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 saves the raw data to a binary file called random.bin.

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

./truerng

The program will:

1. Automatically detect connected TrueRNG devices
2. Read 1024 blocks of 1024 bytes each (1MB total)
3. Count ones and zeros in real-time
4. Display read rate in KB/s
5. Save raw data to random.bin
6. Display final statistics

Configuration

You can modify the following constants in main.c:

• BLOCKSIZE: Number of bytes to read per block (default: 1024)
• NUMLOOPS: Number of blocks to read (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 equivalent functionality with better performance

Output

Sample output:

TrueRNG Counting Ones vs Zeros Example
http://ubld.it
==================================================
TrueRNG Found
Using com port:  /dev/ttyUSB0
Block Size:      1024 Bytes
Number of loops: 1024
Total size:      1048576 Bytes
Writing to:      random.bin
==================================================
1048576 Bytes Read at  45.23 Kbytes/s

Results
=======
Total Ones : 4194234
Total Zeros: 4194314

Total Bits : 8388608

There are 80 more zeros in the Capture!
=======