Merge pull request #7 from bricke/test_padding

no conflicts

README.md

@@ -28,7 +28,12 @@ QAESEncryption::ExpandKey => expandKey(...)
 ```
 
 #### Padding
-Please note that as of today all input that does not comes as a muptiple of 16 will be padded with zeros to the closest multiple value.
+By default the padding method is `ISO`, however, the class supports:
+```
+ZERO
+PKCS7
+ISO
+```
 
 ### Example
 Sample code using a 128bit key in ECB mode
@@ -59,6 +64,10 @@ Example for 256bit CBC using QString
 
   QByteArray encodeText = encryption.encode(inputStr.toLocal8Bit(), hashKey, hashIV);
   QByteArray decodeText = encryption.decode(encodeText, hashKey, hashIV);
+
+  QString decodedString = QString(QAESEncryption::RemovePadding(decodeText));
+
+  //decodedString == inputStr !!
 ```
 
 ### Example via static invocation

main.cpp

@@ -2,6 +2,7 @@
 #include <QTest>
 #include "unit_test/aestest.h"
 
+
 int main(int argc, char *argv[])
 {
     QCoreApplication a(argc, argv);

qaesencryption.cpp

@@ -85,6 +85,7 @@ QByteArray QAESEncryption::getPadding(int currSize, int alignment)
 {
     QByteArray ret(0);
     int size = (alignment - currSize % alignment) % alignment;
+    if (size == 0) return ret;
     switch(m_padding)
     {
     case PADDING::ZERO:
@@ -158,6 +159,29 @@ QByteArray QAESEncryption::expandKey(const QByteArray &key)
   return roundKey;
 }
 
+QByteArray QAESEncryption::RemovePadding(const QByteArray &rawText, QAESEncryption::PADDING padding)
+{
+    QByteArray ret(rawText);
+    switch (padding)
+    {
+    case PADDING::ZERO:
+        //Works only if the last byte of the decoded array is not zero
+        while (ret.at(ret.length()-1) == 0x00)
+            ret.remove(ret.length()-1, 1);
+        break;
+    case PADDING::PKCS7:
+        ret.remove(ret.length() - ret.at(ret.length()-1), ret.at(ret.length()-1));
+        break;
+    case PADDING::ISO:
+        ret.truncate(ret.lastIndexOf(0x80));
+        break;
+    default:
+        //do nothing
+        break;
+    }
+    return ret;
+}
+
 // This function adds the round key to state.
 // The round key is added to the state by an XOR function.
 void QAESEncryption::addRoundKey(const quint8 round, const QByteArray expKey)

qaesencryption.h

@@ -29,8 +29,9 @@ public:
     static QByteArray Crypt(QAESEncryption::AES level, QAESEncryption::MODE mode, const QByteArray &rawText, const QByteArray &key, const QByteArray &iv = NULL);
     static QByteArray Decrypt(QAESEncryption::AES level, QAESEncryption::MODE mode, const QByteArray &rawText, const QByteArray &key, const QByteArray &iv = NULL);
     static QByteArray ExpandKey(QAESEncryption::AES level, QAESEncryption::MODE mode, const QByteArray &key);
+    static QByteArray RemovePadding(const QByteArray &rawText, QAESEncryption::PADDING padding = PADDING::ISO);
 
-    QAESEncryption(QAESEncryption::AES level, QAESEncryption::MODE mode, QAESEncryption::PADDING padding = QAESEncryption::ZERO);
+    QAESEncryption(QAESEncryption::AES level, QAESEncryption::MODE mode, QAESEncryption::PADDING padding = QAESEncryption::ISO);
 
     QByteArray encode(const QByteArray &rawText, const QByteArray &key, const QByteArray &iv = NULL);
     QByteArray decode(const QByteArray &rawText, const QByteArray &key, const QByteArray &iv = NULL);

unit_test/aestest.cpp

@@ -59,7 +59,6 @@ void AesTest::ECB128Crypt()
 {
     QByteArray hexText, outputHex;
     QAESEncryption encryption(QAESEncryption::AES_128, QAESEncryption::ECB);
-
     QCOMPARE(encryption.encode(in, key16), outECB128);
 }
 
@@ -103,7 +102,7 @@ void AesTest::ECB256Decrypt()
 
 void AesTest::ECB256String()
 {
-    QAESEncryption encryption(QAESEncryption::AES_256, QAESEncryption::ECB);
+    QAESEncryption encryption(QAESEncryption::AES_256, QAESEncryption::ECB, QAESEncryption::PADDING::ISO);
 
     QString inputStr("The Advanced Encryption Standard (AES), also known by its original name Rijndael "
                         "is a specification for the encryption of electronic data established by the U.S. "
@@ -113,12 +112,13 @@ void AesTest::ECB256String()
     QByteArray hashKey = QCryptographicHash::hash(key.toLocal8Bit(), QCryptographicHash::Sha256);
 
     QByteArray encodeText = encryption.encode(inputStr.toLocal8Bit(), hashKey);
+    QByteArray decodedText = QAESEncryption::RemovePadding(encryption.decode(encodeText, hashKey), QAESEncryption::PADDING::ISO);
 
-    QCOMPARE(QString(encryption.decode(encodeText, hashKey)), inputStr);
+    QCOMPARE(QString(decodedText), inputStr);
 }
 
 
-//==================CBC TESTING=========================
+////==================CBC TESTING=========================
 
 void AesTest::CBC128Crypt()
 {
@@ -148,6 +148,6 @@ void AesTest::CFB256String()
     QByteArray hashKey = QCryptographicHash::hash(key.toLocal8Bit(), QCryptographicHash::Sha256);
 
     QByteArray encodeText = encryption.encode(inputStr.toLocal8Bit(), hashKey, iv);
-
-    QCOMPARE(QString(encryption.decode(encodeText, hashKey, iv)), inputStr);
+    QByteArray decodedText = QAESEncryption::RemovePadding(encryption.decode(encodeText, hashKey, iv));
+    QCOMPARE(QString(decodedText), inputStr);
 }