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)
• -d, --device <DEVICE> - Select specific device (index, port, or type)
  • Examples: 1, /dev/ttyACM0, pro, prov2, truerng
• -l, --list - List all available TrueRNG devices
• -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.

Device Selection

When multiple TrueRNG devices are connected, you can select a specific device using the -d option:

• By index: Use the device number from --list (e.g., -d 1, -d 2)
• By port path: Use the full device path (e.g., -d /dev/ttyACM0)
• By device type: Use device type keywords:
  • truerng - Select original TrueRNG device
  • pro - Select TrueRNGpro device
  • prov2 - Select TrueRNGproV2 device

# List all available devices
./truerng --list

# Use first device from list
./truerng -d 1 -n 1MB

# Use specific port
./truerng -d /dev/ttyACM1 -n 512K

# Use TrueRNGpro device
./truerng -d pro -n 2MB -f hex

Examples

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

# List available devices
./truerng --list

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

# Generate 2.5MB using specific device and pipe to another program
./truerng -d 2 -n 2.5MB | xxd

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

# Generate 512KB as hex and save to file using specific port
./truerng -d /dev/ttyACM0 -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
• Multiple devices: Automatically detects and warns when multiple devices are present

Multiple Device Handling

When multiple TrueRNG devices are connected:

• Without -d option: Uses the first available device with a warning
• With -d option: Uses the specified device
• Use --list to see all available devices and their details

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

Device Listing

./truerng --list
Available TrueRNG devices:
  1. TrueRNGproV2 at /dev/ttyACM0 (VID:04D8 PID:EBB5)
  2. TrueRNG at /dev/ttyACM2 (VID:04D8 PID:F5FE)

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
=======

Multiple Device Warning

Multiple TrueRNG devices found - using first available
(Use -d option to select specific device or --list to see all)
TrueRNG - True Random Number Generator
==================================================
TrueRNGproV2 Found
Using port: /dev/ttyACM0
...

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)
  -d, --device <DEVICE>    Select specific device (index, port, or type)
                           Examples: 1, /dev/ttyACM0, pro, prov2
  -l, --list               List all available TrueRNG devices
  -q, --quiet              Suppress statistics/progress
  -v, --verbose            Show detailed device information
  -h, --help               Show this help message

Device Selection:
  When multiple devices are present, use -d to select:
    -d 1                   Select first device from list
    -d /dev/ttyACM1        Select by port path
    -d pro                 Select TrueRNGpro device
    -d prov2               Select TrueRNGproV2 device
    -d truerng             Select original TrueRNG device

Examples:
  truerng --list                            # List available devices
  truerng -n 1K -f hex                      # Use first available device
  truerng -d 2 -n 1MB                       # Use second device from list
  truerng -d /dev/ttyACM1 -n 512K           # Use specific port
  truerng -d pro -n 1GB -o random.dat       # Use TrueRNGpro device