TrueRNG C Implementation

This is a C equivalent of the Python main.py script for reading data from TrueRNG devices.

Overview

The program reads random data from a TrueRNG device via serial port, counts the number of ones and zeros in the data, and provides flexible output options including multiple formats and size specifications.

Supported Devices

• TrueRNG (PID: 04D8, HID: F5FE)
• TrueRNGpro (PID: 16D0, HID: 0AA0)
• TrueRNGproV2 (PID: 04D8, HID: EBB5)

Requirements

• Linux system with termios support
• GCC compiler
• TrueRNG device connected via USB
• Appropriate permissions to access the serial device (may need root or proper udev rules)

Building

make

Or manually:

gcc -Wall -Wextra -std=c99 -O2 -o truerng main.c

Usage

Basic Usage

./truerng

Command Line Options

./truerng [OPTIONS]

Options:

• -n, --bytes <N> - Number of bytes to generate (default: 1048576)
  • Supports size suffixes: K, MB, GB, TB (case-insensitive)
  • Examples: 1024, 1K, 2.5MB, 1GB, 512k, 1tb
• -f, --format <FORMAT> - Output format: binary, hex, base64, decimal
  • Default: binary when piped, hex in interactive mode
• -o, --output <FILE> - Output filename (works with all formats)
• -q, --quiet - Suppress statistics/progress output
• -v, --verbose - Show detailed device information
• -h, --help - Show help message

Size Suffixes

The -n option supports convenient size suffixes (case-insensitive):

• K or KB: Kilobytes (1024 bytes)
• M or MB: Megabytes (1,048,576 bytes)
• G or GB: Gigabytes (1,073,741,824 bytes)
• T or TB: Terabytes (1,099,511,627,776 bytes)

Decimal values are supported: 1.5MB, 2.5GB, etc.

Examples

# Basic usage - interactive mode with hex output
./truerng

# Generate 1KB of data in hex format
./truerng -n 1K -f hex

# Generate 2.5MB and pipe to another program
./truerng -n 2.5MB | xxd

# Save 1GB of binary data to file quietly
./truerng -n 1GB -o random.dat -q

# Generate 512KB as hex and save to file
./truerng -n 512K -f hex -o output.hex

# Generate base64 output with verbose device info
./truerng -n 1MB -f base64 -v

# Backward compatibility - plain numbers still work
./truerng -n 1048576 -f binary

Output Formats

• binary: Raw binary data (default for piped output)
• hex: Hexadecimal representation (default for interactive mode)
• base64: Base64 encoded output
• decimal: Decimal byte values

Modes

The program automatically detects the execution context:

• Interactive mode: Shows progress, statistics, and defaults to hex output
• Piped mode: Optimized for piping, defaults to binary output
• File output: Can be combined with any format using -o option

Configuration

You can modify the following constants in main.c:

• BLOCKSIZE: Number of bytes to read per block (default: 1024)

Permissions

On Linux, you may need to set proper permissions for the serial device:

sudo chmod 666 /dev/ttyUSB0  # Replace with your device

Or add your user to the dialout group:

sudo usermod -a -G dialout $USER

Differences from Python Version

The C implementation:

• Uses native Linux serial port APIs instead of pyserial
• Implements USB device detection via sysfs
• Uses lookup tables for efficient bit counting
• Provides enhanced command line interface with size suffixes
• Supports multiple output formats (binary, hex, base64, decimal)
• Provides equivalent functionality with better performance

Sample Output

Interactive Mode

TrueRNG - True Random Number Generator
==================================================
TrueRNGproV2 Found
Using port: /dev/ttyACM0
Generating: 1024 bytes
Starting data collection...
1024/1024 Bytes Read at 504.19 Kbytes/s

Results
=======
Total time: 0.02 seconds
Total Ones:  4072
Total Zeros: 4120
Total Bits:  8192
Extra zeros: 48
=======

Piped Mode with Verbose

TrueRNG - True Random Number Generator
Mode: Piped (Verbose)
==================================================
TrueRNGproV2 Found
Using port: /dev/ttyACM0
Generating: 2048 bytes
Starting data collection...
2048/2048 Bytes Read at 462.17 Kbytes/s

Results
=======
Total time: 0.04 seconds
Total Ones:  8144
Total Zeros: 8248
Total Bits:  16392
Extra zeros: 104
=======

Quiet Mode

./truerng -n 1K -o data.bin -q
# No output - data saved silently to data.bin

Help Output

./truerng --help
TrueRNG - True Random Number Generator
Usage: truerng [OPTIONS]

Options:
  -n, --bytes <N>          Number of bytes to generate (default: 1048576)
                           Supports suffixes: K, MB, GB, TB (e.g., 1K, 2.5MB, 1GB)
  -f, --format <FORMAT>    Output format: binary, hex, base64, decimal (default: binary when piped, interactive otherwise)
  -o, --output <FILE>      Output filename (ignored in piped mode)
  -q, --quiet              Suppress statistics/progress
  -v, --verbose            Show detailed device information
  -h, --help               Show this help message

Examples:
  truerng -n 1024 -f hex                    # Interactive mode with hex output
  truerng -n 1K -f hex                      # Same as above using K suffix
  truerng -n 2.5MB | xxd                    # Piped mode with MB suffix
  truerng -n 1GB -o random.dat -q           # Save 1GB to file quietly
  truerng -n 512K -f hex -o output.hex      # Save 512KB as hex to file