From 31abd3eb3df6bd520fece598e31047a0f377953e Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Tue, 7 Jul 2020 09:31:55 +0300 Subject: [PATCH] crypto: sun8i-ce - permit asynchronous skcipher as fallback Even though the sun8i-ce 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 Acked-by: Corentin Labbe Tested-by: Corentin Labbe Signed-off-by: Herbert Xu --- .../crypto/allwinner/sun8i-ce/sun8i-ce-cipher.c | 41 +++++++++++----------- drivers/crypto/allwinner/sun8i-ce/sun8i-ce.h | 8 +++-- 2 files changed, 25 insertions(+), 24 deletions(-) diff --git a/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-cipher.c b/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-cipher.c index 3665a0a..1e4f9a58 100644 --- a/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-cipher.c +++ b/drivers/crypto/allwinner/sun8i-ce/sun8i-ce-cipher.c @@ -58,23 +58,20 @@ static int sun8i_ce_cipher_fallback(struct skcipher_request *areq) #ifdef CONFIG_CRYPTO_DEV_SUN8I_CE_DEBUG struct skcipher_alg *alg = crypto_skcipher_alg(tfm); struct sun8i_ce_alg_template *algt; -#endif - SYNC_SKCIPHER_REQUEST_ON_STACK(subreq, op->fallback_tfm); -#ifdef CONFIG_CRYPTO_DEV_SUN8I_CE_DEBUG algt = container_of(alg, struct sun8i_ce_alg_template, alg.skcipher); algt->stat_fb++; #endif - skcipher_request_set_sync_tfm(subreq, op->fallback_tfm); - skcipher_request_set_callback(subreq, areq->base.flags, NULL, NULL); - skcipher_request_set_crypt(subreq, 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 & CE_DECRYPTION) - err = crypto_skcipher_decrypt(subreq); + err = crypto_skcipher_decrypt(&rctx->fallback_req); else - err = crypto_skcipher_encrypt(subreq); - skcipher_request_zero(subreq); + err = crypto_skcipher_encrypt(&rctx->fallback_req); return err; } @@ -335,18 +332,20 @@ int sun8i_ce_cipher_init(struct crypto_tfm *tfm) algt = container_of(alg, struct sun8i_ce_alg_template, alg.skcipher); op->ce = algt->ce; - sktfm->reqsize = sizeof(struct sun8i_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->ce->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 sun8i_cipher_req_ctx) + + crypto_skcipher_reqsize(op->fallback_tfm); + + dev_info(op->ce->dev, "Fallback for %s is %s\n", crypto_tfm_alg_driver_name(&sktfm->base), - crypto_tfm_alg_driver_name(crypto_skcipher_tfm(&op->fallback_tfm->base))); + crypto_tfm_alg_driver_name(crypto_skcipher_tfm(op->fallback_tfm))); op->enginectx.op.do_one_request = sun8i_ce_handle_cipher_request; op->enginectx.op.prepare_request = NULL; @@ -359,7 +358,7 @@ int sun8i_ce_cipher_init(struct crypto_tfm *tfm) return 0; error_pm: pm_runtime_put_noidle(op->ce->dev); - crypto_free_sync_skcipher(op->fallback_tfm); + crypto_free_skcipher(op->fallback_tfm); return err; } @@ -371,7 +370,7 @@ void sun8i_ce_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); pm_runtime_put_sync_suspend(op->ce->dev); } @@ -401,10 +400,10 @@ int sun8i_ce_aes_setkey(struct crypto_skcipher *tfm, const u8 *key, if (!op->key) return -ENOMEM; - crypto_sync_skcipher_clear_flags(op->fallback_tfm, CRYPTO_TFM_REQ_MASK); - crypto_sync_skcipher_set_flags(op->fallback_tfm, tfm->base.crt_flags & CRYPTO_TFM_REQ_MASK); + crypto_skcipher_clear_flags(op->fallback_tfm, CRYPTO_TFM_REQ_MASK); + crypto_skcipher_set_flags(op->fallback_tfm, tfm->base.crt_flags & CRYPTO_TFM_REQ_MASK); - return crypto_sync_skcipher_setkey(op->fallback_tfm, key, keylen); + return crypto_skcipher_setkey(op->fallback_tfm, key, keylen); } int sun8i_ce_des3_setkey(struct crypto_skcipher *tfm, const u8 *key, @@ -426,8 +425,8 @@ int sun8i_ce_des3_setkey(struct crypto_skcipher *tfm, const u8 *key, if (!op->key) return -ENOMEM; - crypto_sync_skcipher_clear_flags(op->fallback_tfm, CRYPTO_TFM_REQ_MASK); - crypto_sync_skcipher_set_flags(op->fallback_tfm, tfm->base.crt_flags & CRYPTO_TFM_REQ_MASK); + crypto_skcipher_clear_flags(op->fallback_tfm, CRYPTO_TFM_REQ_MASK); + crypto_skcipher_set_flags(op->fallback_tfm, tfm->base.crt_flags & CRYPTO_TFM_REQ_MASK); - return crypto_sync_skcipher_setkey(op->fallback_tfm, key, keylen); + return crypto_skcipher_setkey(op->fallback_tfm, key, keylen); } diff --git a/drivers/crypto/allwinner/sun8i-ce/sun8i-ce.h b/drivers/crypto/allwinner/sun8i-ce/sun8i-ce.h index 0e9eac3..963645f 100644 --- a/drivers/crypto/allwinner/sun8i-ce/sun8i-ce.h +++ b/drivers/crypto/allwinner/sun8i-ce/sun8i-ce.h @@ -181,12 +181,14 @@ struct sun8i_ce_dev { /* * struct sun8i_cipher_req_ctx - context for a skcipher request - * @op_dir: direction (encrypt vs decrypt) for this request - * @flow: the flow to use for this request + * @op_dir: direction (encrypt vs decrypt) for this request + * @flow: the flow to use for this request + * @fallback_req: request struct for invoking the fallback skcipher TFM */ struct sun8i_cipher_req_ctx { u32 op_dir; int flow; + struct skcipher_request fallback_req; // keep at the end }; /* @@ -202,7 +204,7 @@ struct sun8i_cipher_tfm_ctx { u32 *key; u32 keylen; struct sun8i_ce_dev *ce; - struct crypto_sync_skcipher *fallback_tfm; + struct crypto_skcipher *fallback_tfm; }; /* -- 2.7.4