// SPDX-License-Identifier: GPL-2.0-or-later
/*
* The AEGIS-128 Authenticated-Encryption Algorithm
*
* Copyright (c) 2017-2018 Ondrej Mosnacek <[email protected]>
* Copyright (C) 2017-2018 Red Hat, Inc. All rights reserved.
*/
#include <crypto/algapi.h>
#include <crypto/internal/aead.h>
#include <crypto/internal/simd.h>
#include <crypto/internal/skcipher.h>
#include <crypto/scatterwalk.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/jump_label.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/scatterlist.h>
#include <asm/simd.h>
#include "aegis.h"
#define AEGIS128_NONCE_SIZE 16
#define AEGIS128_STATE_BLOCKS 5
#define AEGIS128_KEY_SIZE 16
#define AEGIS128_MIN_AUTH_SIZE 8
#define AEGIS128_MAX_AUTH_SIZE 16
struct aegis_state {
union aegis_block blocks[AEGIS128_STATE_BLOCKS];
};
struct aegis_ctx {
union aegis_block key;
};
static __ro_after_init DEFINE_STATIC_KEY_FALSE(have_simd);
static const union aegis_block crypto_aegis_const[2] = {
{ .words64 = {
cpu_to_le64(U64_C(0x0d08050302010100)),
cpu_to_le64(U64_C(0x6279e99059372215)),
} },
{ .words64 = {
cpu_to_le64(U64_C(0xf12fc26d55183ddb)),
cpu_to_le64(U64_C(0xdd28b57342311120)),
} },
};
static bool aegis128_do_simd(void)
{
#ifdef CONFIG_CRYPTO_AEGIS128_SIMD
if (static_branch_likely(&have_simd))
return crypto_simd_usable();
#endif
return false;
}
static void crypto_aegis128_update(struct aegis_state *state)
{
union aegis_block tmp;
unsigned int i;
tmp = state->blocks[AEGIS128_STATE_BLOCKS - 1];
for (i = AEGIS128_STATE_BLOCKS - 1; i > 0; i--)
crypto_aegis_aesenc(&state->blocks[i], &state->blocks[i - 1],
&state->blocks[i]);
crypto_aegis_aesenc(&state->blocks[0], &tmp, &state->blocks[0]);
}
static void crypto_aegis128_update_a(struct aegis_state *state,
const union aegis_block *msg,
bool do_simd)
{
if (IS_ENABLED(CONFIG_CRYPTO_AEGIS128_SIMD) && do_simd) {
crypto_aegis128_update_simd(state, msg);
return;
}
crypto_aegis128_update(state);
crypto_aegis_block_xor(&state->blocks[0], msg);
}
static void crypto_aegis128_update_u(struct aegis_state *state, const void *msg,
bool do_simd)
{
if (IS_ENABLED(CONFIG_CRYPTO_AEGIS128_SIMD) && do_simd) {
crypto_aegis128_update_simd(state, msg);
return;
}
crypto_aegis128_update(state);
crypto_xor(state->blocks[0].bytes, msg, AEGIS_BLOCK_SIZE);
}
static void crypto_aegis128_init(struct aegis_state *state,
const union aegis_block *key,
const u8 *iv)
{
union aegis_block key_iv;
unsigned int i;
key_iv = *key;
crypto_xor(key_iv.bytes, iv, AEGIS_BLOCK_SIZE);
state->blocks[0] = key_iv;
state->blocks[1] = crypto_aegis_const[1];
state->blocks[2] = crypto_aegis_const[0];
state->blocks[3] = *key;
state->blocks[4] = *key;
crypto_aegis_block_xor(&state->blocks[3], &crypto_aegis_const[0]);
crypto_aegis_block_xor(&state->blocks[4], &crypto_aegis_const[1]);
for (i = 0; i < 5; i++) {
crypto_aegis128_update_a(state, key, false);
crypto_aegis128_update_a(state, &key_iv, false);
}
}
static void crypto_aegis128_ad(struct aegis_state *state,
const u8 *src, unsigned int size,
