linux/arch/arm64/crypto/aes-neonbs-glue.c
Ard Biesheuvel 88a3f582be crypto: arm64/aes - don't use IV buffer to return final keystream block
The arm64 bit sliced AES core code uses the IV buffer to pass the final
keystream block back to the glue code if the input is not a multiple of
the block size, so that the asm code does not have to deal with anything
except 16 byte blocks. This is done under the assumption that the outgoing
IV is meaningless anyway in this case, given that chaining is no longer
possible under these circumstances.

However, as it turns out, the CCM driver does expect the IV to retain
a value that is equal to the original IV except for the counter value,
and even interprets byte zero as a length indicator, which may result
in memory corruption if the IV is overwritten with something else.

So use a separate buffer to return the final keystream block.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2017-02-03 18:16:20 +08:00

440 lines
11 KiB
C

/*
* Bit sliced AES using NEON instructions
*
* Copyright (C) 2016 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/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 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, int first);
asmlinkage void neon_aes_cbc_encrypt(u8 out[], u8 const in[], u32 const rk[],
int rounds, int blocks, u8 iv[],
int first);
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_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, 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;
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, first = 1;
err = skcipher_walk_virt(&walk, req, true);
kernel_neon_begin();
while (walk.nbytes >= AES_BLOCK_SIZE) {
unsigned int blocks = walk.nbytes / AES_BLOCK_SIZE;
/* fall back to the non-bitsliced NEON implementation */
neon_aes_cbc_encrypt(walk.dst.virt.addr, walk.src.virt.addr,
ctx->enc, ctx->key.rounds, blocks, walk.iv,
first);
err = skcipher_walk_done(&walk, walk.nbytes % AES_BLOCK_SIZE);
first = 0;
}
kernel_neon_end();
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, 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 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;
if (dst != src)
memcpy(dst, src, walk.total % AES_BLOCK_SIZE);
crypto_xor(dst, 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);
struct crypto_aes_ctx rk;
int err;
err = xts_verify_key(tfm, in_key, key_len);
if (err)
return err;
key_len /= 2;
err = crypto_aes_expand_key(&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,
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);
kernel_neon_begin();
neon_aes_ecb_encrypt(walk.iv, walk.iv, ctx->twkey,
ctx->key.rounds, 1, 1);
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,
.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 = "ctr(aes)",
.base.cra_driver_name = "ctr-aes-neonbs",
.base.cra_priority = 250 - 1,
.base.cra_blocksize = 1,
.base.cra_ctxsize = sizeof(struct aesbs_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_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,
.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_ASIMD))
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;
}
module_init(aes_init);
module_exit(aes_exit);