Cardano-node: [BUG] - 1.13.0: `cardano-api` doesn't prevent submission of transactions that would fail to deserialise

[deepfire]

Internal

Summary

TxSignedShelley transactions with TxOut's containing negative Coin values are perfectly serialisable and transmissible using the cardano-api -- only to be failing to deserialise in a most cryptic manner:

ApiErrorCBOR (DecoderErrorDeserialiseFailure \"TxSigned\" (DeserialiseFailure 80 \"expected word\"))

This can be observed locally, by using a Tx with negative coin values and performing a ser/des roundtrip: txSignedFromCBOR . txSignedToCBOR.

A Shown transaction, as well as it's CBOR-ised forms are attached.

cardano-api commit id is exactly 1.13.0: 9925ef37dccbe7f423f3ceb81a5e1da3d924393b.

Additional context

• TxSignedShelley.hs.txt

• TxSignedShelley.cbor.pretty.txt

• TxSignedShelley.cbor.txt

[erikd]

I think any attempt to encode a negative amount in a transaction should be rejected by the API as an error. In fact, not even at the API level, but in ledger-specs.

[dcoutts]

We can do this validation step in the cardano-api tx construction, as part of the other sanity checks we have to do there (like Byron txs having the same number of witnesses as inputs).

[erikd]

But doesn't that sanity check belong in legder-specs ?

[bergr01]

{"at":"2020-06-21T23:36:38.53Z","env":"1.13.0:25efa","ns":["cardano.node.ChainDB"],"data":{"snapshot":{"snapshot":"DiskSnapshot 84","kind":"snapshot"},"kind":"TraceLedgerEvent.InvalidSnapshot","failure":"InitFailureRead (ReadFailed (DeserialiseFailure 334 \"An error occured while decoding Negative Coin.\nError: -2970552586033663663\"))"},"app":[],"msg":"","pid":"21865","loc":null,"host":"myserver","sev":"Error","thread":"33"}
{"at":"2020-06-21T23:36:38.54Z","env":"1.13.0:25efa","ns":["cardano.node.ChainDB"],"data":{"snapshot":{"snapshot":"DiskSnapshot 83","kind":"snapshot"},"kind":"TraceLedgerEvent.InvalidSnapshot","failure":"InitFailureRead (ReadFailed (DeserialiseFailure 334 \"An error occured while decoding Negative Coin.\nError: -2970247507364504374\"))"},"app":[],"msg":"","pid":"21865","loc":null,"host":"myserver","sev":"Error","thread":"33"}

Are the above errors related to/caused by this same issue?

[mrBliss]

{"at":"2020-06-21T23:36:38.53Z","env":"1.13.0:25efa","ns":["cardano.node.ChainDB"],"data":{"snapshot":{"snapshot":"DiskSnapshot 84","kind":"snapshot"},"kind":"TraceLedgerEvent.InvalidSnapshot","failure":"InitFailureRead (ReadFailed (DeserialiseFailure 334 "An error occured while decoding Negative Coin.\nError: -2970552586033663663"))"},"app":[],"msg":"","pid":"21865","loc":null,"host":"myserver","sev":"Error","thread":"33"}
{"at":"2020-06-21T23:36:38.54Z","env":"1.13.0:25efa","ns":["cardano.node.ChainDB"],"data":{"snapshot":{"snapshot":"DiskSnapshot 83","kind":"snapshot"},"kind":"TraceLedgerEvent.InvalidSnapshot","failure":"InitFailureRead (ReadFailed (DeserialiseFailure 334 "An error occured while decoding Negative Coin.\nError: -2970247507364504374"))"},"app":[],"msg":"","pid":"21865","loc":null,"host":"myserver","sev":"Error","thread":"33"}

Are the above errors related to/caused by this same issue?

Indeed. (See https://github.com/input-output-hk/cardano-node/issues/1312#issuecomment-647329374)