bool do_simd)
{
if (AEGIS_ALIGNED(src)) {
const union aegis_block *src_blk =
(const union aegis_block *)src;
while (size >= AEGIS_BLOCK_SIZE) {
crypto_aegis128_update_a(state, src_blk, do_simd);
size -= AEGIS_BLOCK_SIZE;
src_blk++;
}
} else {
while (size >= AEGIS_BLOCK_SIZE) {
crypto_aegis128_update_u(state, src, do_simd);
size -= AEGIS_BLOCK_SIZE;
src += AEGIS_BLOCK_SIZE;
}
}
}
static void crypto_aegis128_wipe_chunk(struct aegis_state *state, u8 *dst,
const u8 *src, unsigned int size)
{
memzero_explicit(dst, size);
}
static void crypto_aegis128_encrypt_chunk(struct aegis_state *state, u8 *dst,
const u8 *src, unsigned int size)
{
union aegis_block tmp;
if (AEGIS_ALIGNED(src) && AEGIS_ALIGNED(dst)) {
while (size >= AEGIS_BLOCK_SIZE) {
union aegis_block *dst_blk =
(union aegis_block *)dst;
const union aegis_block *src_blk =
(const union aegis_block *)src;
tmp = state->blocks[2];
crypto_aegis_block_and(&tmp, &state->blocks[3]);
crypto_aegis_block_xor(&tmp, &state->blocks[4]);
crypto_aegis_block_xor(&tmp, &state->blocks[1]);
crypto_aegis_block_xor(&tmp, src_blk);
crypto_aegis128_update_a(state, src_blk, false);
*dst_blk = tmp;
size -= AEGIS_BLOCK_SIZE;
src += AEGIS_BLOCK_SIZE;
dst += AEGIS_BLOCK_SIZE;
}
} else {
while (size >= AEGIS_BLOCK_SIZE) {
tmp = state->blocks[2];
crypto_aegis_block_and(&tmp, &state->blocks[3]);
crypto_aegis_block_xor(&tmp, &state->blocks[4]);
crypto_aegis_block_xor(&tmp, &state->blocks[1]);
crypto_xor(tmp.bytes, src, AEGIS_BLOCK_SIZE);
crypto_aegis128_update_u(state, src, false);
memcpy(dst, tmp.bytes, AEGIS_BLOCK_SIZE);
size -= AEGIS_BLOCK_SIZE;
src += AEGIS_BLOCK_SIZE;
dst += AEGIS_BLOCK_SIZE;
}
}
if (size > 0) {
union aegis_block msg = {};
memcpy(msg.bytes, src, size);
tmp = state->blocks[2];
crypto_aegis_block_and(&tmp, &state->blocks[3]);
crypto_aegis_block_xor(&tmp, &state->blocks[4]);
crypto_aegis_block_xor(&tmp, &state->blocks[1]);
crypto_aegis128_update_a(state, &msg, false);
crypto_aegis_block_xor(&msg, &tmp);
memcpy(dst, msg.bytes, size);
}
}
static void crypto_aegis128_decrypt_chunk(struct aegis_state *state, u8 *dst,
const u8 *src, unsigned int size)
{
union aegis_block tmp;
if (AEGIS_ALIGNED(src) && AEGIS_ALIGNED(dst)) {
while (size >= AEGIS_BLOCK_SIZE) {
union aegis_block *dst_blk =
(union aegis_block *)dst;
const union aegis_block *src_blk =
(const union aegis_block *)src;
tmp = state->blocks[2];
crypto_aegis_block_and(&tmp, &state->blocks[3]);
crypto_aegis_block_xor(&tmp, &state->blocks[4]);
crypto_aegis_block_xor(&tmp, &state->blocks[1]);
crypto_aegis_block_xor(&tmp, src_blk);
crypto_aegis128_update_a(state, &tmp, false);
*dst_blk = tmp;
size -= AEGIS_BLOCK_SIZE;
src += AEGIS_BLOCK_SIZE;
dst += AEGIS_BLOCK_SIZE;
}
} else {
while (size >= AEGIS_BLOCK_SIZE) {
tmp = state->blocks[2];
crypto_aegis_block_and(&tmp, &state->blocks[3]);
crypto_aegis_block_xor(&tmp, &state->blocks[4]);
crypto_aegis_block_xor(&tmp, &state->blocks[1]);
crypto_xor(tmp.bytes, src, AEGIS_BLOCK_SIZE);
crypto_aegis128_update_a(state, &tmp, false);
