Merge pull request #2613 from keep-network/governable-parameters

Governable random beacon parameters

This PR adds a contract containing governable parameters that will be
needed by Random Beacon v2. The parameters are taken from RFC-19.

Author: pdyraga

solidity/random-beacon/contracts/RandomBeacon.sol

@@ -0,0 +1,174 @@
+// ▓▓▌ ▓▓ ▐▓▓ ▓▓▓▓▓▓▓▓▓▓▌▐▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓ ▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓ ▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▄
+// ▓▓▓▓▓▓▓▓▓▓ ▓▓▓▓▓▓▓▓▓▓▌▐▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓ ▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓ ▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓
+//   ▓▓▓▓▓▓    ▓▓▓▓▓▓▓▀    ▐▓▓▓▓▓▓    ▐▓▓▓▓▓   ▓▓▓▓▓▓     ▓▓▓▓▓   ▐▓▓▓▓▓▌   ▐▓▓▓▓▓▓
+//   ▓▓▓▓▓▓▄▄▓▓▓▓▓▓▓▀      ▐▓▓▓▓▓▓▄▄▄▄         ▓▓▓▓▓▓▄▄▄▄         ▐▓▓▓▓▓▌   ▐▓▓▓▓▓▓
+//   ▓▓▓▓▓▓▓▓▓▓▓▓▓▀        ▐▓▓▓▓▓▓▓▓▓▓         ▓▓▓▓▓▓▓▓▓▓         ▐▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓
+//   ▓▓▓▓▓▓▀▀▓▓▓▓▓▓▄       ▐▓▓▓▓▓▓▀▀▀▀         ▓▓▓▓▓▓▀▀▀▀         ▐▓▓▓▓▓▓▓▓▓▓▓▓▓▓▀
+//   ▓▓▓▓▓▓   ▀▓▓▓▓▓▓▄     ▐▓▓▓▓▓▓     ▓▓▓▓▓   ▓▓▓▓▓▓     ▓▓▓▓▓   ▐▓▓▓▓▓▌
+// ▓▓▓▓▓▓▓▓▓▓ █▓▓▓▓▓▓▓▓▓ ▐▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓ ▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓  ▓▓▓▓▓▓▓▓▓▓
+// ▓▓▓▓▓▓▓▓▓▓ ▓▓▓▓▓▓▓▓▓▓ ▐▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓ ▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓  ▓▓▓▓▓▓▓▓▓▓
+//
+//                           Trust math, not hardware.
+
+// SPDX-License-Identifier: MIT
+
+pragma solidity ^0.8.6;
+
+import "@openzeppelin/contracts/access/Ownable.sol";
+
+/// @title Random beacon
+/// @notice Random beacon contract which represents the on-chain part of the
+///         random beacon functionality
+/// @dev Should be owned by the random beacon governance contract
+contract RandomBeacon is Ownable {
+    /// @notice Relay request fee in T
+    uint256 public relayRequestFee;
+
+    /// @notice The number of blocks for a member to become eligible to submit
+    ///         relay entry
+    uint256 public relayEntrySubmissionEligibilityDelay;
+
+    /// @notice Hard timeout for a relay entry
+    uint256 public relayEntryHardTimeout;
+
+    /// @notice Callback gas limit
+    uint256 public callbackGasLimit;
+
+    /// @notice The frequency of a new group creation
+    uint256 public groupCreationFrequency;
+
+    /// @notice Group lifetime
+    uint256 public groupLifetime;
+
+    /// @notice The number of blocks for which a DKG result can be challenged
+    uint256 public dkgResultChallengePeriodLength;
+
+    /// @notice The number of blocks for a member to become eligible to submit
+    ///         DKG result
+    uint256 public dkgSubmissionEligibilityDelay;
+
+    /// @notice Reward for submitting DKG result
+    uint256 public dkgResultSubmissionReward;
+
+    /// @notice Reward for unlocking the sortition pool if DKG timed out
+    uint256 public sortitionPoolUnlockingReward;
+
+    /// @notice Slashing amount for not submitting relay entry
+    uint256 public relayEntrySubmissionFailureSlashingAmount;
+
+    /// @notice Slashing amount for submitting malicious DKG result
+    uint256 public maliciousDkgResultSlashingAmount;
+
+    event RelayEntryParametersUpdated(
+        uint256 relayRequestFee,
+        uint256 relayEntrySubmissionEligibilityDelay,
+        uint256 RelayEntryHardTimeout,
+        uint256 callbackGasLimit
+    );
+
+    event GroupCreationParametersUpdated(
+        uint256 groupCreationFrequency,
+        uint256 groupLifetime,
+        uint256 dkgResultChallengePeriodLength,
+        uint256 dkgSubmissionEligibilityDelay
+    );
+
+    event RewardParametersUpdated(
+        uint256 dkgResultSubmissionReward,
+        uint256 sortitionPoolUnlockingReward
+    );
+
+    event SlashingParametersUpdated(
+        uint256 relayEntrySubmissionFailureSlashingAmount,
+        uint256 maliciousDkgResultSlashingAmount
+    );
+
+    /// @notice Updates the values of relay entry parameters
