tomato/toxcore/shared_key_cache.c
Green Sky aae086cc65 Squashed 'external/toxcore/c-toxcore/' changes from e2c01e457b..b03b571272
b03b571272 fix: flaky tcp test This only fixes the symptoms, not the real problem. Sometimes or consistently on some platforms a socket might need a moment before it can be written to.
32e67ab4c2 cleanup: use typedef for private message ID's in callback
7b1db6adc1 feat: add message IDs to private group messages
99e0bcc27d refactor: Observers/ignored peers can now send and receive custom packets
b3c3c49d26 fix: Disable IPv6 in Windows cross-compilation tests
e742deddff feat: Check hashes of Windows dependencies when cross-compiling
dfb9a0b02b fix: Test the current Windows Dockerfile, not an old Dockerhub image
14de93ccec chore: Use WineHQ's Wine as Debian Bookworm's crashes
ed37616249 docs: Update the Windows cross-compilation section
9bb79c174f cleanup: Remove a couple of unnecessary misc_tools dependencies
19475adb70 chore: Statically link OpenMP into the cracker fun util on Windows
1be311e51f feat: Build the fun utils when cross-compiling to Windows
88133f8446 chore: Strip Windows binaries
3cc0ae7535 refactor: Copy over all of the required static dependencies
c4fa8f7fb1 feat: Generate .def, .exp and .lib files when building for Windows
74bbac5363 feat: Let CMake create the dll instead of doing so ourselves
246642e9ae feat: Harden Windows cross-compilation
8d431c0d11 chore: Bump Windows build dependency versions
e519f7998b fix: Remove unnecessary wsock32 dependency on Windows
ed2b60c217 chore: Use a specific non-broken slimcc version.
d7f21010a1 chore: Update github actions.
e71a68b7f2 docs: Update the list of CMake options
77e08876ff chore: Remove mod and founder from group API naming scheme
12bc042767 docs: add the experimental api build option to INSTALL.md
e1fa5cae96 refactor: Rename Queries to Query to align with other enums.
be82a3ea30 fix: Correct type for conference offline peer numbers.
0627c36716 test: Add pkgsrc build.
92578afe4b test: Add FreeBSD VM action on GitHub.
52ece0f57b test: Build toxcore on NetBSD (VM).
3fe8ee2c11 chore: Only install tox_private.h on request.
9a8dfa06ab fix: save_compatibility_test failing on big-endian systems
86f5e55578 fix: Don't serve files from websockify.
710eb674a5 fix: Correctly pass extended public keys to group moderation code.
021db7031c refactor: Use `struct`s for extended public/secret keys.
a1e999fd80 chore: Compile libsodium reference implementation with compcert.
fbe3c19cf5 cleanup: correct a few nullable annotations
623e3ee5c3 cleanup: Don't use `memcpy` to cast arbitrary `struct`s to `uint8_t[]`.
c71567dc18 fix: Pass array, not array pointer, to `memcmp`.
9b46a08144 cleanup: Never pass `void*` directly to `memcpy`.
5d7b7a7bbc refactor: Use tox rng to seed the keypair generation.
961891d568 cleanup: Small improvements found by PVS Studio.
8201019f0d chore: Disable NGC saving by default, enable through Tox_Options.
5dd9ee3f65 cleanup: Replace pointer arithmetic with explicit `&arr[i]`.
ca4606d49d refactor: Use strong typedef for NGC peer id.
442213b722 cleanup: Simplify custom packet length check in NGC.
08d3393def fix: Correct a few potential null derefs in bootstrap daemon.
b9877b32b0 fix: Add missing memunlock of local variable when it goes out of scope.
dab5fe44b9 fix: Zero out stack-allocated secret key before return.
f058103299 refactor: Make prune_gc_sanctions_list more obviously correct.
3ba7a0dec9 docs: Add static analysis tool list to README.
8d0811a0f3 docs: Run prettier-markdown on markdown files.
969e3a2bfc refactor: Fix network test not using the strong typedef
93c83fbc7c refactor: Use strong typedef instead of struct for `Socket`.
9fe18b176f fix: Fix some false positive from PVS Studio.
7c44379ccb cleanup: Check that WINXP macro exists before comparing it.
5c93231bef refactor: Make tox mutex non-recursive.
aacff73939 docs: Fix up doxyfile.
d55fc85ff5 docs: Add more documentation to crypto_core.
5bdaaaedb6 refactor: Remove `Tox *` from `tox_dispatch`.
e202341e76 refactor: Don't rely on tox_dispatch passing tox in tests.
