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feature/cpp20-buffer-pool
shadowsocks-libev/tests/reference/aead2022.cpp
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Max Lv 34da0def95 Move the C codecs to tests/reference and drop uthash from ss-manager 
The programs now use only the C++ codecs. The C stream/AEAD/AEAD-2022
implementations stay as the reference the differential tests and the C
unit tests compare against. Key derivation and the cipher tables used by
the doc snippets move to src/crypto/keys.{hpp,cpp}.

ss-manager keeps its servers in an ss_list (at most MAX_PORT_NUM,
looked up only on control messages) instead of a uthash table, and
tests/test_manager.py covers add/ping/list/remove end to end.
2026-10-15 00:34:31 +08:00

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/*
* aead2022.c - Shadowsocks 2022 Edition (SIP022) AEAD ciphers
*
* Copyright (C) 2013 - 2026, Max Lv <max.c.lv@gmail.com>
*
* This file is part of the shadowsocks-libev.
*
* shadowsocks-libev is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3 of the License, or
* (at your option) any later version.
*
* shadowsocks-libev is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with shadowsocks-libev; see the file COPYING. If not, see
* <http://www.gnu.org/licenses/>.
*
* Spec: https://github.com/Shadowsocks-NET/shadowsocks-specs/blob/main/2022-1-shadowsocks-2022-edition.md
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <time.h>
#include <sodium.h>
#include "aead.h"
#include "aead_internal.h"
#include "cache.h"
#include "utils.h"
#include "blake3/blake3.h"
/* SIP022 constants */
#define SS2022_HDR_TYPE_CLIENT 0
#define SS2022_HDR_TYPE_SERVER 1
/* TCP decrypt state machine (cipher_ctx_t.hdr_stage) */
#define SS2022_STAGE_FIXED_HDR 0
#define SS2022_STAGE_VAR_HDR 1 /* request: variable header; response: first payload */
#define SS2022_STAGE_STREAM 2
/* request fixed-length header: type(1) + timestamp(8) + length(2) */
#define SS2022_REQ_FIXED_LEN 11
/* response fixed-length header: type(1) + timestamp(8) + request salt + length(2) */
#define SS2022_RESP_FIXED_LEN(salt_len) (11 + (salt_len))
#define SS2022_FIXED_BUF_LEN (11 + MAX_KEY_LENGTH)
#define SS2022_CHUNK_LEN_SIZE 2
#define SS2022_CHUNK_MASK 0xFFFF
#define SS2022_TAG_LEN 16
#define SS2022_SALT_POOL_CAP 65536
/*
* Role handling. AEAD-2022 is asymmetric: the client encrypts request
* streams and decrypts response streams, the server does the opposite.
* The default follows the module this file is compiled into; unit tests
* override it with aead_set_role().
*/
#ifdef MODULE_REMOTE
static int aead_role = CRYPTO_ROLE_SERVER;
#else
static int aead_role = CRYPTO_ROLE_CLIENT;
#endif
void
aead_set_role(int role)
{
aead_role = role;
}
int
aead_get_role(void)
{
return aead_role;
}
/*
* session_subkey := blake3::derive_key(context, key || salt)
* salt is the per-stream random salt for TCP, or the session ID for UDP.
*/
void
ss2022_derive_subkey(const uint8_t *key, size_t key_len,
const uint8_t *salt, size_t salt_len,
uint8_t *subkey, size_t subkey_len)
{
uint8_t material[2 * MAX_KEY_LENGTH];
blake3_hasher hasher;
memcpy(material, key, key_len);
memcpy(material + key_len, salt, salt_len);
blake3_hasher_init_derive_key(&hasher, SS2022_SUBKEY_CTX);
blake3_hasher_update(&hasher, material, key_len + salt_len);
blake3_hasher_finalize(&hasher, subkey, subkey_len);
sodium_memzero(material, sizeof(material));
}
/*
* Server-side salt pool. SIP022 requires exact salt matching with 60s of
* retention and forbids bloom filters (false positives are not allowed),
* so ppbloom cannot be reused here.
