From b9e699f91236cb1cc97a3d02ccb8063af5e4cc46 Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Fri, 27 Aug 2021 09:03:36 +0200 Subject: [PATCH] crypto: arm64/gcm-aes-ce - remove non-SIMD fallback path Now that kernel mode SIMD is guaranteed to be available when executing in task or softirq context, we no longer need scalar fallbacks to use when the NEON is unavailable. So get rid of them. Reviewed-by: Eric Biggers Signed-off-by: Ard Biesheuvel Signed-off-by: Herbert Xu --- arch/arm64/crypto/ghash-ce-glue.c | 217 ++++++++---------------------- 1 file changed, 55 insertions(+), 162 deletions(-) diff --git a/arch/arm64/crypto/ghash-ce-glue.c b/arch/arm64/crypto/ghash-ce-glue.c index 720cd3a58da3..15794fe21a0b 100644 --- a/arch/arm64/crypto/ghash-ce-glue.c +++ b/arch/arm64/crypto/ghash-ce-glue.c @@ -362,84 +362,36 @@ static int gcm_encrypt(struct aead_request *req) err = skcipher_walk_aead_encrypt(&walk, req, false); - if (likely(crypto_simd_usable())) { - do { - const u8 *src = walk.src.virt.addr; - u8 *dst = walk.dst.virt.addr; - int nbytes = walk.nbytes; - - tag = (u8 *)&lengths; - - if (unlikely(nbytes > 0 && nbytes < AES_BLOCK_SIZE)) { - src = dst = memcpy(buf + sizeof(buf) - nbytes, - src, nbytes); - } else if (nbytes < walk.total) { - nbytes &= ~(AES_BLOCK_SIZE - 1); - tag = NULL; - } - - kernel_neon_begin(); - pmull_gcm_encrypt(nbytes, dst, src, ctx->ghash_key.h, - dg, iv, ctx->aes_key.key_enc, nrounds, - tag); - kernel_neon_end(); - - if (unlikely(!nbytes)) - break; - - if (unlikely(nbytes > 0 && nbytes < AES_BLOCK_SIZE)) - memcpy(walk.dst.virt.addr, - buf + sizeof(buf) - nbytes, nbytes); - - err = skcipher_walk_done(&walk, walk.nbytes - nbytes); - } while (walk.nbytes); - } else { - while (walk.nbytes >= AES_BLOCK_SIZE) { - int blocks = walk.nbytes / AES_BLOCK_SIZE; - const u8 *src = walk.src.virt.addr; - u8 *dst = walk.dst.virt.addr; - int remaining = blocks; - - do { - aes_encrypt(&ctx->aes_key, buf, iv); - crypto_xor_cpy(dst, src, buf, AES_BLOCK_SIZE); - crypto_inc(iv, AES_BLOCK_SIZE); - - dst += AES_BLOCK_SIZE; - src += AES_BLOCK_SIZE; - } while (--remaining > 0); - - ghash_do_update(blocks, dg, walk.dst.virt.addr, - &ctx->ghash_key, NULL); - - err = skcipher_walk_done(&walk, - walk.nbytes % AES_BLOCK_SIZE); - } - - /* handle the tail */ - if (walk.nbytes) { - aes_encrypt(&ctx->aes_key, buf, iv); - - crypto_xor_cpy(walk.dst.virt.addr, walk.src.virt.addr, - buf, walk.nbytes); - - memcpy(buf, walk.dst.virt.addr, walk.nbytes); - memset(buf + walk.nbytes, 0, sizeof(buf) - walk.nbytes); - } + do { + const u8 *src = walk.src.virt.addr; + u8 *dst = walk.dst.virt.addr; + int nbytes = walk.nbytes; tag = (u8 *)&lengths; - ghash_do_update(1, dg, tag, &ctx->ghash_key, - walk.nbytes ? buf : NULL); - if (walk.nbytes) - err = skcipher_walk_done(&walk, 0); + if (unlikely(nbytes > 0 && nbytes < AES_BLOCK_SIZE)) { + src = dst = memcpy(buf + sizeof(buf) - nbytes, + src, nbytes); + } else if (nbytes < walk.total) { + nbytes &= ~(AES_BLOCK_SIZE - 1); + tag = NULL; + } - put_unaligned_be64(dg[1], tag); - put_unaligned_be64(dg[0], tag + 8); - put_unaligned_be32(1, iv + GCM_IV_SIZE); - aes_encrypt(&ctx->aes_key, iv, iv); - crypto_xor(tag, iv, AES_BLOCK_SIZE); - } + kernel_neon_begin(); + pmull_gcm_encrypt(nbytes, dst, src, ctx->ghash_key.h, + dg, iv, ctx->aes_key.key_enc, nrounds, + tag); + kernel_neon_end(); + + if (unlikely(!nbytes)) + break; + + if (unlikely(nbytes > 0 && nbytes < AES_BLOCK_SIZE)) + memcpy(walk.dst.virt.addr, + buf + sizeof(buf) - nbytes, nbytes); + + err = skcipher_walk_done(&walk, walk.nbytes - nbytes); + } while (walk.nbytes); if (err) return err; @@ -464,6 +416,7 @@ static int gcm_decrypt(struct aead_request *req) u64 dg[2] = {}; be128 lengths; u8 *tag; + int ret; int err; lengths.a = cpu_to_be64(req->assoclen * 8); @@ -481,101 +434,41 @@ static int gcm_decrypt(struct aead_request *req) err = skcipher_walk_aead_decrypt(&walk, req, false); - if (likely(crypto_simd_usable())) { - int ret; - - do { - const u8 *src = walk.src.virt.addr; - u8 *dst = walk.dst.virt.addr; - int nbytes = walk.nbytes; - - tag = (u8 *)&lengths; - - if (unlikely(nbytes > 0 && nbytes < AES_BLOCK_SIZE)) { - src = dst = memcpy(buf + sizeof(buf) - nbytes, - src, nbytes); - } else if (nbytes < walk.total) { - nbytes &= ~(AES_BLOCK_SIZE - 1); - tag = NULL; - } - - kernel_neon_begin(); - ret = pmull_gcm_decrypt(nbytes, dst, src, - ctx->ghash_key.h, - dg, iv, ctx->aes_key.key_enc, - nrounds, tag, otag, authsize); - kernel_neon_end(); - - if (unlikely(!nbytes)) - break; - - if (unlikely(nbytes > 0 && nbytes < AES_BLOCK_SIZE)) - memcpy(walk.dst.virt.addr, - buf + sizeof(buf) - nbytes, nbytes); - - err = skcipher_walk_done(&walk, walk.nbytes - nbytes); - } while (walk.nbytes); - - if (err) - return err; - if (ret) - return -EBADMSG; - } else { - while (walk.nbytes >= AES_BLOCK_SIZE) { - int blocks = walk.nbytes / AES_BLOCK_SIZE; - const u8 *src = walk.src.virt.addr; - u8 *dst = walk.dst.virt.addr; - - ghash_do_update(blocks, dg, walk.src.virt.addr, - &ctx->ghash_key, NULL); - - do { - aes_encrypt(&ctx->aes_key, buf, iv); - crypto_xor_cpy(dst, src, buf, AES_BLOCK_SIZE); - crypto_inc(iv, AES_BLOCK_SIZE); - - dst += AES_BLOCK_SIZE; - src += AES_BLOCK_SIZE; - } while (--blocks > 0); - - err = skcipher_walk_done(&walk, - walk.nbytes % AES_BLOCK_SIZE); - } - - /* handle the tail */ - if (walk.nbytes) { - memcpy(buf, walk.src.virt.addr, walk.nbytes); - memset(buf + walk.nbytes, 0, sizeof(buf) - walk.nbytes); - } + do { + const u8 *src = walk.src.virt.addr; + u8 *dst = walk.dst.virt.addr; + int nbytes = walk.nbytes; tag = (u8 *)&lengths; - ghash_do_update(1, dg, tag, &ctx->ghash_key, - walk.nbytes ? buf : NULL); - if (walk.nbytes) { - aes_encrypt(&ctx->aes_key, buf, iv); - - crypto_xor_cpy(walk.dst.virt.addr, walk.src.virt.addr, - buf, walk.nbytes); - - err = skcipher_walk_done(&walk, 0); + if (unlikely(nbytes > 0 && nbytes < AES_BLOCK_SIZE)) { + src = dst = memcpy(buf + sizeof(buf) - nbytes, + src, nbytes); + } else if (nbytes < walk.total) { + nbytes &= ~(AES_BLOCK_SIZE - 1); + tag = NULL; } - if (err) - return err; + kernel_neon_begin(); + ret = pmull_gcm_decrypt(nbytes, dst, src, ctx->ghash_key.h, + dg, iv, ctx->aes_key.key_enc, + nrounds, tag, otag, authsize); + kernel_neon_end(); - put_unaligned_be64(dg[1], tag); - put_unaligned_be64(dg[0], tag + 8); - put_unaligned_be32(1, iv + GCM_IV_SIZE); - aes_encrypt(&ctx->aes_key, iv, iv); - crypto_xor(tag, iv, AES_BLOCK_SIZE); + if (unlikely(!nbytes)) + break; - if (crypto_memneq(tag, otag, authsize)) { - memzero_explicit(tag, AES_BLOCK_SIZE); - return -EBADMSG; - } - } - return 0; + if (unlikely(nbytes > 0 && nbytes < AES_BLOCK_SIZE)) + memcpy(walk.dst.virt.addr, + buf + sizeof(buf) - nbytes, nbytes); + + err = skcipher_walk_done(&walk, walk.nbytes - nbytes); + } while (walk.nbytes); + + if (err) + return err; + + return ret ? -EBADMSG : 0; } static struct aead_alg gcm_aes_alg = {