#include <asm/neon.h>
#include <asm/simd.h>
#include <crypto/aes.h>
#include <crypto/ctr.h>
#include <crypto/internal/simd.h>
#include <crypto/internal/skcipher.h>
#include <crypto/scatterwalk.h>
#include <crypto/xts.h>
#include <linux/module.h>
MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
MODULE_DESCRIPTION("Bit sliced AES using NEON instructions");
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[]);
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[]);
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[]);
asmlinkage void neon_aes_ctr_encrypt(u8 out[], u8 const in[], u32 const rk[],
int rounds, int bytes, u8 ctr[]);
asmlinkage void neon_aes_xts_encrypt(u8 out[], u8 const in[],
u32 const rk1[], int rounds, int bytes,
u32 const rk2[], u8 iv[], int first);
asmlinkage void neon_aes_xts_decrypt(u8 out[], u8 const in[],
u32 const rk1[], int rounds, int bytes,
u32 const rk2[], u8 iv[], int first);
struct aesbs_ctx {
u8 rk[13 * (8 * AES_BLOCK_SIZE) + 32];
int rounds;
} __aligned(AES_BLOCK_SIZE);
struct aesbs_cbc_ctr_ctx {
struct aesbs_ctx key;
u32 enc[AES_MAX_KEYLENGTH_U32];
};
struct aesbs_xts_ctx {
struct aesbs_ctx key;
u32 twkey[AES_MAX_KEYLENGTH_U32];
struct crypto_aes_ctx cts;
};
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;
rk = kmalloc(sizeof(*rk), GFP_KERNEL);
if (!rk)
return -ENOMEM;
err = aes_expandkey(rk, in_key, key_len);
if (err)
goto out;
ctx->rounds = 6 + key_len / 4;
scoped_ksimd()
aesbs_convert_key(ctx->rk, rk->key_enc, ctx->rounds);
out:
kfree_sensitive(rk);
return err;
}
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);
scoped_ksimd()
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);
}
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_ctr_setkey(struct crypto_skcipher *tfm, const u8 *in_key,
unsigned int key_len)
{
struct aesbs_cbc_ctr_ctx *ctx = crypto_skcipher_ctx(tfm);
struct crypto_aes_ctx *rk;
int err;
rk = kmalloc(sizeof(*rk), GFP_KERNEL);
if (!rk)
return -ENOMEM;
err = aes_expandkey(rk, in_key, key_len);
if (err)
goto out;
ctx->key.rounds = 6 + key_len / 4;
memcpy(ctx->enc, rk->key_enc, sizeof(ctx->enc));
scoped_ksimd()
aesbs_convert_key(ctx->key.rk, rk->key_enc, ctx->key.rounds);
out:
kfree_sensitive(rk);
return err;
}
static int cbc_encrypt(struct skcipher_request *req)
{
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
struct aesbs_cbc_ctr_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;
scoped_ksimd()
neon_aes_cbc_encrypt(walk.dst.virt.addr,
walk.src.virt.addr,
ctx->enc, ctx->key.rounds, blocks,
walk.iv);
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_ctr_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);
scoped_ksimd()
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);
}
return err;
}
static int ctr_encrypt(struct skcipher_request *req)
{
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
struct aesbs_cbc_ctr_ctx *ctx = crypto_skcipher_ctx(tfm);
struct skcipher_walk walk;
int err;
err = skcipher_walk_virt(&walk, req, false);
while (walk.nbytes > 0) {
int blocks = (walk.nbytes / AES_BLOCK_SIZE) & ~7;
int nbytes = walk.nbytes % (8 * AES_BLOCK_SIZE);
const u8 *src = walk.src.virt.addr;
u8 *dst = walk.dst.virt.addr;
scoped_ksimd() {
if (blocks >= 8) {
aesbs_ctr_encrypt(dst, src, ctx->key.rk,
ctx->key.rounds, blocks,
walk.iv);
dst += blocks * AES_BLOCK_SIZE;
src += blocks * AES_BLOCK_SIZE;
}
if (nbytes && walk.nbytes == walk.total) {
u8 buf[AES_BLOCK_SIZE];
u8 *d = dst;
if (unlikely(nbytes < AES_BLOCK_SIZE))
src = dst = memcpy(buf + sizeof(buf) -
nbytes, src, nbytes);
neon_aes_ctr_encrypt(dst, src, ctx->enc,
ctx->key.rounds, nbytes,
walk.iv);
if (unlikely(nbytes < AES_BLOCK_SIZE))
memcpy(d, dst, nbytes);
nbytes = 0;
}
}
err = skcipher_walk_done(&walk, nbytes);
}