*/
static struct cache *ss2022_salt_pool = NULL;
static int
ss2022_salt_check_and_add(const uint8_t *salt, size_t salt_len)
{
if (ss2022_salt_pool == NULL) {
if (cache_create_keyed(&ss2022_salt_pool, SS2022_SALT_POOL_CAP, MAX_KEY_LENGTH, NULL) != 0)
return CRYPTO_ERROR;
}
cache_clear(ss2022_salt_pool, SS2022_SALT_RETENTION);
if (cache_key_exist(ss2022_salt_pool, (char *)salt, salt_len)) {
LOGE("crypto: AEAD-2022: repeat salt detected");
return CRYPTO_ERROR;
}
cache_insert(ss2022_salt_pool, (char *)salt, salt_len, NULL);
return CRYPTO_OK;
}
static int
ss2022_check_timestamp(uint64_t ts)
{
uint64_t now = (uint64_t)time(NULL);
uint64_t diff = now > ts ? now - ts : ts - now;
return diff <= SS2022_TIME_WINDOW ? CRYPTO_OK : CRYPTO_ERROR;
}
static void
store16_be(uint8_t *p, uint16_t v)
{
p[0] = (uint8_t)(v >> 8);
p[1] = (uint8_t)v;
}
static void
store64_be(uint8_t *p, uint64_t v)
{
for (int i = 7; i >= 0; i--) {
p[i] = (uint8_t)(v & 0xff);
v >>= 8;
}
}
static uint64_t
load64_be(const uint8_t *p)
{
uint64_t v = 0;
for (int i = 0; i < 8; i++)
v = (v << 8) | p[i];
return v;
}
/*
* Length of the SOCKS5 address (ATYP + address + port) at the head of buf,
* or 0 if it is malformed or truncated.
*/
static size_t
ss2022_socks_addr_len(const uint8_t *buf, size_t len)
{
if (len < 1)
return 0;
size_t addr_len;
switch (buf[0] & ADDRTYPE_MASK) {
case 1: /* IPv4 */
addr_len = 1 + 4;
break;
case 4: /* IPv6 */
addr_len = 1 + 16;
break;
case 3: /* domain */
if (len < 2)
return 0;
addr_len = 2 + buf[1];
break;
default:
return 0;
}
return (len >= addr_len + 2) ? addr_len + 2 : 0;
}
/* Encrypt one chunk at c, then advance the counting nonce. */
static int
ss2022_seal(cipher_ctx_t *ctx, uint8_t *c, const uint8_t *p, size_t plen)
{
size_t clen = plen + SS2022_TAG_LEN;
int err = aead_cipher_encrypt(ctx, c, &clen, (uint8_t *)p, plen,
NULL, 0, ctx->nonce, ctx->skey);
if (err)
return -1;
sodium_increment(ctx->nonce, ctx->cipher->nonce_len);
return (int)clen;
}
/* Decrypt one chunk (mlen includes the tag), then advance the nonce. */
static int
ss2022_open(cipher_ctx_t *ctx, uint8_t *p, const uint8_t *c, size_t mlen)
{
size_t plen = mlen - SS2022_TAG_LEN;
int err = aead_cipher_decrypt(ctx, p, &plen, (uint8_t *)c, mlen,
NULL, 0, ctx->nonce, ctx->skey);
if (err)
return -1;
sodium_increment(ctx->nonce, ctx->cipher->nonce_len);
return (int)plen;
}
/* ------------------------------------------------------------------ TCP */
/*
* Build the request variable-length header body:
* ATYP || address || port || padding length || padding || initial payload
* The caller's first plaintext holds the SOCKS address, optionally followed
* by initial payload bytes. SIP022 requires padding when there is no initial
* payload, so random padding is added in that case.
*/
static int
ss2022_build_req_varhdr(const uint8_t *first, size_t first_len,
uint8_t **out, size_t *out_len)
{
size_t addr_len = ss2022_socks_addr_len(first, first_len);
if (addr_len == 0) {
LOGE("AEAD-2022: malformed SOCKS address in request header");
return CRYPTO_ERROR;
}
size_t payload_len = first_len - addr_len;
uint16_t pad_len = 0;
if (payload_len == 0) {
uint16_t r;
rand_bytes(&r, sizeof(r));
pad_len = (uint16_t)(r % SS2022_MAX_PADDING) + 1;
}
size_t total = addr_len + 2 + pad_len + payload_len;
uint8_t *buf = (uint8_t *)ss_malloc(total);
memcpy(buf, first, addr_len);
store16_be(buf + addr_len, pad_len);
if (pad_len > 0)
rand_bytes(buf + addr_len + 2, pad_len);
if (payload_len > 0)
memcpy(buf + addr_len + 2 + pad_len, first + addr_len, payload_len);
*out = buf;
*out_len = total;
return CRYPTO_OK;
}
/*
* Emit salt and header chunks for the first write of a stream. The salt and
* headers are written into one buffer so the caller sends them in a single
* write, as SIP022 requires.