memcpy(dst, tmp.bytes, AEGIS_BLOCK_SIZE);
size -= AEGIS_BLOCK_SIZE;
src += AEGIS_BLOCK_SIZE;
dst += AEGIS_BLOCK_SIZE;
}
}
if (size > 0) {
union aegis_block msg = {};
memcpy(msg.bytes, src, size);
tmp = state->blocks[2];
crypto_aegis_block_and(&tmp, &state->blocks[3]);
crypto_aegis_block_xor(&tmp, &state->blocks[4]);
crypto_aegis_block_xor(&tmp, &state->blocks[1]);
crypto_aegis_block_xor(&msg, &tmp);
memset(msg.bytes + size, 0, AEGIS_BLOCK_SIZE - size);
crypto_aegis128_update_a(state, &msg, false);
memcpy(dst, msg.bytes, size);
}
}
static void crypto_aegis128_process_ad(struct aegis_state *state,
struct scatterlist *sg_src,
unsigned int assoclen,
bool do_simd)
{
struct scatter_walk walk;
union aegis_block buf;
unsigned int pos = 0;
scatterwalk_start(&walk, sg_src);
while (assoclen != 0) {
unsigned int size = scatterwalk_clamp(&walk, assoclen);
unsigned int left = size;
void *mapped = scatterwalk_map(&walk);
const u8 *src = (const u8 *)mapped;
if (pos + size >= AEGIS_BLOCK_SIZE) {
if (pos > 0) {
unsigned int fill = AEGIS_BLOCK_SIZE - pos;
memcpy(buf.bytes + pos, src, fill);
crypto_aegis128_update_a(state, &buf, do_simd);
pos = 0;
left -= fill;
src += fill;
}
crypto_aegis128_ad(state, src, left, do_simd);
src += left & ~(AEGIS_BLOCK_SIZE - 1);
left &= AEGIS_BLOCK_SIZE - 1;
}
memcpy(buf.bytes + pos, src, left);
pos += left;
assoclen -= size;
scatterwalk_unmap(mapped);
scatterwalk_advance(&walk, size);
scatterwalk_done(&walk, 0, assoclen);
}
if (pos > 0) {
memset(buf.bytes + pos, 0, AEGIS_BLOCK_SIZE - pos);
crypto_aegis128_update_a(state, &buf, do_simd);
}
}
static __always_inline
int crypto_aegis128_process_crypt(struct aegis_state *state,
struct skcipher_walk *walk,
void (*crypt)(struct aegis_state *state,
u8 *dst,
const u8 *src,
unsigned int size))
{
int err = 0;
while (walk->nbytes) {
unsigned int nbytes = walk->nbytes;
if (nbytes < walk->total)
nbytes = round_down(nbytes, walk->stride);
crypt(state, walk->dst.virt.addr, walk->src.virt.addr, nbytes);
err = skcipher_walk_done(walk, walk->nbytes - nbytes);
}
return err;
}
static void crypto_aegis128_final(struct aegis_state *state,
union aegis_block *tag_xor,
u64 assoclen, u64 cryptlen)
{
u64 assocbits = assoclen * 8;
u64 cryptbits = cryptlen * 8;
union aegis_block tmp;
unsigned int i;
tmp.words64[0] = cpu_to_le64(assocbits);
tmp.words64[1] = cpu_to_le64(cryptbits);
crypto_aegis_block_xor(&tmp, &state->blocks[3]);
for (i = 0; i < 7; i++)
crypto_aegis128_update_a(state, &tmp, false);
for (i = 0; i < AEGIS128_STATE_BLOCKS; i++)
crypto_aegis_block_xor(tag_xor, &state->blocks[i]);
}
static int crypto_aegis128_setkey(struct crypto_aead *aead, const u8 *key,
unsigned int keylen)
{
struct aegis_ctx *ctx = crypto_aead_ctx(aead);
if (keylen != AEGIS128_KEY_SIZE)
return -EINVAL;
memcpy(ctx->key.bytes, key, AEGIS128_KEY_SIZE);
return 0;
}
static int crypto_aegis128_setauthsize(struct crypto_aead *tfm,
unsigned int authsize)
{
if (authsize > AEGIS128_MAX_AUTH_SIZE)
return -EINVAL;
