RFR: 8285493: ECC calculation error

[Xue-Lei Andrew Fan]

On Tue, 26 Apr 2022 21:02:49 GMT, Weijun Wang <weijun at openjdk.org> wrote:

> Only numbers from the same modular fields can be involved in arithmetic calculations. Add `assert` to guarantee this.
> 
> Also, found one broken case and rewrote it.

src/jdk.crypto.ec/share/classes/sun/security/ec/ECDSAOperations.java line 261:

> 259:         IntegerModuloP result = p1.asAffine().getX();
> 260:         b2a(result, orderField, temp1);
> 261:         return MessageDigest.isEqual(temp1, r);

I did not get the point of this update.  Is it the broken case you mentioned in the PR description?  What's the issue of the original code?

src/jdk.crypto.ec/share/classes/sun/security/ec/ECDSAOperations.java line 261:

> 259:         IntegerModuloP result = p1.asAffine().getX();
> 260:         b2a(result, orderField, temp1);
> 261:         return MessageDigest.isEqual(temp1, r);

I did not get the point of this update.  Is it the broken case you mentioned in the PR description?  What's the issue of the original code?

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PR: https://git.openjdk.java.net/jdk/pull/8409