*/
static int
ss2022_emit_header(cipher_ctx_t *ctx, buffer_t *out, size_t *out_len,
const uint8_t *first, size_t first_len, size_t capacity)
{
size_t salt_len = ctx->cipher->key_len;
uint64_t now = (uint64_t)time(NULL);
uint8_t fixed[SS2022_FIXED_BUF_LEN];
size_t fixed_len;
uint8_t *body = NULL;
size_t body_len = 0;
int body_owned = 0;
int rc = CRYPTO_ERROR;
size_t o;
int n;
if (ctx->role == CRYPTO_ROLE_CLIENT) {
if (ss2022_build_req_varhdr(first, first_len, &body, &body_len)
!= CRYPTO_OK)
return CRYPTO_ERROR;
body_owned = 1;
if (body_len > SS2022_CHUNK_MASK) {
LOGE("AEAD-2022: request header too large");
goto done;
}
fixed_len = SS2022_REQ_FIXED_LEN;
fixed[0] = SS2022_HDR_TYPE_CLIENT;
store64_be(fixed + 1, now);
store16_be(fixed + 9, (uint16_t)body_len);
} else {
/*
* The response fixed header doubles as the first length chunk and
* echoes the request salt, which lives in the paired decrypt ctx.
*/
cipher_ctx_t *peer = ctx->peer;
if (peer == NULL || !peer->init) {
LOGE("AEAD-2022: response header needs the request salt");
return CRYPTO_ERROR;
}
if (first_len > SS2022_CHUNK_MASK) {
LOGE("AEAD-2022: response payload too large");
return CRYPTO_ERROR;
}
body = (uint8_t *)first;
body_len = first_len;
fixed_len = SS2022_RESP_FIXED_LEN(salt_len);
fixed[0] = SS2022_HDR_TYPE_SERVER;
store64_be(fixed + 1, now);
memcpy(fixed + 9, peer->salt, salt_len);
store16_be(fixed + 9 + salt_len, (uint16_t)body_len);
}
brealloc(out, salt_len + fixed_len + SS2022_TAG_LEN
+ body_len + SS2022_TAG_LEN, capacity);
memcpy(out->data, ctx->salt, salt_len);
o = salt_len;
n = ss2022_seal(ctx, (uint8_t *)out->data + o, fixed, fixed_len);
if (n < 0)
goto done;
o += n;
n = ss2022_seal(ctx, (uint8_t *)out->data + o, body, body_len);
if (n < 0)
goto done;
o += n;
*out_len = o;
rc = CRYPTO_OK;
done:
if (body_owned)
ss_free(body);
return rc;
}
int
ss2022_tcp_encrypt(buffer_t *plaintext, cipher_ctx_t *ctx, size_t capacity)
{
static buffer_t tmp = { 0, 0, 0, NULL };
if (plaintext->len == 0)
return CRYPTO_OK;
if (!ctx->init) {
aead_cipher_ctx_set_key(ctx, 1);
ctx->init = 1;
size_t out_len = 0;
int err = ss2022_emit_header(ctx, &tmp, &out_len,
(uint8_t *)plaintext->data,
plaintext->len, capacity);
if (err)
return err;
tmp.len = out_len;
bswap_data(plaintext, &tmp);
plaintext->len = out_len;
return CRYPTO_OK;
}
/* Steady state: length chunk followed by payload chunk. */
size_t remaining = plaintext->len;
uint8_t *src = (uint8_t *)plaintext->data;
size_t total_out = 0;
size_t nchunks = (plaintext->len + SS2022_CHUNK_MASK - 1) / SS2022_CHUNK_MASK;
brealloc(&tmp, plaintext->len
+ nchunks * (SS2022_CHUNK_LEN_SIZE + 2 * SS2022_TAG_LEN),
capacity);
while (remaining > 0) {
uint16_t plen = remaining > SS2022_CHUNK_MASK
? SS2022_CHUNK_MASK : (uint16_t)remaining;
uint8_t len_buf[SS2022_CHUNK_LEN_SIZE];
store16_be(len_buf, plen);
int n = ss2022_seal(ctx, (uint8_t *)tmp.data + total_out,
len_buf, SS2022_CHUNK_LEN_SIZE);
if (n < 0)
return CRYPTO_ERROR;
total_out += n;
n = ss2022_seal(ctx, (uint8_t *)tmp.data + total_out, src, plen);
if (n < 0)
return CRYPTO_ERROR;
total_out += n;
src += plen;
remaining -= plen;
}
tmp.len = total_out;
bswap_data(plaintext, &tmp);
plaintext->len = total_out;
return CRYPTO_OK;
}
/*
* Parse a decrypted request variable-length header and emit the SOCKS
* address followed by any initial payload, which is the layout the
* ss-server request path already understands.
