linux/arch/arm/crypto/aes-ce-glue.c
Ard Biesheuvel e77fe9cce3 crypto: arm/aes-ce - stop using the SIMD helper
Now that ARM permits use of the NEON unit in softirq context as well as
task context, there is no longer a need to rely on the SIMD helper
module to construct async skciphers wrapping the sync ones, as the
latter can always be called directly.

So remove these wrappers and the dependency on the SIMD helper. This
permits the use of these algorithms by callers that only support
synchronous use.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2025-04-07 13:22:27 +08:00

648 lines
18 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* aes-ce-glue.c - wrapper code for ARMv8 AES
*
* Copyright (C) 2015 Linaro Ltd <ard.biesheuvel@linaro.org>
*/
#include <asm/hwcap.h>
#include <asm/neon.h>
#include <asm/simd.h>
#include <linux/unaligned.h>
#include <crypto/aes.h>
#include <crypto/internal/skcipher.h>
#include <crypto/scatterwalk.h>
#include <linux/cpufeature.h>
#include <linux/module.h>
#include <crypto/xts.h>
MODULE_DESCRIPTION("AES-ECB/CBC/CTR/XTS using ARMv8 Crypto Extensions");
MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
MODULE_LICENSE("GPL v2");
/* defined in aes-ce-core.S */
asmlinkage u32 ce_aes_sub(u32 input);
asmlinkage void ce_aes_invert(void *dst, void *src);
asmlinkage void ce_aes_ecb_encrypt(u8 out[], u8 const in[], u32 const rk[],
int rounds, int blocks);
asmlinkage void ce_aes_ecb_decrypt(u8 out[], u8 const in[], u32 const rk[],
int rounds, int blocks);
asmlinkage void ce_aes_cbc_encrypt(u8 out[], u8 const in[], u32 const rk[],
int rounds, int blocks, u8 iv[]);
asmlinkage void ce_aes_cbc_decrypt(u8 out[], u8 const in[], u32 const rk[],
int rounds, int blocks, u8 iv[]);
asmlinkage void ce_aes_cbc_cts_encrypt(u8 out[], u8 const in[], u32 const rk[],
int rounds, int bytes, u8 const iv[]);
asmlinkage void ce_aes_cbc_cts_decrypt(u8 out[], u8 const in[], u32 const rk[],
int rounds, int bytes, u8 const iv[]);
asmlinkage void ce_aes_ctr_encrypt(u8 out[], u8 const in[], u32 const rk[],
int rounds, int blocks, u8 ctr[]);
asmlinkage void ce_aes_xts_encrypt(u8 out[], u8 const in[], u32 const rk1[],
int rounds, int bytes, u8 iv[],
u32 const rk2[], int first);
asmlinkage void ce_aes_xts_decrypt(u8 out[], u8 const in[], u32 const rk1[],
int rounds, int bytes, u8 iv[],
u32 const rk2[], int first);
struct aes_block {
u8 b[AES_BLOCK_SIZE];
};
static int num_rounds(struct crypto_aes_ctx *ctx)
{
/*
* # of rounds specified by AES:
* 128 bit key 10 rounds
* 192 bit key 12 rounds
* 256 bit key 14 rounds
* => n byte key => 6 + (n/4) rounds
*/
return 6 + ctx->key_length / 4;
}
static int ce_aes_expandkey(struct crypto_aes_ctx *ctx, const u8 *in_key,
unsigned int key_len)
{
/*
* The AES key schedule round constants
*/
static u8 const rcon[] = {
0x01, 0x02, 0x04, 0x08, 0x10, 0x20, 0x40, 0x80, 0x1b, 0x36,
};
u32 kwords = key_len / sizeof(u32);
struct aes_block *key_enc, *key_dec;
int i, j;
if (key_len != AES_KEYSIZE_128 &&
key_len != AES_KEYSIZE_192 &&
key_len != AES_KEYSIZE_256)
return -EINVAL;
ctx->key_length = key_len;
for (i = 0; i < kwords; i++)
ctx->key_enc[i] = get_unaligned_le32(in_key + i * sizeof(u32));
kernel_neon_begin();
for (i = 0; i < sizeof(rcon); i++) {
u32 *rki = ctx->key_enc + (i * kwords);
u32 *rko = rki + kwords;
rko[0] = ror32(ce_aes_sub(rki[kwords - 1]), 8);
rko[0] = rko[0] ^ rki[0] ^ rcon[i];
rko[1] = rko[0] ^ rki[1];
rko[2] = rko[1] ^ rki[2];
rko[3] = rko[2] ^ rki[3];
if (key_len == AES_KEYSIZE_192) {
if (i >= 7)
break;
rko[4] = rko[3] ^ rki[4];
rko[5] = rko[4] ^ rki[5];
} else if (key_len == AES_KEYSIZE_256) {
if (i >= 6)
break;
rko[4] = ce_aes_sub(rko[3]) ^ rki[4];
rko[5] = rko[4] ^ rki[5];
rko[6] = rko[5] ^ rki[6];
rko[7] = rko[6] ^ rki[7];
}
}
/*
* Generate the decryption keys for the Equivalent Inverse Cipher.
