all: v2 refactoring to use feed byte identifier (#23)

Author: pmerkleplant

Diff for: .env.example

@@ -34,7 +34,7 @@ export ECDSA_VS="[]"
 export ECDSA_RS="[]"
 export ECDSA_SS="[]"
 ## IScribe::drop
-export FEED_INDEX=
+export FEED_ID=
 ## IScribeOptimistic::setOpChallengePeriod
 export OP_CHALLENGE_PERIOD=
 ## IScribeOptimistic::setMaxChallengeReward
@@ -51,4 +51,4 @@ export TEST_POKE_VAL=
 export TEST_POKE_AGE=
 export TEST_SCHNORR_SIGNATURE=
 export TEST_SCHNORR_COMMITMENT=
-export TEST_SCHNORR_SIGNERS_BLOB=
+export TEST_SCHNORR_FEED_IDS=

Diff for: .gas-snapshot

@@ -1,77 +1,69 @@
-LibBytesTest:test_getByteAtIndex() (gas: 378)
 LibSecp256k1Test:testVectors_addAffinePoint() (gas: 2502307)
 LibSecp256k1Test:test_isZeroPoint() (gas: 465)
 LibSecp256k1Test:test_yParity() (gas: 530)
 ScribeInvariantTest:invariant_bar_IsNeverZero() (runs: 256, calls: 3840, reverts: 0)
-ScribeInvariantTest:invariant_feeds_ImageIsZeroToLengthOfPubKeys() (runs: 256, calls: 3840, reverts: 0)
-ScribeInvariantTest:invariant_feeds_LinkToTheirPublicKeys() (runs: 256, calls: 3840, reverts: 0)
 ScribeInvariantTest:invariant_poke_PokeTimestampsAreStrictlyMonotonicallyIncreasing() (runs: 256, calls: 3840, reverts: 0)
-ScribeInvariantTest:invariant_pubKeys_AtIndexZeroIsZeroPoint() (runs: 256, calls: 3840, reverts: 0)
-ScribeInvariantTest:invariant_pubKeys_LengthIsStrictlyMonotonicallyIncreasing() (runs: 256, calls: 3840, reverts: 0)
-ScribeInvariantTest:invariant_pubKeys_NonZeroPubKeyExistsAtMostOnce() (runs: 256, calls: 3840, reverts: 0)
-ScribeInvariantTest:invariant_pubKeys_ZeroPointIsNeverAddedAsPubKey() (runs: 256, calls: 3840, reverts: 0)
-ScribeOptimisticTest:test_Deployment() (gas: 59359)
-ScribeOptimisticTest:test_afterAuthedAction_1_drop() (gas: 248804)
-ScribeOptimisticTest:test_afterAuthedAction_1_setBar() (gas: 295659)
-ScribeOptimisticTest:test_afterAuthedAction_1_setChallengePeriod() (gas: 294180)
-ScribeOptimisticTest:test_afterAuthedAction_2_drop() (gas: 325741)
-ScribeOptimisticTest:test_afterAuthedAction_2_setBar() (gas: 384823)
-ScribeOptimisticTest:test_afterAuthedAction_2_setChallengePeriod() (gas: 384423)
-ScribeOptimisticTest:test_afterAuthedAction_3_drop() (gas: 251454)
-ScribeOptimisticTest:test_afterAuthedAction_3_setBar() (gas: 298843)
-ScribeOptimisticTest:test_afterAuthedAction_3_setChallengePeriod() (gas: 298316)
-ScribeOptimisticTest:test_afterAuthedAction_4_drop() (gas: 327250)
-ScribeOptimisticTest:test_afterAuthedAction_4_setBar() (gas: 386044)
-ScribeOptimisticTest:test_afterAuthedAction_4_setChallengePeriod() (gas: 384786)
-ScribeOptimisticTest:test_drop_IndexZero() (gas: 44243)
-ScribeOptimisticTest:test_drop_Multiple_IsAuthProtected() (gas: 14770)
-ScribeOptimisticTest:test_drop_Single_IsAuthProtected() (gas: 12782)
-ScribeOptimisticTest:test_latestAnswer_isTollProtected() (gas: 12505)
+ScribeInvariantTest:invariant_pubKeys_CannotIndexOutOfBoundsViaUint8Index() (runs: 256, calls: 3840, reverts: 0)
+ScribeInvariantTest:invariant_pubKeys_IndexedViaFeedId() (runs: 256, calls: 3840, reverts: 0)
+ScribeOptimisticTest:test_Deployment() (gas: 1204337)
+ScribeOptimisticTest:test_afterAuthedAction_1_drop() (gas: 202463)
+ScribeOptimisticTest:test_afterAuthedAction_1_setBar() (gas: 238545)
+ScribeOptimisticTest:test_afterAuthedAction_1_setChallengePeriod() (gas: 237041)
+ScribeOptimisticTest:test_afterAuthedAction_2_drop() (gas: 285432)
+ScribeOptimisticTest:test_afterAuthedAction_2_setBar() (gas: 325402)
+ScribeOptimisticTest:test_afterAuthedAction_2_setChallengePeriod() (gas: 324955)
