[docs] update state spec

when deciding if we should send evidence to it

CHANGELOG_PENDING.md

@@ -12,10 +12,17 @@ BREAKING CHANGES:
   * [rpc] \#2298 `/abci_query` takes `prove` argument instead of `trusted` and switches the default
     behaviour to `prove=false`
   * [privval] \#2459 Split `SocketPVMsg`s implementations into Request and Response, where the Response may contain a error message (returned by the remote signer)
+  * [genesis] \#2565 `consensus_params.evidence_params.max_age` is now `time.Duration` (nanosecond count)
+        ```json
+        "evidence_params": {
+          "max_age": "48h0m0s"
+        }
+        ```
 
 * Apps
   * [abci] \#2298 ResponseQuery.Proof is now a structured merkle.Proof, not just
     arbitrary bytes
+  * [abci] \#2565 InitChain `ConsensusParams.EvidenceParams.MaxAge` is now `google.protobuf.Duration` (see https://developers.google.com/protocol-buffers/docs/reference/csharp/class/google/protobuf/well-known-types/duration)
 
 * Go API
   * [node] Remove node.RunForever

Gopkg.lock

@@ -517,6 +517,7 @@
     "github.com/gogo/protobuf/proto",
     "github.com/gogo/protobuf/types",
     "github.com/golang/protobuf/proto",
+    "github.com/golang/protobuf/ptypes/duration",
     "github.com/golang/protobuf/ptypes/timestamp",
     "github.com/gorilla/websocket",
     "github.com/jmhodges/levigo",

Makefile

@@ -44,7 +44,7 @@ protoc_all: protoc_libs protoc_merkle protoc_abci protoc_grpc
 	## See https://stackoverflow.com/a/25518702
 	## Note the $< here is substituted for the %.proto
 	## Note the $@ here is substituted for the %.pb.go
-	protoc $(INCLUDE) $< --gogo_out=Mgoogle/protobuf/timestamp.proto=github.com/golang/protobuf/ptypes/timestamp,plugins=grpc:.
+	protoc $(INCLUDE) $< --gogo_out=Mgoogle/protobuf/timestamp.proto=github.com/golang/protobuf/ptypes/timestamp,Mgoogle/protobuf/duration.proto=github.com/golang/protobuf/ptypes/duration,plugins=grpc:.
 
 ########################################
 ### Build ABCI

abci/types/types.proto

@@ -5,6 +5,7 @@ package types;
 // https://github.com/gogo/protobuf/blob/master/extensions.md
 import "github.com/gogo/protobuf/gogoproto/gogo.proto";
 import "google/protobuf/timestamp.proto";
+import "google/protobuf/duration.proto";
 import "github.com/tendermint/tendermint/libs/common/types.proto";
 import "github.com/tendermint/tendermint/crypto/merkle/merkle.proto";
 
@@ -217,8 +218,8 @@ message BlockSize {
 
 // EvidenceParams contains limits on the evidence.
 message EvidenceParams {
-  // Note: must be greater than 0
-  int64 max_age = 1;
+  // Note: must be greater than 0 if provided
+  google.protobuf.Duration max_age = 1 [(gogoproto.nullable)=false, (gogoproto.stdduration)=true];
 }
 
 message LastCommitInfo {

abci/types/typespb_test.go

@@ -13,6 +13,7 @@ import golang_proto "github.com/golang/protobuf/proto"
 import fmt "fmt"
 import math "math"
 import _ "github.com/gogo/protobuf/gogoproto"
+import _ "github.com/golang/protobuf/ptypes/duration"
 import _ "github.com/golang/protobuf/ptypes/timestamp"
 import _ "github.com/tendermint/tendermint/crypto/merkle"
 import _ "github.com/tendermint/tendermint/libs/common"

consensus/reactor.go

@@ -8,8 +8,7 @@ import (
 
 	"github.com/pkg/errors"
 
