From d25ea6716a24128afa827b7d0637f360e3643c5f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Colin=20Axn=C3=A9r?=
 <25233464+colin-axner@users.noreply.github.com>
Date: Tue, 12 Oct 2021 12:09:15 +0200
Subject: [PATCH] add memo length validation

---
 modules/apps/27-interchain-accounts/types/packet.go   |  6 ++++++
 .../apps/27-interchain-accounts/types/packet_test.go  | 11 +++++++++++
 2 files changed, 17 insertions(+)

diff --git a/modules/apps/27-interchain-accounts/types/packet.go b/modules/apps/27-interchain-accounts/types/packet.go
index da3dd035783..d69dfebd30a 100644
--- a/modules/apps/27-interchain-accounts/types/packet.go
+++ b/modules/apps/27-interchain-accounts/types/packet.go
@@ -6,12 +6,18 @@ import (
 	sdkerrors "github.com/cosmos/cosmos-sdk/types/errors"
 )
 
+const MaxMemoCharLength = 256
+
 // ValidateBasic performs basic validation of the interchain account packet data.
 // The memo may be empty.
 func (iapd InterchainAccountPacketData) ValidateBasic() error {
 	if iapd.Data == nil {
 		return sdkerrors.Wrap(ErrInvalidOutgoingData, "packet data cannot be empty")
 	}
+
+	if len(iapd.Memo) > MaxMemoCharLength {
+		return sdkerrors.Wrapf(ErrInvalidOutgoingData, "packet data memo cannot be greater than %d characters", MaxMemoCharLength)
+	}
 	// TODO: add type validation when data type enum supports unspecified type
 
 	return nil
diff --git a/modules/apps/27-interchain-accounts/types/packet_test.go b/modules/apps/27-interchain-accounts/types/packet_test.go
index 9dc8eebfb34..ce2fab2f5ca 100644
--- a/modules/apps/27-interchain-accounts/types/packet_test.go
+++ b/modules/apps/27-interchain-accounts/types/packet_test.go
@@ -4,6 +4,8 @@ import (
 	"github.com/cosmos/ibc-go/v2/modules/apps/27-interchain-accounts/types"
 )
 
+var largeMemo = "Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum"
+
 func (suite *TypesTestSuite) TestValidateBasic() {
 	testCases := []struct {
 		name       string
@@ -36,6 +38,15 @@ func (suite *TypesTestSuite) TestValidateBasic() {
 			},
 			false,
 		},
+		{
+			"memo too large",
+			types.InterchainAccountPacketData{
+				Type: types.EXECUTE_TX,
+				Data: []byte("data"),
+				Memo: largeMemo,
+			},
+			false,
+		},
 	}
 
 	for _, tc := range testCases {