ffr

#!/bin/bash

VER="0.1.3"
REQUIRED_PROGRAMS=("sed" "tr" "screen")

LINE="―――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――――" 

CONN_ERR="Is your Flipper Zero connected via USB?"
PRESS_ANY_KEY="Press any key to continue..."
SCREEN_IDLE="16"
CONF_FILE="screen.conf"
CURRENT_TIME=$(date +"%Y-%m-%d_%H-%M")

OUTPUT_FILE="random.$CURRENT_TIME"
OUTPUT_FILE_IR="$OUTPUT_FILE.ir"
OUTPUT_FILE_TXT="$OUTPUT_FILE.txt"

USAGE="Usage: $0 <NUMBER>\nWhere NUMBER is the desired duration of the experiment in seconds."

#================================================================================================
# Check whether the user provided duration of the experiment
#================================================================================================

if [ -n "$1" ]; then
  # Check for numeric
  if [[ "$1" =~ ^[0-9]+$ ]]; then
    SCREEN_IDLE=$1
  else
    echo -e $USAGE
    exit 1  
  fi
fi

#================================================================================================
# Check whether all the needed programs are present
#================================================================================================

# Function to check if a program is installed
check_program() {
    command -v "$1" &>/dev/null
}


# Array for missing programs
missing_programs=()

# Check whether programs are installed...
for program in "${REQUIRED_PROGRAMS[@]}"; do
    if ! check_program "$program"; then
        missing_programs+=("$program")
    fi
done

# Some programs not found, meh... quit.
if [ ${#missing_programs[@]} -gt 0 ]; then
    echo "Oops... The following programs are missing on your machine: ${missing_programs[*]}"
    echo "Please install them using your package manager, e.g.:"
    echo "sudo apt update && sudo apt install ${missing_programs[*]}"
    exit 1
fi



#================================================================================================
# Welcome splash
#================================================================================================
echo -e "flipper-fire-rng v$VER"
echo -e "\n$LINE"
echo -e "          [🔥] C0113CT TRU3 R4ND0MN3SS 0F TH3 CH40S [🔥]"

echo -e "$LINE\n"
echo -e "  ⚠️   Make sure qFlipper is not running\n"
echo -e "  You'll need:"
echo -e "  \t- Your Flipper Zero (connected via USB)"
echo -e "  \t- A lighter\n"



echo -e "  $PRESS_ANY_KEY"
read -n 1


#================================================================================================
# Make sure Flipper Zero is connected
#================================================================================================

# Device directory path
DIR="/dev/serial/by-id/"

# Check if the device directory exists (if not, Flipper is definitely not attached)
if [ ! -d "$DIR" ]; then
    echo "Error: Directory $DIR does not exist."
    echo $CONN_ERR
    exit 1
fi

# Search for a Filler device (name starts with "usb-Flipper_Devices_Inc")
DEVICE=$(ls "$DIR" | grep -m 1 "^usb-Flipper_Devices_Inc")

# Check if a matching device was found
if [ -z "$DEVICE" ]; then
    echo "Error: No Flipper device found ('usb-Flipper_Devices_Inc......')."
    echo $CONN_ERR
    exit 1
fi

# Did we find the Flipper?
# echo "  Flipper Zero device found .... $DEVICE"

DEVICE=$DIR$DEVICE

#================================================================================================
# Show instructions
#================================================================================================
echo -e "$LINE\n"
echo -e "  On the next screen you'll be connected to the Flipper."
echo -e "  When you see an empty screen, start flicking your lighter "
echo -e "  one hand away from the Flipper's IR receiver.\n\n"
echo -e "  ⚠️   \033[31;1;4mKeep a sane distance between the lighter and the Flipper!\033[0m\n"
echo -e "  ⚠️   \e[4mRemember!\e[0m Only you are responsible for any potential damage!\n\n"

echo -e "  The infrared radiation of the sparks and flame will become"
echo -e "  digitised RANDOMNESS. You have $SCREEN_IDLE seconds for flicking.\n" 

echo -e "  $PRESS_ANY_KEY"
read -n 1



#================================================================================================
# Write configuration file for `screen`
#================================================================================================

echo -e "screen $DEVICE 230400" > $CONF_FILE
echo -e "reset" >> $CONF_FILE
echo -e "idle $SCREEN_IDLE quit" >> $CONF_FILE
echo -e "logfile $OUTPUT_FILE_IR" >> $CONF_FILE
echo -e "log on" >> $CONF_FILE
echo stuff '"ir rx raw\r"' >> $CONF_FILE


#================================================================================================
# Capture randomness
#================================================================================================
screen -c $CONF_FILE

#================================================================================================
# Process the data, clean up, and display the result
#================================================================================================
# Remove "RAW <number> sample". Filter out all non-digits. Remove new lines.
sed '/RAW, [0-9]\+ sample/d' < $OUTPUT_FILE_IR | sed 's/[^0-9]//g' | tr -d '\n' > $OUTPUT_FILE_TXT

echo -e "$LINE"
echo -e "  Result saved to $OUTPUT_FILE_TXT"
echo -e "$LINE"

cat $OUTPUT_FILE_TXT
echo -e "\n$LINE\n"
unlink $OUTPUT_FILE_IR