-	"github.com/tendermint/go-amino"
-
+	amino "github.com/tendermint/go-amino"
 	cstypes "github.com/tendermint/tendermint/consensus/types"
 	cmn "github.com/tendermint/tendermint/libs/common"
 	tmevents "github.com/tendermint/tendermint/libs/events"
@@ -948,8 +947,8 @@ func (ps *PeerState) ToJSON() ([]byte, error) {
 	return cdc.MarshalJSON(ps)
 }
 
-// GetHeight returns an atomic snapshot of the PeerRoundState's height
-// used by the mempool to ensure peers are caught up before broadcasting new txs
+// GetHeight returns an atomic snapshot of the PeerRoundState's height used by
+// the mempool to ensure peers are caught up before broadcasting new txs.
 func (ps *PeerState) GetHeight() int64 {
 	ps.mtx.Lock()
 	defer ps.mtx.Unlock()

docs/spec/abci/abci.md

@@ -443,11 +443,10 @@ Commit are included in the header of the next block.
 ### EvidenceParams
 
 - **Fields**:
-  - `MaxAge (int64)`: Max age of evidence, in blocks. Evidence older than this
-    is considered stale and ignored.
+  - `MaxAge (google.protobuf.Duration)`: Max age of evidence. Evidence older
+    than this is considered stale and ignored.
         - This should correspond with an app's "unbonding period" or other
           similar mechanism for handling Nothing-At-Stake attacks.
-        - NOTE: this should change to time (instead of blocks)!
 
 ### Proof
 

docs/spec/blockchain/state.md

@@ -101,7 +101,7 @@ type BlockGossip struct {
 }
 
 type EvidenceParams struct {
-	MaxAge int64
+	MaxAge time.Duration
 }
 ```
 
@@ -129,5 +129,5 @@ size of each part is `ConsensusParams.BlockGossip.BlockPartSizeBytes`.
 For evidence in a block to be valid, it must satisfy:
 