if (authsize < AEGIS128_MIN_AUTH_SIZE)
return -EINVAL;
return 0;
}
static int crypto_aegis128_encrypt_generic(struct aead_request *req)
{
struct crypto_aead *tfm = crypto_aead_reqtfm(req);
union aegis_block tag = {};
unsigned int authsize = crypto_aead_authsize(tfm);
struct aegis_ctx *ctx = crypto_aead_ctx(tfm);
unsigned int cryptlen = req->cryptlen;
struct skcipher_walk walk;
struct aegis_state state;
skcipher_walk_aead_encrypt(&walk, req, false);
crypto_aegis128_init(&state, &ctx->key, req->iv);
crypto_aegis128_process_ad(&state, req->src, req->assoclen, false);
crypto_aegis128_process_crypt(&state, &walk,
crypto_aegis128_encrypt_chunk);
crypto_aegis128_final(&state, &tag, req->assoclen, cryptlen);
scatterwalk_map_and_copy(tag.bytes, req->dst, req->assoclen + cryptlen,
authsize, 1);
return 0;
}
static int crypto_aegis128_decrypt_generic(struct aead_request *req)
{
static const u8 zeros[AEGIS128_MAX_AUTH_SIZE] = {};
struct crypto_aead *tfm = crypto_aead_reqtfm(req);
union aegis_block tag;
unsigned int authsize = crypto_aead_authsize(tfm);
unsigned int cryptlen = req->cryptlen - authsize;
struct aegis_ctx *ctx = crypto_aead_ctx(tfm);
struct skcipher_walk walk;
struct aegis_state state;
scatterwalk_map_and_copy(tag.bytes, req->src, req->assoclen + cryptlen,
authsize, 0);
skcipher_walk_aead_decrypt(&walk, req, false);
crypto_aegis128_init(&state, &ctx->key, req->iv);
crypto_aegis128_process_ad(&state, req->src, req->assoclen, false);
crypto_aegis128_process_crypt(&state, &walk,
crypto_aegis128_decrypt_chunk);
crypto_aegis128_final(&state, &tag, req->assoclen, cryptlen);
if (unlikely(crypto_memneq(tag.bytes, zeros, authsize))) {
/*
* From Chapter 4. 'Security Analysis' of the AEGIS spec [0]
*
* "3. If verification fails, the decrypted plaintext and the
* wrong authentication tag should not be given as output."
*
* [0] https://competitions.cr.yp.to/round3/aegisv11.pdf
*/
skcipher_walk_aead_decrypt(&walk, req, false);
crypto_aegis128_process_crypt(NULL, &walk,
crypto_aegis128_wipe_chunk);
memzero_explicit(&tag, sizeof(tag));
return -EBADMSG;
}
return 0;
}
static int crypto_aegis128_encrypt_simd(struct aead_request *req)
{
struct crypto_aead *tfm = crypto_aead_reqtfm(req);
union aegis_block tag = {};
unsigned int authsize = crypto_aead_authsize(tfm);
struct aegis_ctx *ctx = crypto_aead_ctx(tfm);
unsigned int cryptlen = req->cryptlen;
struct skcipher_walk walk;
struct aegis_state state;
if (!aegis128_do_simd())
return crypto_aegis128_encrypt_generic(req);
skcipher_walk_aead_encrypt(&walk, req, false);
crypto_aegis128_init_simd(&state, &ctx->key, req->iv);
crypto_aegis128_process_ad(&state, req->src, req->assoclen, true);
crypto_aegis128_process_crypt(&state, &walk,
crypto_aegis128_encrypt_chunk_simd);
crypto_aegis128_final_simd(&state, &tag, req->assoclen, cryptlen, 0);
scatterwalk_map_and_copy(tag.bytes, req->dst, req->assoclen + cryptlen,
authsize, 1);
return 0;
}
static int crypto_aegis128_decrypt_simd(struct aead_request *req)
{
