# Qt-AES
Small and portable AES encryption class for Qt.
Supports all key sizes - 128/192/256 bits - ECB, CBC and CFB modes

## Usage

### Available Methods
```
//Encode of rawText with key
//iv is used in CBC mode
//return the encrypted byte array
QByteArray encode(const QByteArray rawText, const QByteArray key, const QByteArray iv = NULL);

//Decode of rawText with key
//iv is used in CBC mode
//return the decrypted byte array
QByteArray decode(const QByteArray rawText, const QByteArray key, const QByteArray iv = NULL);

//Key expansion in Rijndael schedule
//return the new expanded key as byte array
QByteArray expandKey(const QByteArray key);
```
The same methods are available as static calls
```
QAESEncryption::Crypt => encode(...)
QAESEncryption::Decrypt => decode(...)
QAESEncryption::ExpandKey => expandKey(...)
```

#### Padding
By default the padding method is `ISO`, however, the class supports:
```
ZERO
PKCS7
ISO
```

### Example
Sample code using a 128bit key in ECB mode
```
#include "qaesencryption.h"

  QAESEncryption encryption(QAESEncryption::AES_128, QAESEncryption::ECB);
  QByteArray encodedText = encryption.encode(plainText, key);

  QByteArray decodedText = encryption.decode(encodedText, key);
```

Example for 256bit CBC using QString
```
#include <QCryptographicHash>
#include "qaesencryption.h"

  QAESEncryption encryption(QAESEncryption::AES_256, QAESEncryption::CBC);

  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. "
                  "National Institute of Standards and Technology (NIST) in 2001");
  QString key("your-string-key");
  QString iv("your-IV-vector");

  QByteArray hashKey = QCryptographicHash::hash(key.toLocal8Bit(), QCryptographicHash::Sha256);
  QByteArray hashIV = QCryptographicHash::hash(iv.toLocal8Bit(), QCryptographicHash::Md5);

  QByteArray encodeText = encryption.encode(inputStr.toLocal8Bit(), hashKey, hashIV);
  QByteArray decodeText = encryption.decode(encodeText, hashKey, hashIV);

  QString decodedString = QString(encryption.removePadding(decodeText));

  //decodedString == inputStr !!
```

### Example via static invocation
Static invocation without creating instances, 256 bit key, ECB mode, starting from *QString* text/key
```
#include <QCryptographicHash>
#include "qaesencryption.h"

  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. "
                  "National Institute of Standards and Technology (NIST) in 2001");
  QString key("your-string-key");
  QString iv("your-IV-vector");

  QByteArray hashKey = QCryptographicHash::hash(key.toLocal8Bit(), QCryptographicHash::Sha256);
  QByteArray hashIV = QCryptographicHash::hash(iv.toLocal8Bit(), QCryptographicHash::Md5);

  //Static invocation
  QByteArray encrypted = QAESEncryption::Crypt(QAESEncryption::AES_256, QAESEncryption::CBC, 
                          inputStr.toLocal8Bit(), hashKey, hashIV);
  //...
  // Removal of Padding via Static function
  QString decodedString = QString(QAESEncryption::RemovePadding(decodeText));

```

## Unit Testing
The unit testing vectors used are included in [NIST-Recommendation for Block Cipher Modes of Operation](http://nvlpubs.nist.gov/nistpubs/Legacy/SP/nistspecialpublication800-38a.pdf)

Please note that this code is not audited or AES-certified by any competent authority, use it at your own risk.

## Dependencies
* qtcore

No OpenSSL required.

## Contact
Question or suggestions are welcome!
Please use the GitHub issue tracking to report suggestions or issues.

## License
This software is provided under the [UNLICENSE](http://unlicense.org/)