 ```
-block.Header.Height - evidence.Height < ConsensusParams.EvidenceParams.MaxAge
+block.Header.Time - evidence.Time < ConsensusParams.EvidenceParams.MaxAge
 ```

evidence/pool.go

@@ -3,6 +3,7 @@ package evidence
 import (
 	"fmt"
 	"sync"
+	"time"
 
 	clist "github.com/tendermint/tendermint/libs/clist"
 	dbm "github.com/tendermint/tendermint/libs/db"
@@ -84,7 +85,7 @@ func (evpool *EvidencePool) Update(block *types.Block, state sm.State) {
 	evpool.mtx.Unlock()
 
 	// remove evidence from pending and mark committed
-	evpool.MarkEvidenceAsCommitted(block.Height, block.Evidence.Evidence)
+	evpool.MarkEvidenceAsCommitted(block.Evidence.Evidence, block.Time)
 }
 
 // AddEvidence checks the evidence is valid and adds it to the pool.
@@ -117,8 +118,9 @@ func (evpool *EvidencePool) AddEvidence(evidence types.Evidence) (err error) {
 	return nil
 }
 
-// MarkEvidenceAsCommitted marks all the evidence as committed and removes it from the queue.
-func (evpool *EvidencePool) MarkEvidenceAsCommitted(height int64, evidence []types.Evidence) {
+// MarkEvidenceAsCommitted marks all the evidence as committed and removes it
+// from the queue.
+func (evpool *EvidencePool) MarkEvidenceAsCommitted(evidence []types.Evidence, lastBlockTime time.Time) {
 	// make a map of committed evidence to remove from the clist
 	blockEvidenceMap := make(map[string]struct{})
 	for _, ev := range evidence {
@@ -127,20 +129,22 @@ func (evpool *EvidencePool) MarkEvidenceAsCommitted(height int64, evidence []typ
 	}
 
 	// remove committed evidence from the clist
-	maxAge := evpool.State().ConsensusParams.EvidenceParams.MaxAge
-	evpool.removeEvidence(height, maxAge, blockEvidenceMap)
-
+	maxAge := evpool.State().ConsensusParams.EvidenceParams.MaxAge.Duration
+	evpool.removeEvidence(blockEvidenceMap, lastBlockTime, maxAge)
 }
 
-func (evpool *EvidencePool) removeEvidence(height, maxAge int64, blockEvidenceMap map[string]struct{}) {
+func (evpool *EvidencePool) removeEvidence(
+	blockEvidenceMap map[string]struct{},
+	lastBlockTime time.Time,
+	maxAge time.Duration,
+) {
 	for e := evpool.evidenceList.Front(); e != nil; e = e.Next() {
 		ev := e.Value.(types.Evidence)
+		evAge := lastBlockTime.Sub(ev.Time())
 
 		// Remove the evidence if it's already in a block
 		// or if it's now too old.
-		if _, ok := blockEvidenceMap[evMapKey(ev)]; ok ||
-			ev.Height() < height-maxAge {
-
+		if _, ok := blockEvidenceMap[evMapKey(ev)]; ok || evAge > maxAge {
 			// remove from clist
 			evpool.evidenceList.Remove(e)
 			e.DetachPrev()

evidence/pool_test.go

@@ -39,7 +39,7 @@ func initializeValidatorState(valAddr []byte, height int64) dbm.DB {
 		LastHeightValidatorsChanged: 1,
 		ConsensusParams: types.ConsensusParams{
 			EvidenceParams: types.EvidenceParams{
-				MaxAge: 1000000,
+				MaxAge: tmtime.DurationPretty{1000000},
 			},
 		},
 	}

evidence/reactor.go

@@ -91,7 +91,7 @@ func (evR *EvidenceReactor) Receive(chID byte, src p2p.Peer, msgBytes []byte) {
 	}
 }
 
-// SetEventSwitch implements events.Eventable.
+// SetEventBus implements events.Eventable.
 func (evR *EvidenceReactor) SetEventBus(b *types.EventBus) {
 	evR.eventBus = b
 }
@@ -153,28 +153,17 @@ func (evR *EvidenceReactor) broadcastEvidenceRoutine(peer p2p.Peer) {
 // Returns the message to send the peer, or nil if the evidence is invalid for the peer.
 // If message is nil, return true if we should sleep and try again.
 func (evR EvidenceReactor) checkSendEvidenceMessage(peer p2p.Peer, ev types.Evidence) (msg EvidenceMessage, retry bool) {
-
-	// make sure the peer is up to date