+ScribeOptimisticTest:test_afterAuthedAction_3_drop() (gas: 205138)
+ScribeOptimisticTest:test_afterAuthedAction_3_setBar() (gas: 241782)
+ScribeOptimisticTest:test_afterAuthedAction_3_setChallengePeriod() (gas: 241184)
+ScribeOptimisticTest:test_afterAuthedAction_4_drop() (gas: 286761)
+ScribeOptimisticTest:test_afterAuthedAction_4_setBar() (gas: 326467)
+ScribeOptimisticTest:test_afterAuthedAction_4_setChallengePeriod() (gas: 325228)
+ScribeOptimisticTest:test_drop_Multiple_IsAuthProtected() (gas: 14650)
+ScribeOptimisticTest:test_drop_Single_IsAuthProtected() (gas: 13533)
+ScribeOptimisticTest:test_latestAnswer_isTollProtected() (gas: 12518)
 ScribeOptimisticTest:test_latestRoundData_isTollProtected() (gas: 14030)
-ScribeOptimisticTest:test_lift_Multiple_FailsIf_ECDSADataInvalid() (gas: 106973)
-ScribeOptimisticTest:test_lift_Multiple_FailsIf_MaxFeedsReached() (gas: 20286949)
-ScribeOptimisticTest:test_lift_Multiple_IsAuthProtected() (gas: 16490)
-ScribeOptimisticTest:test_lift_Single_FailsIf_ECDSADataInvalid() (gas: 22135)
-ScribeOptimisticTest:test_lift_Single_FailsIf_MaxFeedsReached() (gas: 19731489)
-ScribeOptimisticTest:test_lift_Single_IsAuthProtected() (gas: 12905)
-ScribeOptimisticTest:test_opChallenge_FailsIf_CalledSubsequently() (gas: 311729)
-ScribeOptimisticTest:test_opChallenge_FailsIf_InvalidSchnorrDataGiven() (gas: 283298)
-ScribeOptimisticTest:test_opChallenge_FailsIf_NoOpPokeToChallenge() (gas: 14897)
-ScribeOptimisticTest:test_peek_isTollProtected() (gas: 12870)
-ScribeOptimisticTest:test_peep_isTollProtected() (gas: 13200)
-ScribeOptimisticTest:test_poke_Initial_FailsIf_AgeIsZero() (gas: 242775)
-ScribeOptimisticTest:test_readWithAge_isTollProtected() (gas: 12357)
-ScribeOptimisticTest:test_read_isTollProtected() (gas: 11823)
-ScribeOptimisticTest:test_setBar_FailsIf_BarIsZero() (gas: 11793)
-ScribeOptimisticTest:test_setBar_IsAuthProtected() (gas: 13730)
-ScribeOptimisticTest:test_setMaxChallengeReward_IsAuthProtected() (gas: 13730)
-ScribeOptimisticTest:test_setOpChallengePeriod_DropsFinalizedOpPoke_If_NonFinalizedAfterUpdate() (gas: 299764)
-ScribeOptimisticTest:test_setOpChallengePeriod_FailsIf_OpChallengePeriodIsZero() (gas: 11567)
-ScribeOptimisticTest:test_setOpChallengePeriod_IsAuthProtected() (gas: 12332)
-ScribeOptimisticTest:test_toll_diss_IsAuthProtected() (gas: 13260)
-ScribeOptimisticTest:test_toll_kiss_IsAuthProtected() (gas: 12419)
-ScribeOptimisticTest:test_tryReadWithAge_isTollProtected() (gas: 13746)
-ScribeOptimisticTest:test_tryRead_isTollProtected() (gas: 12986)
-ScribeTest:test_Deployment() (gas: 42326)
-ScribeTest:test_drop_IndexZero() (gas: 16904)
-ScribeTest:test_drop_Multiple_IsAuthProtected() (gas: 13794)
-ScribeTest:test_drop_Single_IsAuthProtected() (gas: 12148)
-ScribeTest:test_latestAnswer_isTollProtected() (gas: 12092)
-ScribeTest:test_latestRoundData_isTollProtected() (gas: 13132)
-ScribeTest:test_lift_Multiple_FailsIf_ECDSADataInvalid() (gas: 106626)
-ScribeTest:test_lift_Multiple_FailsIf_MaxFeedsReached() (gas: 20286275)
-ScribeTest:test_lift_Multiple_IsAuthProtected() (gas: 15605)
-ScribeTest:test_lift_Single_FailsIf_ECDSADataInvalid() (gas: 21437)
-ScribeTest:test_lift_Single_FailsIf_MaxFeedsReached() (gas: 19732318)
-ScribeTest:test_lift_Single_IsAuthProtected() (gas: 12535)
-ScribeTest:test_peek_isTollProtected() (gas: 12373)
-ScribeTest:test_peep_isTollProtected() (gas: 12461)
-ScribeTest:test_poke_Initial_FailsIf_AgeIsZero() (gas: 239335)
