From 1fddc014ee1727b00f1e5b7cb89ee8e7072694c9 Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Fri, 8 Nov 2019 13:22:11 +0100 Subject: [PATCH] crypto: arm64/chacha - depend on generic chacha library instead of crypto driver 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 Signed-off-by: Herbert Xu --- arch/arm64/crypto/Kconfig | 2 +- arch/arm64/crypto/chacha-neon-glue.c | 40 +++++++++++++++------------- 2 files changed, 23 insertions(+), 19 deletions(-) diff --git a/arch/arm64/crypto/Kconfig b/arch/arm64/crypto/Kconfig index 286e3514d34c5..22c6642ae4648 100644 --- 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_SKCIPHER - select CRYPTO_CHACHA20 + select CRYPTO_LIB_CHACHA_GENERIC config CRYPTO_NHPOLY1305_NEON tristate "NHPoly1305 hash function using NEON instructions (for Adiantum)" diff --git a/arch/arm64/crypto/chacha-neon-glue.c b/arch/arm64/crypto/chacha-neon-glue.c index d4cc61bfe79df..cae2cb92eca86 100644 --- 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 skcipher_request *req, 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 skcipher_request *req, 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_request *req) 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_request *req) u32 state[16]; u8 real_iv[16]; - if (req->cryptlen <= CHACHA_BLOCK_SIZE || !crypto_simd_usable()) - return crypto_xchacha_crypt(req); + chacha_init_generic(state, ctx->key, req->iv); - crypto_chacha_init(state, ctx, 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, } -- 2.39.5