* This involves reversing the order of the round keys, and applying
* the Inverse Mix Columns transformation on all but the first and
* the last one.
*/
key_enc = (struct aes_block *)ctx->key_enc;
key_dec = (struct aes_block *)ctx->key_dec;
j = num_rounds(ctx);
key_dec[0] = key_enc[j];
for (i = 1, j--; j > 0; i++, j--)
ce_aes_invert(key_dec + i, key_enc + j);
key_dec[i] = key_enc[0];
kernel_neon_end();
return 0;
}
static int ce_aes_setkey(struct crypto_skcipher *tfm, const u8 *in_key,
unsigned int key_len)
{
struct crypto_aes_ctx *ctx = crypto_skcipher_ctx(tfm);
return ce_aes_expandkey(ctx, in_key, key_len);
}
struct crypto_aes_xts_ctx {
struct crypto_aes_ctx key1;
struct crypto_aes_ctx __aligned(8) key2;
};
static int xts_set_key(struct crypto_skcipher *tfm, const u8 *in_key,
unsigned int key_len)
{
struct crypto_aes_xts_ctx *ctx = crypto_skcipher_ctx(tfm);
int ret;
ret = xts_verify_key(tfm, in_key, key_len);
if (ret)
return ret;
ret = ce_aes_expandkey(&ctx->key1, in_key, key_len / 2);
if (!ret)
ret = ce_aes_expandkey(&ctx->key2, &in_key[key_len / 2],
key_len / 2);
return ret;
}
static int ecb_encrypt(struct skcipher_request *req)
{
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
struct crypto_aes_ctx *ctx = crypto_skcipher_ctx(tfm);
struct skcipher_walk walk;
unsigned int blocks;
int err;
err = skcipher_walk_virt(&walk, req, false);
while ((blocks = (walk.nbytes / AES_BLOCK_SIZE))) {
kernel_neon_begin();
ce_aes_ecb_encrypt(walk.dst.virt.addr, walk.src.virt.addr,
ctx->key_enc, num_rounds(ctx), blocks);
kernel_neon_end();
err = skcipher_walk_done(&walk, walk.nbytes % AES_BLOCK_SIZE);
}
return err;
}
static int ecb_decrypt(struct skcipher_request *req)
{
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
struct crypto_aes_ctx *ctx = crypto_skcipher_ctx(tfm);
struct skcipher_walk walk;
unsigned int blocks;
int err;
err = skcipher_walk_virt(&walk, req, false);
while ((blocks = (walk.nbytes / AES_BLOCK_SIZE))) {
kernel_neon_begin();
ce_aes_ecb_decrypt(walk.dst.virt.addr, walk.src.virt.addr,
ctx->key_dec, num_rounds(ctx), blocks);
kernel_neon_end();
err = skcipher_walk_done(&walk, walk.nbytes % AES_BLOCK_SIZE);
}
return err;
}
static int cbc_encrypt_walk(struct skcipher_request *req,
struct skcipher_walk *walk)
{
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
struct crypto_aes_ctx *ctx = crypto_skcipher_ctx(tfm);
unsigned int blocks;
int err = 0;
while ((blocks = (walk->nbytes / AES_BLOCK_SIZE))) {
kernel_neon_begin();
ce_aes_cbc_encrypt(walk->dst.virt.addr, walk->src.virt.addr,
ctx->key_enc, num_rounds(ctx), blocks,
walk->iv);
kernel_neon_end();
err = skcipher_walk_done(walk, walk->nbytes % AES_BLOCK_SIZE);
}
return err;
}
static int cbc_encrypt(struct skcipher_request *req)
{
struct skcipher_walk walk;
int err;
err = skcipher_walk_virt(&walk, req, false);
if (err)
return err;
return cbc_encrypt_walk(req, &walk);
}
static int cbc_decrypt_walk(struct skcipher_request *req,
struct skcipher_walk *walk)
{
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
struct crypto_aes_ctx *ctx = crypto_skcipher_ctx(tfm);
