Check staticcall Result From SHA-256 Precompile
#457
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This PR changes the `_sha256` implementation to check the result from the static call. There is a very subtle bug with not checking, where, for very large inputs, you would be able to get the precompile to revert but have the function finish executing successfully (and use whatever is in the scratch space as the digest). Note that **we do not check the length of the `returndata`**. This is intentional and the same thing that the Solidity compiler does for the builtin `sha256` function.
nlordell
requested review from
akshay-ap,
mmv08 and
remedcu
and removed request for
a team
mmv08
approved these changes
Jul 5, 2024
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Fixes hats-finance#14, also see hats-finance#22 for some additional context.
This PR changes the
_sha256implementation to check the result from the static call. There is a very subtle bug with not checking, where, for very large inputs, you would be able to get the precompile to revert but have the function finish executing successfully (and use whatever is in the scratch space as the digest).Note that we do not check the length of the
returndata. This is intentional and the same thing that the Solidity compiler does for the builtinsha256function.