373 lines
9.9 KiB
C
373 lines
9.9 KiB
C
// SPDX-License-Identifier: GPL-2.0 OR MIT
|
|
/*
|
|
* Copyright (C) 2015-2019 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
|
|
*
|
|
* This is an implementation of the ChaCha20Poly1305 AEAD construction.
|
|
*
|
|
* Information: https://tools.ietf.org/html/rfc8439
|
|
*/
|
|
|
|
#include <crypto/algapi.h>
|
|
#include <crypto/chacha20poly1305.h>
|
|
#include <crypto/chacha.h>
|
|
#include <crypto/poly1305.h>
|
|
#include <crypto/scatterwalk.h>
|
|
|
|
#include <asm/unaligned.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/init.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/module.h>
|
|
|
|
#define CHACHA_KEY_WORDS (CHACHA_KEY_SIZE / sizeof(u32))
|
|
|
|
bool __init chacha20poly1305_selftest(void);
|
|
|
|
static void chacha_load_key(u32 *k, const u8 *in)
|
|
{
|
|
k[0] = get_unaligned_le32(in);
|
|
k[1] = get_unaligned_le32(in + 4);
|
|
k[2] = get_unaligned_le32(in + 8);
|
|
k[3] = get_unaligned_le32(in + 12);
|
|
k[4] = get_unaligned_le32(in + 16);
|
|
k[5] = get_unaligned_le32(in + 20);
|
|
k[6] = get_unaligned_le32(in + 24);
|
|
k[7] = get_unaligned_le32(in + 28);
|
|
}
|
|
|
|
static void xchacha_init(u32 *chacha_state, const u8 *key, const u8 *nonce)
|
|
{
|
|
u32 k[CHACHA_KEY_WORDS];
|
|
u8 iv[CHACHA_IV_SIZE];
|
|
|
|
memset(iv, 0, 8);
|
|
memcpy(iv + 8, nonce + 16, 8);
|
|
|
|
chacha_load_key(k, key);
|
|
|
|
/* Compute the subkey given the original key and first 128 nonce bits */
|
|
chacha_init(chacha_state, k, nonce);
|
|
hchacha_block(chacha_state, k, 20);
|
|
|
|
chacha_init(chacha_state, k, iv);
|
|
|
|
memzero_explicit(k, sizeof(k));
|
|
memzero_explicit(iv, sizeof(iv));
|
|
}
|
|
|
|
static void
|
|
__chacha20poly1305_encrypt(u8 *dst, const u8 *src, const size_t src_len,
|
|
const u8 *ad, const size_t ad_len, u32 *chacha_state)
|
|
{
|
|
const u8 *pad0 = page_address(ZERO_PAGE(0));
|
|
struct poly1305_desc_ctx poly1305_state;
|
|
union {
|
|
u8 block0[POLY1305_KEY_SIZE];
|
|
__le64 lens[2];
|
|
} b;
|
|
|
|
chacha20_crypt(chacha_state, b.block0, pad0, sizeof(b.block0));
|
|
poly1305_init(&poly1305_state, b.block0);
|
|
|
|
poly1305_update(&poly1305_state, ad, ad_len);
|
|
if (ad_len & 0xf)
|
|
poly1305_update(&poly1305_state, pad0, 0x10 - (ad_len & 0xf));
|
|
|
|
chacha20_crypt(chacha_state, dst, src, src_len);
|
|
|
|
poly1305_update(&poly1305_state, dst, src_len);
|
|
if (src_len & 0xf)
|
|
poly1305_update(&poly1305_state, pad0, 0x10 - (src_len & 0xf));
|
|
|
|
b.lens[0] = cpu_to_le64(ad_len);
|
|
b.lens[1] = cpu_to_le64(src_len);
|
|
poly1305_update(&poly1305_state, (u8 *)b.lens, sizeof(b.lens));
|
|
|
|
poly1305_final(&poly1305_state, dst + src_len);
|
|
|
|
memzero_explicit(chacha_state, CHACHA_STATE_WORDS * sizeof(u32));
