CPUNet Miner

cpunet_miner is a Rust-based CPU miner for the CPUNet Bitcoin test network. It speaks the Stratum v1 protocol, applies the CPUNet-specific proof-of-work tweak (a cpunet\0 suffix in the double SHA-256 preimage), and uses the midstate optimisation to accelerate hashing on the CPU.

Features

• Stratum v1 client supporting subscribe, authorize, difficulty, and job notifications.
• Multi-threaded CPU mining loop with nonce/extranonce coordination.
• CPUNet hashing (double SHA-256 of header || "cpunet\0") implemented with midstate reuse.
• Share submission tracking and basic logging for accepted/rejected shares.
• Benchmark mode to measure CPUNet hash performance.

Usage

cargo run --release -- \
  -o stratum+tcp://localhost:3333 \
  -O user:password \
  -t 4

Options

• -o, --url <URL>: Stratum endpoint (e.g. stratum+tcp://localhost:3333).
• -O, --userpass <USER:PASS>: Worker credentials in user:pass form.
• -t, --threads <N>: Number of mining threads (defaults to available CPUs).
• --benchmark: Run the hashing benchmark and exit.
• -D, --debug: Print detailed debug output (including hash preimages when shares are found).
• -f, --fudge <FACTOR>: Scale the pool difficulty/target before submitting shares (useful for debugging).

Development Notes

• The miner relies on the braidpool/rust-bitcoin fork, which exposes the CPUNet block header hashing changes.
• Unit tests cover the midstate hashing path and difficulty-to-target conversion.