EC JWK 'x' and 'y' param leading zero padding bug

[Vladimir Dzhuvinov]

Reported by email:

---

From: Anders Rundgren Subject: EC JWK Bug in NimbusDS Date: Tue, 21 Jan 2014 13:28:24 +0100 (01/21/2014 02:28:24 PM)

Hi Vladimir, I may have accidentally found a bug in NimbusDS.

http://www.ietf.org/mail-archive/web/jose/current/msg03901.html

Cheers, Anders

[Vladimir Dzhuvinov]

Further comments and suggestions from Anders:

---

My fix to the problem was using a table:

https://code.google.com/p/openkeystore/source/browse/javascript/trunk/src/crypto/KeySerializing.js

I.e. if you know the curve you can from a table find how long a coordinate is supposed to be and then pad it to the proper length.

---

Hi Vladimir, I enclosed a bunch of such from my tests. Note that the JSON keys are not following JWK but the line below is a genuine SPKI.

I think the fix is finding the fieldsize : ((ECPublicKey)public_key).getParams ().getCurve ().getField ().getFieldSize ())

The number of bytes to output is: (fieldsize + 7)/8

Good luck!

Anders

[Vladimir Dzhuvinov]

Test vector fixed in commit 95d2a1e, merging with master branch.