|
|
memzero_explicit(&b, sizeof(b));
|
|
}
|
|
|
|
void chacha20poly1305_encrypt(u8 *dst, const u8 *src, const size_t src_len,
|
|
const u8 *ad, const size_t ad_len,
|
|
const u64 nonce,
|
|
const u8 key[CHACHA20POLY1305_KEY_SIZE])
|
|
{
|
|
u32 chacha_state[CHACHA_STATE_WORDS];
|
|
u32 k[CHACHA_KEY_WORDS];
|
|
__le64 iv[2];
|
|
|
|
chacha_load_key(k, key);
|
|
|
|
iv[0] = 0;
|
|
iv[1] = cpu_to_le64(nonce);
|
|
|
|
chacha_init(chacha_state, k, (u8 *)iv);
|
|
__chacha20poly1305_encrypt(dst, src, src_len, ad, ad_len, chacha_state);
|
|
|
|
memzero_explicit(iv, sizeof(iv));
|
|
memzero_explicit(k, sizeof(k));
|
|
}
|
|
EXPORT_SYMBOL(chacha20poly1305_encrypt);
|
|
|
|
void xchacha20poly1305_encrypt(u8 *dst, const u8 *src, const size_t src_len,
|
|
const u8 *ad, const size_t ad_len,
|
|
const u8 nonce[XCHACHA20POLY1305_NONCE_SIZE],
|
|
const u8 key[CHACHA20POLY1305_KEY_SIZE])
|
|
{
|
|
u32 chacha_state[CHACHA_STATE_WORDS];
|
|
|
|
xchacha_init(chacha_state, key, nonce);
|
|
__chacha20poly1305_encrypt(dst, src, src_len, ad, ad_len, chacha_state);
|
|
}
|
|
EXPORT_SYMBOL(xchacha20poly1305_encrypt);
|
|
|
|
static bool
|
|
__chacha20poly1305_decrypt(u8 *dst, const u8 *src, const size_t src_len,
|
|
const u8 *ad, const size_t ad_len, u32 *chacha_state)
|
|
{
|
|
const u8 *pad0 = page_address(ZERO_PAGE(0));
|
|
struct poly1305_desc_ctx poly1305_state;
|
|
size_t dst_len;
|
|
int ret;
|
|
union {
|
|
u8 block0[POLY1305_KEY_SIZE];
|
|
u8 mac[POLY1305_DIGEST_SIZE];
|
|
__le64 lens[2];
|
|
} b;
|
|
|
|
if (unlikely(src_len < POLY1305_DIGEST_SIZE))
|
|
return false;
|
|
|
|
chacha20_crypt(chacha_state, b.block0, pad0, sizeof(b.block0));
|
|
poly1305_init(&poly1305_state, b.block0);
|
|
|
|
poly1305_update(&poly1305_state, ad, ad_len);
|
|
if (ad_len & 0xf)
|
|
poly1305_update(&poly1305_state, pad0, 0x10 - (ad_len & 0xf));
|
|
|
|
dst_len = src_len - POLY1305_DIGEST_SIZE;
|
|
poly1305_update(&poly1305_state, src, dst_len);
|
|
if (dst_len & 0xf)
|
|
poly1305_update(&poly1305_state, pad0, 0x10 - (dst_len & 0xf));
|
|
|
|
b.lens[0] = cpu_to_le64(ad_len);
|
|
b.lens[1] = cpu_to_le64(dst_len);
|
|
poly1305_update(&poly1305_state, (u8 *)b.lens, sizeof(b.lens));
|
|
|
|
poly1305_final(&poly1305_state, b.mac);
|
|
|
|
ret = crypto_memneq(b.mac, src + dst_len, POLY1305_DIGEST_SIZE);
|
|
if (likely(!ret))
|
|
chacha20_crypt(chacha_state, dst, src, dst_len);
|
|
|
|
memzero_explicit(&b, sizeof(b));
|
|
|
|
return !ret;
|
|
}
|
|
|
|
bool chacha20poly1305_decrypt(u8 *dst, const u8 *src, const size_t src_len,
|
|
const u8 *ad, const size_t ad_len,
|
|
const u64 nonce,
|
|
const u8 key[CHACHA20POLY1305_KEY_SIZE])
|
|
{
|
|
u32 chacha_state[CHACHA_STATE_WORDS];
|
|
u32 k[CHACHA_KEY_WORDS];
|
|
__le64 iv[2];
|
|
bool ret;