34df938f52 chore: Use C++ mode for clang-tidy.
8b05296a78 chore: Check that both gtest and gmock exist for tests.
42010660e1 test: Add slimcc compiler compatibility test.
b473630321 chore: Add some comments to the astyle config.
b7404f24f6 cleanup: Remove implicit bool conversions.
4e2dba4d9f chore: Reformat sources with astyle.
4359e3a6bc chore: Rename C++ headers to .hh suffixes.
0c05566e58 cleanup: Further `#include` cleanups.
8d29935b7a chore: Only check the bootstrap daemon checksum on release.
f70e588bc6 cleanup: Add more `const` where possible.
511bfe39c8 cleanup: Use Bazel modules to enforce proper `#include` hygiene.
1710a0d091 refactor: Move pack/unpack `IP_Port` from DHT into network module.
a975943564 chore: Really fix coverage docker image build.
c08409390f chore: Fix post-submit coverage image.
39aadf8922 fix: Don't use `memcmp` to compare `IP_Port`s.
d94246a906 fix: partially fix a bug that prevented group part messages from sending.
eeaa039222 chore: Fix rpm build; add a CI check for it.
8328449c1a chore: Speed up docker builds a bit by reducing layer count.
d6d67d56f3 cleanup: Add `const` where possible in auto tests.
6aa9e6850d cleanup: Minor cleanup of event unpack code.
bdf460a3a9 refactor: Rename `system_{memory,...}` to `os_{memory,...}`.
203e1af81e fix: a few off by one errors in group autotests
5c093c4888 cleanup: Remove all uses of `SIZEOF_VLA`.
662c2140f3 test: Add goblint static analyser.
8f07755834 cleanup: Use `memzero(x, s)` instead of `memset(x, 0, s)`.
a7258e40cf cleanup: Use explicit 0 instead of `PACKET_ID_PADDING`.
6370d0f15d cleanup: Expand the `Tox_Options` accessor macros.
14a1a0b9bd cleanup: Remove plan9 support.
a05dccad13 test: Add a simple new/delete test for Tox.
1cdcf938b9 cleanup: Add comment after every `#endif`.
ba99d4dc4b test: Fix comment I broke in the events test PR.
e07248debb refactor: Migrate auto_tests to new events API.
bdd42b5452 refactor: Add common msgpack array packer with callback.
3c659f5288 cleanup: Rename group to conference in groupav documentation.
89957be230 cleanup: Ensure handler params are named after callback params.
c650d9d345 refactor: Pass `this` pointer as first param to s11n callbacks.
e7fb91ddb8 refactor: Allow NULL pointers for byte arrays in events.
5e2c8cabc1 cleanup: make some improvements to group moderation test
259de4867e cleanup: Remove `bin_pack_{new,free}`.
21a8ff5895 cleanup: skip a do_gc iteration before removing peers marked for deletion
16809dc36e feat: Add dht_get_nodes_response event to the events system.

git-subtree-dir: external/toxcore/c-toxcore
git-subtree-split: b03b5712720de9a9901ea12fd741f177327a7021
2024-03-07 23:12:55 +01:00

172 lines
5.5 KiB
C

/* SPDX-License-Identifier: GPL-3.0-or-later
* Copyright © 2022 The TokTok team.
*/
#include "shared_key_cache.h"
#include <stdint.h>
#include <string.h> // memcpy(...)
#include "attributes.h"
#include "ccompat.h"
#include "crypto_core.h"
#include "logger.h"
#include "mem.h"
#include "mono_time.h"
typedef struct Shared_Key {
uint8_t public_key[CRYPTO_PUBLIC_KEY_SIZE];
uint8_t shared_key[CRYPTO_SHARED_KEY_SIZE];
uint64_t time_last_requested;
} Shared_Key;
struct Shared_Key_Cache {
Shared_Key *keys;
const uint8_t *self_secret_key;
uint64_t timeout; /** After this time (in seconds), a key is erased on the next housekeeping cycle */
const Mono_Time *mono_time;
const Memory *mem;
const Logger *log;
uint8_t keys_per_slot;
};
non_null()
static bool shared_key_is_empty(const Logger *log, const Shared_Key *k)
{
LOGGER_ASSERT(log, k != nullptr, "shared key must not be NULL");
/*
* Since time can never be 0, we use that to determine if a key slot is empty.
* Additionally this allows us to use crypto_memzero and leave the slot in a valid state.
