feat!: make grant expiration optional (#11060)

## Description

Closes: #11095 



---

### Author Checklist

*All items are required. Please add a note to the item if the item is not applicable and
please add links to any relevant follow up issues.*

I have...

- [ ] included the correct [type prefix](https://github.com/commitizen/conventional-commit-types/blob/v3.0.0/index.json) in the PR title
- [ ] added `!` to the type prefix if API or client breaking change
- [ ] targeted the correct branch (see [PR Targeting](https://github.com/cosmos/cosmos-sdk/blob/master/CONTRIBUTING.md#pr-targeting))
- [ ] provided a link to the relevant issue or specification
- [ ] followed the guidelines for [building modules](https://github.com/cosmos/cosmos-sdk/blob/master/docs/building-modules)
- [ ] included the necessary unit and integration [tests](https://github.com/cosmos/cosmos-sdk/blob/master/CONTRIBUTING.md#testing)
- [ ] added a changelog entry to `CHANGELOG.md`
- [ ] included comments for [documenting Go code](https://blog.golang.org/godoc)
- [ ] updated the relevant documentation or specification
- [ ] reviewed "Files changed" and left comments if necessary
- [ ] confirmed all CI checks have passed

### Reviewers Checklist

*All items are required. Please add a note if the item is not applicable and please add
your handle next to the items reviewed if you only reviewed selected items.*

I have...

- [ ] confirmed the correct [type prefix](https://github.com/commitizen/conventional-commit-types/blob/v3.0.0/index.json) in the PR title
- [ ] confirmed `!` in the type prefix if API or client breaking change
- [ ] confirmed all author checklist items have been addressed 
- [ ] reviewed state machine logic
- [ ] reviewed API design and naming
- [ ] reviewed documentation is accurate
- [ ] reviewed tests and test coverage
- [ ] manually tested (if applicable)

CHANGELOG.md

@@ -74,6 +74,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 * [\#11234](https://github.com/cosmos/cosmos-sdk/pull/11234) Add `GRPCClient` field to Client Context. If `GRPCClient` field is set to nil, the `Invoke` method would use ABCI query, otherwise use gprc.
 * [\#10962](https://github.com/cosmos/cosmos-sdk/pull/10962) ADR-040: Add state migration from iavl (v1Store) to smt (v2Store) 
 * (types) [\#10948](https://github.com/cosmos/cosmos-sdk/issues/10948) Add `app-db-backend` to the `app.toml` config to replace the compile-time `types.DBbackend` variable.
+* (authz)[\#11060](https://github.com/cosmos/cosmos-sdk/pull/11060) Support grant with no expire time.
 
 ### API Breaking Changes
 
@@ -142,6 +143,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 * (x/authz) [\#10447](https://github.com/cosmos/cosmos-sdk/pull/10447) authz `NewGrant` takes a new argument: block time, to correctly validate expire time.
 * [\#10961](https://github.com/cosmos/cosmos-sdk/pull/10961) Support third-party modules to add extension snapshots to state-sync.
 * [\#11274](https://github.com/cosmos/cosmos-sdk/pull/11274) `types/errors.New` now is an alias for `types/errors.Register` and should only be used in initialization code.
+* (authz)[\#11060](https://github.com/cosmos/cosmos-sdk/pull/11060) `authz.NewMsgGrant` `expiration` is now a pointer. When `nil` is used then no expiration will be set (grant won't expire).
 
 
 ### Client Breaking Changes
@@ -161,6 +163,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 * [\#10625](https://github.com/cosmos/cosmos-sdk/pull/10625) Rename `--fee-account` CLI flag to `--fee-granter`
 * [\#10684](https://github.com/cosmos/cosmos-sdk/pull/10684) Rename `edit-validator` command's `--moniker` flag to `--new-moniker`
 * [\#11116](https://github.com/cosmos/cosmos-sdk/pull/11116) `software-upgrade` and `cancel-software-upgrade` gov proposal commands have changed to `legacy-software-upgrade` and `legacy-cancel-software-upgrade`.
+* (authz)[\#11060](https://github.com/cosmos/cosmos-sdk/pull/11060) Changed the default value of the `--expiration` `tx grant` CLI Flag: was now + 1year, update: null (no expire date).
 
 ### Improvements
 
@@ -250,6 +253,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 * [\#11019](https://github.com/cosmos/cosmos-sdk/pull/11019) Add `MsgCreatePermanentLockedAccount` and CLI method for creating permanent locked account
 * (x/feegrant) [\#10830](https://github.com/cosmos/cosmos-sdk/pull/10830) Expired allowances will be pruned from state.
 * (x/authz,x/feegrant) [\#11214](https://github.com/cosmos/cosmos-sdk/pull/11214) Fix Amino JSON encoding of authz and feegrant Msgs to be consistent with other modules.
+* (authz)[\#11060](https://github.com/cosmos/cosmos-sdk/pull/11060) Support grant with no expire time.
 
