IF IBC 07

IF-IBC-07

ICS20 - Type mismatch for amount packet field between code and spec

Severity: Low
Type: Specification deviation
Difficulty: easy
Involved artifacts: ICS 20

Description

The ICS20 specification uses uint256 for FungibleTokenPacketData.Amount

interface FungibleTokenPacketData {
  denomination: string
  amount: uint256
  sender: string
  receiver: string
}

The code uses uint64

type FungibleTokenPacketData struct {
	// the token denomination to be transferred
	Denom string
	// the token amount to be transferred
	Amount uint64
	// the sender address
	Sender string
	// the recipient address on the destination chain
	Receiver string
}

The confusion is maybe due the coin type where the amount is a BigInt.

Problem Scenarios

The user might send an amount that is a bigger integer than accepted and have his/her transaction abort due to an overflow.

Recommendation

Change the spec.