-ScribeTest:test_readWithAge_isTollProtected() (gas: 11969)
-ScribeTest:test_read_isTollProtected() (gas: 11695)
-ScribeTest:test_setBar_FailsIf_BarIsZero() (gas: 11392)
-ScribeTest:test_setBar_IsAuthProtected() (gas: 12823)
-ScribeTest:test_toll_diss_IsAuthProtected() (gas: 12533)
-ScribeTest:test_toll_kiss_IsAuthProtected() (gas: 12088)
-ScribeTest:test_tryReadWithAge_isTollProtected() (gas: 12871)
-ScribeTest:test_tryRead_isTollProtected() (gas: 12287)
+ScribeOptimisticTest:test_lift_Multiple_FailsIf_ECDSADataInvalid() (gas: 78843)
+ScribeOptimisticTest:test_lift_Multiple_IsAuthProtected() (gas: 16509)
+ScribeOptimisticTest:test_lift_Single_FailsIf_ECDSADataInvalid() (gas: 21864)
+ScribeOptimisticTest:test_lift_Single_FailsIf_FeedIdAlreadyLifted() (gas: 73859)
+ScribeOptimisticTest:test_lift_Single_IsAuthProtected() (gas: 13053)
+ScribeOptimisticTest:test_opChallenge_CalldataEncodingAttack() (gas: 1528876)
+ScribeOptimisticTest:test_opChallenge_FailsIf_CalledSubsequently() (gas: 256890)
+ScribeOptimisticTest:test_opChallenge_FailsIf_InvalidSchnorrDataGiven() (gas: 226291)
+ScribeOptimisticTest:test_opChallenge_FailsIf_NoOpPokeToChallenge() (gas: 14879)
+ScribeOptimisticTest:test_peek_isTollProtected() (gas: 12886)
+ScribeOptimisticTest:test_peep_isTollProtected() (gas: 13216)
+ScribeOptimisticTest:test_poke_Initial_FailsIf_AgeIsZero() (gas: 185331)
+ScribeOptimisticTest:test_readWithAge_isTollProtected() (gas: 12397)
+ScribeOptimisticTest:test_read_isTollProtected() (gas: 11836)
+ScribeOptimisticTest:test_setBar_FailsIf_BarIsZero() (gas: 11908)
+ScribeOptimisticTest:test_setBar_IsAuthProtected() (gas: 13803)
+ScribeOptimisticTest:test_setMaxChallengeReward_IsAuthProtected() (gas: 13698)
+ScribeOptimisticTest:test_setOpChallengePeriod_DropsFinalizedOpPoke_If_NonFinalizedAfterUpdate() (gas: 242619)
+ScribeOptimisticTest:test_setOpChallengePeriod_FailsIf_OpChallengePeriodIsZero() (gas: 11633)
+ScribeOptimisticTest:test_setOpChallengePeriod_IsAuthProtected() (gas: 12393)
+ScribeOptimisticTest:test_toll_diss_IsAuthProtected() (gas: 13268)
+ScribeOptimisticTest:test_toll_kiss_IsAuthProtected() (gas: 12517)
+ScribeOptimisticTest:test_tryReadWithAge_isTollProtected() (gas: 13786)
+ScribeOptimisticTest:test_tryRead_isTollProtected() (gas: 13047)
+ScribeTest:test_Deployment() (gas: 1185225)
+ScribeTest:test_drop_Multiple_IsAuthProtected() (gas: 13643)
+ScribeTest:test_drop_Single_IsAuthProtected() (gas: 12648)
+ScribeTest:test_latestAnswer_isTollProtected() (gas: 12053)
+ScribeTest:test_latestRoundData_isTollProtected() (gas: 13080)
+ScribeTest:test_lift_Multiple_FailsIf_ECDSADataInvalid() (gas: 78456)
+ScribeTest:test_lift_Multiple_IsAuthProtected() (gas: 15556)
+ScribeTest:test_lift_Single_FailsIf_ECDSADataInvalid() (gas: 21117)
+ScribeTest:test_lift_Single_FailsIf_FeedIdAlreadyLifted() (gas: 73352)
+ScribeTest:test_lift_Single_IsAuthProtected() (gas: 12631)
+ScribeTest:test_peek_isTollProtected() (gas: 12337)
+ScribeTest:test_peep_isTollProtected() (gas: 12425)
+ScribeTest:test_poke_Initial_FailsIf_AgeIsZero() (gas: 181717)
+ScribeTest:test_readWithAge_isTollProtected() (gas: 11957)
+ScribeTest:test_read_isTollProtected() (gas: 11678)
+ScribeTest:test_setBar_FailsIf_BarIsZero() (gas: 11457)
+ScribeTest:test_setBar_IsAuthProtected() (gas: 12846)
+ScribeTest:test_toll_diss_IsAuthProtected() (gas: 12489)
+ScribeTest:test_toll_kiss_IsAuthProtected() (gas: 12156)
+ScribeTest:test_tryReadWithAge_isTollProtected() (gas: 12838)
+ScribeTest:test_tryRead_isTollProtected() (gas: 12298)

