Context

We previously did not check if an input array was of the expected length in the verify_shard function from src/lib_crypto_dal.

The problem is that the following assert [https://gitlab.com/tezos/tezos/-/blob/master/src/lib_crypto_dal/cryptobox.ml#L1499] is called with an array evaluations whose length doesn't equal the one from domain. The domain array is initialized with the length t.shard_length [https://gitlab.com/tezos/tezos/-/blob/master/src/lib_crypto_dal/cryptobox.ml#L1633], but we didn't check that the input evaluations array has the same length t.shard_length, thus the assert line 1499 is triggered.

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Edited May 22, 2023 by Julien Coolen