Issue 8

[Edward-Lo]

Description

There is a lack of sanity check in the ClaimFLM method of flamingo staking contract.

Staking/flamingo-contract-staking/flamingo-contract-staking/StakingReocrd.cs

    public static bool ClaimFLM(byte[] fromAddress, byte[] assetId, byte[] callingScript) 
    {
        if (!Runtime.CheckWitness(fromAddress)) return false;
        byte[] key = assetId.Concat(fromAddress);
        StakingReocrd stakingReocrd = (StakingReocrd)Storage.Get(key).Deserialize();
        if (!stakingReocrd.fromAddress.Equals(fromAddress))
        {   
            return false;
        }
        UpdateStackRecord(assetId, GetCurrentTimeStamp());
        BigInteger newProfit = SettleProfit(stakingReocrd.timeStamp, stakingReocrd.amount, assetId);
        var profitAmount = stakingReocrd.Profit + newProfit;
        SaveUserStaking(fromAddress, stakingReocrd.amount, stakingReocrd.assetId, Blockchain.GetHeight(), 0, key);
        if (!MintFLM(fromAddress, profitAmount, callingScript))    
        {
            return false;
        }
        return true;
    }        

ClaimFLM will try to combine assetId and fromAddress as a key to retrieve the StakingReocrd.

However, it doesn't check whether the record can be successfully retrieved, but tries to deserialize the result directly by calling Deserialize.

Recommendation

Staking/flamingo-contract-staking/flamingo-contract-staking/StakingReocrd.cs

    public static bool ClaimFLM(byte[] fromAddress, byte[] assetId, byte[] callingScript) 
    {
        if (!Runtime.CheckWitness(fromAddress)) return false;
        byte[] key = assetId.Concat(fromAddress);
        var result = Storage.Get(key);
        if (result.Length == 0) return false;
        StakingReocrd stakingReocrd = (StakingReocrd)result.Deserialize();
        if (!stakingReocrd.fromAddress.Equals(fromAddress))
        {   
            return false;
        }
        UpdateStackRecord(assetId, GetCurrentTimeStamp());
        BigInteger newProfit = SettleProfit(stakingReocrd.timeStamp, stakingReocrd.amount, assetId);
        var profitAmount = stakingReocrd.Profit + newProfit;
        SaveUserStaking(fromAddress, stakingReocrd.amount, stakingReocrd.assetId, Blockchain.GetHeight(), 0, key);
        if (!MintFLM(fromAddress, profitAmount, callingScript))    
        {
            return false;
        }
        return true;
    }