Diff for: .gitignore

@@ -1,3 +1,6 @@
+# VSCode settings
+.vscode/
+
 # Compiler files
 cache/
 out/

Diff for: CHANGELOG.md

@@ -4,10 +4,23 @@ All notable changes to this project will be documented in this file.
 
 The format is based on [Common Changelog](https://common-changelog.org/).
 
+[2.0.0]: https://github.com/chronicleprotocol/scribe/releases/tag/v2.0.0
 [1.2.0]: https://github.com/chronicleprotocol/scribe/releases/tag/v1.2.0
 [1.1.0]: https://github.com/chronicleprotocol/scribe/releases/tag/v1.1.0
 [1.0.0]: https://github.com/chronicleprotocol/scribe/releases/tag/v1.0.0
 
+## [2.0.0] - 2023-11-27
+
+### Changed
+
+- **Breaking** Use 1-byte identifier for feeds based on highest-order byte of their addresses instead of their storage array's index ([#23](https://github.com/chronicleprotocol/scribe/pull/23))
+- **Breaking** Change `IScribe` and `IScribeOptimistic` interfaces to account for new feed identification ([#23](https://github.com/chronicleprotocol/scribe/pull/23))
+
+### Fixed
+
+- DOS vector in `ScribeOptimistic::opPoke` making `ScribeOptimistic::opChallenge` economically unprofitable ([#23](https://github.com/chronicleprotocol/scribe/pull/23))
+- Possibility to successfully `opChallenge` a valid `opPoke` via non-default calldata encoding ([#23](https://github.com/chronicleprotocol/scribe/pull/23))
+
 ## [1.2.0] - 2023-09-29
 
