Fix ECH sample with proper signature verification

src/main/java/org/creativeturbogiants/crypto/Main.kt

@@ -1,6 +1,7 @@
 package org.creativeturbogiants.crypto
 
 import org.creativeturbogiants.crypto.curve25519.Curve25519
+import org.creativeturbogiants.crypto.utils.bytesToHex
 
 fun main(args: Array<String>) {
 
@@ -15,45 +16,36 @@ fun main(args: Array<String>) {
  val secret2 = cipher.calculateAgreement(keyPair2.publicKey, keyPair1.privateKey)
 
  println("---------------------------------------------------------------------------------------------")
- println("User 1 public key = ${bytesToHex(keyPair1.publicKey)}")
- println("User 1 private key = ${bytesToHex(keyPair1.privateKey)}")
+ println("Alice")
+ println("Public key = ${bytesToHex(keyPair1.publicKey)}")
+ println("Private key = ${bytesToHex(keyPair1.privateKey)}")
 
  println("---------------------------------------------------------------------------------------------")
- println("User 2 public key = ${bytesToHex(keyPair2.publicKey)}")
- println("User 2 private key = ${bytesToHex(keyPair2.privateKey)}")
+ println("Bob")
+ println("public key = ${bytesToHex(keyPair2.publicKey)}")
+ println("private key = ${bytesToHex(keyPair2.privateKey)}")
 
  println("---------------------------------------------------------------------------------------------")
- println("User 1 shared secret key = ${bytesToHex(secret1)}")
- println("User 2 shared secret key = ${bytesToHex(secret2)}")
+ println("Alice shared key  = ${bytesToHex(secret1)}")
+ println("Bob shared key  = ${bytesToHex(secret2)}")
 
  println("---------------------------------------------------------------------------------------------")
  val signature = cipher.calculateSignature(
  keyPair1.privateKey, "test".toByteArray()
  )
 
- println("Message Signature : ${bytesToHex(signature)}")
+ println("Signature : ${bytesToHex(signature)}")
 
  val isValidSignature = cipher.verifySignature(
  keyPair1.publicKey, "test".toByteArray(), signature
  )
 
- println("Message Signature Valid : $isValidSignature")
+ println("Valid  : $isValidSignature")
 
  val sig = bytesToHex(signature)
- println("Message length : ${sig.length} bit symmetric cipher ${sig.length == 128}")
- println("Message in bytes : ${signature.size} bytes")
+ println("   : ${sig.length} bit symmetric cipher")
+ println("  : ${signature.size} bytes")
 
 }
 
-private val HEX_ARRAY = "0123456789ABCDEF".toCharArray()
 
-fun bytesToHex(bytes: ByteArray): String {
- val hexChars = CharArray(bytes.size * 2)
- for (j in bytes.indices) {
- val v = bytes[j].toInt() and 0xFF
- hexChars[j * 2] = HEX_ARRAY[v.ushr(4)]
- hexChars[j * 2 + 1] = HEX_ARRAY[v and 0x0F]
- }
-
- return String(hexChars)
-}