struct crypto_aead *tfm = crypto_aead_reqtfm(req);
union aegis_block tag;
unsigned int authsize = crypto_aead_authsize(tfm);
unsigned int cryptlen = req->cryptlen - authsize;
struct aegis_ctx *ctx = crypto_aead_ctx(tfm);
struct skcipher_walk walk;
struct aegis_state state;
if (!aegis128_do_simd())
return crypto_aegis128_decrypt_generic(req);
scatterwalk_map_and_copy(tag.bytes, req->src, req->assoclen + cryptlen,
authsize, 0);
skcipher_walk_aead_decrypt(&walk, req, false);
crypto_aegis128_init_simd(&state, &ctx->key, req->iv);
crypto_aegis128_process_ad(&state, req->src, req->assoclen, true);
crypto_aegis128_process_crypt(&state, &walk,
crypto_aegis128_decrypt_chunk_simd);
if (unlikely(crypto_aegis128_final_simd(&state, &tag, req->assoclen,
cryptlen, authsize))) {
skcipher_walk_aead_decrypt(&walk, req, false);
crypto_aegis128_process_crypt(NULL, &walk,
crypto_aegis128_wipe_chunk);
return -EBADMSG;
}
return 0;
}
static struct aead_alg crypto_aegis128_alg_generic = {
.setkey = crypto_aegis128_setkey,
.setauthsize = crypto_aegis128_setauthsize,
.encrypt = crypto_aegis128_encrypt_generic,
.decrypt = crypto_aegis128_decrypt_generic,
.ivsize = AEGIS128_NONCE_SIZE,
.maxauthsize = AEGIS128_MAX_AUTH_SIZE,
.chunksize = AEGIS_BLOCK_SIZE,
.base.cra_blocksize = 1,
.base.cra_ctxsize = sizeof(struct aegis_ctx),
.base.cra_alignmask = 0,
.base.cra_priority = 100,
.base.cra_name = "aegis128",
.base.cra_driver_name = "aegis128-generic",
.base.cra_module = THIS_MODULE,
};
static struct aead_alg crypto_aegis128_alg_simd = {
.setkey = crypto_aegis128_setkey,
.setauthsize = crypto_aegis128_setauthsize,
.encrypt = crypto_aegis128_encrypt_simd,
.decrypt = crypto_aegis128_decrypt_simd,
.ivsize = AEGIS128_NONCE_SIZE,
.maxauthsize = AEGIS128_MAX_AUTH_SIZE,
.chunksize = AEGIS_BLOCK_SIZE,
.base.cra_blocksize = 1,
.base.cra_ctxsize = sizeof(struct aegis_ctx),
.base.cra_alignmask = 0,
.base.cra_priority = 200,
.base.cra_name = "aegis128",
.base.cra_driver_name = "aegis128-simd",
.base.cra_module = THIS_MODULE,
};
static int __init crypto_aegis128_module_init(void)
{
int ret;
ret = crypto_register_aead(&crypto_aegis128_alg_generic);
if (ret)
return ret;
if (IS_ENABLED(CONFIG_CRYPTO_AEGIS128_SIMD) &&
crypto_aegis128_have_simd()) {
ret = crypto_register_aead(&crypto_aegis128_alg_simd);
if (ret) {
crypto_unregister_aead(&crypto_aegis128_alg_generic);
return ret;
}
static_branch_enable(&have_simd);
}
return 0;
}
static void __exit crypto_aegis128_module_exit(void)
{
if (IS_ENABLED(CONFIG_CRYPTO_AEGIS128_SIMD) &&
crypto_aegis128_have_simd())
crypto_unregister_aead(&crypto_aegis128_alg_simd);
crypto_unregister_aead(&crypto_aegis128_alg_generic);
}
subsys_initcall(crypto_aegis128_module_init);
module_exit(crypto_aegis128_module_exit);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Ondrej Mosnacek <[email protected]>");
MODULE_DESCRIPTION("AEGIS-128 AEAD algorithm");
MODULE_ALIAS_CRYPTO("aegis128");
MODULE_ALIAS_CRYPTO("aegis128-generic");
MODULE_ALIAS_CRYPTO("aegis128-simd");
Codebase Browser
linux