blob: 5d934a0039d76d22cda3c6f702238819960ba50a [file] [log] [blame]
/*
* linux/arch/arm/crypto/aesbs-glue.c - glue code for NEON bit sliced AES
*
* Copyright (C) 2013 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/ablk_helper.h>
#include <crypto/algapi.h>
#include <linux/module.h>
#include <crypto/xts.h>
#include "aes_glue.h"
#define BIT_SLICED_KEY_MAXSIZE (128 * (AES_MAXNR - 1) + 2 * AES_BLOCK_SIZE)
struct BS_KEY {
struct AES_KEY rk;
int converted;
u8 __aligned(8) bs[BIT_SLICED_KEY_MAXSIZE];
} __aligned(8);
asmlinkage void bsaes_enc_key_convert(u8 out[], struct AES_KEY const *in);
asmlinkage void bsaes_dec_key_convert(u8 out[], struct AES_KEY const *in);
asmlinkage void bsaes_cbc_encrypt(u8 const in[], u8 out[], u32 bytes,
struct BS_KEY *key, u8 iv[]);
asmlinkage void bsaes_ctr32_encrypt_blocks(u8 const in[], u8 out[], u32 blocks,
struct BS_KEY *key, u8 const iv[]);
asmlinkage void bsaes_xts_encrypt(u8 const in[], u8 out[], u32 bytes,
struct BS_KEY *key, u8 tweak[]);
asmlinkage void bsaes_xts_decrypt(u8 const in[], u8 out[], u32 bytes,
struct BS_KEY *key, u8 tweak[]);
struct aesbs_cbc_ctx {
struct AES_KEY enc;
struct BS_KEY dec;
};
struct aesbs_ctr_ctx {
struct BS_KEY enc;
};
struct aesbs_xts_ctx {
struct BS_KEY enc;
struct BS_KEY dec;
struct AES_KEY twkey;
};
static int aesbs_cbc_set_key(struct crypto_tfm *tfm, const u8 *in_key,
unsigned int key_len)
{
struct aesbs_cbc_ctx *ctx = crypto_tfm_ctx(tfm);
int bits = key_len * 8;
if (private_AES_set_encrypt_key(in_key, bits, &ctx->enc)) {
tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
return -EINVAL;
}
ctx->dec.rk = ctx->enc;
private_AES_set_decrypt_key(in_key, bits, &ctx->dec.rk);
ctx->dec.converted = 0;
return 0;
}
static int aesbs_ctr_set_key(struct crypto_tfm *tfm, const u8 *in_key,
unsigned int key_len)
{
struct aesbs_ctr_ctx *ctx = crypto_tfm_ctx(tfm);
int bits = key_len * 8;
if (private_AES_set_encrypt_key(in_key, bits, &ctx->enc.rk)) {
tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
return -EINVAL;
}
ctx->enc.converted = 0;
return 0;
}
static int aesbs_xts_set_key(struct crypto_tfm *tfm, const u8 *in_key,
unsigned int key_len)
{
struct aesbs_xts_ctx *ctx = crypto_tfm_ctx(tfm);
int bits = key_len * 4;
int err;
err = xts_check_key(tfm, in_key, key_len);
if (err)
return err;
if (private_AES_set_encrypt_key(in_key, bits, &ctx->enc.rk)) {
tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
return -EINVAL;
}
ctx->dec.rk = ctx->enc.rk;
private_AES_set_decrypt_key(in_key, bits, &ctx->dec.rk);
private_AES_set_encrypt_key(in_key + key_len / 2, bits, &ctx->twkey);
ctx->enc.converted = ctx->dec.converted = 0;
return 0;
}
static int aesbs_cbc_encrypt(struct blkcipher_desc *desc,
struct scatterlist *dst,
struct scatterlist *src, unsigned int nbytes)
{
struct aesbs_cbc_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