unsigned int blocks;
int err = 0;
while ((blocks = (walk->nbytes / AES_BLOCK_SIZE))) {
kernel_neon_begin();
ce_aes_cbc_decrypt(walk->dst.virt.addr, walk->src.virt.addr,
ctx->key_dec, num_rounds(ctx), 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 skcipher_walk walk;
int err;
err = skcipher_walk_virt(&walk, req, false);
if (err)
return err;
return cbc_decrypt_walk(req, &walk);
}
static int cts_cbc_encrypt(struct skcipher_request *req)
{
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
struct crypto_aes_ctx *ctx = crypto_skcipher_ctx(tfm);
int cbc_blocks = DIV_ROUND_UP(req->cryptlen, AES_BLOCK_SIZE) - 2;
struct scatterlist *src = req->src, *dst = req->dst;
struct scatterlist sg_src[2], sg_dst[2];
struct skcipher_request subreq;
struct skcipher_walk walk;
int err;
skcipher_request_set_tfm(&subreq, tfm);
skcipher_request_set_callback(&subreq, skcipher_request_flags(req),
NULL, NULL);
if (req->cryptlen <= AES_BLOCK_SIZE) {
if (req->cryptlen < AES_BLOCK_SIZE)
return -EINVAL;
cbc_blocks = 1;
}
if (cbc_blocks > 0) {
skcipher_request_set_crypt(&subreq, req->src, req->dst,
cbc_blocks * AES_BLOCK_SIZE,
req->iv);
err = skcipher_walk_virt(&walk, &subreq, false) ?:
cbc_encrypt_walk(&subreq, &walk);
if (err)
return err;
if (req->cryptlen == AES_BLOCK_SIZE)
return 0;
dst = src = scatterwalk_ffwd(sg_src, req->src, subreq.cryptlen);
if (req->dst != req->src)
dst = scatterwalk_ffwd(sg_dst, req->dst,
subreq.cryptlen);
}
/* handle ciphertext stealing */
skcipher_request_set_crypt(&subreq, src, dst,
req->cryptlen - cbc_blocks * AES_BLOCK_SIZE,
req->iv);
err = skcipher_walk_virt(&walk, &subreq, false);
if (err)
return err;
kernel_neon_begin();
ce_aes_cbc_cts_encrypt(walk.dst.virt.addr, walk.src.virt.addr,
ctx->key_enc, num_rounds(ctx), walk.nbytes,
walk.iv);
kernel_neon_end();
return skcipher_walk_done(&walk, 0);
}
static int cts_cbc_decrypt(struct skcipher_request *req)
{
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
struct crypto_aes_ctx *ctx = crypto_skcipher_ctx(tfm);
int cbc_blocks = DIV_ROUND_UP(req->cryptlen, AES_BLOCK_SIZE) - 2;
struct scatterlist *src = req->src, *dst = req->dst;
struct scatterlist sg_src[2], sg_dst[2];
struct skcipher_request subreq;
struct skcipher_walk walk;
int err;
skcipher_request_set_tfm(&subreq, tfm);
skcipher_request_set_callback(&subreq, skcipher_request_flags(req),
NULL, NULL);
if (req->cryptlen <= AES_BLOCK_SIZE) {
if (req->cryptlen < AES_BLOCK_SIZE)
return -EINVAL;
cbc_blocks = 1;
}
if (cbc_blocks > 0) {
skcipher_request_set_crypt(&subreq, req->src, req->dst,
cbc_blocks * AES_BLOCK_SIZE,
req->iv);
err = skcipher_walk_virt(&walk, &subreq, false) ?:
cbc_decrypt_walk(&subreq, &walk);
if (err)
return err;
if (req->cryptlen == AES_BLOCK_SIZE)
return 0;
dst = src = scatterwalk_ffwd(sg_src, req->src, subreq.cryptlen);
if (req->dst != req->src)
dst = scatterwalk_ffwd(sg_dst, req->dst,
subreq.cryptlen);
}
/* handle ciphertext stealing */
skcipher_request_set_crypt(&subreq, src, dst,
req->cryptlen - cbc_blocks * AES_BLOCK_SIZE,
req->iv);
err = skcipher_walk_virt(&walk, &subreq, false);
