Messages in this thread | | | Date | Tue, 8 Nov 2016 09:26:26 -0800 | From | Eric Biggers <> | Subject | Re: [PATCH v4] poly1305: generic C can be faster on chips with slow unaligned access |
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On Tue, Nov 08, 2016 at 08:52:39AM +0100, Martin Willi wrote: > > > Not sure what the exact alignment rules for key/iv are, but maybe we > want to replace the same function in chacha20_generic.c as well? > > Martin
chacha20-generic provides a blkcipher API and sets an alignmask of sizeof(u32) - 1. This applies to the key buffer for ->setkey() and to the mapped addresses for the input/output buffers and IV during the blkcipher walk. So it does not appear to have the problems that poly1305 has.
I do however see one small problem which is that 'u8 stream[CHACHA20_BLOCK_SIZE];' is, strictly speaking, not guaranteed to be aligned to u32.
Eric
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