crypto: chacha20-generic - refactor to allow varying number of rounds
authorEric Biggers <ebiggers@google.com>
Sat, 17 Nov 2018 01:26:21 +0000 (17:26 -0800)
committerHerbert Xu <herbert@gondor.apana.org.au>
Tue, 20 Nov 2018 06:26:55 +0000 (14:26 +0800)
commit1ca1b917940c24ca3d1f490118c5474168622953
tree26cde5a85d0792a8dd709a6f5316f76af8801a35
parentde61d7ae5d3789dcba3749a418f76613fbee8414
crypto: chacha20-generic - refactor to allow varying number of rounds

In preparation for adding XChaCha12 support, rename/refactor
chacha20-generic to support different numbers of rounds.  The
justification for needing XChaCha12 support is explained in more detail
in the patch "crypto: chacha - add XChaCha12 support".

The only difference between ChaCha{8,12,20} are the number of rounds
itself; all other parts of the algorithm are the same.  Therefore,
remove the "20" from all definitions, structures, functions, files, etc.
that will be shared by all ChaCha versions.

Also make ->setkey() store the round count in the chacha_ctx (previously
chacha20_ctx).  The generic code then passes the round count through to
chacha_block().  There will be a ->setkey() function for each explicitly
allowed round count; the encrypt/decrypt functions will be the same.  I
decided not to do it the opposite way (same ->setkey() function for all
round counts, with different encrypt/decrypt functions) because that
would have required more boilerplate code in architecture-specific
implementations of ChaCha and XChaCha.

Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Martin Willi <martin@strongswan.org>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
16 files changed:
arch/arm/crypto/chacha20-neon-glue.c
arch/arm64/crypto/chacha20-neon-glue.c
arch/x86/crypto/chacha20_glue.c
crypto/Makefile
crypto/chacha20_generic.c [deleted file]
crypto/chacha20poly1305.c
crypto/chacha_generic.c [new file with mode: 0644]
drivers/char/random.c
drivers/crypto/caam/caamalg.c
drivers/crypto/caam/caamalg_qi2.c
drivers/crypto/caam/compat.h
include/crypto/chacha.h [new file with mode: 0644]
include/crypto/chacha20.h [deleted file]
lib/Makefile
lib/chacha.c [new file with mode: 0644]
lib/chacha20.c [deleted file]