From 4e39d0712ec40079c45703b43806bb05b2cfa9b0 Mon Sep 17 00:00:00 2001 From: Eric Biggers Date: Mon, 5 May 2025 12:10:40 -0700 Subject: [PATCH] crypto: gcm - use memcpy_sglist() instead of null skcipher For copying data between two scatterlists, just use memcpy_sglist() instead of the so-called "null skcipher". This is much simpler. Signed-off-by: Eric Biggers Signed-off-by: Herbert Xu --- crypto/Kconfig | 1 - crypto/gcm.c | 41 ++++------------------------------------- 2 files changed, 4 insertions(+), 38 deletions(-) diff --git a/crypto/Kconfig b/crypto/Kconfig index 537602b8e60e..231791703594 100644 --- a/crypto/Kconfig +++ b/crypto/Kconfig @@ -805,7 +805,6 @@ config CRYPTO_GCM select CRYPTO_CTR select CRYPTO_AEAD select CRYPTO_GHASH - select CRYPTO_NULL select CRYPTO_MANAGER help GCM (Galois/Counter Mode) authenticated encryption mode and GMAC diff --git a/crypto/gcm.c b/crypto/gcm.c index 54ca9faf0e0c..97716482bed0 100644 --- a/crypto/gcm.c +++ b/crypto/gcm.c @@ -9,7 +9,6 @@ #include #include #include -#include #include #include #include @@ -46,7 +45,6 @@ struct crypto_rfc4543_instance_ctx { struct crypto_rfc4543_ctx { struct crypto_aead *child; - struct crypto_sync_skcipher *null; u8 nonce[4]; }; @@ -79,8 +77,6 @@ static struct { struct scatterlist sg; } *gcm_zeroes; -static int crypto_rfc4543_copy_src_to_dst(struct aead_request *req, bool enc); - static inline struct crypto_gcm_req_priv_ctx *crypto_gcm_reqctx( struct aead_request *req) { @@ -930,12 +926,12 @@ static int crypto_rfc4543_crypt(struct aead_request *req, bool enc) unsigned int authsize = crypto_aead_authsize(aead); u8 *iv = PTR_ALIGN((u8 *)(rctx + 1) + crypto_aead_reqsize(ctx->child), crypto_aead_alignmask(ctx->child) + 1); - int err; if (req->src != req->dst) { - err = crypto_rfc4543_copy_src_to_dst(req, enc); - if (err) - return err; + unsigned int nbytes = req->assoclen + req->cryptlen - + (enc ? 0 : authsize); + + memcpy_sglist(req->dst, req->src, nbytes); } memcpy(iv, ctx->nonce, 4); @@ -952,22 +948,6 @@ static int crypto_rfc4543_crypt(struct aead_request *req, bool enc) return enc ? crypto_aead_encrypt(subreq) : crypto_aead_decrypt(subreq); } -static int crypto_rfc4543_copy_src_to_dst(struct aead_request *req, bool enc) -{ - struct crypto_aead *aead = crypto_aead_reqtfm(req); - struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(aead); - unsigned int authsize = crypto_aead_authsize(aead); - unsigned int nbytes = req->assoclen + req->cryptlen - - (enc ? 0 : authsize); - SYNC_SKCIPHER_REQUEST_ON_STACK(nreq, ctx->null); - - skcipher_request_set_sync_tfm(nreq, ctx->null); - skcipher_request_set_callback(nreq, req->base.flags, NULL, NULL); - skcipher_request_set_crypt(nreq, req->src, req->dst, nbytes, NULL); - - return crypto_skcipher_encrypt(nreq); -} - static int crypto_rfc4543_encrypt(struct aead_request *req) { return crypto_ipsec_check_assoclen(req->assoclen) ?: @@ -987,21 +967,13 @@ static int crypto_rfc4543_init_tfm(struct crypto_aead *tfm) struct crypto_aead_spawn *spawn = &ictx->aead; struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(tfm); struct crypto_aead *aead; - struct crypto_sync_skcipher *null; unsigned long align; - int err = 0; aead = crypto_spawn_aead(spawn); if (IS_ERR(aead)) return PTR_ERR(aead); - null = crypto_get_default_null_skcipher(); - err = PTR_ERR(null); - if (IS_ERR(null)) - goto err_free_aead; - ctx->child = aead; - ctx->null = null; align = crypto_aead_alignmask(aead); align &= ~(crypto_tfm_ctx_alignment() - 1); @@ -1012,10 +984,6 @@ static int crypto_rfc4543_init_tfm(struct crypto_aead *tfm) align + GCM_AES_IV_SIZE); return 0; - -err_free_aead: - crypto_free_aead(aead); - return err; } static void crypto_rfc4543_exit_tfm(struct crypto_aead *tfm) @@ -1023,7 +991,6 @@ static void crypto_rfc4543_exit_tfm(struct crypto_aead *tfm) struct crypto_rfc4543_ctx *ctx = crypto_aead_ctx(tfm); crypto_free_aead(ctx->child); - crypto_put_default_null_skcipher(); } static void crypto_rfc4543_free(struct aead_instance *inst) -- 2.25.1