-	evHeight := ev.Height()
 	peerState, ok := peer.Get(types.PeerStateKey).(PeerState)
 	if !ok {
 		evR.Logger.Info("Found peer without PeerState", "peer", peer)
 		return nil, true
 	}
 
-	// NOTE: We only send evidence to peers where
-	// peerHeight - maxAge < evidenceHeight < peerHeight
-	maxAge := evR.evpool.State().ConsensusParams.EvidenceParams.MaxAge
+	// NOTE: We only send evidence to peers where evidenceHeight < peerHeight
 	peerHeight := peerState.GetHeight()
-	if peerHeight < evHeight {
+	if peerHeight < ev.Height() {
 		// peer is behind. sleep while he catches up
 		return nil, true
-	} else if peerHeight > evHeight+maxAge {
-		// evidence is too old, skip
-		// NOTE: if evidence is too old for an honest peer,
-		// then we're behind and either it already got committed or it never will!
-		evR.Logger.Info("Not sending peer old evidence", "peerHeight", peerHeight, "evHeight", evHeight, "maxAge", maxAge, "peer", peer)
-		return nil, false
 	}
 
 	// send evidence

evidence/reactor_test.go

@@ -132,7 +132,7 @@ func TestReactorBroadcastEvidence(t *testing.T) {
 	// set the peer height on each reactor
 	for _, r := range reactors {
 		for _, peer := range r.Switch.Peers().List() {
-			ps := peerState{height}
+			ps := testPeerState{height}
 			peer.Set(types.PeerStateKey, ps)
 		}
 	}
@@ -143,11 +143,13 @@ func TestReactorBroadcastEvidence(t *testing.T) {
 	waitForEvidence(t, evList, reactors)
 }
 
-type peerState struct {
+type testPeerState struct {
 	height int64
 }
 
-func (ps peerState) GetHeight() int64 {
+var _ PeerState = (*testPeerState)(nil)
+
+func (ps testPeerState) GetHeight() int64 {
 	return ps.height
 }
 
@@ -165,7 +167,7 @@ func TestReactorSelectiveBroadcast(t *testing.T) {
 	// make reactors from statedb
 	reactors := makeAndConnectEvidenceReactors(config, []dbm.DB{stateDB1, stateDB2})
 	peer := reactors[0].Switch.Peers().List()[0]
-	ps := peerState{height2}
+	ps := testPeerState{height2}
 	peer.Set(types.PeerStateKey, ps)
 
 	// send a bunch of valid evidence to the first reactor's evpool

state/state_test.go

@@ -4,6 +4,7 @@ import (
 	"bytes"
 	"fmt"
 	"testing"
+	"time"
 
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
@@ -12,6 +13,7 @@ import (
 	"github.com/tendermint/tendermint/crypto/ed25519"
 	cmn "github.com/tendermint/tendermint/libs/common"
 	dbm "github.com/tendermint/tendermint/libs/db"
+	tmtime "github.com/tendermint/tendermint/types/time"
 
 	cfg "github.com/tendermint/tendermint/config"
 	"github.com/tendermint/tendermint/types"
@@ -386,14 +388,14 @@ func TestConsensusParamsChangesSaveLoad(t *testing.T) {
 	}
 }
 
-func makeParams(blockBytes, blockGas, evidenceAge int64) types.ConsensusParams {
+func makeParams(blockBytes, blockGas int64, evidenceAge time.Duration) types.ConsensusParams {
 	return types.ConsensusParams{
 		BlockSize: types.BlockSize{
 			MaxBytes: blockBytes,
 			MaxGas:   blockGas,
 		},
 		EvidenceParams: types.EvidenceParams{
-			MaxAge: evidenceAge,
+			MaxAge: tmtime.DurationPretty{evidenceAge},
 		},
 	}
 }
@@ -403,7 +405,7 @@ func pk() []byte {
 }
 
 func TestApplyUpdates(t *testing.T) {
-	initParams := makeParams(1, 2, 3)
+	initParams := makeParams(1, 2, 3*time.Second)
 
 	cases := [...]struct {
 		init     types.ConsensusParams
@@ -419,14 +421,14 @@ func TestApplyUpdates(t *testing.T) {
 					MaxGas:   55,
 				},
 			},
-			makeParams(44, 55, 3)},
+			makeParams(44, 55, 3*time.Second)},
 		3: {initParams,
 			abci.ConsensusParams{
 				EvidenceParams: &abci.EvidenceParams{
-					MaxAge: 66,
+					MaxAge: 66 * time.Second,
