From 1d63e4557f0d11fd795c7acd50a241da2d8bf89f Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Tue, 7 Jul 2020 09:31:52 +0300 Subject: [PATCH] crypto: amlogic-gxl - permit async skcipher as fallback Even though the amlogic-gxl driver implements asynchronous versions of ecb(aes) and cbc(aes), the fallbacks it allocates are required to be synchronous. Given that SIMD based software implementations are usually asynchronous as well, even though they rarely complete asynchronously (this typically only happens in cases where the request was made from softirq context, while SIMD was already in use in the task context that it interrupted), these implementations are disregarded, and either the generic C version or another table based version implemented in assembler is selected instead. Since falling back to synchronous AES is not only a performance issue, but potentially a security issue as well (due to the fact that table based AES is not time invariant), let's fix this, by allocating an ordinary skcipher as the fallback, and invoke it with the completion routine that was given to the outer request. Signed-off-by: Ard Biesheuvel Tested-by: Corentin Labbe Signed-off-by: Herbert Xu --- drivers/crypto/amlogic/amlogic-gxl-cipher.c | 27 +++++++++++++-------------- drivers/crypto/amlogic/amlogic-gxl.h | 3 ++- 2 files changed, 15 insertions(+), 15 deletions(-) diff --git a/drivers/crypto/amlogic/amlogic-gxl-cipher.c b/drivers/crypto/amlogic/amlogic-gxl-cipher.c index 9819dd5..5880b94 100644 --- a/drivers/crypto/amlogic/amlogic-gxl-cipher.c +++ b/drivers/crypto/amlogic/amlogic-gxl-cipher.c @@ -64,22 +64,20 @@ static int meson_cipher_do_fallback(struct skcipher_request *areq) #ifdef CONFIG_CRYPTO_DEV_AMLOGIC_GXL_DEBUG struct skcipher_alg *alg = crypto_skcipher_alg(tfm); struct meson_alg_template *algt; -#endif - SYNC_SKCIPHER_REQUEST_ON_STACK(req, op->fallback_tfm); -#ifdef CONFIG_CRYPTO_DEV_AMLOGIC_GXL_DEBUG algt = container_of(alg, struct meson_alg_template, alg.skcipher); algt->stat_fb++; #endif - skcipher_request_set_sync_tfm(req, op->fallback_tfm); - skcipher_request_set_callback(req, areq->base.flags, NULL, NULL); - skcipher_request_set_crypt(req, areq->src, areq->dst, + skcipher_request_set_tfm(&rctx->fallback_req, op->fallback_tfm); + skcipher_request_set_callback(&rctx->fallback_req, areq->base.flags, + areq->base.complete, areq->base.data); + skcipher_request_set_crypt(&rctx->fallback_req, areq->src, areq->dst, areq->cryptlen, areq->iv); + if (rctx->op_dir == MESON_DECRYPT) - err = crypto_skcipher_decrypt(req); + err = crypto_skcipher_decrypt(&rctx->fallback_req); else - err = crypto_skcipher_encrypt(req); - skcipher_request_zero(req); + err = crypto_skcipher_encrypt(&rctx->fallback_req); return err; } @@ -321,15 +319,16 @@ int meson_cipher_init(struct crypto_tfm *tfm) algt = container_of(alg, struct meson_alg_template, alg.skcipher); op->mc = algt->mc; - sktfm->reqsize = sizeof(struct meson_cipher_req_ctx); - - op->fallback_tfm = crypto_alloc_sync_skcipher(name, 0, CRYPTO_ALG_NEED_FALLBACK); + op->fallback_tfm = crypto_alloc_skcipher(name, 0, CRYPTO_ALG_NEED_FALLBACK); if (IS_ERR(op->fallback_tfm)) { dev_err(op->mc->dev, "ERROR: Cannot allocate fallback for %s %ld\n", name, PTR_ERR(op->fallback_tfm)); return PTR_ERR(op->fallback_tfm); } + sktfm->reqsize = sizeof(struct meson_cipher_req_ctx) + + crypto_skcipher_reqsize(op->fallback_tfm); + op->enginectx.op.do_one_request = meson_handle_cipher_request; op->enginectx.op.prepare_request = NULL; op->enginectx.op.unprepare_request = NULL; @@ -345,7 +344,7 @@ void meson_cipher_exit(struct crypto_tfm *tfm) memzero_explicit(op->key, op->keylen); kfree(op->key); } - crypto_free_sync_skcipher(op->fallback_tfm); + crypto_free_skcipher(op->fallback_tfm); } int meson_aes_setkey(struct crypto_skcipher *tfm, const u8 *key, @@ -377,5 +376,5 @@ int meson_aes_setkey(struct crypto_skcipher *tfm, const u8 *key, if (!op->key) return -ENOMEM; - return crypto_sync_skcipher_setkey(op->fallback_tfm, key, keylen); + return crypto_skcipher_setkey(op->fallback_tfm, key, keylen); } diff --git a/drivers/crypto/amlogic/amlogic-gxl.h b/drivers/crypto/amlogic/amlogic-gxl.h index b7f2de9..dc0f142 100644 --- a/drivers/crypto/amlogic/amlogic-gxl.h +++ b/drivers/crypto/amlogic/amlogic-gxl.h @@ -109,6 +109,7 @@ struct meson_dev { struct meson_cipher_req_ctx { u32 op_dir; int flow; + struct skcipher_request fallback_req; // keep at the end }; /* @@ -126,7 +127,7 @@ struct meson_cipher_tfm_ctx { u32 keylen; u32 keymode; struct meson_dev *mc; - struct crypto_sync_skcipher *fallback_tfm; + struct crypto_skcipher *fallback_tfm; }; /* -- 2.7.4