if (err)
return err;
kernel_neon_begin();
ce_aes_cbc_cts_decrypt(walk.dst.virt.addr, walk.src.virt.addr,
ctx->key_dec, num_rounds(ctx), walk.nbytes,
walk.iv);
kernel_neon_end();
return skcipher_walk_done(&walk, 0);
}
static int ctr_encrypt(struct skcipher_request *req)
{
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
struct crypto_aes_ctx *ctx = crypto_skcipher_ctx(tfm);
struct skcipher_walk walk;
int err, blocks;
err = skcipher_walk_virt(&walk, req, false);
while ((blocks = (walk.nbytes / AES_BLOCK_SIZE))) {
kernel_neon_begin();
ce_aes_ctr_encrypt(walk.dst.virt.addr, walk.src.virt.addr,
ctx->key_enc, num_rounds(ctx), blocks,
walk.iv);
kernel_neon_end();
err = skcipher_walk_done(&walk, walk.nbytes % AES_BLOCK_SIZE);
}
if (walk.nbytes) {
u8 __aligned(8) tail[AES_BLOCK_SIZE];
const u8 *tsrc = walk.src.virt.addr;
unsigned int nbytes = walk.nbytes;
u8 *tdst = walk.dst.virt.addr;
/*
* Tell aes_ctr_encrypt() to process a tail block.
*/
blocks = -1;
kernel_neon_begin();
ce_aes_ctr_encrypt(tail, NULL, ctx->key_enc, num_rounds(ctx),
blocks, walk.iv);
kernel_neon_end();
crypto_xor_cpy(tdst, tsrc, tail, nbytes);
err = skcipher_walk_done(&walk, 0);
}
return err;
}
static int xts_encrypt(struct skcipher_request *req)
{
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
struct crypto_aes_xts_ctx *ctx = crypto_skcipher_ctx(tfm);
int err, first, rounds = num_rounds(&ctx->key1);
int tail = req->cryptlen % AES_BLOCK_SIZE;
struct scatterlist sg_src[2], sg_dst[2];
struct skcipher_request subreq;
struct scatterlist *src, *dst;
struct skcipher_walk walk;
if (req->cryptlen < AES_BLOCK_SIZE)
return -EINVAL;
err = skcipher_walk_virt(&walk, req, false);
if (unlikely(tail > 0 && walk.nbytes < walk.total)) {
int xts_blocks = DIV_ROUND_UP(req->cryptlen,
AES_BLOCK_SIZE) - 2;
skcipher_walk_abort(&walk);
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;
err = skcipher_walk_virt(&walk, req, false);
} else {
tail = 0;
}
for (first = 1; walk.nbytes >= AES_BLOCK_SIZE; first = 0) {
int nbytes = walk.nbytes;
if (walk.nbytes < walk.total)
nbytes &= ~(AES_BLOCK_SIZE - 1);
kernel_neon_begin();
ce_aes_xts_encrypt(walk.dst.virt.addr, walk.src.virt.addr,
ctx->key1.key_enc, rounds, nbytes, walk.iv,
ctx->key2.key_enc, first);
kernel_neon_end();
err = skcipher_walk_done(&walk, walk.nbytes - 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;
kernel_neon_begin();
ce_aes_xts_encrypt(walk.dst.virt.addr, walk.src.virt.addr,
ctx->key1.key_enc, rounds, walk.nbytes, walk.iv,
ctx->key2.key_enc, first);
kernel_neon_end();
return skcipher_walk_done(&walk, 0);
}
static int xts_decrypt(struct skcipher_request *req)
{
struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
struct crypto_aes_xts_ctx *ctx = crypto_skcipher_ctx(tfm);
int err, first, rounds = num_rounds(&ctx->key1);
int tail = req->cryptlen % AES_BLOCK_SIZE;
struct scatterlist sg_src[2], sg_dst[2];
struct skcipher_request subreq;
struct scatterlist *src, *dst;
struct skcipher_walk walk;
if (req->cryptlen < AES_BLOCK_SIZE)
return -EINVAL;
err = skcipher_walk_virt(&walk, req, false);
