Reject MLD_PREHASH_NONE in prehash APIs#1228
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Signed-off-by: Fredrik Dahlgren <fredrik.dahlgren@trailofbits.com>
Signed-off-by: Fredrik Dahlgren <fredrik.dahlgren@trailofbits.com>
This was referenced Jun 26, 2026
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CBMC Results (ML-DSA-65, REDUCE-RAM)Full Results (205 proofs)
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CBMC Results (ML-DSA-44, REDUCE-RAM)Full Results (205 proofs)
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CBMC Results (ML-DSA-87, REDUCE-RAM)Full Results (205 proofs)
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CBMC Results (ML-DSA-65)Full Results (205 proofs)
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Contributor
CBMC Results (ML-DSA-44)Full Results (205 proofs)
|
Contributor
CBMC Results (ML-DSA-87)Full Results (205 proofs)
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| MLD_CT_TESTING_DECLASSIFY(&rc, sizeof(rc)); | ||
| MLD_CT_TESTING_DECLASSIFY(&siglen, sizeof(siglen)); |
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I don't those declassifications are necessary? Those values should be public already, I believe.
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| CHECK(randombytes(ph1, sizeof(ph1)) == 0); | ||
| MLD_CT_TESTING_SECRET(ph1, sizeof(ph1)); | ||
| CHECK(randombytes(ph2, sizeof(ph2)) == 0); | ||
| MLD_CT_TESTING_SECRET(ph2, sizeof(ph2)); |
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What's the difference between the tests exercising ph1 vs. ph2?
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| * Supported hash algorithm constants: | ||
| * MLD_PREHASH_SHA2_224, MLD_PREHASH_SHA2_256, MLD_PREHASH_SHA2_384, | ||
| * MLD_PREHASH_SHA2_512, MLD_PREHASH_SHA2_512_224, MLD_PREHASH_SHA2_512_256, | ||
| * MLD_PREHASH_SHA3_224, MLD_PREHASH_SHA3_256, MLD_PREHASH_SHA3_384, | ||
| * MLD_PREHASH_SHA3_512, MLD_PREHASH_SHAKE_128, MLD_PREHASH_SHAKE_256. | ||
| * MLD_PREHASH_NONE is rejected by this HashML-DSA API. |
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Nit: This is still indented under the Supported hash algorithm constants: block.
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| * MLD_PREHASH_NONE is rejected by this HashML-DSA API. | |
| * Supported hash algorithm constants: | |
| * MLD_PREHASH_SHA2_224, MLD_PREHASH_SHA2_256, MLD_PREHASH_SHA2_384, | |
| * MLD_PREHASH_SHA2_512, MLD_PREHASH_SHA2_512_224, MLD_PREHASH_SHA2_512_256, | |
| * MLD_PREHASH_SHA3_224, MLD_PREHASH_SHA3_256, MLD_PREHASH_SHA3_384, | |
| * MLD_PREHASH_SHA3_512, MLD_PREHASH_SHAKE_128, MLD_PREHASH_SHAKE_256. | |
| * | |
| * MLD_PREHASH_NONE is rejected by this API. |
hanno-becker
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Jun 27, 2026
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Thank you @fegge, I support this change.
Minor nit regarding the documentation, and I believe the test can be simplified -- see comments.
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Summary
MLD_PREHASH_NONEin the unstable pre-hash signing and verification APIs.MLD_PREHASH_NONEis not supported by these HashML-DSA entry points.Validation
clang-format -i mldsa/src/sign.c mldsa/src/sign.h mldsa/mldsa_native.h test/src/test_mldsa.c: passedgit diff --check -- mldsa/src/sign.c mldsa/src/sign.h mldsa/mldsa_native.h test/src/test_mldsa.c: passedmake run_func -j4: passed./scripts/formatbecausenixpkgs-fmtis not installed in this local environment./scripts/lintbecauseshfmtis not installed in this local environmentFixes #1215
This work was completed by Trail of Bits as part of the Patch The Planet project in collaboration with OpenAI. The issue was identified primarily by the Codex coding agent, and manually reviewed before submission.