openwrt/target/linux/generic/backport-5.4/080-wireguard-0005-crypto-arm64-chacha-depend-on-generic-chacha-library.patch
Jason A. Donenfeld 3888fa7880 kernel: 5.4: import wireguard backport
Rather than using the clunky, old, slower wireguard-linux-compat out of
tree module, this commit does a patch-by-patch backport of upstream's
wireguard to 5.4. This specific backport is in widespread use, being
part of SUSE's enterprise kernel, Oracle's enterprise kernel, Google's
Android kernel, Gentoo's distro kernel, and probably more I've forgotten
about. It's definately the "more proper" way of adding wireguard to a
kernel than the ugly compat.h hell of the wireguard-linux-compat repo.
And most importantly for OpenWRT, it allows using the same module
configuration code for 5.10 as for 5.4, with no need for bifurcation.

These patches are from the backport tree which is maintained in the
open here: https://git.zx2c4.com/wireguard-linux/log/?h=backport-5.4.y
I'll be sending PRs to update this as needed.

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
2021-02-26 20:41:01 +01:00

130 lines
4.4 KiB
Diff

From 527b7f4f3e244c58e07fdb7d850acb45821e1c52 Mon Sep 17 00:00:00 2001
From: Ard Biesheuvel <ardb@kernel.org>
Date: Fri, 8 Nov 2019 13:22:11 +0100
Subject: [PATCH 005/124] crypto: arm64/chacha - depend on generic chacha
library instead of crypto driver
commit c77da4867cbb7841177275dbb250f5c09679fae4 upstream.
Depend on the generic ChaCha library routines instead of pulling in the
generic ChaCha skcipher driver, which is more than we need, and makes
managing the dependencies between the generic library, generic driver,
accelerated library and driver more complicated.
While at it, drop the logic to prefer the scalar code on short inputs.
Turning the NEON on and off is cheap these days, and one major use case
for ChaCha20 is ChaCha20-Poly1305, which is guaranteed to hit the scalar
path upon every invocation (when doing the Poly1305 nonce generation)
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
---
arch/arm64/crypto/Kconfig | 2 +-
arch/arm64/crypto/chacha-neon-glue.c | 40 +++++++++++++++-------------
2 files changed, 23 insertions(+), 19 deletions(-)
--- a/arch/arm64/crypto/Kconfig
+++ b/arch/arm64/crypto/Kconfig
@@ -103,7 +103,7 @@ config CRYPTO_CHACHA20_NEON
tristate "ChaCha20, XChaCha20, and XChaCha12 stream ciphers using NEON instructions"
depends on KERNEL_MODE_NEON
select CRYPTO_BLKCIPHER
- select CRYPTO_CHACHA20
+ select CRYPTO_LIB_CHACHA_GENERIC
config CRYPTO_NHPOLY1305_NEON
tristate "NHPoly1305 hash function using NEON instructions (for Adiantum)"
--- a/arch/arm64/crypto/chacha-neon-glue.c
+++ b/arch/arm64/crypto/chacha-neon-glue.c
@@ -68,7 +68,7 @@ static int chacha_neon_stream_xor(struct
err = skcipher_walk_virt(&walk, req, false);
- crypto_chacha_init(state, ctx, iv);
+ chacha_init_generic(state, ctx->key, iv);
while (walk.nbytes > 0) {
unsigned int nbytes = walk.nbytes;
@@ -76,10 +76,16 @@ static int chacha_neon_stream_xor(struct
if (nbytes < walk.total)
nbytes = rounddown(nbytes, walk.stride);
- kernel_neon_begin();
- chacha_doneon(state, walk.dst.virt.addr, walk.src.virt.addr,
- nbytes, ctx->nrounds);
- kernel_neon_end();
+ if (!crypto_simd_usable()) {
+ chacha_crypt_generic(state, walk.dst.virt.addr,
+ walk.src.virt.addr, nbytes,
+ ctx->nrounds);
+ } else {
+ kernel_neon_begin();
+ chacha_doneon(state, walk.dst.virt.addr,
+ walk.src.virt.addr, nbytes, ctx->nrounds);
+ kernel_neon_end();
+ }
err = skcipher_walk_done(&walk, walk.nbytes - nbytes);
}
@@ -91,9 +97,6 @@ static int chacha_neon(struct skcipher_r
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
struct chacha_ctx *ctx = crypto_skcipher_ctx(tfm);
- if (req->cryptlen <= CHACHA_BLOCK_SIZE || !crypto_simd_usable())
- return crypto_chacha_crypt(req);
-
return chacha_neon_stream_xor(req, ctx, req->iv);
}
@@ -105,14 +108,15 @@ static int xchacha_neon(struct skcipher_
u32 state[16];
u8 real_iv[16];
- if (req->cryptlen <= CHACHA_BLOCK_SIZE || !crypto_simd_usable())
- return crypto_xchacha_crypt(req);
-
- crypto_chacha_init(state, ctx, req->iv);
+ chacha_init_generic(state, ctx->key, req->iv);
- kernel_neon_begin();
- hchacha_block_neon(state, subctx.key, ctx->nrounds);
- kernel_neon_end();
+ if (crypto_simd_usable()) {
+ kernel_neon_begin();
+ hchacha_block_neon(state, subctx.key, ctx->nrounds);
+ kernel_neon_end();
+ } else {
+ hchacha_block_generic(state, subctx.key, ctx->nrounds);
+ }
subctx.nrounds = ctx->nrounds;
memcpy(&real_iv[0], req->iv + 24, 8);
@@ -134,7 +138,7 @@ static struct skcipher_alg algs[] = {
.ivsize = CHACHA_IV_SIZE,
.chunksize = CHACHA_BLOCK_SIZE,
.walksize = 5 * CHACHA_BLOCK_SIZE,
- .setkey = crypto_chacha20_setkey,
+ .setkey = chacha20_setkey,
.encrypt = chacha_neon,
.decrypt = chacha_neon,
}, {
@@ -150,7 +154,7 @@ static struct skcipher_alg algs[] = {
.ivsize = XCHACHA_IV_SIZE,
.chunksize = CHACHA_BLOCK_SIZE,
.walksize = 5 * CHACHA_BLOCK_SIZE,
- .setkey = crypto_chacha20_setkey,
+ .setkey = chacha20_setkey,
.encrypt = xchacha_neon,
.decrypt = xchacha_neon,
}, {
@@ -166,7 +170,7 @@ static struct skcipher_alg algs[] = {
.ivsize = XCHACHA_IV_SIZE,
.chunksize = CHACHA_BLOCK_SIZE,
.walksize = 5 * CHACHA_BLOCK_SIZE,
- .setkey = crypto_chacha12_setkey,
+ .setkey = chacha12_setkey,
.encrypt = xchacha_neon,
.decrypt = xchacha_neon,
}