 ### Deprecated
 

proto/cosmos/authz/v1beta1/authz.proto

@@ -22,8 +22,11 @@ message GenericAuthorization {
 // Grant gives permissions to execute
 // the provide method with expiration time.
 message Grant {
-  google.protobuf.Any       authorization = 1 [(cosmos_proto.accepts_interface) = "Authorization"];
-  google.protobuf.Timestamp expiration    = 2 [(gogoproto.stdtime) = true, (gogoproto.nullable) = false];
+  google.protobuf.Any authorization = 1 [(cosmos_proto.accepts_interface) = "Authorization"];
+  // time when the grant will expire and will be pruned. If null, then the grant
+  // doesn't have a time expiration (other conditions  in `authorization`
+  // may apply to invalidate the grant)
+  google.protobuf.Timestamp expiration = 2 [(gogoproto.stdtime) = true, (gogoproto.nullable) = true];
 }
 
 // GrantAuthorization extends a grant with both the addresses of the grantee and granter.
@@ -33,11 +36,11 @@ message GrantAuthorization {
   string grantee = 2 [(cosmos_proto.scalar) = "cosmos.AddressString"];
 
   google.protobuf.Any       authorization = 3 [(cosmos_proto.accepts_interface) = "Authorization"];
-  google.protobuf.Timestamp expiration    = 4 [(gogoproto.nullable) = false, (gogoproto.stdtime) = true];
+  google.protobuf.Timestamp expiration    = 4 [(gogoproto.stdtime) = true];
 }
 
 // GrantQueueItem contains the list of TypeURL of a sdk.Msg.
 message GrantQueueItem {
   // msg_type_urls contains the list of TypeURL of a sdk.Msg.
-  repeated string msg_type_urls = 1; 
+  repeated string msg_type_urls = 1;
 }

x/authz/authorization_grant.go

@@ -9,27 +9,25 @@ import (
 	sdkerrors "github.com/cosmos/cosmos-sdk/types/errors"
 )
 
-// NewGrant returns new Grant. It returns an error if the expiration is before
-// the current block time, which is passed into the `blockTime` arg.
-func NewGrant(blockTime time.Time, a Authorization, expiration time.Time) (Grant, error) {
-	if !expiration.After(blockTime) {
+// NewGrant returns new Grant. Expiration is optional and noop if null.
+// It returns an error if the expiration is before the current block time,
+// which is passed into the `blockTime` arg.
+func NewGrant(blockTime time.Time, a Authorization, expiration *time.Time) (Grant, error) {
+	if expiration != nil && !expiration.After(blockTime) {
 		return Grant{}, sdkerrors.ErrInvalidRequest.Wrapf("expiration must be after the current block time (%v), got %v", blockTime.Format(time.RFC3339), expiration.Format(time.RFC3339))
 	}
-	g := Grant{
-		Expiration: expiration,
-	}
 	msg, ok := a.(proto.Message)
 	if !ok {
 		return Grant{}, sdkerrors.Wrapf(sdkerrors.ErrPackAny, "cannot proto marshal %T", a)
 	}
-
 	any, err := cdctypes.NewAnyWithValue(msg)
 	if err != nil {
 		return Grant{}, err
 	}
-	g.Authorization = any
-
-	return g, nil
+	return Grant{
+		Expiration:    expiration,
+		Authorization: any,
+	}, nil
 }
 
 var (

x/authz/authorization_grant_test.go

@@ -23,13 +23,14 @@ func TestNewGrant(t *testing.T) {
 		title     string
 		a         Authorization
 		blockTime time.Time
-		expire    time.Time
+		expire    *time.Time
 		err       string
 	}{
-		{"wrong expire time (1)", a, time.Unix(10, 0), time.Unix(8, 0), "expiration must be after"},
-		{"wrong expire time (2)", a, time.Unix(10, 0), time.Unix(10, 0), "expiration must be after"},
-		{"good expire time (1)", a, time.Unix(10, 0), time.Unix(10, 1), ""},
-		{"good expire time (2)", a, time.Unix(10, 0), time.Unix(11, 0), ""},
+		{"wrong expire time (1)", a, time.Unix(10, 0), unixTime(8, 0), "expiration must be after"},
+		{"wrong expire time (2)", a, time.Unix(10, 0), unixTime(10, 0), "expiration must be after"},
+		{"good expire time (1)", a, time.Unix(10, 0), unixTime(10, 1), ""},
+		{"good expire time (2)", a, time.Unix(10, 0), unixTime(11, 0), ""},
+		{"good expire time (nil)", a, time.Unix(10, 0), nil, ""},
 	}
 
 	for _, tc := range tcs {
@@ -41,3 +42,8 @@ func TestNewGrant(t *testing.T) {
 	}
 
 }
+
+func unixTime(s, ns int64) *time.Time {
+	t := time.Unix(s, ns)
+	return &t
+}