From ec808bbef0b15ad103771222d419245617378f32 Mon Sep 17 00:00:00 2001 From: Ard Biesheuvel Date: Mon, 24 Jul 2017 11:28:15 +0100 Subject: crypto: arm64/aes-bs - implement non-SIMD fallback for AES-CTR Of the various chaining modes implemented by the bit sliced AES driver, only CTR is exposed as a synchronous cipher, and requires a fallback in order to remain usable once we update the kernel mode NEON handling logic to disallow nested use. So wire up the existing CTR fallback C code. Signed-off-by: Ard Biesheuvel Signed-off-by: Herbert Xu --- arch/arm64/crypto/Kconfig | 1 + arch/arm64/crypto/aes-neonbs-glue.c | 48 +++++++++++++++++++++++++++++++++---- 2 files changed, 44 insertions(+), 5 deletions(-) (limited to 'arch/arm64/crypto') diff --git a/arch/arm64/crypto/Kconfig b/arch/arm64/crypto/Kconfig index a068dcbe2518..f9e264b83366 100644 --- a/arch/arm64/crypto/Kconfig +++ b/arch/arm64/crypto/Kconfig @@ -89,6 +89,7 @@ config CRYPTO_AES_ARM64_BS depends on KERNEL_MODE_NEON select CRYPTO_BLKCIPHER select CRYPTO_AES_ARM64_NEON_BLK + select CRYPTO_AES_ARM64 select CRYPTO_SIMD endif diff --git a/arch/arm64/crypto/aes-neonbs-glue.c b/arch/arm64/crypto/aes-neonbs-glue.c index 9001aec16007..c55d68ccb89f 100644 --- a/arch/arm64/crypto/aes-neonbs-glue.c +++ b/arch/arm64/crypto/aes-neonbs-glue.c @@ -1,7 +1,7 @@ /* * Bit sliced AES using NEON instructions * - * Copyright (C) 2016 Linaro Ltd + * Copyright (C) 2016 - 2017 Linaro Ltd * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as @@ -9,12 +9,15 @@ */ #include +#include #include #include #include #include #include +#include "aes-ctr-fallback.h" + MODULE_AUTHOR("Ard Biesheuvel "); MODULE_LICENSE("GPL v2"); @@ -58,6 +61,11 @@ struct aesbs_cbc_ctx { u32 enc[AES_MAX_KEYLENGTH_U32]; }; +struct aesbs_ctr_ctx { + struct aesbs_ctx key; /* must be first member */ + struct crypto_aes_ctx fallback; +}; + struct aesbs_xts_ctx { struct aesbs_ctx key; u32 twkey[AES_MAX_KEYLENGTH_U32]; @@ -196,6 +204,25 @@ static int cbc_decrypt(struct skcipher_request *req) return err; } +static int aesbs_ctr_setkey_sync(struct crypto_skcipher *tfm, const u8 *in_key, + unsigned int key_len) +{ + struct aesbs_ctr_ctx *ctx = crypto_skcipher_ctx(tfm); + int err; + + err = crypto_aes_expand_key(&ctx->fallback, in_key, key_len); + if (err) + return err; + + ctx->key.rounds = 6 + key_len / 4; + + kernel_neon_begin(); + aesbs_convert_key(ctx->key.rk, ctx->fallback.key_enc, ctx->key.rounds); + kernel_neon_end(); + + return 0; +} + static int ctr_encrypt(struct skcipher_request *req) { struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); @@ -259,6 +286,17 @@ static int aesbs_xts_setkey(struct crypto_skcipher *tfm, const u8 *in_key, return aesbs_setkey(tfm, in_key, key_len); } +static int ctr_encrypt_sync(struct skcipher_request *req) +{ + struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req); + struct aesbs_ctr_ctx *ctx = crypto_skcipher_ctx(tfm); + + if (!may_use_simd()) + return aes_ctr_encrypt_fallback(&ctx->fallback, req); + + return ctr_encrypt(req); +} + static int __xts_crypt(struct skcipher_request *req, void (*fn)(u8 out[], u8 const in[], u8 const rk[], int rounds, int blocks, u8 iv[])) @@ -355,7 +393,7 @@ static struct skcipher_alg aes_algs[] = { { .base.cra_driver_name = "ctr-aes-neonbs", .base.cra_priority = 250 - 1, .base.cra_blocksize = 1, - .base.cra_ctxsize = sizeof(struct aesbs_ctx), + .base.cra_ctxsize = sizeof(struct aesbs_ctr_ctx), .base.cra_module = THIS_MODULE, .min_keysize = AES_MIN_KEY_SIZE, @@ -363,9 +401,9 @@ static struct skcipher_alg aes_algs[] = { { .chunksize = AES_BLOCK_SIZE, .walksize = 8 * AES_BLOCK_SIZE, .ivsize = AES_BLOCK_SIZE, - .setkey = aesbs_setkey, - .encrypt = ctr_encrypt, - .decrypt = ctr_encrypt, + .setkey = aesbs_ctr_setkey_sync, + .encrypt = ctr_encrypt_sync, + .decrypt = ctr_encrypt_sync, }, { .base.cra_name = "__xts(aes)", .base.cra_driver_name = "__xts-aes-neonbs", -- cgit v1.2.3-59-g8ed1b