From 76a2a3edf79383cd4cd3c5ee64d03b5e64e84334 Mon Sep 17 00:00:00 2001
From: Ugljesa Jovanovic <ionspinf@gmail.com>
Date: Thu, 21 May 2020 23:34:22 +0200
Subject: [PATCH] Xor directly from argon matrix without intermediary array

---
 .../ionspin/kotlin/crypto/keyderivation/argon2/Argon2.kt | 9 ++-------
 .../kotlin/crypto/keyderivation/argon2/Argon2Utils.kt    | 9 +++++++++
 .../ionspin/kotlin/crypto/hash/argon/Argon2MatrixTest.kt | 2 +-
 3 files changed, 12 insertions(+), 8 deletions(-)

diff --git a/multiplatform-crypto/src/commonMain/kotlin/com/ionspin/kotlin/crypto/keyderivation/argon2/Argon2.kt b/multiplatform-crypto/src/commonMain/kotlin/com/ionspin/kotlin/crypto/keyderivation/argon2/Argon2.kt
index 85d92cb..3fcb9d0 100644
--- a/multiplatform-crypto/src/commonMain/kotlin/com/ionspin/kotlin/crypto/keyderivation/argon2/Argon2.kt
+++ b/multiplatform-crypto/src/commonMain/kotlin/com/ionspin/kotlin/crypto/keyderivation/argon2/Argon2.kt
@@ -25,10 +25,7 @@ import com.ionspin.kotlin.crypto.keyderivation.KeyDerivationFunction
 import com.ionspin.kotlin.crypto.keyderivation.argon2.Argon2Utils.argonBlake2bArbitraryLenghtHash
 import com.ionspin.kotlin.crypto.keyderivation.argon2.Argon2Utils.compressionFunctionG
 import com.ionspin.kotlin.crypto.keyderivation.argon2.Argon2Utils.validateArgonParameters
-import com.ionspin.kotlin.crypto.util.fromLittleEndianArrayToUInt
-import com.ionspin.kotlin.crypto.util.hexColumsPrint
-import com.ionspin.kotlin.crypto.util.toLittleEndianUByteArray
-import com.ionspin.kotlin.crypto.util.xor
+import com.ionspin.kotlin.crypto.util.*
 
 /**
  * Created by Ugljesa Jovanovic
@@ -330,10 +327,8 @@ class Argon2(
         //Temporary fold
         val acc = matrix.getBlockAt(0, columnCount - 1).copyOf()
         for (i in 1 until parallelism) {
-            acc.hexColumsPrint(1024)
-            (acc xor matrix.getBlockAt(i, columnCount -1)).copyInto(acc)
+            (acc.xorWithBlock(matrix, i, columnCount - 1).copyInto(acc))
         }
-        acc.hexColumsPrint(1024)
         //Hash the xored last blocks
         val hash = argonBlake2bArbitraryLenghtHash(acc, tagLength)
         matrix.clearMatrix()
diff --git a/multiplatform-crypto/src/commonMain/kotlin/com/ionspin/kotlin/crypto/keyderivation/argon2/Argon2Utils.kt b/multiplatform-crypto/src/commonMain/kotlin/com/ionspin/kotlin/crypto/keyderivation/argon2/Argon2Utils.kt
index e3744d4..ebbad77 100644
--- a/multiplatform-crypto/src/commonMain/kotlin/com/ionspin/kotlin/crypto/keyderivation/argon2/Argon2Utils.kt
+++ b/multiplatform-crypto/src/commonMain/kotlin/com/ionspin/kotlin/crypto/keyderivation/argon2/Argon2Utils.kt
@@ -19,6 +19,7 @@
 package com.ionspin.kotlin.crypto.keyderivation.argon2
 
 import com.ionspin.kotlin.crypto.hash.blake2b.Blake2b
+import com.ionspin.kotlin.crypto.keyderivation.argon2.Argon2Utils.BLOCK_SIZE
 import com.ionspin.kotlin.crypto.util.arrayChunked
 import com.ionspin.kotlin.crypto.util.fromLittleEndianArrayToULong
 import com.ionspin.kotlin.crypto.util.plus
@@ -32,6 +33,7 @@ import com.ionspin.kotlin.crypto.util.xor
  * on 16-May-2020
  */
 object Argon2Utils {
+    const val BLOCK_SIZE = 1024
 
     const val R1 = 32
     const val R2 = 24
@@ -185,4 +187,11 @@ object Argon2Utils {
         }
 
     }
+}
+
+// ------------ Arithmetic and other utils
+
+@ExperimentalUnsignedTypes
+fun UByteArray.xorWithBlock(other : Argon2Matrix, rowPosition: Int, columnPosition: Int) : UByteArray {
+    return UByteArray(BLOCK_SIZE) { this[it] xor other[rowPosition, columnPosition, it] }
 }
\ No newline at end of file
diff --git a/multiplatform-crypto/src/commonTest/kotlin/com/ionspin/kotlin/crypto/hash/argon/Argon2MatrixTest.kt b/multiplatform-crypto/src/commonTest/kotlin/com/ionspin/kotlin/crypto/hash/argon/Argon2MatrixTest.kt
index b8af5a4..3cdc432 100644
--- a/multiplatform-crypto/src/commonTest/kotlin/com/ionspin/kotlin/crypto/hash/argon/Argon2MatrixTest.kt
+++ b/multiplatform-crypto/src/commonTest/kotlin/com/ionspin/kotlin/crypto/hash/argon/Argon2MatrixTest.kt
@@ -72,7 +72,7 @@ class Argon2MatrixTest {
             zeroesBlock.contentEquals(argon2Matrix.getBlockAt(0, 0)) &&
                     onesBlock.contentEquals(argon2Matrix.getBlockAt(0, 1)) &&
                     twosBlock.contentEquals(argon2Matrix.getBlockAt(1, 0)) &&
-                    threesBlock.contentEquals(argon2Matrix.getBlockAt(1, 1)) 
+                    threesBlock.contentEquals(argon2Matrix.getBlockAt(1, 1))
         }
     }
 }
\ No newline at end of file