Add solo machine timestamp check (cosmos#7392)

* add check in header updates for non decreasing timestamp Add check in update.go that the header timestamp is non decreasing compared to the consensus state timestamp. Unit test added in update_test.go * update error message * update godoc Co-authored-by: Federico Kunze <[email protected]> Co-authored-by: mergify[bot] <37929162+mergify[bot]@users.noreply.github.com>
surgebuild · Sep 25, 2020 · 2a4d0ec · 2a4d0ec
1 parent 0ddb2bd
commit 2a4d0ec
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diff --git a/x/ibc/light-clients/solomachine/types/update.go b/x/ibc/light-clients/solomachine/types/update.go
@@ -11,6 +11,8 @@ import (
 // CheckHeaderAndUpdateState checks if the provided header is valid and updates
 // the consensus state if appropriate. It returns an error if:
 // - the client or header provided are not parseable to solo machine types
+// - the header sequence does not match the current sequence
+// - the header timestamp is less than the consensus state timestamp
 // - the currently registered public key did not provide the update signature
 func (cs ClientState) CheckHeaderAndUpdateState(
 	ctx sdk.Context, cdc codec.BinaryMarshaler, clientStore sdk.KVStore,
@@ -37,7 +39,15 @@ func checkHeader(cdc codec.BinaryMarshaler, clientState *ClientState, header *He
 	if header.Sequence != clientState.Sequence {
 		return sdkerrors.Wrapf(
 			clienttypes.ErrInvalidHeader,
-			"sequence provided in the header does not match the client state sequence (%d != %d)", header.Sequence, clientState.Sequence,
+			"header sequence does not match the client state sequence (%d != %d)", header.Sequence, clientState.Sequence,
+		)
+	}
+
+	// assert update timestamp is not less than current consensus state timestamp
+	if header.Timestamp < clientState.ConsensusState.Timestamp {
+		return sdkerrors.Wrapf(
+			clienttypes.ErrInvalidHeader,
+			"header timestamp is less than to the consensus state timestamp (%d < %d)", header.Timestamp, clientState.ConsensusState.Timestamp,
 		)
 	}
 

diff --git a/x/ibc/light-clients/solomachine/types/update_test.go b/x/ibc/light-clients/solomachine/types/update_test.go
@@ -54,6 +54,15 @@ func (suite *SoloMachineTestSuite) TestCheckHeaderAndUpdateState() {
 			},
 			false,
 		},
+		{
+			"invalid timestamp in header",
+			func() {
+				clientState = suite.solomachine.ClientState()
+				h := suite.solomachine.CreateHeader()
+				h.Timestamp--
+				header = h
+			}, false,
+		},
 		{
 			"signature uses wrong sequence",
 			func() {