From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wr1-f66.google.com ([209.85.221.66]:46535 "EHLO mail-wr1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726751AbfHSOSB (ORCPT ); Mon, 19 Aug 2019 10:18:01 -0400 Received: by mail-wr1-f66.google.com with SMTP id z1so8898001wru.13 for ; Mon, 19 Aug 2019 07:17:59 -0700 (PDT) From: Ard Biesheuvel Subject: [PATCH v13 3/6] crypto: arm64/aes-cts-cbc - factor out CBC en/decryption of a walk Date: Mon, 19 Aug 2019 17:17:35 +0300 Message-Id: <20190819141738.1231-4-ard.biesheuvel@linaro.org> In-Reply-To: <20190819141738.1231-1-ard.biesheuvel@linaro.org> References: <20190819141738.1231-1-ard.biesheuvel@linaro.org> Sender: linux-fscrypt-owner@vger.kernel.org To: linux-crypto@vger.kernel.org Cc: Ard Biesheuvel , Herbert Xu , Eric Biggers , dm-devel@redhat.com, linux-fscrypt@vger.kernel.org, Gilad Ben-Yossef , Milan Broz List-ID: The plain CBC driver and the CTS one share some code that iterates over a scatterwalk and invokes the CBC asm code to do the processing. The upcoming ESSIV/CBC mode will clone that pattern for the third time, so let's factor it out first. Signed-off-by: Ard Biesheuvel --- arch/arm64/crypto/aes-glue.c | 82 ++++++++++---------- 1 file changed, 40 insertions(+), 42 deletions(-) diff --git a/arch/arm64/crypto/aes-glue.c b/arch/arm64/crypto/aes-glue.c index 55d6d4838708..23abf335f1ee 100644 --- a/arch/arm64/crypto/aes-glue.c +++ b/arch/arm64/crypto/aes-glue.c @@ -186,46 +186,64 @@ static int ecb_decrypt(struct skcipher_request *req) return err; } -static int cbc_encrypt(struct skcipher_request *req) +static int cbc_encrypt_walk(struct skcipher_request *req, + struct skcipher_walk *walk) { struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); struct crypto_aes_ctx *ctx = crypto_skcipher_ctx(tfm); - int err, rounds = 6 + ctx->key_length / 4; - struct skcipher_walk walk; + int err = 0, rounds = 6 + ctx->key_length / 4; unsigned int blocks; - err = skcipher_walk_virt(&walk, req, false); - - while ((blocks = (walk.nbytes / AES_BLOCK_SIZE))) { + while ((blocks = (walk->nbytes / AES_BLOCK_SIZE))) { kernel_neon_begin(); - aes_cbc_encrypt(walk.dst.virt.addr, walk.src.virt.addr, - ctx->key_enc, rounds, blocks, walk.iv); + aes_cbc_encrypt(walk->dst.virt.addr, walk->src.virt.addr, + ctx->key_enc, rounds, blocks, walk->iv); kernel_neon_end(); - err = skcipher_walk_done(&walk, walk.nbytes % AES_BLOCK_SIZE); + err = skcipher_walk_done(walk, walk->nbytes % AES_BLOCK_SIZE); } return err; } -static int cbc_decrypt(struct skcipher_request *req) +static int cbc_encrypt(struct skcipher_request *req) { - struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); - struct crypto_aes_ctx *ctx = crypto_skcipher_ctx(tfm); - int err, rounds = 6 + ctx->key_length / 4; struct skcipher_walk walk; - unsigned int blocks; + int err; err = skcipher_walk_virt(&walk, req, false); + if (err) + return err; + return cbc_encrypt_walk(req, &walk); +} - while ((blocks = (walk.nbytes / AES_BLOCK_SIZE))) { +static int cbc_decrypt_walk(struct skcipher_request *req, + struct skcipher_walk *walk) +{ + struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); + struct crypto_aes_ctx *ctx = crypto_skcipher_ctx(tfm); + int err = 0, rounds = 6 + ctx->key_length / 4; + unsigned int blocks; + + while ((blocks = (walk->nbytes / AES_BLOCK_SIZE))) { kernel_neon_begin(); - aes_cbc_decrypt(walk.dst.virt.addr, walk.src.virt.addr, - ctx->key_dec, rounds, blocks, walk.iv); + aes_cbc_decrypt(walk->dst.virt.addr, walk->src.virt.addr, + ctx->key_dec, rounds, blocks, walk->iv); kernel_neon_end(); - err = skcipher_walk_done(&walk, walk.nbytes % AES_BLOCK_SIZE); + err = skcipher_walk_done(walk, walk->nbytes % AES_BLOCK_SIZE); } return err; } +static int cbc_decrypt(struct skcipher_request *req) +{ + struct skcipher_walk walk; + int err; + + err = skcipher_walk_virt(&walk, req, false); + if (err) + return err; + return cbc_decrypt_walk(req, &walk); +} + static int cts_cbc_init_tfm(struct crypto_skcipher *tfm) { crypto_skcipher_set_reqsize(tfm, sizeof(struct cts_cbc_req_ctx)); @@ -251,22 +269,12 @@ static int cts_cbc_encrypt(struct skcipher_request *req) } if (cbc_blocks > 0) { - unsigned int blocks; - skcipher_request_set_crypt(&rctx->subreq, req->src, req->dst, cbc_blocks * AES_BLOCK_SIZE, req->iv); - err = skcipher_walk_virt(&walk, &rctx->subreq, false); - - while ((blocks = (walk.nbytes / AES_BLOCK_SIZE))) { - kernel_neon_begin(); - aes_cbc_encrypt(walk.dst.virt.addr, walk.src.virt.addr, - ctx->key_enc, rounds, blocks, walk.iv); - kernel_neon_end(); - err = skcipher_walk_done(&walk, - walk.nbytes % AES_BLOCK_SIZE); - } + err = skcipher_walk_virt(&walk, &rctx->subreq, false) ?: + cbc_encrypt_walk(&rctx->subreq, &walk); if (err) return err; @@ -316,22 +324,12 @@ static int cts_cbc_decrypt(struct skcipher_request *req) } if (cbc_blocks > 0) { - unsigned int blocks; - skcipher_request_set_crypt(&rctx->subreq, req->src, req->dst, cbc_blocks * AES_BLOCK_SIZE, req->iv); - err = skcipher_walk_virt(&walk, &rctx->subreq, false); - - while ((blocks = (walk.nbytes / AES_BLOCK_SIZE))) { - kernel_neon_begin(); - aes_cbc_decrypt(walk.dst.virt.addr, walk.src.virt.addr, - ctx->key_dec, rounds, blocks, walk.iv); - kernel_neon_end(); - err = skcipher_walk_done(&walk, - walk.nbytes % AES_BLOCK_SIZE); - } + err = skcipher_walk_virt(&walk, &rctx->subreq, false) ?: + cbc_decrypt_walk(&rctx->subreq, &walk); if (err) return err; -- 2.17.1