:
  chainId: "0"
  sender: croesus
  gasLimit: 800
  gasPrice: 0.00001
  ttl: 86400
networkId: "testnet04"
signers:
  - public: 2993f795d133fa5d0fd877a641cabc8b28cd36147f666988cacbaa4379d1ff93
    caps:
      - name: coin.GAS
        args: []
      - name: coin.ROTATE
        args: ["rotest"]
  - public: dea647009295dc015ba6e6359b85bafe09d2ce935a03c3bf83f775442d539025
    caps:
      - name: coin.TRANSFER
        args: ["rotest","croesus",100]
type: exec