RFR: 8368841: X25519 implementation differs from the specification in RFC 7748 [v3]

[Shawn M Emery]

On Thu, 19 Feb 2026 20:03:25 GMT, Ben Perez <bperez at openjdk.org> wrote:

>> Our implementation of X25519 does not zero the MSB of the `u` coordinate as required by RFC 7748. Currently the test `jdk/sun/security/ec/xec/TestXDH.java` zeroes the bit manually while parsing test vectors, which is likely why this went uncaught.
>
> Ben Perez has updated the pull request incrementally with one additional commit since the last revision:
> 
>   removed parsing functionality in TestXDH that manually clears MSB

Thank you for the changes.

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Marked as reviewed by smemery at github.com (no known OpenJDK username).

PR Review: https://git.openjdk.org/jdk/pull/29750#pullrequestreview-3828946573