feat: Add x/authz SendAuthorization AllowList (#12648)

## Description

Closes: #12609 



---

### Author Checklist

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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/main/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/main/docs/building-modules)
- [ ] included the necessary unit and integration [tests](https://github.com/cosmos/cosmos-sdk/blob/main/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

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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

@@ -39,6 +39,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 
 ### Features
 
+* (x/authz) [#12648](https://github.com/cosmos/cosmos-sdk/pull/12648) Add an allow list, an optional list of addresses allowed to receive bank assests via authz MsgSend grant.
 * (cli) [#12028](https://github.com/cosmos/cosmos-sdk/pull/12028) Add the `tendermint key-migrate` to perform Tendermint v0.35 DB key migration.
 * (sdk.Coins) [#12627](https://github.com/cosmos/cosmos-sdk/pull/12627) Make a Denoms method on sdk.Coins.
 
@@ -63,6 +64,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 
 ### API Breaking Changes
 
+* (x/bank) [#12648](https://github.com/cosmos/cosmos-sdk/pull/12648) `NewSendAuthorization` takes a new argument of  an optional list of addresses allowed to receive bank assests via authz MsgSend grant. You can pass `nil` for the same behavior as before, i.e. any recipient is allowed.
 * (x/bank) [\#12593](https://github.com/cosmos/cosmos-sdk/pull/12593) Add `SpendableCoin` method to `BaseViewKeeper`
 * (x/slashing) [#12581](https://github.com/cosmos/cosmos-sdk/pull/12581) Remove `x/slashing` legacy querier.
 * (types) [\#12355](https://github.com/cosmos/cosmos-sdk/pull/12355) Remove the compile-time `types.DBbackend` variable. Removes usage of the same in server/util.go

proto/cosmos/bank/v1beta1/authz.proto

@@ -16,4 +16,10 @@ message SendAuthorization {
 
   repeated cosmos.base.v1beta1.Coin spend_limit = 1
       [(gogoproto.nullable) = false, (gogoproto.castrepeated) = "github.com/cosmos/cosmos-sdk/types.Coins"];
+
+  // allow_list specifies an optional list of addresses to whom the grantee can send tokens on behalf of the 
+  // granter. If omitted, any recipient is allowed. 
+  //
+  // Since: cosmos-sdk 0.47
+  repeated string allow_list = 2;
 }

x/authz/client/cli/tx.go

@@ -26,6 +26,7 @@ const (
 	FlagExpiration        = "expiration"
 	FlagAllowedValidators = "allowed-validators"
 	FlagDenyValidators    = "deny-validators"
+	FlagAllowList         = "allow-list"
 	delegate              = "delegate"
 	redelegate            = "redelegate"
 	unbond                = "unbond"
@@ -93,7 +94,18 @@ Examples:
 					return fmt.Errorf("spend-limit should be greater than zero")
 				}
 
-				authorization = bank.NewSendAuthorization(spendLimit)
+				allowList, err := cmd.Flags().GetStringSlice(FlagAllowList)
+				if err != nil {
+					return err
+				}
+
+				allowed, err := bech32toAccAddresses(allowList)
+				if err != nil {
+					return err
+				}
+
+				authorization = bank.NewSendAuthorization(spendLimit, allowed)
+
 			case "generic":
 				msgType, err := cmd.Flags().GetString(FlagMsgType)
 				if err != nil {
@@ -140,12 +152,12 @@ Examples:
 					delegateLimit = &spendLimit
 				}
 
-				allowed, err := bech32toValidatorAddresses(allowValidators)
+				allowed, err := bech32toValAddresses(allowValidators)
 				if err != nil {
 					return err
 				}
 
-				denied, err := bech32toValidatorAddresses(denyValidators)
+				denied, err := bech32toValAddresses(denyValidators)
 				if err != nil {
 					return err
 				}
@@ -184,6 +196,7 @@ Examples:
 	cmd.Flags().String(FlagSpendLimit, "", "SpendLimit for Send Authorization, an array of Coins allowed spend")
 	cmd.Flags().StringSlice(FlagAllowedValidators, []string{}, "Allowed validators addresses separated by ,")
 	cmd.Flags().StringSlice(FlagDenyValidators, []string{}, "Deny validators addresses separated by ,")
+	cmd.Flags().StringSlice(FlagAllowList, []string{}, "Allowed addresses grantee is allowed to send funds separated by ,")
 	cmd.Flags().Int64(FlagExpiration, 0, "Expire time as Unix timestamp. Set zero (0) for no expiry. Default is 0.")
 	return cmd
 }
@@ -273,7 +286,8 @@ Example:
 	return cmd
 }
 
-func bech32toValidatorAddresses(validators []string) ([]sdk.ValAddress, error) {
+// bech32toValAddresses returns []ValAddress from a list of Bech32 string addresses.
+func bech32toValAddresses(validators []string) ([]sdk.ValAddress, error) {
 	vals := make([]sdk.ValAddress, len(validators))
 	for i, validator := range validators {
 		addr, err := sdk.ValAddressFromBech32(validator)
@@ -284,3 +298,16 @@ func bech32toValidatorAddresses(validators []string) ([]sdk.ValAddress, error) {
 	}
 	return vals, nil
 }
+
+// bech32toAccAddresses returns []AccAddress from a list of Bech32 string addresses.
+func bech32toAccAddresses(accAddrs []string) ([]sdk.AccAddress, error) {
+	addrs := make([]sdk.AccAddress, len(accAddrs))
+	for i, addr := range accAddrs {
+		accAddr, err := sdk.AccAddressFromBech32(addr)
+		if err != nil {
+			return nil, err
+		}
+		addrs[i] = accAddr
+	}
+	return addrs, nil
+}

x/authz/client/testutil/grpc.go

@@ -195,7 +195,7 @@ func (s *IntegrationTestSuite) TestQueryGranterGrantsGRPC() {
 			fmt.Sprintf("%s/cosmos/authz/v1beta1/grants/granter/%s", val.APIAddress, val.Address.String()),
 			false,
 			"",
-			7,
+			8,
 		},
 	}
 	for _, tc := range testCases {