internal/ed25519strict verifies the author signature of alg 1 with the
strict profile of the spec v0.11 draft (29.9): A canonical and not of
small order, checked with an encoding check and the table of the eight
points of small order, then crypto/ed25519 for S, R and the equation
without the cofactor. No arithmetic on points and no new module.
testdata/vectors/ed25519_strict.json has 18 signatures after the cases of
«Taming the many EdDSAs», built by testkit with arithmetic on the curve in
math/big, only for the vectors, which also checks the table of small
order. crypto/ed25519 accepts 11 of them that the profile rejects: the
eight points of small order and the non-canonical keys as A.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
dev
c402857b95