65 lines
1.5 KiB
C
65 lines
1.5 KiB
C
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#pragma once
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#include <vector>
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#include <queue>
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#include <random> // std::linear_congruential_engine
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#include <cstdint>
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#include "acio2emu/internal/lz.h"
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namespace acio2emu {
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struct Packet {
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uint8_t node;
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uint8_t tag;
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std::vector<uint8_t> payload;
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};
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class PacketDecoder {
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private:
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Packet packet_ = {};
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// order matters, don't change this enum!
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enum payloadEncoding {
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byteStuffing,
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raw,
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unknown,
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replace,
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lz,
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} encoding_;
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uint32_t payload_size_ = 0, payload_size_count_ = 0;
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// payloadEncoding::replace state
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uint8_t substitute_;
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// payloadEncoding::lz state
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detail::InflateTransformer inflate_;
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// deobfuscation state
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bool obfuscated_;
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std::linear_congruential_engine<uint32_t, 1103515245, 12345, 0> lcg_;
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enum class readStep {
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idle,
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readNode,
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readTag,
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readPayloadSize,
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readPayloadFlags,
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readReplacementByte,
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readPayload,
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readEscaped,
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} step_ = readStep::idle;
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void set_step_(readStep s);
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void reset_(readStep s);
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int update_payload_size_(uint8_t b);
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uint8_t deobfuscate_(uint8_t b);
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public:
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bool update(uint8_t b);
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const Packet &packet();
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};
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bool encode_packet(std::queue<uint8_t> &out, uint8_t node, uint8_t tag, const std::vector<uint8_t> &payload);
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}
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