2178d6a70c
A maintainable, extensible BitTorrent client (C11, Linux/io_uring) targeting 10 GbE saturation. All torrent functionality is built from scratch; liburing is the only linked third-party dependency on the data path. Implements Phases 1-7 of the roadmap: - core: page-aligned buffer pool, MPMC/Treiber queues, bitfields, worker pool - crypto: SHA-1/256 (SHA-NI + scalar), Merkle (BEP-52), RC4 (MSE) - bencode/metainfo: zero-copy parser, v1/v2/hybrid .torrent + magnet - peer: sans-IO wire codec, MSE/PE handshake state machine, BEP-10, ut_metadata, PEX - piece/storage: block-level multi-peer engine, rarest-first + endgame, per-file completion events + single-file relocate (move-as-you-finish) - tracker/dht: HTTP + UDP (BEP-15) trackers, BEP-5 KRPC iterative lookup - platform: io_uring reactor (SQPOLL, registered buffers, SEND_ZC) - surface: versioned RPC, native plugin ABI, sandboxed Lua scripting, nautd/nautctl Verified against libtorrent (single/multi/hybrid, MSE, magnet-via-DHT, swarm); unit + interop tests green; ASan/UBSan/TSan clean. Scripting reference in docs/scripting.md. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
40 lines
1.8 KiB
C
40 lines
1.8 KiB
C
/* merkle.h — BitTorrent v2 (BEP-52) SHA-256 Merkle trees.
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*
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* In v2 each file is split into 16 KiB leaf blocks; the leaf hashes form a
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* binary Merkle tree whose interior nodes are SHA-256(left || right). When the
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* leaf count is not a power of two, the tree is padded with *zero hashes* (a
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* block of 32 zero bytes at the leaf level, then SHA-256 of two children up the
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* tree) so the shape is a perfect binary tree. The root at the "piece layer"
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* boundary gives per-piece verifiability; the whole-file root goes in the
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* metainfo file tree.
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*
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* This module provides the tree primitive; metainfo/storage wire it to files.
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*/
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#ifndef NAUT_MERKLE_H
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#define NAUT_MERKLE_H
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#include "naut/common.h"
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#include "naut/hash.h"
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#define NAUT_MERKLE_LEAF (16u * 1024u) /* BEP-52 block size */
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/* Compute the Merkle root of `nleaves` 32-byte leaf hashes, padding up to the
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* next power of two with zero hashes. nleaves==0 yields the all-zero hash.
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* `leaves` is nleaves*32 bytes; out is 32 bytes. Scratch is allocated
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* internally. Returns NAUT_OK or NAUT_ERR_NOMEM. */
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naut_err naut_merkle_root(const uint8_t *leaves, size_t nleaves,
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uint8_t out[NAUT_SHA256_LEN]);
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/* As above but pad to a fixed `block_count` (>= nleaves, power of two) rather
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* than the next power of two — used to compute a piece-layer root where the
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* tree height is fixed by the piece size. */
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naut_err naut_merkle_root_padded(const uint8_t *leaves, size_t nleaves,
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size_t block_count,
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uint8_t out[NAUT_SHA256_LEN]);
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/* Hash a contiguous data buffer into leaf hashes (one SHA-256 per 16 KiB, last
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* leaf may be short). out must hold ceil(len/16KiB)*32 bytes. Returns the leaf
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* count. */
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size_t naut_merkle_leaves(const uint8_t *data, size_t len, uint8_t *out);
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#endif /* NAUT_MERKLE_H */
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