 				},
 			},
-			makeParams(1, 2, 66)},
+			makeParams(1, 2, 66*time.Second)},
 	}
 
 	for i, tc := range cases {

state/validation.go

@@ -168,13 +168,11 @@ func validateBlock(stateDB dbm.DB, state State, block *types.Block) error {
 // - it is internally consistent
 // - it was properly signed by the alleged equivocator
 func VerifyEvidence(stateDB dbm.DB, state State, evidence types.Evidence) error {
-	height := state.LastBlockHeight
-
-	evidenceAge := height - evidence.Height()
-	maxAge := state.ConsensusParams.EvidenceParams.MaxAge
+	evidenceAge := state.LastBlockTime.Sub(evidence.Time())
+	maxAge := state.ConsensusParams.EvidenceParams.MaxAge.Duration
 	if evidenceAge > maxAge {
-		return fmt.Errorf("Evidence from height %d is too old. Min height is %d",
-			evidence.Height(), height-maxAge)
+		return fmt.Errorf("Evidence from %v is too old. Expecting evidence no older than %v",
+			evidence.Time(), state.LastBlockTime.Add(-maxAge))
 	}
 
 	valset, err := LoadValidators(stateDB, evidence.Height())

types/evidence.go

@@ -3,8 +3,10 @@ package types
 import (
 	"bytes"
 	"fmt"
+	"time"
 
 	"github.com/tendermint/tendermint/crypto/tmhash"
+	tmtime "github.com/tendermint/tendermint/types/time"
 
 	amino "github.com/tendermint/go-amino"
 
@@ -54,6 +56,7 @@ func (err *ErrEvidenceOverflow) Error() string {
 // Evidence represents any provable malicious activity by a validator
 type Evidence interface {
 	Height() int64                                     // height of the equivocation
+	Time() time.Time                                   // when the evidence was created
 	Address() []byte                                   // address of the equivocating validator
 	Bytes() []byte                                     // bytes which compromise the evidence
 	Hash() []byte                                      // hash of the evidence
@@ -102,6 +105,11 @@ func (dve *DuplicateVoteEvidence) Height() int64 {
 	return dve.VoteA.Height
 }
 
+// Time returns the time when the evidence was created.
+func (dve *DuplicateVoteEvidence) Time() time.Time {
+	return dve.VoteA.Timestamp
+}
+
 // Address returns the address of the validator.
 func (dve *DuplicateVoteEvidence) Address() []byte {
 	return dve.PubKey.Address()
@@ -188,6 +196,7 @@ func NewMockGoodEvidence(height int64, idx int, address []byte) MockGoodEvidence
 }
 
 func (e MockGoodEvidence) Height() int64   { return e.Height_ }
+func (e MockGoodEvidence) Time() time.Time { return tmtime.Now() }
 func (e MockGoodEvidence) Address() []byte { return e.Address_ }
 func (e MockGoodEvidence) Hash() []byte {
 	return []byte(fmt.Sprintf("%d-%x", e.Height_, e.Address_))

types/params.go

@@ -1,9 +1,12 @@
 package types
 
 import (
+	"time"
+
 	abci "github.com/tendermint/tendermint/abci/types"
 	"github.com/tendermint/tendermint/crypto/tmhash"
 	cmn "github.com/tendermint/tendermint/libs/common"
+	tmtime "github.com/tendermint/tendermint/types/time"
 )
 
 const (
@@ -29,7 +32,7 @@ type BlockSize struct {
 
 // EvidenceParams determine how we handle evidence of malfeasance
 type EvidenceParams struct {
-	MaxAge int64 `json:"max_age"` // only accept new evidence more recent than this
+	MaxAge tmtime.DurationPretty `json:"max_age"` // only accept new evidence more recent than this
 }
 
 // DefaultConsensusParams returns a default ConsensusParams.
@@ -51,7 +54,7 @@ func DefaultBlockSize() BlockSize {
 // DefaultEvidenceParams Params returns a default EvidenceParams.
 func DefaultEvidenceParams() EvidenceParams {
 	return EvidenceParams{
