Function: changeBlockDurationMillis(uint64 newBlockDurationMillis, uint64 nonce, ValidatorSet activeColdValidatorSet, address[] signers, Signature[] signatures)

This function can be used to change the block duration.

Inputs

• newBlockDurationMillis

  • Control: Arbitrary.

  • Constraints: None.

  • Impact: New block duration.

• nonce

  • Control: Arbitrary.

  • Constraints: None.

  • Impact: Nonce used as part of the signed hash.

• activeColdValidatorSet

  • Control: Arbitrary.

  • Constraints: Hash must match the stored validator set hash.

  • Impact: Active set of validators --- used to validate signatures.

• signers

  • Control: Arbitrary.

  • Constraints: Length must match signatures.

  • Impact: Addresses of the signers of the action.

• signatures

  • Control: Arbitrary.

  • Constraints: Each element must be a valid signature for the corresponding address in signers.

  • Impact: Signatures authorizing the action.

Branches and code coverage (including function calls)

Intended branches

• Checks that the same message has not been used, checks the validity of the validator signatures, and updates the block duration.

  Test coverage

Negative behavior

• Reverts if the same message has already been used.

  Negative test

• Reverts if the hash of the provided validator set does not match the stored one.

  Negative test

• Reverts if a signature does not correspond with the signer.

  Negative test

• Reverts if the signers' cumulative voting power is insufficient.

  Negative test

• Reverts if the length of the signers and signatures do not match.

  Negative test

Function call analysis

• rootFunction -> hash(agent)

  • What is controllable? agent, indirectly (some parts of the hash).

  • If return value controllable, how is it used and how can it go wrong? Not controllable, used to identify the transfer.

  • What happens if it reverts, reenters, or does other unusual control flow? Reverts and reentrancy cannot happen.

• rootFunction -> checkMessageNotUsed(message)

  • What is controllable? message, indirectly (some parts of the hash).

  • If return value controllable, how is it used and how can it go wrong? N/A.

  • What happens if it reverts, reenters, or does other unusual control flow? Reverts bubble up; reentrancy cannot happen (no external calls).

• rootFunction -> checkValidatorSignatures(...)

  • What is controllable? message (some parts of the hash), activeColdValidatorSet, signers, and signatures.

  • If return value controllable, how is it used and how can it go wrong? N/A.

  • What happens if it reverts, reenters, or does other unusual control flow? Reverts bubble up; reentrancy cannot happen (no external calls).