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);
struct crypto_aes_ctx rk;
int err;
err = xts_verify_key(tfm, in_key, key_len);
if (err)
return err;
key_len /= 2;
err = aes_expandkey(&ctx->cts, in_key, key_len);
if (err)
return err;
err = aes_expandkey(&rk, in_key + key_len, key_len);
if (err)
return err;
memcpy(ctx->twkey, rk.key_enc, sizeof(ctx->twkey));
return aesbs_setkey(tfm, in_key, key_len);
}
static int __xts_crypt(struct skcipher_request *req, bool encrypt,
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);
int tail = req->cryptlen % (8 * AES_BLOCK_SIZE);
struct scatterlist sg_src[2], sg_dst[2];
struct skcipher_request subreq;
struct scatterlist *src, *dst;
struct skcipher_walk walk;
int nbytes, err;
int first = 1;
const u8 *in;
u8 *out;
if (req->cryptlen < AES_BLOCK_SIZE)
return -EINVAL;
if (unlikely(tail > 0 && tail < AES_BLOCK_SIZE)) {
int xts_blocks = DIV_ROUND_UP(req->cryptlen,
AES_BLOCK_SIZE) - 2;
skcipher_request_set_tfm(&subreq, tfm);
skcipher_request_set_callback(&subreq,
skcipher_request_flags(req),
NULL, NULL);
skcipher_request_set_crypt(&subreq, req->src, req->dst,
xts_blocks * AES_BLOCK_SIZE,
req->iv);
req = &subreq;
} else {
tail = 0;
}
err = skcipher_walk_virt(&walk, req, false);
if (err)
return err;
scoped_ksimd() {
while (walk.nbytes >= AES_BLOCK_SIZE) {
int blocks = (walk.nbytes / AES_BLOCK_SIZE) & ~7;
out = walk.dst.virt.addr;
in = walk.src.virt.addr;
nbytes = walk.nbytes;
if (blocks >= 8) {
if (first == 1)
neon_aes_ecb_encrypt(walk.iv, walk.iv,
ctx->twkey,
ctx->key.rounds, 1);
first = 2;
fn(out, in, ctx->key.rk, ctx->key.rounds, blocks,
walk.iv);
out += blocks * AES_BLOCK_SIZE;
in += blocks * AES_BLOCK_SIZE;
nbytes -= blocks * AES_BLOCK_SIZE;
}
if (walk.nbytes == walk.total && nbytes > 0) {
if (encrypt)
neon_aes_xts_encrypt(out, in, ctx->cts.key_enc,
ctx->key.rounds, nbytes,
ctx->twkey, walk.iv, first);
else
neon_aes_xts_decrypt(out, in, ctx->cts.key_dec,
ctx->key.rounds, nbytes,
ctx->twkey, walk.iv, first);
nbytes = first = 0;
}
err = skcipher_walk_done(&walk, nbytes);
}
if (err || likely(!tail))
return err;
dst = src = scatterwalk_ffwd(sg_src, req->src, req->cryptlen);
if (req->dst != req->src)
dst = scatterwalk_ffwd(sg_dst, req->dst, req->cryptlen);
skcipher_request_set_crypt(req, src, dst, AES_BLOCK_SIZE + tail,
req->iv);
err = skcipher_walk_virt(&walk, req, false);
if (err)
return err;
out = walk.dst.virt.addr;
in = walk.src.virt.addr;
nbytes = walk.nbytes;
if (encrypt)
neon_aes_xts_encrypt(out, in, ctx->cts.key_enc,
ctx->key.rounds, nbytes, ctx->twkey,
walk.iv, first);
else
neon_aes_xts_decrypt(out, in, ctx->cts.key_dec,
ctx->key.rounds, nbytes, ctx->twkey,
walk.iv, first);
}
return skcipher_walk_done(&walk, 0);
}
static int xts_encrypt(struct skcipher_request *req)
{
return __xts_crypt(req, true, aesbs_xts_encrypt);
}
static int xts_decrypt(struct skcipher_request *req)
{
return __xts_crypt(req, false, 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,
.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_ctr_ctx),
.base.cra_module = THIS_MODULE,
.min_keysize = AES_MIN_KEY_SIZE,
.max_keysize = AES_MAX_KEY_SIZE,
.walksize = 8 * AES_BLOCK_SIZE,
.ivsize = AES_BLOCK_SIZE,
.setkey = aesbs_cbc_ctr_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_cbc_ctr_ctx),
.base.cra_module = THIS_MODULE,
.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_cbc_ctr_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,
.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 void aes_exit(void)
{
crypto_unregister_skciphers(aes_algs, ARRAY_SIZE(aes_algs));
}
static int __init aes_init(void)
{
if (!cpu_have_named_feature(ASIMD))
return -ENODEV;
return crypto_register_skciphers(aes_algs, ARRAY_SIZE(aes_algs));
}
module_init(aes_init);
module_exit(aes_exit);