struct blkcipher_walk walk;
int err;
blkcipher_walk_init(&walk, dst, src, nbytes);
err = blkcipher_walk_virt(desc, &walk);
while (walk.nbytes) {
u32 blocks = walk.nbytes / AES_BLOCK_SIZE;
u8 *src = walk.src.virt.addr;
if (walk.dst.virt.addr == walk.src.virt.addr) {
u8 *iv = walk.iv;
do {
crypto_xor(src, iv, AES_BLOCK_SIZE);
AES_encrypt(src, src, &ctx->enc);
iv = src;
src += AES_BLOCK_SIZE;
} while (--blocks);
memcpy(walk.iv, iv, AES_BLOCK_SIZE);
} else {
u8 *dst = walk.dst.virt.addr;
do {
crypto_xor(walk.iv, src, AES_BLOCK_SIZE);
AES_encrypt(walk.iv, dst, &ctx->enc);
memcpy(walk.iv, dst, AES_BLOCK_SIZE);
src += AES_BLOCK_SIZE;
dst += AES_BLOCK_SIZE;
} while (--blocks);
}
err = blkcipher_walk_done(desc, &walk, walk.nbytes % AES_BLOCK_SIZE);
}
return err;
}
static int aesbs_cbc_decrypt(struct blkcipher_desc *desc,
struct scatterlist *dst,
struct scatterlist *src, unsigned int nbytes)
{
struct aesbs_cbc_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
struct blkcipher_walk walk;
int err;
blkcipher_walk_init(&walk, dst, src, nbytes);
err = blkcipher_walk_virt_block(desc, &walk, 8 * AES_BLOCK_SIZE);
while ((walk.nbytes / AES_BLOCK_SIZE) >= 8) {
kernel_neon_begin();
bsaes_cbc_encrypt(walk.src.virt.addr, walk.dst.virt.addr,
walk.nbytes, &ctx->dec, walk.iv);
kernel_neon_end();
err = blkcipher_walk_done(desc, &walk, walk.nbytes % AES_BLOCK_SIZE);
}
while (walk.nbytes) {
u32 blocks = walk.nbytes / AES_BLOCK_SIZE;
u8 *dst = walk.dst.virt.addr;
u8 *src = walk.src.virt.addr;
u8 bk[2][AES_BLOCK_SIZE];
u8 *iv = walk.iv;
do {
if (walk.dst.virt.addr == walk.src.virt.addr)
memcpy(bk[blocks & 1], src, AES_BLOCK_SIZE);
AES_decrypt(src, dst, &ctx->dec.rk);
crypto_xor(dst, iv, AES_BLOCK_SIZE);
if (walk.dst.virt.addr == walk.src.virt.addr)
iv = bk[blocks & 1];
else
iv = src;
dst += AES_BLOCK_SIZE;
src += AES_BLOCK_SIZE;
} while (--blocks);
err = blkcipher_walk_done(desc, &walk, walk.nbytes % AES_BLOCK_SIZE);
}
return err;
}
static void inc_be128_ctr(__be32 ctr[], u32 addend)
{
int i;
for (i = 3; i >= 0; i--, addend = 1) {
u32 n = be32_to_cpu(ctr[i]) + addend;
ctr[i] = cpu_to_be32(n);
if (n >= addend)
break;
}
}
static int aesbs_ctr_encrypt(struct blkcipher_desc *desc,
struct scatterlist *dst, struct scatterlist *src,
unsigned int nbytes)
{
struct aesbs_ctr_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
struct blkcipher_walk walk;
u32 blocks;
int err;
blkcipher_walk_init(&walk, dst, src, nbytes);
err = blkcipher_walk_virt_block(desc, &walk, 8 * AES_BLOCK_SIZE);
while ((blocks = walk.nbytes / AES_BLOCK_SIZE)) {
u32 tail = walk.nbytes % AES_BLOCK_SIZE;
__be32 *ctr = (__be32 *)walk.iv;
u32 headroom = UINT_MAX - be32_to_cpu(ctr[3]);
/* avoid 32 bit counter overflow in the NEON code */
if (unlikely(headroom < blocks)) {
blocks = headroom + 1;
tail = walk.nbytes - blocks * AES_BLOCK_SIZE;
}
kernel_neon_begin();
