core/core.c (view raw)
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#include "core/core.h"
#include "common/memory.h"
#include "core/peer_table.h"
#include "mldsa/mldsa_native.h"
#include "mlkem/mlkem_native.h"
#include "proto_circe.h"
#include "tinycrypt/kangarootwelve128.h"
#include "tinycrypt/x25519.h"
#include <stdbool.h>
#include <stddef.h>
#include <stdint.h>
#define CIRCE_P1305_MAC_LEN 16
#define CIRCE_CORE_ASSERT(x, err) \
do \
{ \
if (!(x)) \
{ \
return err; \
} \
} \
while (false)
#define CIRCE_CORE_ASSERT_WITH_CLEANUP(x, err, errvar, label) \
do \
{ \
if (!(x)) \
{ \
(errvar) = (err); \
goto label; \
} \
} \
while (false)
/* GENERAL HELPER FUNCTIONS */
#if defined(__GNUC__) || defined(__clang__)
#define CIRCE_FIRST_FREE_OUTGOING_PACKET_ENTRY(ctx) \
__builtin_ffsll ((ctx)->outgoing_packet_table_free_mask)
#define CIRCE_FIRST_TAKEN_OUTGOING_PACKET_ENTRY(ctx) \
__builtin_ffsll (~((ctx)->outgoing_packet_table_free_mask))
#define CIRCE_FIRST_FREE_PEER_TABLE_ENTRY(ctx) \
__builtin_ffsll ((ctx)->peer_table_free_mask)
#else
#error Circe can currently only be built with GCC or Clang.
#endif
static bool
locations_equal (const struct circe_location a, const struct circe_location b)
{
if (a.ip_type != b.ip_type)
{
return false;
}
else if (a.port != b.port)
{
return false;
}
else if (a.ip_type == CIRCE_ADDRESS_IPV4)
{
return circe_memory_equal (a.ip_addr.ipv4, b.ip_addr.ipv4,
sizeof (a.ip_addr.ipv4));
}
else if (a.ip_type == CIRCE_ADDRESS_IPV6)
{
return circe_memory_equal (a.ip_addr.ipv6, b.ip_addr.ipv6,
sizeof (a.ip_addr.ipv6));
}
// What?
return false;
}
static enum circe_result
peer_table_lookup (struct circe_context *ctx,
const uint8_t tunnel_id[CIRCE_TUNNEL_ID_LEN],
struct circe_peer **const out)
{
size_t start_idx = tunnel_id[0] % CIRCE_PEER_TABLE_LEN;
for (size_t i = 0; i < CIRCE_PEER_TABLE_LEN; ++i)
{
if (circe_memory_equal (
tunnel_id,
ctx->peer_table[(i + start_idx) % CIRCE_PEER_TABLE_LEN]
.tunnel_id,
CIRCE_TUNNEL_ID_LEN))
{
*out = &(ctx->peer_table[(i + start_idx) % CIRCE_PEER_TABLE_LEN]);
return CIRCE_RESULT_SUCCESS;
}
}
size_t out_idx = CIRCE_FIRST_FREE_PEER_TABLE_ENTRY (ctx);
if (out_idx == 0)
{
return CIRCE_RESULT_PEER_TABLE_FULL;
}
if (!ctx->recall_peer_callback (ctx->ctx_handle, tunnel_id,
&ctx->peer_table[out_idx - 1]))
{
return CIRCE_RESULT_UNKNOWN_REMOTE;
}
ctx->peer_table_free_mask &= ~(1ull << (out_idx - 1));
ctx->peer_handshake_pending_mask |= (1ull << (out_idx - 1));
*out = &(ctx->peer_table[out_idx - 1]);
(*out)->last_handshake_stage = CIRCE_HANDSHAKE_STAGE_OPEN;
proto_circe_v1_rx_init (&(*out)->dgram_rx_state, (*out)->dgram_rx_buffer,
sizeof ((*out)->dgram_rx_buffer));
return CIRCE_RESULT_HANDSHAKE_PENDING;
}
static void
close_without_saying_goodbye (struct circe_context *ctx,
