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/*
* Bit sliced AES using NEON instructions
*
* Copyright (C) 2016 - 2017 Linaro Ltd <ard.biesheuvel@linaro.org>
*
* 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
* published by the Free Software Foundation.
*/
#include <asm/neon.h>
#include <asm/simd.h>
#include <crypto/aes.h>
#include <crypto/internal/simd.h>
#include <crypto/internal/skcipher.h>
#include <crypto/xts.h>
#include <linux/module.h>
#include "aes-ctr-fallback.h"
MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
MODULE_LICENSE("GPL v2");
MODULE_ALIAS_CRYPTO("ecb(aes)");
MODULE_ALIAS_CRYPTO("cbc(aes)");
MODULE_ALIAS_CRYPTO("ctr(aes)");
MODULE_ALIAS_CRYPTO("xts(aes)");
asmlinkage void aesbs_convert_key(u8 out[], u32 const rk[], int rounds);
asmlinkage void aesbs_ecb_encrypt(u8 out[], u8 const in[], u8 const rk[],
int rounds, int blocks);
asmlinkage void aesbs_ecb_decrypt(u8 out[], u8 const in[], u8 const rk[],
int rounds, int blocks);
asmlinkage void aesbs_cbc_decrypt(u8 out[], u8 const in[], u8 const rk[],
int rounds, int blocks, u8 iv[]);
asmlinkage void aesbs_ctr_encrypt(u8 out[], u8 const in[], u8 const rk[],
int rounds, int blocks, u8 iv[], u8 final[]);
asmlinkage void aesbs_xts_encrypt(u8 out[], u8 const in[], u8 const rk[],
int rounds, int blocks, u8 iv[]);
asmlinkage void aesbs_xts_decrypt(u8 out[], u8 const in[], u8 const rk[],
int rounds, int blocks, u8 iv[]);
/* borrowed from aes-neon-blk.ko */
asmlinkage void neon_aes_ecb_encrypt(u8 out[], u8 const in[], u32 const rk[],
int rounds, int blocks);
asmlinkage void neon_aes_cbc_encrypt(u8 out[], u8 const in[], u32 const rk[],
int rounds, int blocks, u8 iv[]);
struct aesbs_ctx {
u8 rk[13 * (8 * AES_BLOCK_SIZE) + 32];
int rounds;
} __aligned(AES_BLOCK_SIZE);
struct aesbs_cbc_ctx {
struct aesbs_ctx key;
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];
};
static int aesbs_setkey(struct crypto_skcipher *tfm, const u8 *in_key,
unsigned int key_len)
{
struct aesbs_ctx *ctx = crypto_skcipher_ctx(tfm);
struct crypto_aes_ctx rk;
int err;
err = crypto_aes_expand_key(&rk, in_key, key_len);
if (err)
return err;
ctx->rounds = 6 + key_len / 4;
kernel_neon_begin();
aesbs_convert_key(ctx->rk, rk.key_enc, ctx->rounds);
kernel_neon_end();
return 0;
}
static int __ecb_crypt(struct skcipher_request *req,
void (*fn)(u8 out[], u8 const in[], u8 const rk[],
int rounds, int blocks))
{
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
struct aesbs_ctx *ctx = crypto_skcipher_ctx(tfm);
struct skcipher_walk walk;
int err;
err = skcipher_walk_virt(&walk, req, false);
while (walk.nbytes >= AES_BLOCK_SIZE) {
unsigned int blocks = walk.nbytes / AES_BLOCK_SIZE;
if (walk.nbytes < walk.total)
blocks = round_down(blocks,
walk.stride / AES_BLOCK_SIZE);
kernel_neon_begin();
fn(walk.dst.virt.addr, walk.src.virt.addr, ctx->rk,
ctx->rounds, blocks);
kernel_neon_end();
err = skcipher_walk_done(&walk,
walk.nbytes - blocks * AES_BLOCK_SIZE);
}
return err;
}
static int ecb_encrypt(struct skcipher_request *req)
{
return __ecb_crypt(req, aesbs_ecb_encrypt);
}
static int ecb_decrypt(struct skcipher_request *req)
{
return __ecb_crypt(req, aesbs_ecb_decrypt);
}
static int aesbs_cbc_setkey(struct crypto_skcipher *tfm, const u8 *in_key,
unsigned int key_len)
{
struct aesbs_cbc_ctx *ctx = crypto_skcipher_ctx(tfm);
struct crypto_aes_ctx rk;
int err;
err = crypto_aes_expand_key(&rk, in_key, key_len);
if (err)
return err;
ctx->key.rounds = 6 + key_len / 4;
memcpy(ctx->enc, rk.key_enc, sizeof(ctx->enc));
kernel_neon_begin();
aesbs_convert_key(ctx->key.rk, rk.key_enc, ctx->key.rounds);
kernel_neon_end();
return 0;
}
static int cbc_encrypt(struct skcipher_request *req)
{
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
struct aesbs_cbc_ctx *ctx = crypto_skcipher_ctx(tfm);
struct skcipher_walk walk;
int err;
err = skcipher_walk_virt(&walk, req, false);
while (walk.nbytes >= AES_BLOCK_SIZE) {
unsigned int blocks = walk.nbytes / AES_BLOCK_SIZE;
/* fall back to the non-bitsliced NEON implementation */
kernel_neon_begin();
neon_aes_cbc_encrypt(walk.dst.virt.addr, walk.src.virt.addr,
ctx->enc, ctx->key.rounds, blocks,
walk.iv);
kernel_neon_end();
err = skcipher_walk_done(&walk, walk.nbytes % AES_BLOCK_SIZE);
}
return err;
}
static int cbc_decrypt(struct skcipher_request *req)
{
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
struct aesbs_cbc_ctx *ctx = crypto_skcipher_ctx(tfm);
struct skcipher_walk walk;
int err;
err = skcipher_walk_virt(&walk, req, false);
while (walk.nbytes >= AES_BLOCK_SIZE) {
unsigned int blocks = walk.nbytes / AES_BLOCK_SIZE;
if (walk.nbytes < walk.total)
blocks = round_down(blocks,
walk.stride / AES_BLOCK_SIZE);
kernel_neon_begin();
aesbs_cbc_decrypt(walk.dst.virt.addr, walk.src.virt.addr,
ctx->key.rk, ctx->key.rounds, blocks,
walk.iv);
kernel_neon_end();
err = skcipher_walk_done(&walk,
walk.nbytes - blocks * AES_BLOCK_SIZE);
}
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,
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