+    /// @dev Can be called only by the contract owner, which should be the
+    ///      random beacon governance contract
+    /// @param _relayRequestFee New relay request fee
+    /// @param _relayEntrySubmissionEligibilityDelay New relay entry submission
+    ///        eligibility delay
+    /// @param _relayEntryHardTimeout New relay entry hard timeout
+    /// @param _callbackGasLimit New callback gas limit
+    function updateRelayEntryParameters(
+        uint256 _relayRequestFee,
+        uint256 _relayEntrySubmissionEligibilityDelay,
+        uint256 _relayEntryHardTimeout,
+        uint256 _callbackGasLimit
+    ) external onlyOwner {
+        relayRequestFee = _relayRequestFee;
+        relayEntrySubmissionEligibilityDelay = _relayEntrySubmissionEligibilityDelay;
+        relayEntryHardTimeout = _relayEntryHardTimeout;
+        callbackGasLimit = _callbackGasLimit;
+        emit RelayEntryParametersUpdated(
+            relayRequestFee,
+            relayEntrySubmissionEligibilityDelay,
+            relayEntryHardTimeout,
+            callbackGasLimit
+        );
+    }
+
+    /// @notice Updates the values of group creation parameters
+    /// @dev Can be called only by the contract owner, which should be the
+    ///      random beacon governance contract
+    /// @param _groupCreationFrequency New group creation frequency
+    /// @param _groupLifetime New group lifetime
+    /// @param _dkgResultChallengePeriodLength New DKG result challenge period
+    ///        length
+    /// @param _dkgSubmissionEligibilityDelay New DKG submission eligibility
+    ///        delay
+    function updateGroupCreationParameters(
+        uint256 _groupCreationFrequency,
+        uint256 _groupLifetime,
+        uint256 _dkgResultChallengePeriodLength,
+        uint256 _dkgSubmissionEligibilityDelay
+    ) external onlyOwner {
+        groupCreationFrequency = _groupCreationFrequency;
+        groupLifetime = _groupLifetime;
+        dkgResultChallengePeriodLength = _dkgResultChallengePeriodLength;
+        dkgSubmissionEligibilityDelay = _dkgSubmissionEligibilityDelay;
+        emit GroupCreationParametersUpdated(
+            groupCreationFrequency,
+            groupLifetime,
+            dkgResultChallengePeriodLength,
+            dkgSubmissionEligibilityDelay
+        );
+    }
+
+    /// @notice Updates the values of reward parameters
+    /// @dev Can be called only by the contract owner, which should be the
+    ///      random beacon governance contract
+    /// @param _dkgResultSubmissionReward New DKG result submission reward
+    /// @param _sortitionPoolUnlockingReward New sortition pool unlocking reward
+    function updateRewardParameters(
+        uint256 _dkgResultSubmissionReward,
+        uint256 _sortitionPoolUnlockingReward
+    ) external onlyOwner {
+        dkgResultSubmissionReward = _dkgResultSubmissionReward;
+        sortitionPoolUnlockingReward = _sortitionPoolUnlockingReward;
+        emit RewardParametersUpdated(
+            dkgResultSubmissionReward,
+            sortitionPoolUnlockingReward
+        );
+    }
+
+    /// @notice Updates the values of slashing parameters
+    /// @dev Can be called only by the contract owner, which should be the
+    ///      random beacon governance contract
+    /// @param _relayEntrySubmissionFailureSlashingAmount New relay entry
+    ///        submission failure amount
+    /// @param _maliciousDkgResultSlashingAmount New malicious DKG result
+    ///        slashing amount
+    function updateSlashingParameters(
+        uint256 _relayEntrySubmissionFailureSlashingAmount,
+        uint256 _maliciousDkgResultSlashingAmount
+    ) external onlyOwner {
+        relayEntrySubmissionFailureSlashingAmount = _relayEntrySubmissionFailureSlashingAmount;
+        maliciousDkgResultSlashingAmount = _maliciousDkgResultSlashingAmount;
+        emit SlashingParametersUpdated(
+            relayEntrySubmissionFailureSlashingAmount,
+            maliciousDkgResultSlashingAmount
+        );
+    }
+}