|
|
|
|
chacha_load_key(k, key);
|
|
|
|
iv[0] = 0;
|
|
iv[1] = cpu_to_le64(nonce);
|
|
|
|
chacha_init(chacha_state, k, (u8 *)iv);
|
|
ret = __chacha20poly1305_decrypt(dst, src, src_len, ad, ad_len,
|
|
chacha_state);
|
|
|
|
memzero_explicit(chacha_state, sizeof(chacha_state));
|
|
memzero_explicit(iv, sizeof(iv));
|
|
memzero_explicit(k, sizeof(k));
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL(chacha20poly1305_decrypt);
|
|
|
|
bool xchacha20poly1305_decrypt(u8 *dst, const u8 *src, const size_t src_len,
|
|
const u8 *ad, const size_t ad_len,
|
|
const u8 nonce[XCHACHA20POLY1305_NONCE_SIZE],
|
|
const u8 key[CHACHA20POLY1305_KEY_SIZE])
|
|
{
|
|
u32 chacha_state[CHACHA_STATE_WORDS];
|
|
|
|
xchacha_init(chacha_state, key, nonce);
|
|
return __chacha20poly1305_decrypt(dst, src, src_len, ad, ad_len,
|
|
chacha_state);
|
|
}
|
|
EXPORT_SYMBOL(xchacha20poly1305_decrypt);
|
|
|
|
static
|
|
bool chacha20poly1305_crypt_sg_inplace(struct scatterlist *src,
|
|
const size_t src_len,
|
|
const u8 *ad, const size_t ad_len,
|
|
const u64 nonce,
|
|
const u8 key[CHACHA20POLY1305_KEY_SIZE],
|
|
int encrypt)
|
|
{
|
|
const u8 *pad0 = page_address(ZERO_PAGE(0));
|
|
struct poly1305_desc_ctx poly1305_state;
|
|
u32 chacha_state[CHACHA_STATE_WORDS];
|
|
struct sg_mapping_iter miter;
|
|
size_t partial = 0;
|
|
unsigned int flags;
|
|
bool ret = true;
|
|
int sl;
|
|
union {
|
|
struct {
|
|
u32 k[CHACHA_KEY_WORDS];
|
|
__le64 iv[2];
|
|
};
|
|
u8 block0[POLY1305_KEY_SIZE];
|
|
u8 chacha_stream[CHACHA_BLOCK_SIZE];
|
|
struct {
|
|
u8 mac[2][POLY1305_DIGEST_SIZE];
|
|
};
|
|
__le64 lens[2];
|
|
} b __aligned(16);
|
|
|
|
if (WARN_ON(src_len > INT_MAX))
|
|
return false;
|
|
|
|
chacha_load_key(b.k, key);
|
|
|
|
b.iv[0] = 0;
|
|
b.iv[1] = cpu_to_le64(nonce);
|
|
|
|
chacha_init(chacha_state, b.k, (u8 *)b.iv);
|
|
chacha20_crypt(chacha_state, b.block0, pad0, sizeof(b.block0));
|
|
poly1305_init(&poly1305_state, b.block0);
|
|
|
|
if (unlikely(ad_len)) {
|
|
poly1305_update(&poly1305_state, ad, ad_len);
|
|
if (ad_len & 0xf)
|
|
poly1305_update(&poly1305_state, pad0, 0x10 - (ad_len & 0xf));
|
|
}
|
|
|
|
flags = SG_MITER_TO_SG;
|
|
if (!preemptible())
|
|
flags |= SG_MITER_ATOMIC;
|
|
|
|
sg_miter_start(&miter, src, sg_nents(src), flags);
|
|
|
|
for (sl = src_len; sl > 0 && sg_miter_next(&miter); sl -= miter.length) {
|
|
u8 *addr = miter.addr;
|
|
size_t length = min_t(size_t, sl, miter.length);
|
|
|
|
if (!encrypt)
|
|
poly1305_update(&poly1305_state, addr, length);
|
|
|
|
if (unlikely(partial)) {
|
|
size_t l = min(length, CHACHA_BLOCK_SIZE - partial);
|
|
|
|
crypto_xor(addr, b.chacha_stream + partial, l);
|
|
partial = (partial + l) & (CHACHA_BLOCK_SIZE - 1);
|
|
|
|
addr += l;
|
|
length -= l;
