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/*
* Bit sliced AES using NEON instructions
*
* Copyright (C) 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 <crypto/aes.h>
#include <crypto/cbc.h>
#include <crypto/internal/simd.h>
#include <crypto/internal/skcipher.h>
#include <crypto/xts.h>
#include <linux/module.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 ctr[], 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[]);
struct aesbs_ctx {
int rounds;
u8 rk[13 * (8 * AES_BLOCK_SIZE) + 32] __aligned(AES_BLOCK_SIZE);
};
struct aesbs_cbc_ctx {
struct aesbs_ctx key;
struct crypto_cipher *enc_tfm;
};
struct aesbs_xts_ctx {
struct aesbs_ctx key;
struct crypto_cipher *tweak_tfm;
};
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, true);
kernel_neon_begin();
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);
fn(walk.dst.virt.addr, walk.src.virt.addr, ctx->rk,
ctx->rounds, blocks);
err = skcipher_walk_done(&walk,
walk.nbytes - blocks * AES_BLOCK_SIZE);
}
kernel_neon_end();
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;
kernel_neon_begin();
aesbs_convert_key(ctx->key.rk, rk.key_enc, ctx->key.rounds);
kernel_neon_end();
return crypto_cipher_setkey(ctx->enc_tfm, in_key, key_len);
}
static void cbc_encrypt_one(struct crypto_skcipher *tfm, const u8 *src, u8 *dst)
{
struct aesbs_cbc_ctx *ctx = crypto_skcipher_ctx(tfm);
crypto_cipher_encrypt_one(ctx->enc_tfm, dst, src);
}
static int cbc_encrypt(struct skcipher_request *req)
{
return crypto_cbc_encrypt_walk(req, cbc_encrypt_one);
}
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, true);
kernel_neon_begin();
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);
aesbs_cbc_decrypt(walk.dst.virt.addr, walk.src.virt.addr,
ctx->key.rk, ctx->key.rounds, blocks,
walk.iv);
err = skcipher_walk_done(&walk,
walk.nbytes - blocks * AES_BLOCK_SIZE);
}
kernel_neon_end();
return err;
}
static int cbc_init(struct crypto_tfm *tfm)
{
struct aesbs_cbc_ctx *ctx = crypto_tfm_ctx(tfm);
ctx->enc_tfm = crypto_alloc_cipher("aes", 0, 0);
return PTR_ERR_OR_ZERO(ctx->enc_tfm);
}
static void cbc_exit(struct crypto_tfm *tfm)
{
struct aesbs_cbc_ctx *ctx = crypto_tfm_ctx(tfm);
crypto_free_cipher(ctx->enc_tfm);
}
static int ctr_encrypt(struct skcipher_request *req)
{
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
struct aesbs_ctx *ctx = crypto_skcipher_ctx(tfm);
struct skcipher_walk walk;
u8 buf[AES_BLOCK_SIZE];
int err;
err = skcipher_walk_virt(&walk, req, true);
kernel_neon_begin();
while (walk.nbytes > 0) {
unsigned int blocks = walk.nbytes / AES_BLOCK_SIZE;
u8 *final = (walk.total % AES_BLOCK_SIZE) ? buf : NULL;
if (walk.nbytes < walk.total) {
blocks = round_down(blocks,
walk.stride / AES_BLOCK_SIZE);
final = NULL;
}
aesbs_ctr_encrypt(walk.dst.virt.addr, walk.src.virt.addr,
ctx->rk, ctx->rounds, blocks, walk.iv, final);
if (final) {
u8 *dst = walk.dst.virt.addr + blocks * AES_BLOCK_SIZE;
u8 *src = walk.src.virt.addr + blocks * AES_BLOCK_SIZE;
crypto_xor_cpy(dst, src, final,
walk.total % AES_BLOCK_SIZE);
err = skcipher_walk_done(&walk, 0);
break;
}
err = skcipher_walk_done(&walk,
walk.nbytes - blocks * AES_BLOCK_SIZE);
}
kernel_neon_end();
return err;
}
static int aesbs_xts_setkey(struct crypto_skcipher *tfm, const u8 *in_key,
unsigned int key_len)
{
struct aesbs_xts_ctx *ctx = crypto_skcipher_ctx(tfm);
int err;
err = xts_verify_key(tfm, in_key, key_len);
if (err)
return err;
key_len /= 2;
err = crypto_cipher_setkey(ctx->tweak_tfm, in_key + key_len, key_len);
if (err)
return err;
return aesbs_setkey(tfm, in_key, key_len);
}
static int xts_init(struct crypto_tfm *tfm)
{
struct aesbs_xts_ctx *ctx = crypto_tfm_ctx(tfm);
ctx->tweak_tfm = crypto_alloc_cipher("aes", 0, 0);
return PTR_ERR_OR_ZERO(ctx->tweak_tfm);
}
static void xts_exit(struct crypto_tfm *tfm)
{
struct aesbs_xts_ctx *ctx = crypto_tfm_ctx(tfm);
crypto_free_cipher(ctx->tweak_tfm);
}