 ### Added

Diff for: README.md

@@ -34,7 +34,7 @@ $ FOUNDRY_PROFILE=intense forge test # Run all tests in intense mode
 $ forge test --nmt "FuzzDifferentialOracleSuite" # Run only non-differential fuzz tests
 ```
 
-Note that in order to run the whole test suite, i.e. including differential fuzz tests, the oracle-suite's [`schnorr`](https://github.com/chronicleprotocol/oracle-suite) binary needs to be present inside the `bin/` directory.
+Note that in order to run the whole test suite, i.e. including differential fuzz tests, the oracle-suite's musig [`schnorr`](https://github.com/chronicleprotocol/musig/tree/master/cmd/schnorr) binary needs to be present inside the `bin/` directory.
 
 Lint:
 

Diff for: assets/benchmarks.png

@@ -2,14 +2,16 @@
 
 The benchmark for `Scribe` is based on the `poke()` function while the benchmark for `ScribeOptimistic` being based on the `opPoke()` function.
 
-| `bar` | `Scribe::poke()`   | `ScribeOptimistic::opPoke()` |
-|-------|--------------------|------------------------------|
-|     5 |             79,428 |                       66,462 |
-|    10 |            106,862 |                       66,534 |
-|    15 |            131,834 |                       66,603 |
-|    20 |            158,263 |                       66,663 |
-|    50 |            315,655 |                       67,437 |
-|   100 |            577,919 |                       68,845 |
+| `bar` | `Scribe::poke()` | `ScribeOptimistic::opPoke()` |
+| ----- | ---------------- | ---------------------------- |
+| 5     | 81,025           | 68,944                       |
+| 10    | 106,395          | 69,004                       |
+| 15    | 134,342          | 69,061                       |
+| 20    | 159,488          | 69,133                       |
+| 50    | 320,473          | 69,908                       |
+| 100   | 585,993          | 71,315                       |
+| 200   | 1,119,535        | 73,759                       |
+| 255   | 1,411,702        | 74,852                       |
 
 The following visualization shows the gas usage for different numbers of `bar`:
 

Diff for: audits/[email protected]

@@ -68,67 +68,24 @@ This document specifies invariants of the Scribe and ScribeOptimistic oracle con
 
 ## `{Scribe, ScribeOptimistic}::_pubKeys`
 
-* `_pubKeys[0]` is the zero point:
+* `_pubKeys`' length is 256:
     ```
-    _pubKeys[0].isZeroPoint()
+    _pubKeys.length == 256
     ```
 
-* A non-zero public key exists at most once:
+* Public keys are stored at the index of their address' first byte:
     ```
-    ∀x ∊ PublicKeys: x.isZeroPoint() ∨ count(x in _pubKeys) <= 1
-    ```
-
-* Length is strictly monotonically increasing:
-    ```
-    preTx(_pubKeys.length) != postTx(_pubKeys.length)
-        → preTx(_pubKeys.length) < posTx(_pubKeys.length)
-    ```
-
-* Existing public key may only be deleted, never mutated:
-    ```
-    ∀x ∊ uint: x < _pubKeys.length ⋀ preTx(_pubKeys[x]) != postTx(_pubKeys[x])
-        → postTx(_pubKeys[x].isZeroPoint())
-    ```
-
-* Newly added public key is non-zero:
-    ```
-    preTx(_pubKeys.length) != postTx(_pubKeys.length)
-        → postTx(!_pubKeys[_pubKeys.length-1].isZeroPoint())
+    ∀id ∊ Uint8: _pubKeys[id].isZeroPoint() ∨ (_pubKeys[id].toAddress() >> 152) == id
     ```
 
 * Only functions `lift` and `drop` may mutate the array's state:
     ```
-    ∀x ∊ uint: preTx(_pubKeys[x]) != postTx(_pubKeys[x])
+    ∀id ∊ Uint8: preTx(_pubKeys[id]) != postTx(_pubKeys[id])
         → msg.sig ∊ {"lift", "drop"}
     ```
 
 * Array's state may only be mutated by auth'ed caller:
     ```
-    ∀x ∊ uint: preTx(_pubKeys[x]) != postTx(_pubKeys[x])
-        → authed(msg.sender)
-    ```
-
-## `{Scribe, ScribeOptimistic}::_feeds`
-
-* Image of mapping is `[0, _pubKeys.length)`:
-    ```
-    ∀x ∊ Address: _feeds[x] ∊ [0, _pubKeys.length)
-    ```
-
-* Image of mapping links to feed's public key in `_pubKeys`:
-    ```
-    ∀x ∊ Address: _feeds[x] = y ⋀ y != 0
-        → _pubKeys[y].toAddress() == x
-    ```
-
-* Only functions `lift` and `drop` may mutate the mapping's state:
-    ```
-    ∀x ∊ Address: preTx(_feeds[x]) != postTx(_feeds[x])
-        → msg.sig ∊ {"lift", "drop"}
-    ```
-
-* Mapping's state may only be mutated by auth'ed caller:
-    ```
-    ∀x ∊ Address: preTx(_feeds[x]) != postTx(_feeds[x])
+    ∀id ∊ Uint8: preTx(_pubKeys[id]) != postTx(_pubKeys[id])
         → authed(msg.sender)
     ```

Diff for: docs/Benchmarks.md

@@ -111,7 +111,7 @@ $ forge script \
 
 Set the following environment variables:
 
-- `FEED_INDEX`: The feed's index
+- `FEED_ID`: The feed's id
 
 Run:
 
@@ -120,7 +120,7 @@ $ forge script \
     --private-key $PRIVATE_KEY \
     --broadcast \
     --rpc-url $RPC_URL \
-    --sig $(cast calldata "drop(address,uint)" $SCRIBE $FEED_INDEX) \
+    --sig $(cast calldata "drop(address,uint)" $SCRIBE $FEED_ID) \
     -vvv \
     script/${SCRIBE_FLAVOUR}.s.sol:${SCRIBE_FLAVOUR}Script
 ```