*/
static int
ss2022_parse_req_varhdr(const uint8_t *h, size_t len, buffer_t *out,
size_t capacity)
{
size_t socks_len = ss2022_socks_addr_len(h, len);
if (socks_len == 0 || len < socks_len + 2)
return CRYPTO_ERROR;
uint16_t pad_len = load16_be(h + socks_len);
size_t pad_ofst = socks_len + 2;
if (pad_len > SS2022_MAX_PADDING || pad_ofst + pad_len > len)
return CRYPTO_ERROR;
size_t payload_ofst = pad_ofst + pad_len;
size_t payload_len = len - payload_ofst;
/* SIP022: a request with neither payload nor padding must be rejected. */
if (payload_len == 0 && pad_len == 0)
return CRYPTO_ERROR;
brealloc(out, socks_len + payload_len, capacity);
memcpy(out->data, h, socks_len);
if (payload_len > 0)
memcpy(out->data + socks_len, h + payload_ofst, payload_len);
out->len = socks_len + payload_len;
return CRYPTO_OK;
}
/* Append n bytes of freshly decrypted plaintext to the output buffer. */
static int
ss2022_drain_chunks(cipher_ctx_t *ctx, buffer_t *chunk, buffer_t *out,
size_t capacity)
{
for (;;) {
if (ctx->next_plen == 0) {
/* Need a length chunk first. */
if (chunk->len < SS2022_CHUNK_LEN_SIZE + SS2022_TAG_LEN)
return CRYPTO_OK;
uint8_t len_buf[SS2022_CHUNK_LEN_SIZE];
int n = ss2022_open(ctx, len_buf,
(uint8_t *)chunk->data + chunk->idx,
SS2022_CHUNK_LEN_SIZE + SS2022_TAG_LEN);
if (n < 0) {
LOGE("AEAD-2022: length chunk authentication failed");
return CRYPTO_ERROR;
}
uint16_t plen = load16_be(len_buf);
if (plen == 0) {
LOGE("AEAD-2022: zero-length payload chunk");
return CRYPTO_ERROR;
}
chunk->idx += SS2022_CHUNK_LEN_SIZE + SS2022_TAG_LEN;
chunk->len -= SS2022_CHUNK_LEN_SIZE + SS2022_TAG_LEN;
ctx->next_plen = plen;
}
/*
* The length chunk's nonce has already been consumed, so the pending
* length is kept in ctx->next_plen until the payload arrives.
*/
size_t need = (size_t)ctx->next_plen + SS2022_TAG_LEN;
if (chunk->len < need)
return CRYPTO_OK;
brealloc(out, out->len + ctx->next_plen, capacity);
int n = ss2022_open(ctx, (uint8_t *)out->data + out->len,
(uint8_t *)chunk->data + chunk->idx, need);
if (n < 0) {
LOGE("AEAD-2022: payload chunk authentication failed");
return CRYPTO_ERROR;
}
chunk->idx += need;
chunk->len -= need;
out->len += n;
ctx->next_plen = 0;
}
}
int
ss2022_tcp_decrypt(buffer_t *ciphertext, cipher_ctx_t *ctx, size_t capacity)
{
static buffer_t out = { 0, 0, 0, NULL };
size_t salt_len = ctx->cipher->key_len;
int is_client = (ctx->role == CRYPTO_ROLE_CLIENT);
if (ctx->chunk == NULL) {
ctx->chunk = (buffer_t *)ss_malloc(sizeof(buffer_t));
memset(ctx->chunk, 0, sizeof(buffer_t));
balloc(ctx->chunk, capacity);
}
buffer_t *chunk = ctx->chunk;
/* Accumulate the newly received ciphertext. */
if (chunk->idx > 0) {
if (chunk->len > 0)
memmove(chunk->data, chunk->data + chunk->idx, chunk->len);
chunk->idx = 0;
}
brealloc(chunk, chunk->len + ciphertext->len, capacity);
memcpy(chunk->data + chunk->len, ciphertext->data, ciphertext->len);
chunk->len += ciphertext->len;
out.len = 0;