bsaes_ctr32_encrypt_blocks(walk.src.virt.addr,
walk.dst.virt.addr, blocks,
&ctx->enc, walk.iv);
kernel_neon_end();
inc_be128_ctr(ctr, blocks);
nbytes -= blocks * AES_BLOCK_SIZE;
if (nbytes && nbytes == tail && nbytes <= AES_BLOCK_SIZE)
break;
err = blkcipher_walk_done(desc, &walk, tail);
}
if (walk.nbytes) {
u8 *tdst = walk.dst.virt.addr + blocks * AES_BLOCK_SIZE;
u8 *tsrc = walk.src.virt.addr + blocks * AES_BLOCK_SIZE;
u8 ks[AES_BLOCK_SIZE];
AES_encrypt(walk.iv, ks, &ctx->enc.rk);
if (tdst != tsrc)
memcpy(tdst, tsrc, nbytes);
crypto_xor(tdst, ks, nbytes);
err = blkcipher_walk_done(desc, &walk, 0);
}
return err;
}
static int aesbs_xts_encrypt(struct blkcipher_desc *desc,
struct scatterlist *dst,
struct scatterlist *src, unsigned int nbytes)
{
struct aesbs_xts_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
struct blkcipher_walk walk;
int err;
blkcipher_walk_init(&walk, dst, src, nbytes);
err = blkcipher_walk_virt_block(desc, &walk, 8 * AES_BLOCK_SIZE);
/* generate the initial tweak */
AES_encrypt(walk.iv, walk.iv, &ctx->twkey);
while (walk.nbytes) {
kernel_neon_begin();
bsaes_xts_encrypt(walk.src.virt.addr, walk.dst.virt.addr,
walk.nbytes, &ctx->enc, walk.iv);
kernel_neon_end();
err = blkcipher_walk_done(desc, &walk, walk.nbytes % AES_BLOCK_SIZE);
}
return err;
}
static int aesbs_xts_decrypt(struct blkcipher_desc *desc,
struct scatterlist *dst,
struct scatterlist *src, unsigned int nbytes)
{
struct aesbs_xts_ctx *ctx = crypto_blkcipher_ctx(desc->tfm);
struct blkcipher_walk walk;
int err;
blkcipher_walk_init(&walk, dst, src, nbytes);
err = blkcipher_walk_virt_block(desc, &walk, 8 * AES_BLOCK_SIZE);
/* generate the initial tweak */
AES_encrypt(walk.iv, walk.iv, &ctx->twkey);
while (walk.nbytes) {
kernel_neon_begin();
bsaes_xts_decrypt(walk.src.virt.addr, walk.dst.virt.addr,
walk.nbytes, &ctx->dec, walk.iv);
kernel_neon_end();
err = blkcipher_walk_done(desc, &walk, walk.nbytes % AES_BLOCK_SIZE);
}
return err;
}
static struct crypto_alg aesbs_algs[] = { {
.cra_name = "__cbc-aes-neonbs",
.cra_driver_name = "__driver-cbc-aes-neonbs",
.cra_priority = 0,
.cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER |
CRYPTO_ALG_INTERNAL,
.cra_blocksize = AES_BLOCK_SIZE,
.cra_ctxsize = sizeof(struct aesbs_cbc_ctx),
.cra_alignmask = 7,
.cra_type = &crypto_blkcipher_type,
.cra_module = THIS_MODULE,
.cra_blkcipher = {
.min_keysize = AES_MIN_KEY_SIZE,
.max_keysize = AES_MAX_KEY_SIZE,
.ivsize = AES_BLOCK_SIZE,
.setkey = aesbs_cbc_set_key,
.encrypt = aesbs_cbc_encrypt,
.decrypt = aesbs_cbc_decrypt,
},
}, {
.cra_name = "__ctr-aes-neonbs",
.cra_driver_name = "__driver-ctr-aes-neonbs",
.cra_priority = 0,
.cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER |
CRYPTO_ALG_INTERNAL,
.cra_blocksize = 1,
.cra_ctxsize = sizeof(struct aesbs_ctr_ctx),
.cra_alignmask = 7,
.cra_type = &crypto_blkcipher_type,
.cra_module = THIS_MODULE,
