From 0000000000000000000000000000000000000000 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 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 Signed-off-by: Herbert Xu Signed-off-by: Jason A. Donenfeld --- 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 @@ -104,7 +104,7 @@ 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, }