From a8ad00a690830d392ed92cd79ee2100d20fbcdc5 Mon Sep 17 00:00:00 2001
From: Ugljesa Jovanovic <ionspinf@gmail.com>
Date: Sat, 21 Sep 2019 22:52:10 +0200
Subject: [PATCH] Remove padding when decrypting

---
 .../kotlin/com/ionspin/kotlin/crypto/symmetric/AesCbc.kt   | 7 +++++--
 .../com/ionspin/kotlin/crypto/symmetric/AesCbcTest.kt      | 4 ++++
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/multiplatform-crypto/src/commonMain/kotlin/com/ionspin/kotlin/crypto/symmetric/AesCbc.kt b/multiplatform-crypto/src/commonMain/kotlin/com/ionspin/kotlin/crypto/symmetric/AesCbc.kt
index b0f1fc0..33663a5 100644
--- a/multiplatform-crypto/src/commonMain/kotlin/com/ionspin/kotlin/crypto/symmetric/AesCbc.kt
+++ b/multiplatform-crypto/src/commonMain/kotlin/com/ionspin/kotlin/crypto/symmetric/AesCbc.kt
@@ -18,7 +18,6 @@ package com.ionspin.kotlin.crypto.symmetric
 
 import com.ionspin.kotlin.crypto.SRNG
 import com.ionspin.kotlin.crypto.chunked
-import com.ionspin.kotlin.crypto.toHexString
 import com.ionspin.kotlin.crypto.xor
 
 /**
@@ -125,7 +124,11 @@ class AesCbc internal constructor(val aesKey: AesKey, val mode: Mode, initializa
     }
 
     fun decrypt(): Array<UByte> {
-        return output.reversed().foldRight(Array<UByte>(0) { 0U }) { arrayOfUBytes, acc -> acc + arrayOfUBytes }
+        val removePaddingCount = output.last().last()
+        val removedPadding = output.last().dropLast(removePaddingCount.toInt() and 0x7F)
+        val preparedOutput = output.dropLast(1).toTypedArray() + removedPadding.toTypedArray()
+
+        return preparedOutput.reversed().foldRight(Array<UByte>(0) { 0U }) { arrayOfUBytes, acc -> acc + arrayOfUBytes }
     }
 
     private fun appendToBuffer(array: Array<UByte>, start: Int) {
diff --git a/multiplatform-crypto/src/commonTest/kotlin/com/ionspin/kotlin/crypto/symmetric/AesCbcTest.kt b/multiplatform-crypto/src/commonTest/kotlin/com/ionspin/kotlin/crypto/symmetric/AesCbcTest.kt
index 442df8d..12c3370 100644
--- a/multiplatform-crypto/src/commonTest/kotlin/com/ionspin/kotlin/crypto/symmetric/AesCbcTest.kt
+++ b/multiplatform-crypto/src/commonTest/kotlin/com/ionspin/kotlin/crypto/symmetric/AesCbcTest.kt
@@ -66,4 +66,8 @@ class AesCbcTest {
 
 
 
+
+
+
+
 }
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