-		MaxAge: 100000, // 27.8 hrs at 1block/s
+		MaxAge: tmtime.DurationPretty{48 * time.Hour},
 	}
 }
 
@@ -72,9 +75,9 @@ func (params *ConsensusParams) Validate() error {
 			params.BlockSize.MaxGas)
 	}
 
-	if params.EvidenceParams.MaxAge <= 0 {
+	if params.EvidenceParams.MaxAge.Duration <= 0 {
 		return cmn.NewError("EvidenceParams.MaxAge must be greater than 0. Got %d",
-			params.EvidenceParams.MaxAge)
+			params.EvidenceParams.MaxAge.Duration)
 	}
 
 	return nil
@@ -109,7 +112,7 @@ func (params ConsensusParams) Update(params2 *abci.ConsensusParams) ConsensusPar
 		res.BlockSize.MaxGas = params2.BlockSize.MaxGas
 	}
 	if params2.EvidenceParams != nil {
-		res.EvidenceParams.MaxAge = params2.EvidenceParams.MaxAge
+		res.EvidenceParams.MaxAge = tmtime.DurationPretty{params2.EvidenceParams.MaxAge}
 	}
 	return res
 }

types/params_test.go

@@ -4,9 +4,11 @@ import (
 	"bytes"
 	"sort"
 	"testing"
+	"time"
 
 	"github.com/stretchr/testify/assert"
 	abci "github.com/tendermint/tendermint/abci/types"
+	tmtime "github.com/tendermint/tendermint/types/time"
 )
 
 func TestConsensusParamsValidation(t *testing.T) {
@@ -15,17 +17,17 @@ func TestConsensusParamsValidation(t *testing.T) {
 		valid  bool
 	}{
 		// test block size
-		0: {makeParams(1, 0, 1), true},
-		1: {makeParams(0, 0, 1), false},
-		2: {makeParams(47*1024*1024, 0, 1), true},
-		3: {makeParams(10, 0, 1), true},
-		4: {makeParams(100*1024*1024, 0, 1), true},
-		5: {makeParams(101*1024*1024, 0, 1), false},
-		6: {makeParams(1024*1024*1024, 0, 1), false},
-		7: {makeParams(1024*1024*1024, 0, -1), false},
+		0: {makeParams(1, 0, 10*time.Second), true},
+		1: {makeParams(0, 0, 10*time.Second), false},
+		2: {makeParams(47*1024*1024, 0, 10*time.Second), true},
+		3: {makeParams(10, 0, 10*time.Second), true},
+		4: {makeParams(100*1024*1024, 0, 10*time.Second), true},
+		5: {makeParams(101*1024*1024, 0, 10*time.Second), false},
+		6: {makeParams(1024*1024*1024, 0, 10*time.Second), false},
+		7: {makeParams(1024*1024*1024, 0, -10*time.Second), false},
 		// test evidence age
 		8: {makeParams(1, 0, 0), false},
-		9: {makeParams(1, 0, -1), false},
+		9: {makeParams(1, 0, -1*time.Millisecond), false},
 	}
 	for i, tc := range testCases {
 		if tc.valid {
@@ -36,28 +38,23 @@ func TestConsensusParamsValidation(t *testing.T) {
 	}
 }
 
-func makeParams(blockBytes, blockGas, evidenceAge int64) ConsensusParams {
+func makeParams(blockBytes, blockGas int64, evidenceAge time.Duration) ConsensusParams {
 	return ConsensusParams{
 		BlockSize: BlockSize{
 			MaxBytes: blockBytes,
 			MaxGas:   blockGas,
 		},
 		EvidenceParams: EvidenceParams{
-			MaxAge: evidenceAge,
+			MaxAge: tmtime.DurationPretty{evidenceAge},
 		},
 	}
 }
 
 func TestConsensusParamsHash(t *testing.T) {
 	params := []ConsensusParams{
-		makeParams(4, 2, 3),
-		makeParams(1, 4, 3),
-		makeParams(1, 2, 4),
-		makeParams(2, 5, 7),
-		makeParams(1, 7, 6),
-		makeParams(9, 5, 4),
-		makeParams(7, 8, 9),
-		makeParams(4, 6, 5),
+		makeParams(4, 2, 3*time.Second),
+		makeParams(1, 4, 3*time.Second),
+		makeParams(1, 2, 4*time.Second),
 	}
 
 	hashes := make([][]byte, len(params))
@@ -83,23 +80,23 @@ func TestConsensusParamsUpdate(t *testing.T) {
 	}{
 		// empty updates
 		{
-			makeParams(1, 2, 3),
+			makeParams(1, 2, 3*time.Second),
 			&abci.ConsensusParams{},
-			makeParams(1, 2, 3),
+			makeParams(1, 2, 3*time.Second),
 		},
 		// fine updates
 		{
-			makeParams(1, 2, 3),
+			makeParams(1, 2, 3*time.Second),
 			&abci.ConsensusParams{
 				BlockSize: &abci.BlockSize{
 					MaxBytes: 100,
 					MaxGas:   200,