Diff for: docs/Invariants.md

@@ -50,25 +50,24 @@ For more info, see [`LibSecp256k1::addAffinePoint()`](../src/libs/LibSecp256k1.s
 
 The `poke()` function has to receive the set of feeds, i.e. public keys, that participated in the Schnorr multi-signature.
 
-To reduce the calldata load, Scribe does not use type `address`, which uses 20 bytes per feed, but encodes the unique feeds' identifier's byte-wise into a `bytes` type called `signersBlob`.
+To reduce the calldata load, Scribe does not use type `address`, which uses 20 bytes per feed, but encodes the feeds' identifier's byte-wise into a `bytes` type called `feedIds`.
 
-For more info, see [`LibSchnorrData.sol`](../src/libs/LibSchnorrData.sol).
+A feed's identifier is defined as the highest order byte of the feed's address and can be computed via `uint8(uint(uint160(feedAddress)) >> 152)`.
 
 ## Lifting Feeds
 
 Feeds _must_ prove the integrity of their public key by proving the ownership of the corresponding private key. The `lift()` function therefore expects an ECDSA signed message, for more info see [`IScribe.feedRegistrationMessage()`](../src/IScribe.sol).
 
 If public key's would not be verified, the Schnorr signature verification would be vulnerable to rogue-key attacks. For more info, see [`docs/Schnorr.md`](./Schnorr.md#key-aggregation-for-multisignatures).
 
-Also, the number of state-changing `lift()` executions is limited to `type(uint8).max-1`, i.e. 254. After reaching this limit, no further `lift()` calls can be executed. For more info, see [`IScribe.maxFeeds()`](../src/IScribe.sol).
-
 ## Chainlink Compatibility
 
 Scribe aims to be partially Chainlink compatible by implementing the most widely, and not deprecated, used functions of the `IChainlinkAggregatorV3` interface.
 
 The following `IChainlinkAggregatorV3` functions are provided:
 - `latestRoundData()`
 - `decimals()`
+- `latestAnswer()`
 
 ## Optimistic-Flavored Scribe
 

Diff for: docs/Management.md

@@ -12,7 +12,7 @@ via_ir = true
 extra_output_files = ["metadata", "irOptimized"]
 
 # Testing
-fuzz = { runs = 10 }
+fuzz = { runs = 50 }
 block_timestamp = 1_680_220_800 # March 31, 2023 at 00:00 GMT
 
 [invariant]