* Remove the stream ciphers
The unauthenticated stream ciphers (aes-*-cfb, aes-*-ctr, camellia-*-cfb,
chacha20, chacha20-ietf, salsa20) are gone from every build, together
with the SS_ENABLE_LEGACY option, the C++ stream codecs, their C test
oracle and the stream-only tests and configurations. A configuration
naming one of them, or RC4/table, now fails at startup with a message
pointing to an AEAD method, and test_cli checks that.
Shell completions list only the supported methods (and now include the
2022 ones), and the docs and the compatibility contract say the stream
ciphers were removed.
* Drop the Mbed TLS CFB requirement and stale stream-cipher examples
CFB was only needed by the removed stream ciphers, so a system Mbed TLS
built without it no longer fails to configure. The public header example
now uses aes-256-gcm.
* Remove ss_event and the C resolver shim
Each program's loop, signals, plugin watcher and stats timer now go
through ss::event::Program (src/event/program.hpp), held on main()'s
stack; ss-manager uses it too. ss-server resolves the manager address
with the relay resolver. With no C caller left, ss_event.cpp/.h,
resolv.cpp/.h and their C tests go; test_resolver_cpp.cpp replaces the
resolver tests against the same delayed local DNS server, and ss_ev is
now an interface target over libuv.
* Reinitialize the event loop after daemonize()
The loop is created before the programs fork into the background, and
kqueue/epoll descriptors do not survive fork(), so ss-server -f (which
ss-manager always uses) died as soon as it ran. Call uv_loop_fork() in
the child.
* 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.
* Replace uthash and ss_list with the C++ containers
The C cache (now used only by the reference codecs) moves to
tests/reference and src/uthash.h is deleted. ACL rules and ss-manager's
servers are ListNodes on IntrusiveLists; destroying an element unlinks
it, so the free paths no longer have to remember to. core.h keeps only
ss_ip. test_rule is ported to C++ and also covers literal rules.
* Describe the C++20/libuv build in the Debian and snap metadata
* Keep clang-tidy clean in the new C++ tests
* Add --max-dns-queries / max_dns_queries
Sizes the resolver's query pool, the last of the capacity settings the
no-heap-after-startup design calls for. Defaults are unchanged: the
connection limit (plus 64 on ss-server, which also resolves for its
statistics).
* Report the C++20 rewrite: allocation, size, throughput and memory
docs/performance.md compares master (C) with the C++ engine on macOS
arm64: zero heap allocations per connection or datagram (from 27-89),
TCP throughput within noise, and about 20 MiB more RSS at 1,000 open
connections from the inline per-connection buffers. docs/cpp-core.md
and CLAUDE.md now describe the finished layout.
* Fix the MinGW build of ss-server: stat_resolver is POSIX-only
* Fix the fully static image and the build image for the C++ sources
docker/static: the C++ unit tests link the static libstdc++, whose error
paths need an unwinder that --rtlib=compiler-rt does not provide; link
llvm-libunwind. The programs themselves still need no C++ runtime.
docker/build: build in the default bundled mode with CMake instead of
against libev/udns (Alpine's Mbed TLS 4 is not supported by system
mode).
* Fall back to the system heap when a library realloc cannot be served
heap_realloc returned NULL when a block outgrew the largest size class or
the budget, and libuv aborts when growing its watcher array fails: a poll
on fd 8190 or above (about 4,000 connections) killed the process.
Move the block to the system heap instead, as malloc and calloc already
do. test_heap_guard_cpp polls fd 16380 with the heaps installed.
* Leave pool room for UDP sessions that are still closing
An evicted session keeps its pool slot until its socket's close callback
runs, so with pool capacity equal to the table's the acquire after an
eviction failed: a full table dropped new-session packets after evicting
a live session for nothing. The AEAD-2022 shared-session pool had the
same problem with entries still referenced by relay sessions.
* Time client-side TCP connections when idle, not only while connecting
ss-local, ss-tunnel and ss-redir only timed the upstream connect (as the
C relays did), so a client that never finished its SOCKS handshake, or a
stream whose peer vanished without a FIN, held a pool slot forever. With
the pool now a hard cap that pauses accepting when full, enough of them
stopped the listener for good. Every connection now starts with the idle
deadline, connected() re-arms it, and traffic refreshes it for all kinds
(the idle timeout keeps its 24 h floor, MIN_TCP_IDLE_TIMEOUT).
* Include <algorithm> for std::min in crypto/keys.cpp (CLANG64)
* test.py: accept host:port for --dns
The tunnel test hard-coded port 53, so it could only use a public
resolver or root. With a port it runs against a local DNS stand-in.
* Use the Mbed TLS compat wrappers for MD5 key derivation
* Fix the documentation build after moving the codecs
utils.cpp's \snippet aead.cpp and stream.cpp now live in src/crypto/,
which was not on Doxygen's EXAMPLE_PATH, so the man1 and HTML builds
failed. List the documentation sources explicitly instead of guessing
their extension.
* Seal the heap: bounded library heaps and zero-allocation program tests
The programs point libuv, c-ares and Mbed TLS (MBEDTLS_PLATFORM_MEMORY in
the bundled build) at their own FixedHeap before anything runs, mark the
end of startup with heap_seal(), and in verbose mode report heap use and
any allocation after it at exit. The library build keeps the host's
allocator.
measure_alloc.py gains --udp, and the alloc_steady_programs_* tests now
fail on any malloc per relayed TCP connection (by name and by address)
or UDP association, for every cipher family.
* Fix GCC -Wsign-compare errors in the converted C modules
GCC enables -Wsign-compare with -Wall for C++ (clang does not), which
turned a few signed/unsigned comparisons in base64, netutils, server and
manager into errors; udp.cpp needed <ctime>.
* Add --max-connections and --max-udp-sessions
The TCP connection pool and the UDP session table are sized from these
options (or max_connections / max_udp_sessions in the configuration
file) at startup instead of fixed constants; the DNS query pool follows
the connection limit. test_limits.py checks that a connection beyond
the limit is refused and that accepting resumes once one closes.
Add `ss-local --printable-salt` / `"printable_salt": true`, disabled by
default. For each outgoing TCP salt it picks a prefix length uniformly
from 6-12 bytes and samples those bytes as printable ASCII (0x20-0x7e)
immediately before key derivation. The salt stays 32 bytes with no
framing or markers, so the wire format is unchanged and any stock
server interoperates. Only chacha20-ietf-poly1305 and aes-256-gcm are
accepted; other ciphers fail at startup. UDP, server responses, and
AEAD-2022 are untouched.
Crypto unit tests cover length distribution, empty first writes, exact
framing overhead, salt-tail preservation, byte-at-a-time decryption,
tampering and replay rejection. CLI tests check local-only exposure and
cipher rejection via flag, config key and bad config type. interop.py
gains --printable-salt and --server-bin for independent stock servers.
docs/printable-salt.md records the design, entropy bound, fingerprint
caveats and route-experiment procedure; docs/encoding-experiments.md
and tests/experiments/ hold the Base85/lowpop85/TLS outer-transport
prototypes. docs/measurements/printable-salt-2026-09-23/ archives the
sanitized results of the aborted field trials.
Co-authored-by: Claude <noreply@anthropic.com>
Max Lv