 				},
 				EvidenceParams: &abci.EvidenceParams{
-					MaxAge: 300,
+					MaxAge: 300 * time.Second,
 				},
 			},
-			makeParams(100, 200, 300),
+			makeParams(100, 200, 300*time.Second),
 		},
 	}
 	for _, tc := range testCases {

types/protobuf.go

@@ -9,6 +9,7 @@ import (
 	"github.com/tendermint/tendermint/crypto"
 	"github.com/tendermint/tendermint/crypto/ed25519"
 	"github.com/tendermint/tendermint/crypto/secp256k1"
+	tmtime "github.com/tendermint/tendermint/types/time"
 )
 
 //-------------------------------------------------------
@@ -119,7 +120,7 @@ func (tm2pb) ConsensusParams(params *ConsensusParams) *abci.ConsensusParams {
 			MaxGas:   params.BlockSize.MaxGas,
 		},
 		EvidenceParams: &abci.EvidenceParams{
-			MaxAge: params.EvidenceParams.MaxAge,
+			MaxAge: params.EvidenceParams.MaxAge.Duration,
 		},
 	}
 }
@@ -209,13 +210,18 @@ func (pb2tm) ValidatorUpdates(vals []abci.ValidatorUpdate) ([]*Validator, error)
 }
 
 func (pb2tm) ConsensusParams(csp *abci.ConsensusParams) ConsensusParams {
-	return ConsensusParams{
-		BlockSize: BlockSize{
+	params := ConsensusParams{}
+
+	// we must defensively consider any structs may be nil
+	if csp.BlockSize != nil {
+		params.BlockSize = BlockSize{
 			MaxBytes: csp.BlockSize.MaxBytes,
 			MaxGas:   csp.BlockSize.MaxGas,
-		},
-		EvidenceParams: EvidenceParams{
-			MaxAge: csp.EvidenceParams.MaxAge,
-		},
+		}
 	}
+	if csp.EvidenceParams != nil {
+		params.EvidenceParams.MaxAge = tmtime.DurationPretty{csp.EvidenceParams.MaxAge}
+	}
+
+	return params
 }

types/protobuf_test.go

@@ -68,7 +68,7 @@ func TestABCIValidators(t *testing.T) {
 
 func TestABCIConsensusParams(t *testing.T) {
 	cp := DefaultConsensusParams()
-	cp.EvidenceParams.MaxAge = 0 // TODO add this to ABCI
+	cp.EvidenceParams.MaxAge.Duration = 0 // TODO add this to ABCI
 	abciCP := TM2PB.ConsensusParams(cp)
 	cp2 := PB2TM.ConsensusParams(abciCP)
 

types/time/duration.go

@@ -0,0 +1,41 @@
+package time
+
+import (
+	"encoding/json"
+	"errors"
+	"time"
+)
+
+// DurationPretty is a wrapper around time.Duration implementing custom
+// marshaller/unmarshaller which make it pretty (e.g. "10s", not
+// "10000000000").
+type DurationPretty struct {
+	time.Duration
+}
+
+// MarshalJSON implements json.Marshaller.
+func (d DurationPretty) MarshalJSON() ([]byte, error) {
+	return json.Marshal(d.String())
+}
+
+// UnmarshalJSON implements json.Unmarshaller.
+func (d *DurationPretty) UnmarshalJSON(b []byte) error {
+	var v interface{}
+	if err := json.Unmarshal(b, &v); err != nil {
+		return err
+	}
+	switch value := v.(type) {
+	case float64:
+		d.Duration = time.Duration(value)
+		return nil
+	case string:
+		var err error
+		d.Duration, err = time.ParseDuration(value)
+		if err != nil {
+			return err
+		}
+		return nil
+	default:
+		return errors.New("invalid duration")
+	}
+}

types/time/duration_test.go

@@ -0,0 +1,31 @@
+package time
+
+import (
+	"testing"
+	"time"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestDurationPretty(t *testing.T) {
+	testCases := []struct {
+		jsonBytes []byte
+		expErr    bool
+		expValue  time.Duration
+	}{
+		{[]byte(`"10s"`), false, 10 * time.Second},
+		{[]byte(`"48h0m0s"`), false, 48 * time.Hour},
+		{[]byte(`"10kkk"`), true, 0},
+		{[]byte(`"kkk"`), true, 0},
+	}
+
+	for i, tc := range testCases {
+		var d DurationPretty
+		if tc.expErr {
+			assert.Error(t, d.UnmarshalJSON(tc.jsonBytes), "#%d", i)
+		} else {
+			assert.NoError(t, d.UnmarshalJSON(tc.jsonBytes), "#%d", i)
+			assert.Equal(t, tc.expValue, d.Duration, "#%d", i)
+		}
+	}
+}