Modified the code to generate unique, cryptographically secure tokens for every request.

Author: Manish Baxi

common/src/main/scala/org/example/security/TokenGenerator.scala

@@ -1,11 +1,26 @@
 package org.example.security
 
+import java.security.SecureRandom
+
 /**
  * Generates string tokens.
  */
-final object TokenGenerator {
+object TokenGenerator {
+  val LENGTH = 32
+
+  private[this] val ALPHABET = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"
+  private[this] val RANDOM = new SecureRandom
+
   /**
    * Generates a string token.
    */
-  def generateToken = "ABCD1234"
+  def generateToken: String = {
+    val builder = new StringBuilder
+
+    for (i <- 1 to LENGTH) {
+      builder.append(ALPHABET.charAt(RANDOM.nextInt(ALPHABET.length)))
+    }
+
+    builder.toString()
+  }
 }