On Fri, Sep 25, 2020 at 11:04 AM Jeffrey Walton <[email protected]> wrote: > > On Fri, Sep 25, 2020 at 10:25 AM Niels Möller <[email protected]> wrote: > > > > Jeffrey Walton <[email protected]> writes: > > ... > It should be easy enough to test. Start with a counter of 0xfffffff8 > and encrypt a couple of [64-byte] blocks. You can use Bernstein's > reference implementation to generate test vectors.[1]
My bad. Start with a counter of 0xfffffff8 and encrypt or decrypt 16*64 bytes. That will get you into the corner case. > Here's a hacked version of Bernstein's code that allows you to set the > counter to something other than 0's: > https://github.com/noloader/cryptopp-test/blob/master/ChaCha20/chacha.c. > See the XXX_ctr_setup function. While not obvious, setting the counter is how you seek in the ChaCha stream. It allows you to encrypt or decrypt an arbitrary block of 64-bytes. Jeff _______________________________________________ nettle-bugs mailing list [email protected] http://lists.lysator.liu.se/mailman/listinfo/nettle-bugs
