WirePayForData with empty Message

[mpoke]

MsgWirePayForData.ValidateBasic doesn't check if msg.MessageSize == 0. As a result, a malicious user could spam the system with WirePayForData transactions with no data. Such attack is possible since the gas consumed per TXs is msg.MessageSize (there are no reads or writes to the store).

Suggestions:

• Add checks to invalidated WirePayForData transactions with MessageSize == 0
• Add to the amount of gas consumed a constant that doesn't depend on the MessageSize

[evan-forbes]

Great find! We definitely have to address the spamming issue, so I don't want to distract from that, but just to note that there is currently a very small base fee added by the default cosmos-sdk for all txs for signature verification and size of tx.

https://github.com/cosmos/cosmos-sdk/blob/fc7ee0bf1e4e6afef4aed98515d418281edb7e62/x/auth/ante/ante.go#L44

https://github.com/cosmos/cosmos-sdk/blob/fc7ee0bf1e4e6afef4aed98515d418281edb7e62/x/auth/ante/ante.go#L48

this is something that we have to consider when designing a goal base fee and proper resource allocation, which we still need to do a lot of work for celestiaorg/celestia-app#658

[mpoke]

there is currently a very small base fee added by the default cosmos-sdk for all txs for signature verification and size of tx.

https://github.com/cosmos/cosmos-sdk/blob/fc7ee0bf1e4e6afef4aed98515d418281edb7e62/x/auth/ante/ante.go#L44

https://github.com/cosmos/cosmos-sdk/blob/fc7ee0bf1e4e6afef4aed98515d418281edb7e62/x/auth/ante/ante.go#L48

Thanks. I was not aware of it, but I was hoping that something like this exists :)

[rootulp]

Add to the amount of gas consumed a constant that doesn't depend on the MessageSize

No longer seems necessary given the above

Add checks to invalidated WirePayForData transactions with MessageSize == 0

Added in celestiaorg/celestia-app#1083