From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 From: "Jason A. Donenfeld" Date: Sun, 5 Jan 2020 22:40:49 -0500 Subject: [PATCH] crypto: {arm,arm64,mips}/poly1305 - remove redundant non-reduction from emit MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit commit 31899908a0d248b030b4464425b86c717e0007d4 upstream. This appears to be some kind of copy and paste error, and is actually dead code. Pre: f = 0 ⇒ (f >> 32) = 0 f = (f >> 32) + le32_to_cpu(digest[0]); Post: 0 ≤ f < 2³² put_unaligned_le32(f, dst); Pre: 0 ≤ f < 2³² ⇒ (f >> 32) = 0 f = (f >> 32) + le32_to_cpu(digest[1]); Post: 0 ≤ f < 2³² put_unaligned_le32(f, dst + 4); Pre: 0 ≤ f < 2³² ⇒ (f >> 32) = 0 f = (f >> 32) + le32_to_cpu(digest[2]); Post: 0 ≤ f < 2³² put_unaligned_le32(f, dst + 8); Pre: 0 ≤ f < 2³² ⇒ (f >> 32) = 0 f = (f >> 32) + le32_to_cpu(digest[3]); Post: 0 ≤ f < 2³² put_unaligned_le32(f, dst + 12); Therefore this sequence is redundant. And Andy's code appears to handle misalignment acceptably. Signed-off-by: Jason A. Donenfeld Tested-by: Ard Biesheuvel Reviewed-by: Ard Biesheuvel Signed-off-by: Herbert Xu Signed-off-by: Jason A. Donenfeld --- arch/arm/crypto/poly1305-glue.c | 18 ++---------------- arch/arm64/crypto/poly1305-glue.c | 18 ++---------------- arch/mips/crypto/poly1305-glue.c | 18 ++---------------- 3 files changed, 6 insertions(+), 48 deletions(-) --- a/arch/arm/crypto/poly1305-glue.c +++ b/arch/arm/crypto/poly1305-glue.c @@ -20,7 +20,7 @@ void poly1305_init_arm(void *state, const u8 *key); void poly1305_blocks_arm(void *state, const u8 *src, u32 len, u32 hibit); -void poly1305_emit_arm(void *state, __le32 *digest, const u32 *nonce); +void poly1305_emit_arm(void *state, u8 *digest, const u32 *nonce); void __weak poly1305_blocks_neon(void *state, const u8 *src, u32 len, u32 hibit) { @@ -179,9 +179,6 @@ EXPORT_SYMBOL(poly1305_update_arch); void poly1305_final_arch(struct poly1305_desc_ctx *dctx, u8 *dst) { - __le32 digest[4]; - u64 f = 0; - if (unlikely(dctx->buflen)) { dctx->buf[dctx->buflen++] = 1; memset(dctx->buf + dctx->buflen, 0, @@ -189,18 +186,7 @@ void poly1305_final_arch(struct poly1305 poly1305_blocks_arm(&dctx->h, dctx->buf, POLY1305_BLOCK_SIZE, 0); } - poly1305_emit_arm(&dctx->h, digest, dctx->s); - - /* mac = (h + s) % (2^128) */ - f = (f >> 32) + le32_to_cpu(digest[0]); - put_unaligned_le32(f, dst); - f = (f >> 32) + le32_to_cpu(digest[1]); - put_unaligned_le32(f, dst + 4); - f = (f >> 32) + le32_to_cpu(digest[2]); - put_unaligned_le32(f, dst + 8); - f = (f >> 32) + le32_to_cpu(digest[3]); - put_unaligned_le32(f, dst + 12); - + poly1305_emit_arm(&dctx->h, dst, dctx->s); *dctx = (struct poly1305_desc_ctx){}; } EXPORT_SYMBOL(poly1305_final_arch); --- a/arch/arm64/crypto/poly1305-glue.c +++ b/arch/arm64/crypto/poly1305-glue.c @@ -21,7 +21,7 @@ asmlinkage void poly1305_init_arm64(void *state, const u8 *key); asmlinkage void poly1305_blocks(void *state, const u8 *src, u32 len, u32 hibit); asmlinkage void poly1305_blocks_neon(void *state, const u8 *src, u32 len, u32 hibit); -asmlinkage void poly1305_emit(void *state, __le32 *digest, const u32 *nonce); +asmlinkage void poly1305_emit(void *state, u8 *digest, const u32 *nonce); static __ro_after_init DEFINE_STATIC_KEY_FALSE(have_neon); @@ -162,9 +162,6 @@ EXPORT_SYMBOL(poly1305_update_arch); void poly1305_final_arch(struct poly1305_desc_ctx *dctx, u8 *dst) { - __le32 digest[4]; - u64 f = 0; - if (unlikely(dctx->buflen)) { dctx->buf[dctx->buflen++] = 1; memset(dctx->buf + dctx->buflen, 0, @@ -172,18 +169,7 @@ void poly1305_final_arch(struct poly1305 poly1305_blocks(&dctx->h, dctx->buf, POLY1305_BLOCK_SIZE, 0); } - poly1305_emit(&dctx->h, digest, dctx->s); - - /* mac = (h + s) % (2^128) */ - f = (f >> 32) + le32_to_cpu(digest[0]); - put_unaligned_le32(f, dst); - f = (f >> 32) + le32_to_cpu(digest[1]); - put_unaligned_le32(f, dst + 4); - f = (f >> 32) + le32_to_cpu(digest[2]); - put_unaligned_le32(f, dst + 8); - f = (f >> 32) + le32_to_cpu(digest[3]); - put_unaligned_le32(f, dst + 12); - + poly1305_emit(&dctx->h, dst, dctx->s); *dctx = (struct poly1305_desc_ctx){}; } EXPORT_SYMBOL(poly1305_final_arch); --- a/arch/mips/crypto/poly1305-glue.c +++ b/arch/mips/crypto/poly1305-glue.c @@ -15,7 +15,7 @@ asmlinkage void poly1305_init_mips(void *state, const u8 *key); asmlinkage void poly1305_blocks_mips(void *state, const u8 *src, u32 len, u32 hibit); -asmlinkage void poly1305_emit_mips(void *state, __le32 *digest, const u32 *nonce); +asmlinkage void poly1305_emit_mips(void *state, u8 *digest, const u32 *nonce); void poly1305_init_arch(struct poly1305_desc_ctx *dctx, const u8 *key) { @@ -134,9 +134,6 @@ EXPORT_SYMBOL(poly1305_update_arch); void poly1305_final_arch(struct poly1305_desc_ctx *dctx, u8 *dst) { - __le32 digest[4]; - u64 f = 0; - if (unlikely(dctx->buflen)) { dctx->buf[dctx->buflen++] = 1; memset(dctx->buf + dctx->buflen, 0, @@ -144,18 +141,7 @@ void poly1305_final_arch(struct poly1305 poly1305_blocks_mips(&dctx->h, dctx->buf, POLY1305_BLOCK_SIZE, 0); } - poly1305_emit_mips(&dctx->h, digest, dctx->s); - - /* mac = (h + s) % (2^128) */ - f = (f >> 32) + le32_to_cpu(digest[0]); - put_unaligned_le32(f, dst); - f = (f >> 32) + le32_to_cpu(digest[1]); - put_unaligned_le32(f, dst + 4); - f = (f >> 32) + le32_to_cpu(digest[2]); - put_unaligned_le32(f, dst + 8); - f = (f >> 32) + le32_to_cpu(digest[3]); - put_unaligned_le32(f, dst + 12); - + poly1305_emit_mips(&dctx->h, dst, dctx->s); *dctx = (struct poly1305_desc_ctx){}; } EXPORT_SYMBOL(poly1305_final_arch);