Rust Core Library & CLI

The core engine is implemented as a standalone Rust crate (plyqr) with zero dependencies on external C libraries.

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1. CLI Commands

The CLI binary provides full-featured commands for operational key management and symbol generation.

Key Generation

cargo run --release -- keygen <key_file>

Generates a 32-byte cryptographically secure random key file.

Dual-Channel Encoding

cargo run --release -- encode \
  <public_file> \
  <private_file> \
  <key_file> \
  <output_prefix> \
  <version> \
  <ec_level> \
  <hidden_per_block> \
  <noise_reserve> \
  <private_ecc> \
  <mask_pattern>

Outputs:

• <output_prefix>.svg: Vector format QR code.
• <output_prefix>.matrix: Serialized module matrix.
• <output_prefix>-public.svg: Baseline public-only reference vector.

Decoding

cargo run --release -- decode \
  <matrix_file> \
  <key_file> \
  <public_out> \
  <private_out>

Extracts public and authenticated private payloads simultaneously.

Capacity Inspection

cargo run --release -- capacity <public_len> <version> <ec_level> <hidden_per_block> <noise_reserve> <private_ecc> <mask_pattern>

Reports the exact maximum private payload byte capacity under the specified configuration parameters.

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2. Rust API Usage

Add plyqr to your Cargo.toml:

[dependencies]
plyqr = { path = "../plyqr" }

Encoding Example

use plyqr::{encode, Options, QrEcLevel};

fn main() -> Result<(), Box<dyn std::error::Error>> {
    let key: [u8; 32] = [0x42; 32]; // Replace with secure key
    let public_data = b"https://example.com/item/1024";
    let private_data = b"CONFIDENTIAL_SERIAL_90821";

    let mut options = Options::default();
    options.version = 10;
    options.ec_level = QrEcLevel::Medium;
    options.hidden_per_block = 4;
    options.noise_reserve = 2;
    options.private_ecc = 8;
    options.public_utf8 = true;

    let symbol = encode(public_data, private_data, &key, &options)?;
    let svg = symbol.to_svg(8)?; // Module pixel scale
    std::fs::write("qrcode.svg", svg)?;

    Ok(())
}