A shell script for generating a password wordlist with a predetermined password inserted at a random position

bruteforce_tester.sh

#!/bin/bash

# Usage explanation if insufficient parameters are provided
if [[ -z "$1" ]]; then
  echo "[x] Usage: $0 <password> [wordlist length]"
  exit 1
fi

# The correct password is taken from the first argument
PASSWORD="$1"

# The wordlist length is taken from the second argument or defaults to 100
WORDLIST_LENGTH="${2:-100}"

# Check if wordlist length is a number and greater than 0
if ! [[ "$WORDLIST_LENGTH" =~ ^[0-9]+$ ]] || [[ "$WORDLIST_LENGTH" -lt 1 ]]; then
  echo "[x] The wordlist length must be a positive integer greater than zero."
  exit 1
fi

# Get the length of the correct password
PASSWORD_LENGTH="${#PASSWORD}"
echo "[*] Analyzing password..."

# Determine the composition of the correct password
CONTAINS_SPECIAL=$(echo "$PASSWORD" | grep -qE '[^a-zA-Z0-9]' && echo "Yes" || echo "No")
CONTAINS_DIGITS=$(echo "$PASSWORD" | grep -qE '[0-9]' && echo "Yes" || echo "No")
CONTAINS_UPPER=$(echo "$PASSWORD" | grep -qE '[A-Z]' && echo "Yes" || echo "No")
CONTAINS_LOWER=$(echo "$PASSWORD" | grep -qE '[a-z]' && echo "Yes" || echo "No")

# Output composition
echo "[+] Password Length: $PASSWORD_LENGTH"
echo "[+] Contains Special Characters: $CONTAINS_SPECIAL"
echo "[+] Contains Digits: $CONTAINS_DIGITS"
echo "[+] Contains Upper Case: $CONTAINS_UPPER"
echo "[+] Contains Lower Case: $CONTAINS_LOWER"

generate_password() {
  local generated_password=""
  local char_pool=""

  [[ "$CONTAINS_UPPER" == "Yes" ]] && char_pool+="A-Z"
  [[ "$CONTAINS_LOWER" == "Yes" ]] && char_pool+="a-z"
  [[ "$CONTAINS_DIGITS" == "Yes" ]] && char_pool+="0-9"
  [[ "$CONTAINS_SPECIAL" == "Yes" ]] && char_pool+="!@#$%^&*()_+-=[]{}|;:,.<>?"

  # If no specific characters were found, default to a broad range
  [[ -z "$char_pool" ]] && char_pool="A-Za-z0-9"

  while [[ "${#generated_password}" -lt "$PASSWORD_LENGTH" ]]
  do
    generated_password+=$(tr -dc "$char_pool" </dev/urandom | head -c 1)
  done

  echo "$generated_password"
}

# Generate random position within the last 50% of the wordlist using /dev/urandom
START_POS=$(( WORDLIST_LENGTH / 2 + 1 ))
POSITION=$(od -An -N2 -tu2 /dev/urandom | awk -v start="$START_POS" -v len="$WORDLIST_LENGTH" '{print int($1 % (len - start + 1) + start)}')
echo "[+] True password will be placed at position $POSITION"

# Output file
OUTPUT_FILE="input.txt"

# Ensure the output file is empty
> "$OUTPUT_FILE"

# Generate random passwords and insert the correct password at a random position
echo "[*] Generating wordlist of length $WORDLIST_LENGTH..."
for i in $(seq 1 $WORDLIST_LENGTH); do
  if [[ "$i" -eq "$POSITION" ]]; then
    # Insert the correct password at the designated position
    echo "$PASSWORD" >> "$OUTPUT_FILE"
  else
    # Generate a random string mimicking the password composition and write to the output file
    generate_password >> "$OUTPUT_FILE"
  fi
done

echo "[+] Wordlist created with the correct password at position $POSITION."

curl -s https://gist.githubusercontent.com/n3rada/b5c8c3303cb831b3a0c670e96a05e3db/raw/33c14439486ec6d2a5b71f05341a57e3b2777359/bruteforce.sh | bash -s -- B669TgHcmL7w8j 100