From 76cadf2244518d3b1610082d037b01e2651ea402 Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Sun, 2 Jun 2019 22:46:34 -0700 Subject: [PATCH] crypto: chacha20poly1305 - a few cleanups - Use sg_init_one() instead of sg_init_table() then sg_set_buf(). - Remove unneeded calls to sg_init_table() prior to scatterwalk_ffwd(). - Simplify initializing the poly tail block. - Simplify computing padlen. This doesn't change any actual behavior. Cc: Martin Willi Signed-off-by: Eric Biggers Signed-off-by: Herbert Xu --- crypto/chacha20poly1305.c | 43 ++++++++++++--------------------------- 1 file changed, 13 insertions(+), 30 deletions(-) diff --git a/crypto/chacha20poly1305.c b/crypto/chacha20poly1305.c index acbbf010222e..76c13dab217d 100644 --- a/crypto/chacha20poly1305.c +++ b/crypto/chacha20poly1305.c @@ -139,14 +139,10 @@ static int chacha_decrypt(struct aead_request *req) chacha_iv(creq->iv, req, 1); - sg_init_table(rctx->src, 2); src = scatterwalk_ffwd(rctx->src, req->src, req->assoclen); dst = src; - - if (req->src != req->dst) { - sg_init_table(rctx->dst, 2); + if (req->src != req->dst) dst = scatterwalk_ffwd(rctx->dst, req->dst, req->assoclen); - } skcipher_request_set_callback(&creq->req, rctx->flags, chacha_decrypt_done, req); @@ -182,15 +178,11 @@ static int poly_tail(struct aead_request *req) struct chachapoly_ctx *ctx = crypto_aead_ctx(tfm); struct chachapoly_req_ctx *rctx = aead_request_ctx(req); struct poly_req *preq = &rctx->u.poly; - __le64 len; int err; - sg_init_table(preq->src, 1); - len = cpu_to_le64(rctx->assoclen); - memcpy(&preq->tail.assoclen, &len, sizeof(len)); - len = cpu_to_le64(rctx->cryptlen); - memcpy(&preq->tail.cryptlen, &len, sizeof(len)); - sg_set_buf(preq->src, &preq->tail, sizeof(preq->tail)); + preq->tail.assoclen = cpu_to_le64(rctx->assoclen); + preq->tail.cryptlen = cpu_to_le64(rctx->cryptlen); + sg_init_one(preq->src, &preq->tail, sizeof(preq->tail)); ahash_request_set_callback(&preq->req, rctx->flags, poly_tail_done, req); @@ -215,13 +207,12 @@ static int poly_cipherpad(struct aead_request *req) struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req)); struct chachapoly_req_ctx *rctx = aead_request_ctx(req); struct poly_req *preq = &rctx->u.poly; - unsigned int padlen, bs = POLY1305_BLOCK_SIZE; + unsigned int padlen; int err; - padlen = (bs - (rctx->cryptlen % bs)) % bs; + padlen = -rctx->cryptlen % POLY1305_BLOCK_SIZE; memset(preq->pad, 0, sizeof(preq->pad)); - sg_init_table(preq->src, 1); - sg_set_buf(preq->src, &preq->pad, padlen); + sg_init_one(preq->src, preq->pad, padlen); ahash_request_set_callback(&preq->req, rctx->flags, poly_cipherpad_done, req); @@ -251,7 +242,6 @@ static int poly_cipher(struct aead_request *req) if (rctx->cryptlen == req->cryptlen) /* encrypting */ crypt = req->dst; - sg_init_table(rctx->src, 2); crypt = scatterwalk_ffwd(rctx->src, crypt, req->assoclen); ahash_request_set_callback(&preq->req, rctx->flags, @@ -276,13 +266,12 @@ static int poly_adpad(struct aead_request *req) struct chachapoly_ctx *ctx = crypto_aead_ctx(crypto_aead_reqtfm(req)); struct chachapoly_req_ctx *rctx = aead_request_ctx(req); struct poly_req *preq = &rctx->u.poly; - unsigned int padlen, bs = POLY1305_BLOCK_SIZE; + unsigned int padlen; int err; - padlen = (bs - (rctx->assoclen % bs)) % bs; + padlen = -rctx->assoclen % POLY1305_BLOCK_SIZE; memset(preq->pad, 0, sizeof(preq->pad)); - sg_init_table(preq->src, 1); - sg_set_buf(preq->src, preq->pad, padlen); + sg_init_one(preq->src, preq->pad, padlen); ahash_request_set_callback(&preq->req, rctx->flags, poly_adpad_done, req); @@ -332,8 +321,7 @@ static int poly_setkey(struct aead_request *req) struct poly_req *preq = &rctx->u.poly; int err; - sg_init_table(preq->src, 1); - sg_set_buf(preq->src, rctx->key, sizeof(rctx->key)); + sg_init_one(preq->src, rctx->key, sizeof(rctx->key)); ahash_request_set_callback(&preq->req, rctx->flags, poly_setkey_done, req); @@ -391,9 +379,8 @@ static int poly_genkey(struct aead_request *req) rctx->assoclen -= 8; } - sg_init_table(creq->src, 1); memset(rctx->key, 0, sizeof(rctx->key)); - sg_set_buf(creq->src, rctx->key, sizeof(rctx->key)); + sg_init_one(creq->src, rctx->key, sizeof(rctx->key)); chacha_iv(creq->iv, req, 0); @@ -428,14 +415,10 @@ static int chacha_encrypt(struct aead_request *req) chacha_iv(creq->iv, req, 1); - sg_init_table(rctx->src, 2); src = scatterwalk_ffwd(rctx->src, req->src, req->assoclen); dst = src; - - if (req->src != req->dst) { - sg_init_table(rctx->dst, 2); + if (req->src != req->dst) dst = scatterwalk_ffwd(rctx->dst, req->dst, req->assoclen); - } skcipher_request_set_callback(&creq->req, rctx->flags, chacha_encrypt_done, req);