HashML-DSA: Replace enum by define to pick pre-hash function #605
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jakemas
approved these changes
Nov 4, 2025
Currently we have an enum for the 12 different pre-hash functions for HashML-DSA. This leads to problems in multi-level builds as we must only define the enum once. Currently we work around this by guarding the enum definition with a pre-processor conditional. However, there is also a (theoretical) concern about the type of the enum being implementation-defined in C90: #537 (comment) It seems cleaner to not use an enum here, but instead use #defines avoiding all the above problems. This commit implements that change. We also eliminate the camel case hashAlg - that was inconsistent with the remaining code base from the start. Resolves #591 Signed-off-by: Matthias J. Kannwischer <[email protected]>
hanno-becker
reviewed
Nov 5, 2025
hanno-becker
approved these changes
Nov 5, 2025
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Thank you @mkannwischer. An enum would conceptually be the right choice here, but we don't use them anywhere else and (further) complicating the multilevel build for it does not seem worth it.
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Currently we have an enum for the 12 different pre-hash functions for HashML-DSA. This leads to problems in multi-level builds as we must only define the enum once. Currently we work around this by guarding the enum definition with a pre-processor conditional.
However, there is also a (theoretical) concern about the type of the enum being implementation-defined in C90:
#537 (comment)
It seems cleaner to not use an enum here, but instead use #defines avoiding all the above problems.
This commit implements that change.
We also eliminate the camel case hashAlg - that was inconsistent with the remaining code base from the start.