Updated proof_of_work.sh with input validation and improvements

proof_of_work.sh

@@ -1,26 +1,45 @@
 #!/bin/bash
 
+# Check if required utilities are installed
 for utils in argon2 xxd bc; do
-    if ! command -v $utils  &> /dev/null; then
+    if ! command -v $utils &> /dev/null; then
         echo "$utils is not installed. Please install it and try again."
         exit 1
     fi
 done
 
+# Read the challenge code from argument or prompt user
 if [ $# -lt 1 ]; then
     read -p "Enter Challenge Code: " challenge
 else
     challenge=$1
 fi 
 
+# Trim whitespace
 challenge=$(echo "$challenge" | xargs)
 
-IFS=':' read -r _ memory_cost time_cost salt difficulty <<< "$challenge" 
+# Validate the challenge format
+if ! [[ $challenge =~ ^([0-9]+):([0-9]+):([A-Za-z0-9]+):([0-9]+)$ ]]; then
+    echo "Invalid challenge format. Expected format: memory_cost:time_cost:salt:difficulty"
+    exit 2
+fi
 
+# Parse challenge code
+IFS=':' read -r memory_cost time_cost salt difficulty <<< "$challenge"
+
+# Trim whitespace
 memory_cost=$(echo "$memory_cost" | xargs)
 time_cost=$(echo "$time_cost" | xargs)
+salt=$(echo "$salt" | xargs)
 difficulty=$(echo "$difficulty" | xargs)
 
+# Debugging output
+echo "Memory Cost: $memory_cost"
+echo "Time Cost: $time_cost"
+echo "Salt: $salt"
+echo "Difficulty: $difficulty"
+
+# Generate prefix for the password
 pw_prefix="UNBLOCK-$(head /dev/urandom | tr -dc A-Z0-9 | head -c 8)-"
 difficulty_raw=$(echo "scale=10; e(l(256) * (4 - l($difficulty) / l(256))) / 1" | bc -l | xargs printf %.0f)	
 
@@ -29,18 +48,19 @@ echo "Time Cost: $time_cost"
 echo
 
 n=1
-
 start_time=$(date +%s)
 
+# Function to display elapsed time
 elapsed_time() {
     current_time=$(date +%s)
     elapsed_time=$((current_time - start_time))
     echo -ne "\rElapsed Time: $elapsed_time seconds."
 }
 
+# Main loop to find the solution
 while true; do
     pw="$pw_prefix$n"
-    hash=$(echo -n "$pw" | argon2 "$salt" -t "$time_cost" -k "$memory_cost" -p 1  -id -v 13 -r)
+    hash=$(echo -n "$pw" | argon2 "$salt" -t "$time_cost" -k "$memory_cost" -p 1 -id -v 13 -r)
     hash_bytes=${hash:0:8}
  
     if [ $((16#$hash_bytes)) -lt "$difficulty_raw" ]; then
@@ -49,7 +69,7 @@ while true; do
         echo "Your unblock code is: $pw"
         echo "This is the code you enter into the site to pass the challenge."
         echo
-        break
+        exit 0
     else
         elapsed_time
         n=$((n + 1))