/* Stage 0: salt and fixed-length header, consumed as one unit. */
if (!ctx->init) {
size_t fixed_len = is_client ? SS2022_RESP_FIXED_LEN(salt_len)
: SS2022_REQ_FIXED_LEN;
size_t need = salt_len + fixed_len + SS2022_TAG_LEN;
if (chunk->len < need) {
ciphertext->len = 0;
return CRYPTO_NEED_MORE;
}
memcpy(ctx->salt, chunk->data + chunk->idx, salt_len);
if (!is_client
&& ss2022_salt_check_and_add(ctx->salt, salt_len) != CRYPTO_OK)
return CRYPTO_ERROR;
aead_cipher_ctx_set_key(ctx, 0);
uint8_t fixed[SS2022_FIXED_BUF_LEN];
int n = ss2022_open(ctx, fixed,
(uint8_t *)chunk->data + chunk->idx + salt_len,
fixed_len + SS2022_TAG_LEN);
if (n < 0) {
LOGE("AEAD-2022: fixed header authentication failed");
return CRYPTO_ERROR;
}
uint8_t want_type = is_client ? SS2022_HDR_TYPE_SERVER
: SS2022_HDR_TYPE_CLIENT;
if (fixed[0] != want_type) {
LOGE("AEAD-2022: unexpected header type %u", fixed[0]);
return CRYPTO_ERROR;
}
if (ss2022_check_timestamp(load64_be(fixed + 1)) != CRYPTO_OK) {
LOGE("AEAD-2022: header timestamp out of window");
return CRYPTO_ERROR;
}
if (is_client) {
cipher_ctx_t *peer = ctx->peer;
if (peer == NULL || memcmp(fixed + 9, peer->salt, salt_len) != 0) {
LOGE("AEAD-2022: response does not echo the request salt");
return CRYPTO_ERROR;
}
ctx->next_plen = load16_be(fixed + 9 + salt_len);
} else {
ctx->hdr_varlen = load16_be(fixed + 9);
}
chunk->idx += need;
chunk->len -= need;
ctx->init = 1;
ctx->hdr_stage = SS2022_STAGE_VAR_HDR;
}
/*
* Stage 1: the request's variable-length header, or the response's first
* payload chunk whose length came from the fixed header.
*/
if (ctx->hdr_stage == SS2022_STAGE_VAR_HDR) {
uint16_t want = is_client ? ctx->next_plen : ctx->hdr_varlen;
size_t need = (size_t)want + SS2022_TAG_LEN;
if (want == 0) {
LOGE("AEAD-2022: empty header chunk");
return CRYPTO_ERROR;
}
if (chunk->len < need) {
ciphertext->len = 0;
return CRYPTO_NEED_MORE;
}
uint8_t *body = (uint8_t *)ss_malloc(want);
int n = ss2022_open(ctx, body,
(uint8_t *)chunk->data + chunk->idx, need);
if (n < 0) {
ss_free(body);
LOGE("AEAD-2022: header chunk authentication failed");
return CRYPTO_ERROR;
}
chunk->idx += need;
chunk->len -= need;
int rc = CRYPTO_OK;
if (is_client) {
brealloc(&out, n, capacity);
memcpy(out.data, body, n);
out.len = n;
} else {
rc = ss2022_parse_req_varhdr(body, n, &out, capacity);
if (rc != CRYPTO_OK)
LOGE("AEAD-2022: malformed request header");
}
ss_free(body);
if (rc != CRYPTO_OK)
return rc;
ctx->next_plen = 0;
ctx->hdr_stage = SS2022_STAGE_STREAM;
}
/* Stage 2: length chunk and payload chunk, repeated. */
if (ss2022_drain_chunks(ctx, chunk, &out, capacity) != CRYPTO_OK)
return CRYPTO_ERROR;
if (chunk->len == 0)
chunk->idx = 0;
if (out.len == 0) {
ciphertext->len = 0;
return CRYPTO_NEED_MORE;
}
brealloc(ciphertext, out.len, capacity);
memcpy(ciphertext->data, out.data, out.len);
ciphertext->len = out.len;
return CRYPTO_OK;
}
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