struct circe_peer *remote_pt_entry)
{
size_t start_idx = remote_pt_entry->identity[0] % CIRCE_PEER_TABLE_LEN;
size_t peer_idx = CIRCE_PEER_TABLE_LEN;
for (size_t i = 0; i < CIRCE_PEER_TABLE_LEN; ++i)
{
if (circe_memory_equal (
remote_pt_entry->identity,
ctx->peer_table[(i + start_idx) % CIRCE_PEER_TABLE_LEN].identity,
CIRCE_IDENTITY_LEN))
{
peer_idx = start_idx;
break;
}
}
if (peer_idx == CIRCE_PEER_TABLE_LEN)
{
// Double-free, perhaps; just ignore it
return;
}
ctx->peer_handshake_pending_mask &= ~(1ull << peer_idx);
ctx->peer_table_free_mask |= 1ull << peer_idx;
circe_memory_set ((uint8_t *)&(ctx->peer_table[peer_idx]), 0x0,
sizeof (struct circe_peer));
}
/* END GENERAL HELPER FUNCTIONS */
/* PUBLIC API */
enum circe_result
circe_initialize_core (
struct circe_context *ctx, uint8_t identity[CIRCE_IDENTITY_LEN],
uint8_t mldsa_privkey[MLDSA_SECRETKEYBYTES (44)], uint64_t now_ms,
void *ctx_handle,
void (*random_bytes_callback) (void *, uint8_t *, uint32_t),
bool (*recall_peer_callback) (void *, const uint8_t[CIRCE_IDENTITY_LEN],
struct circe_peer *))
{
ctx->last_tick_ms = now_ms;
circe_memory_copy (identity, ctx->my_identity, CIRCE_IDENTITY_LEN);
circe_memory_copy (mldsa_privkey, ctx->my_mldsa_privkey,
MLDSA_SECRETKEYBYTES (44));
ctx->peer_handshake_pending_mask = 0x0ull;
ctx->peer_table_free_mask = ~0x0ull;
ctx->outgoing_packet_table_free_mask = ~0x0ull;
circe_memory_set ((uint8_t *)ctx->outgoing_packets, 0x0,
sizeof (ctx->outgoing_packets));
circe_memory_set ((uint8_t *)ctx->peer_table, 0x0, sizeof (ctx->peer_table));
ctx->ctx_handle = ctx_handle;
ctx->random_bytes_callback = random_bytes_callback;
ctx->recall_peer_callback = recall_peer_callback;
return CIRCE_RESULT_SUCCESS;
}
enum circe_result
circe_handle_packet (struct circe_context *ctx,
const struct circe_location remote,
const uint8_t *restrict in, size_t len,
uint8_t *restrict out, size_t *out_len, uint64_t now_ms,
struct circe_event *events, size_t *n_events)
{
proto_circe_v1_frag_t fragment;
if (proto_circe_v1_peek (in, len, &fragment) != PBA_OK)
{
return CIRCE_RESULT_INVALID_PACKET;
}
struct circe_peer *remote_pt_entry;
peer_table_lookup (ctx, fragment.hdr.tunnel_id, &remote_pt_entry);
uint8_t *frag_key;
return CIRCE_RESULT_SUCCESS;
}
enum circe_result
circe_send_outgoing_packet (struct circe_context *ctx,
const uint8_t remote_identity[CIRCE_IDENTITY_LEN],
const uint8_t *in, size_t len, uint64_t now_ms,
struct circe_event *events, size_t *n_events);
enum circe_deadline circe_next_deadline (struct circe_context *ctx,
uint64_t *ms_timestamp);
enum circe_result circe_tick (struct circe_context *ctx, uint64_t now_ms,
struct circe_outgoing_packet *out,
bool *new_packet_out);
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