|
|
}
|
|
|
|
if (likely(length >= CHACHA_BLOCK_SIZE || length == sl)) {
|
|
size_t l = length;
|
|
|
|
if (unlikely(length < sl))
|
|
l &= ~(CHACHA_BLOCK_SIZE - 1);
|
|
chacha20_crypt(chacha_state, addr, addr, l);
|
|
addr += l;
|
|
length -= l;
|
|
}
|
|
|
|
if (unlikely(length > 0)) {
|
|
chacha20_crypt(chacha_state, b.chacha_stream, pad0,
|
|
CHACHA_BLOCK_SIZE);
|
|
crypto_xor(addr, b.chacha_stream, length);
|
|
partial = length;
|
|
}
|
|
|
|
if (encrypt)
|
|
poly1305_update(&poly1305_state, miter.addr,
|
|
min_t(size_t, sl, miter.length));
|
|
}
|
|
|
|
if (src_len & 0xf)
|
|
poly1305_update(&poly1305_state, pad0, 0x10 - (src_len & 0xf));
|
|
|
|
b.lens[0] = cpu_to_le64(ad_len);
|
|
b.lens[1] = cpu_to_le64(src_len);
|
|
poly1305_update(&poly1305_state, (u8 *)b.lens, sizeof(b.lens));
|
|
|
|
if (likely(sl <= -POLY1305_DIGEST_SIZE)) {
|
|
if (encrypt) {
|
|
poly1305_final(&poly1305_state,
|
|
miter.addr + miter.length + sl);
|
|
ret = true;
|
|
} else {
|
|
poly1305_final(&poly1305_state, b.mac[0]);
|
|
ret = !crypto_memneq(b.mac[0],
|
|
miter.addr + miter.length + sl,
|
|
POLY1305_DIGEST_SIZE);
|
|
}
|
|
}
|
|
|
|
sg_miter_stop(&miter);
|
|
|
|
if (unlikely(sl > -POLY1305_DIGEST_SIZE)) {
|
|
poly1305_final(&poly1305_state, b.mac[1]);
|
|
scatterwalk_map_and_copy(b.mac[encrypt], src, src_len,
|
|
sizeof(b.mac[1]), encrypt);
|
|
ret = encrypt ||
|
|
!crypto_memneq(b.mac[0], b.mac[1], POLY1305_DIGEST_SIZE);
|
|
}
|
|
|
|
memzero_explicit(chacha_state, sizeof(chacha_state));
|
|
memzero_explicit(&b, sizeof(b));
|
|
|
|
return ret;
|
|
}
|
|
|
|
bool chacha20poly1305_encrypt_sg_inplace(struct scatterlist *src, size_t src_len,
|
|
const u8 *ad, const size_t ad_len,
|
|
const u64 nonce,
|
|
const u8 key[CHACHA20POLY1305_KEY_SIZE])
|
|
{
|
|
return chacha20poly1305_crypt_sg_inplace(src, src_len, ad, ad_len,
|
|
nonce, key, 1);
|
|
}
|
|
EXPORT_SYMBOL(chacha20poly1305_encrypt_sg_inplace);
|
|
|
|
bool chacha20poly1305_decrypt_sg_inplace(struct scatterlist *src, size_t src_len,
|
|
const u8 *ad, const size_t ad_len,
|
|
const u64 nonce,
|
|
const u8 key[CHACHA20POLY1305_KEY_SIZE])
|
|
{
|
|
if (unlikely(src_len < POLY1305_DIGEST_SIZE))
|
|
return false;
|
|
|
|
return chacha20poly1305_crypt_sg_inplace(src,
|
|
src_len - POLY1305_DIGEST_SIZE,
|
|
ad, ad_len, nonce, key, 0);
|
|
}
|
|
EXPORT_SYMBOL(chacha20poly1305_decrypt_sg_inplace);
|
|
|
|
static int __init mod_init(void)
|
|
{
|
|
if (!IS_ENABLED(CONFIG_CRYPTO_MANAGER_DISABLE_TESTS) &&
|
|
WARN_ON(!chacha20poly1305_selftest()))
|
|
return -ENODEV;
|
|
return 0;
|
|
}
|
|
|
|
module_init(mod_init);
|
|
MODULE_LICENSE("GPL v2");
|
|
MODULE_DESCRIPTION("ChaCha20Poly1305 AEAD construction");
|
|
MODULE_AUTHOR("Jason A. Donenfeld <Jason@zx2c4.com>");
|