parse call data from Card Manager

internal/common/calldata.go

@@ -14,7 +14,9 @@ var (
 	ErrNotTransfer     = errors.New("not a transfer")
 
 	executeSigSingle = crypto.Keccak256([]byte("execute(address,uint256,bytes)"))[:4]
-	transferSig      = crypto.Keccak256([]byte("transfer(address,uint256)"))[:4]
+
+	transferSig = crypto.Keccak256([]byte("transfer(address,uint256)"))[:4]
+	withdrawSig = crypto.Keccak256([]byte("withdraw(bytes32,address,address,uint256)"))[:4]
 )
 
 // ParseERC20Transfer parses the calldata of an ERC20 transfer from a smart contract Execute function
@@ -41,24 +43,52 @@ func ParseERC20Transfer(calldata []byte) (common.Address, common.Address, *big.I
 	// The third argument is the funcData, which starts 96 bytes offset from the start of the args
 	funcData := args[128:132]
 
+	// The first 4 bytes of the funcData is the transfer function selector
 	trfFuncSelector := funcData[:4]
-	if !bytes.Equal(trfFuncSelector, transferSig) {
-		return common.Address{}, common.Address{}, nil, ErrNotTransfer
-	}
 
-	funcArgs := args[132:]
+	// Depending on the function selector, the arguments are in different positions
+	switch string(trfFuncSelector) {
+	case string(transferSig):
+		// Standard ERC20 transfer
+		funcArgs := args[132:]
 
-	// The first argument of the funcData is the to address, which is 32 bytes offset from the start of the funcData
-	to := common.BytesToAddress(funcArgs[32-20 : 32])
-	if len(to.Bytes()) == 0 {
-		return common.Address{}, common.Address{}, nil, ErrInvalidCalldata
-	}
+		// The first argument of the funcData is the to address, which is 32 bytes offset from the start of the funcData
+		to := common.BytesToAddress(funcArgs[32-20 : 32])
+		if len(to.Bytes()) == 0 {
+			return common.Address{}, common.Address{}, nil, ErrInvalidCalldata
+		}
 
-	// The second argument of the funcData is the amount, which is 64 bytes offset from the start of the funcData
-	amount := new(big.Int).SetBytes(funcArgs[64-32 : 64])
-	if amount.Cmp(big.NewInt(0)) == 0 {
-		return common.Address{}, common.Address{}, nil, ErrInvalidCalldata
+		// The second argument of the funcData is the amount, which is 64 bytes offset from the start of the funcData
+		amount := new(big.Int).SetBytes(funcArgs[64-32 : 64])
+		if amount.Cmp(big.NewInt(0)) == 0 {
+			return common.Address{}, common.Address{}, nil, ErrInvalidCalldata
+		}
+
+		return dest, to, amount, nil
+	case string(withdrawSig):
+		// Withdraw function from the Card Manager
+		funcArgs := args[132:]
+
+		// The second argument of the funcData is the token address, which is 64 bytes offset from the start of the funcData
+		dest := common.BytesToAddress(funcArgs[64-20 : 64])
+		if len(dest.Bytes()) == 0 {
+			return common.Address{}, common.Address{}, nil, ErrInvalidCalldata
+		}
+
+		// The third argument of the funcData is the to address, which is 96 bytes offset from the start of the funcData
+		to := common.BytesToAddress(funcArgs[96-20 : 96])
+		if len(to.Bytes()) == 0 {
+			return common.Address{}, common.Address{}, nil, ErrInvalidCalldata
+		}
+
+		// The fourth argument of the funcData is the amount, which is 128 bytes offset from the start of the funcData
+		amount := new(big.Int).SetBytes(funcArgs[128-32 : 128])
+		if amount.Cmp(big.NewInt(0)) == 0 {
+			return common.Address{}, common.Address{}, nil, ErrInvalidCalldata
+		}
+
+		return dest, to, amount, nil
 	}
 
-	return dest, to, amount, nil
+	return common.Address{}, common.Address{}, nil, ErrNotTransfer
 }

internal/common/calldata_test.go

@@ -11,6 +11,7 @@ var testCases = []string{
 	"0x",
 	"0xb61d27f60000000000000000000000005815e61ef72c9e6107b5c5a05fd121f334f7a7f1000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000600000000000000000000000000000000000000000000000000000000000000044a9059cbb00000000000000000000000029d755c17df3ed2ecae6e42d694fb4f7e2ff6010000000000000000000000000000000000000000000000000000000000000000100000000000000000000000000000000000000000000000000000000",
 	"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",
+	"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",
 }
 
 type caseResult struct {
@@ -38,6 +39,11 @@ var expected = []caseResult{
 		Amount: big.NewInt(0),
 		Err:    ErrNotTransfer,
 	},
+	{
+		Dest:   common.HexToAddress("0x5815E61eF72c9E6107b5c5A05FD121F334f7a7f1"),
+		To:     common.HexToAddress("0xcfa21B33D304D57c4E964e3819588Eb5ac06B4D9"),
+		Amount: big.NewInt(1000000),
+	},
 }
 
 func TestParseERC20Transfer(t *testing.T) {