From 97b70180b7f97224762b63f211305a8052d07960 Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Tue, 17 Nov 2020 14:32:13 +0100 Subject: crypto: aegis128/neon - move final tag check to SIMD domain Instead of calculating the tag and returning it to the caller on decryption, use a SIMD compare and min across vector to perform the comparison. This is slightly more efficient, and removes the need on the caller's part to wipe the tag from memory if the decryption failed. While at it, switch to unsigned int when passing cryptlen and assoclen - we don't support input sizes where it matters anyway. Signed-off-by: Ard Biesheuvel Reviewed-by: Ondrej Mosnacek Signed-off-by: Herbert Xu --- crypto/aegis128-core.c | 21 +++++++++++++++------ 1 file changed, 15 insertions(+), 6 deletions(-) (limited to 'crypto/aegis128-core.c') diff --git a/crypto/aegis128-core.c b/crypto/aegis128-core.c index 3a71235892f5..859c7b905618 100644 --- a/crypto/aegis128-core.c +++ b/crypto/aegis128-core.c @@ -67,9 +67,11 @@ void crypto_aegis128_encrypt_chunk_simd(struct aegis_state *state, u8 *dst, const u8 *src, unsigned int size); void crypto_aegis128_decrypt_chunk_simd(struct aegis_state *state, u8 *dst, const u8 *src, unsigned int size); -void crypto_aegis128_final_simd(struct aegis_state *state, - union aegis_block *tag_xor, - u64 assoclen, u64 cryptlen); +int crypto_aegis128_final_simd(struct aegis_state *state, + union aegis_block *tag_xor, + unsigned int assoclen, + unsigned int cryptlen, + unsigned int authsize); static void crypto_aegis128_update(struct aegis_state *state) { @@ -411,7 +413,7 @@ static int crypto_aegis128_encrypt(struct aead_request *req) crypto_aegis128_process_crypt(&state, &walk, crypto_aegis128_encrypt_chunk_simd); crypto_aegis128_final_simd(&state, &tag, req->assoclen, - cryptlen); + cryptlen, 0); } else { crypto_aegis128_init(&state, &ctx->key, req->iv); crypto_aegis128_process_ad(&state, req->src, req->assoclen); @@ -445,8 +447,15 @@ static int crypto_aegis128_decrypt(struct aead_request *req) crypto_aegis128_process_ad(&state, req->src, req->assoclen); crypto_aegis128_process_crypt(&state, &walk, crypto_aegis128_decrypt_chunk_simd); - crypto_aegis128_final_simd(&state, &tag, req->assoclen, - cryptlen); + if (unlikely(crypto_aegis128_final_simd(&state, &tag, + req->assoclen, + cryptlen, authsize))) { + skcipher_walk_aead_decrypt(&walk, req, false); + crypto_aegis128_process_crypt(NULL, req, &walk, + crypto_aegis128_wipe_chunk); + return -EBADMSG; + } + return 0; } else { crypto_aegis128_init(&state, &ctx->key, req->iv); crypto_aegis128_process_ad(&state, req->src, req->assoclen); -- cgit v1.2.3