if (unlikely(tail > 0 && walk.nbytes < walk.total)) {
int xts_blocks = DIV_ROUND_UP(req->cryptlen,
AES_BLOCK_SIZE) - 2;
skcipher_walk_abort(&walk);
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;
err = skcipher_walk_virt(&walk, req, false);
} else {
tail = 0;
}
for (first = 1; walk.nbytes >= AES_BLOCK_SIZE; first = 0) {
int nbytes = walk.nbytes;
if (walk.nbytes < walk.total)
nbytes &= ~(AES_BLOCK_SIZE - 1);
kernel_neon_begin();
ce_aes_xts_decrypt(walk.dst.virt.addr, walk.src.virt.addr,
ctx->key1.key_dec, rounds, nbytes, walk.iv,
ctx->key2.key_enc, first);
kernel_neon_end();
err = skcipher_walk_done(&walk, walk.nbytes - 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;
kernel_neon_begin();
ce_aes_xts_decrypt(walk.dst.virt.addr, walk.src.virt.addr,
ctx->key1.key_dec, rounds, walk.nbytes, walk.iv,
ctx->key2.key_enc, first);
kernel_neon_end();
return skcipher_walk_done(&walk, 0);
}
static struct skcipher_alg aes_algs[] = { {
.base.cra_name = "ecb(aes)",
.base.cra_driver_name = "ecb-aes-ce",
.base.cra_priority = 300,
.base.cra_blocksize = AES_BLOCK_SIZE,
.base.cra_ctxsize = sizeof(struct crypto_aes_ctx),
.base.cra_module = THIS_MODULE,
.min_keysize = AES_MIN_KEY_SIZE,
.max_keysize = AES_MAX_KEY_SIZE,
.setkey = ce_aes_setkey,
.encrypt = ecb_encrypt,
.decrypt = ecb_decrypt,
}, {
.base.cra_name = "cbc(aes)",
.base.cra_driver_name = "cbc-aes-ce",
.base.cra_priority = 300,
.base.cra_blocksize = AES_BLOCK_SIZE,
.base.cra_ctxsize = sizeof(struct crypto_aes_ctx),
.base.cra_module = THIS_MODULE,
.min_keysize = AES_MIN_KEY_SIZE,
.max_keysize = AES_MAX_KEY_SIZE,
.ivsize = AES_BLOCK_SIZE,
.setkey = ce_aes_setkey,
.encrypt = cbc_encrypt,
.decrypt = cbc_decrypt,
}, {
.base.cra_name = "cts(cbc(aes))",
.base.cra_driver_name = "cts-cbc-aes-ce",
.base.cra_priority = 300,
.base.cra_blocksize = AES_BLOCK_SIZE,
.base.cra_ctxsize = sizeof(struct crypto_aes_ctx),
.base.cra_module = THIS_MODULE,
.min_keysize = AES_MIN_KEY_SIZE,
.max_keysize = AES_MAX_KEY_SIZE,
.ivsize = AES_BLOCK_SIZE,
.walksize = 2 * AES_BLOCK_SIZE,
.setkey = ce_aes_setkey,
.encrypt = cts_cbc_encrypt,
.decrypt = cts_cbc_decrypt,
}, {
.base.cra_name = "ctr(aes)",
.base.cra_driver_name = "ctr-aes-ce",
.base.cra_priority = 300,
.base.cra_blocksize = 1,
.base.cra_ctxsize = sizeof(struct crypto_aes_ctx),
.base.cra_module = THIS_MODULE,
.min_keysize = AES_MIN_KEY_SIZE,
.max_keysize = AES_MAX_KEY_SIZE,
.ivsize = AES_BLOCK_SIZE,
.chunksize = AES_BLOCK_SIZE,
.setkey = ce_aes_setkey,
.encrypt = ctr_encrypt,
.decrypt = ctr_encrypt,
}, {
.base.cra_name = "xts(aes)",
.base.cra_driver_name = "xts-aes-ce",
.base.cra_priority = 300,
.base.cra_blocksize = AES_BLOCK_SIZE,
.base.cra_ctxsize = sizeof(struct crypto_aes_xts_ctx),
.base.cra_module = THIS_MODULE,
.min_keysize = 2 * AES_MIN_KEY_SIZE,
.max_keysize = 2 * AES_MAX_KEY_SIZE,
.ivsize = AES_BLOCK_SIZE,
.walksize = 2 * AES_BLOCK_SIZE,
.setkey = xts_set_key,
.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)
{
return crypto_register_skciphers(aes_algs, ARRAY_SIZE(aes_algs));
}
module_cpu_feature_match(AES, aes_init);
module_exit(aes_exit);