static int __xts_crypt(struct skcipher_request *req,
void (*fn)(u8 out[], u8 const in[], u8 const rk[],
int rounds, int blocks, u8 iv[]))
{
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
struct aesbs_xts_ctx *ctx = crypto_skcipher_ctx(tfm);
struct skcipher_walk walk;
int err;
err = skcipher_walk_virt(&walk, req, true);
crypto_cipher_encrypt_one(ctx->tweak_tfm, walk.iv, walk.iv);
kernel_neon_begin();
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);
fn(walk.dst.virt.addr, walk.src.virt.addr, ctx->key.rk,
ctx->key.rounds, blocks, walk.iv);
err = skcipher_walk_done(&walk,
walk.nbytes - blocks * AES_BLOCK_SIZE);
}
kernel_neon_end();
return err;
}
static int xts_encrypt(struct skcipher_request *req)
{
return __xts_crypt(req, aesbs_xts_encrypt);
}
static int xts_decrypt(struct skcipher_request *req)
{
return __xts_crypt(req, aesbs_xts_decrypt);
}
static struct skcipher_alg aes_algs[] = { {
.base.cra_name = "__ecb(aes)",
.base.cra_driver_name = "__ecb-aes-neonbs",
.base.cra_priority = 250,
.base.cra_blocksize = AES_BLOCK_SIZE,
.base.cra_ctxsize = sizeof(struct aesbs_ctx),
.base.cra_module = THIS_MODULE,
.base.cra_flags = CRYPTO_ALG_INTERNAL,
.min_keysize = AES_MIN_KEY_SIZE,
.max_keysize = AES_MAX_KEY_SIZE,
.walksize = 8 * AES_BLOCK_SIZE,
.setkey = aesbs_setkey,
.encrypt = ecb_encrypt,
.decrypt = ecb_decrypt,
}, {
.base.cra_name = "__cbc(aes)",
.base.cra_driver_name = "__cbc-aes-neonbs",
.base.cra_priority = 250,
.base.cra_blocksize = AES_BLOCK_SIZE,
.base.cra_ctxsize = sizeof(struct aesbs_cbc_ctx),
.base.cra_module = THIS_MODULE,
.base.cra_flags = CRYPTO_ALG_INTERNAL,
.base.cra_init = cbc_init,
.base.cra_exit = cbc_exit,
.min_keysize = AES_MIN_KEY_SIZE,
.max_keysize = AES_MAX_KEY_SIZE,
.walksize = 8 * AES_BLOCK_SIZE,
.ivsize = AES_BLOCK_SIZE,
.setkey = aesbs_cbc_setkey,
.encrypt = cbc_encrypt,
.decrypt = cbc_decrypt,
}, {
.base.cra_name = "__ctr(aes)",
.base.cra_driver_name = "__ctr-aes-neonbs",
.base.cra_priority = 250,
.base.cra_blocksize = 1,
.base.cra_ctxsize = sizeof(struct aesbs_ctx),
.base.cra_module = THIS_MODULE,
.base.cra_flags = CRYPTO_ALG_INTERNAL,
.min_keysize = AES_MIN_KEY_SIZE,
.max_keysize = AES_MAX_KEY_SIZE,
.chunksize = AES_BLOCK_SIZE,
.walksize = 8 * AES_BLOCK_SIZE,
.ivsize = AES_BLOCK_SIZE,
.setkey = aesbs_setkey,
.encrypt = ctr_encrypt,
.decrypt = ctr_encrypt,
}, {
.base.cra_name = "__xts(aes)",
.base.cra_driver_name = "__xts-aes-neonbs",
.base.cra_priority = 250,
.base.cra_blocksize = AES_BLOCK_SIZE,
.base.cra_ctxsize = sizeof(struct aesbs_xts_ctx),
.base.cra_module = THIS_MODULE,
.base.cra_flags = CRYPTO_ALG_INTERNAL,
.base.cra_init = xts_init,
.base.cra_exit = xts_exit,
.min_keysize = 2 * AES_MIN_KEY_SIZE,
.max_keysize = 2 * AES_MAX_KEY_SIZE,
.walksize = 8 * AES_BLOCK_SIZE,
.ivsize = AES_BLOCK_SIZE,
.setkey = aesbs_xts_setkey,
.encrypt = xts_encrypt,
.decrypt = xts_decrypt,
} };
static struct simd_skcipher_alg *aes_simd_algs[ARRAY_SIZE(aes_algs)];
static void aes_exit(void)
{
int i;
for (i = 0; i < ARRAY_SIZE(aes_simd_algs); i++)
if (aes_simd_algs[i])
simd_skcipher_free(aes_simd_algs[i]);
crypto_unregister_skciphers(aes_algs, ARRAY_SIZE(aes_algs));
}
static int __init aes_init(void)
{
struct simd_skcipher_alg *simd;
const char *basename;
const char *algname;
const char *drvname;
int err;
int i;
if (!(elf_hwcap & HWCAP_NEON))
return -ENODEV;
err = crypto_register_skciphers(aes_algs, ARRAY_SIZE(aes_algs));
if (err)
return err;
for (i = 0; i < ARRAY_SIZE(aes_algs); i++) {
if (!(aes_algs[i].base.cra_flags & CRYPTO_ALG_INTERNAL))
continue;
algname = aes_algs[i].base.cra_name + 2;
drvname = aes_algs[i].base.cra_driver_name + 2;
basename = aes_algs[i].base.cra_driver_name;
simd = simd_skcipher_create_compat(algname, drvname, basename);
err = PTR_ERR(simd);
if (IS_ERR(simd))
goto unregister_simds;
aes_simd_algs[i] = simd;
}
return 0;
unregister_simds:
aes_exit();
return err;
}
late_initcall(aes_init);
module_exit(aes_exit);