.cra_blkcipher = {
.min_keysize = AES_MIN_KEY_SIZE,
.max_keysize = AES_MAX_KEY_SIZE,
.ivsize = AES_BLOCK_SIZE,
.setkey = aesbs_ctr_set_key,
.encrypt = aesbs_ctr_encrypt,
.decrypt = aesbs_ctr_encrypt,
},
}, {
.cra_name = "__xts-aes-neonbs",
.cra_driver_name = "__driver-xts-aes-neonbs",
.cra_priority = 0,
.cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER |
CRYPTO_ALG_INTERNAL,
.cra_blocksize = AES_BLOCK_SIZE,
.cra_ctxsize = sizeof(struct aesbs_xts_ctx),
.cra_alignmask = 7,
.cra_type = &crypto_blkcipher_type,
.cra_module = THIS_MODULE,
.cra_blkcipher = {
.min_keysize = 2 * AES_MIN_KEY_SIZE,
.max_keysize = 2 * AES_MAX_KEY_SIZE,
.ivsize = AES_BLOCK_SIZE,
.setkey = aesbs_xts_set_key,
.encrypt = aesbs_xts_encrypt,
.decrypt = aesbs_xts_decrypt,
},
}, {
.cra_name = "cbc(aes)",
.cra_driver_name = "cbc-aes-neonbs",
.cra_priority = 250,
.cra_flags = CRYPTO_ALG_TYPE_ABLKCIPHER|CRYPTO_ALG_ASYNC,
.cra_blocksize = AES_BLOCK_SIZE,
.cra_ctxsize = sizeof(struct async_helper_ctx),
.cra_alignmask = 7,
.cra_type = &crypto_ablkcipher_type,
.cra_module = THIS_MODULE,
.cra_init = ablk_init,
.cra_exit = ablk_exit,
.cra_ablkcipher = {
.min_keysize = AES_MIN_KEY_SIZE,
.max_keysize = AES_MAX_KEY_SIZE,
.ivsize = AES_BLOCK_SIZE,
.setkey = ablk_set_key,
.encrypt = __ablk_encrypt,
.decrypt = ablk_decrypt,
}
}, {
.cra_name = "ctr(aes)",
.cra_driver_name = "ctr-aes-neonbs",
.cra_priority = 250,
.cra_flags = CRYPTO_ALG_TYPE_ABLKCIPHER|CRYPTO_ALG_ASYNC,
.cra_blocksize = 1,
.cra_ctxsize = sizeof(struct async_helper_ctx),
.cra_alignmask = 7,
.cra_type = &crypto_ablkcipher_type,
.cra_module = THIS_MODULE,
.cra_init = ablk_init,
.cra_exit = ablk_exit,
.cra_ablkcipher = {
.min_keysize = AES_MIN_KEY_SIZE,
.max_keysize = AES_MAX_KEY_SIZE,
.ivsize = AES_BLOCK_SIZE,
.setkey = ablk_set_key,
.encrypt = ablk_encrypt,
.decrypt = ablk_decrypt,
}
}, {
.cra_name = "xts(aes)",
.cra_driver_name = "xts-aes-neonbs",
.cra_priority = 250,
.cra_flags = CRYPTO_ALG_TYPE_ABLKCIPHER|CRYPTO_ALG_ASYNC,
.cra_blocksize = AES_BLOCK_SIZE,
.cra_ctxsize = sizeof(struct async_helper_ctx),
.cra_alignmask = 7,
.cra_type = &crypto_ablkcipher_type,
.cra_module = THIS_MODULE,
.cra_init = ablk_init,
.cra_exit = ablk_exit,
.cra_ablkcipher = {
.min_keysize = 2 * AES_MIN_KEY_SIZE,
.max_keysize = 2 * AES_MAX_KEY_SIZE,
.ivsize = AES_BLOCK_SIZE,
.setkey = ablk_set_key,
.encrypt = ablk_encrypt,
.decrypt = ablk_decrypt,
}
} };
static int __init aesbs_mod_init(void)
{
if (!cpu_has_neon())
return -ENODEV;
return crypto_register_algs(aesbs_algs, ARRAY_SIZE(aesbs_algs));
}
static void __exit aesbs_mod_exit(void)
{
crypto_unregister_algs(aesbs_algs, ARRAY_SIZE(aesbs_algs));
}
module_init(aesbs_mod_init);
module_exit(aesbs_mod_exit);
MODULE_DESCRIPTION("Bit sliced AES in CBC/CTR/XTS modes using NEON");
MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
MODULE_LICENSE("GPL");