*/
return k->time_last_requested == 0;
}
non_null()
static void shared_key_set_empty(const Logger *log, Shared_Key *k)
{
crypto_memzero(k, sizeof(Shared_Key));
LOGGER_ASSERT(log, shared_key_is_empty(log, k), "shared key must be empty after clearing it");
}
Shared_Key_Cache *shared_key_cache_new(const Logger *log, const Mono_Time *mono_time, const Memory *mem, const uint8_t *self_secret_key, uint64_t timeout, uint8_t keys_per_slot)
{
if (mono_time == nullptr || self_secret_key == nullptr || timeout == 0 || keys_per_slot == 0) {
return nullptr;
}
// Time must not be zero, since we use that as special value for empty slots
if (mono_time_get(mono_time) == 0) {
// Fail loudly in debug environments
LOGGER_FATAL(log, "time must not be zero (mono_time not initialised?)");
return nullptr;
}
Shared_Key_Cache *res = (Shared_Key_Cache *)mem_alloc(mem, sizeof(Shared_Key_Cache));
if (res == nullptr) {
return nullptr;
}
res->self_secret_key = self_secret_key;
res->mono_time = mono_time;
res->mem = mem;
res->log = log;
res->keys_per_slot = keys_per_slot;
// We take one byte from the public key for each bucket and store keys_per_slot elements there
const size_t cache_size = 256 * keys_per_slot;
Shared_Key *keys = (Shared_Key *)mem_valloc(mem, cache_size, sizeof(Shared_Key));
if (keys == nullptr) {
mem_delete(mem, res);
return nullptr;
}
crypto_memlock(keys, cache_size * sizeof(Shared_Key));
res->keys = keys;
return res;
}
void shared_key_cache_free(Shared_Key_Cache *cache)
{
if (cache == nullptr) {
return;
}
const size_t cache_size = 256 * cache->keys_per_slot;
// Don't leave key material in memory
crypto_memzero(cache->keys, cache_size * sizeof(Shared_Key));
crypto_memunlock(cache->keys, cache_size * sizeof(Shared_Key));
mem_delete(cache->mem, cache->keys);
mem_delete(cache->mem, cache);
}
/* NOTE: On each lookup housekeeping is performed to evict keys that did timeout. */
const uint8_t *shared_key_cache_lookup(Shared_Key_Cache *cache, const uint8_t public_key[CRYPTO_PUBLIC_KEY_SIZE])
{
// caching the time is not necessary, but calls to mono_time_get(...) are not free
const uint64_t cur_time = mono_time_get(cache->mono_time);
// We can't use the first and last bytes because they are masked in curve25519. Selected 8 for good alignment.
const uint8_t bucket_idx = public_key[8];
Shared_Key *bucket_start = &cache->keys[bucket_idx * cache->keys_per_slot];
const uint8_t *found = nullptr;
// Perform lookup
for (size_t i = 0; i < cache->keys_per_slot; ++i) {
if (shared_key_is_empty(cache->log, &bucket_start[i])) {
continue;
}
if (pk_equal(public_key, bucket_start[i].public_key)) {
found = bucket_start[i].shared_key;
bucket_start[i].time_last_requested = cur_time;
break;
}
}
// Perform housekeeping for this bucket
for (size_t i = 0; i < cache->keys_per_slot; ++i) {
if (shared_key_is_empty(cache->log, &bucket_start[i])) {
continue;
}
const bool timed_out = (bucket_start[i].time_last_requested + cache->timeout) < cur_time;
if (timed_out) {
shared_key_set_empty(cache->log, &bucket_start[i]);
}
}
if (found == nullptr) {
// Insert into cache
uint64_t oldest_timestamp = UINT64_MAX;
size_t oldest_index = 0;
/*
* Find least recently used entry, unused entries are prioritised,
* because their time_last_requested field is zeroed.
*/
for (size_t i = 0; i < cache->keys_per_slot; ++i) {
if (bucket_start[i].time_last_requested < oldest_timestamp) {
oldest_timestamp = bucket_start[i].time_last_requested;
oldest_index = i;
}
}
// Compute the shared key for the cache
if (encrypt_precompute(public_key, cache->self_secret_key, bucket_start[oldest_index].shared_key) != 0) {
// Don't put anything in the cache on error
return nullptr;
}
// update cache entry
memcpy(bucket_start[oldest_index].public_key, public_key, CRYPTO_PUBLIC_KEY_SIZE);
bucket_start[oldest_index].time_last_requested = cur_time;
found = bucket_start[oldest_index].shared_key;
}
return found;
}