4 files changed, 83 insertions, 65 deletions

diff --git a/src/crypt/cryptaes.cpp b/src/crypt/cryptaes.cpp
index b74ae03..0129c31 100644
--- a/src/crypt/cryptaes.cpp
+++ b/src/crypt/cryptaes.cpp
@@ -32,80 +32,22 @@ const EVP_CIPHER *CryptAes::algorithm()
 
 void CryptAes::encrypt()
 {
-    EVP_MD_CTX *ctx;
+    m_key = CryptEngine::createPasswordHash(m_key);
 
-    /* Create and initialise the context */
-    if (!(ctx = EVP_MD_CTX_create()))
-    {
-        handleOpenSslError();
-    }
-
-    /* Initialise the encryption operation. IMPORTANT - ensure you use a key
-     * and IV size appropriate for your cipher */
-    if (1 != EVP_DigestInit_ex(ctx, EVP_sha256(), NULL))
-    {
-        handleOpenSslError();
-    }
-
-    /* Provide the message to be encrypted, and obtain the encrypted output.
-     * EVP_EncryptUpdate can be called multiple times if necessary
-     */
-    if (1 != EVP_DigestUpdate(ctx, m_key.data(), m_key.size()))
-    {
-        handleOpenSslError();
-    }
-
-    m_key = QByteArray(256, 0);
-
-    /* Finalise the encryption. Further ciphertext bytes may be written at
-     * this stage.
-     */
-    if (1 != EVP_DigestFinal_ex(ctx, (unsigned char *) m_key.data(), NULL))
-    {
-        handleOpenSslError();
-    }
-
-    EVP_MD_CTX_destroy(ctx);
+    m_iv = CryptEngine::createRandomIv(IVLENGTH);
 
     CryptClassEvp::encrypt();
+
+    m_cryptText = m_iv + m_cryptText;
 }
 
 void CryptAes::decrypt()
 {
-    EVP_MD_CTX *ctx;
-
-    /* Create and initialise the context */
-    if (!(ctx = EVP_MD_CTX_create()))
-    {
-        handleOpenSslError();
-    }
-
-    /* Initialise the encryption operation. IMPORTANT - ensure you use a key
-     * and IV size appropriate for your cipher */
-    if (1 != EVP_DigestInit_ex(ctx, EVP_sha256(), NULL))
-    {
-        handleOpenSslError();
-    }
+    m_key = CryptEngine::createPasswordHash(m_key);
 
-    /* Provide the message to be encrypted, and obtain the encrypted output.
-     * EVP_EncryptUpdate can be called multiple times if necessary
-     */
-    if (1 != EVP_DigestUpdate(ctx, m_key.data(), m_key.size()))
-    {
-        handleOpenSslError();
-    }
-
-    m_key = QByteArray(256, 0);
-
-    /* Finalise the encryption. Further ciphertext bytes may be written at
-     * this stage.
-     */
-    if (1 != EVP_DigestFinal_ex(ctx, (unsigned char *) m_key.data(), NULL))
-    {
-        handleOpenSslError();
-    }
+    m_iv = m_cryptText.left(IVLENGTH);
 
-    EVP_MD_CTX_destroy(ctx);
+    m_cryptText = m_cryptText.remove(0, IVLENGTH);
 
     CryptClassEvp::decrypt();
 }
diff --git a/src/crypt/cryptaes.h b/src/crypt/cryptaes.h
index 58ddba1..e0de1b1 100644
--- a/src/crypt/cryptaes.h
+++ b/src/crypt/cryptaes.h
@@ -2,6 +2,7 @@
 #define CRYPTAES_H
 
 #include "cryptclassevp.h"
+#include "cryptengine.h"
 
 #include <QDebug>
 
@@ -16,6 +17,9 @@ public:
 
     virtual void encrypt();
     virtual void decrypt();
+
+private:
+    static const int IVLENGTH = 8;
 };
 
 #endif // CRYPTAES_H
diff --git a/src/crypt/cryptengine.cpp b/src/crypt/cryptengine.cpp
index fcee6f2..905fa7d 100644
--- a/src/crypt/cryptengine.cpp
+++ b/src/crypt/cryptengine.cpp
@@ -18,6 +18,67 @@ void CryptEngine::generateRandomKey()
     m_cryptClass->generateRandomKey();
 }
 
+QByteArray CryptEngine::createPasswordHash(const QString &password)
+{
+    QByteArray ret(256, 0);
+
+    EVP_MD_CTX *ctx;
+
+    /* Create and initialise the context */
+    if (!(ctx = EVP_MD_CTX_create()))
+    {
+        handleOpenSslError();
+    }
+
+    /* Initialise the encryption operation. IMPORTANT - ensure you use a key
+     * and IV size appropriate for your cipher */
+    if (1 != EVP_DigestInit_ex(ctx, EVP_sha256(), NULL))
+    {
+        handleOpenSslError();
+    }
+
+    /* Provide the message to be encrypted, and obtain the encrypted output.
+     * EVP_EncryptUpdate can be called multiple times if necessary
+     */
+    if (1 != EVP_DigestUpdate(ctx, password.data(), password.size()))
+    {
+        handleOpenSslError();
+    }
+
+    /* Finalise the encryption. Further ciphertext bytes may be written at
+     * this stage.
+     */
+    if (1 != EVP_DigestFinal_ex(ctx, (unsigned char *) ret.data(), NULL))
+    {
+        handleOpenSslError();
+    }
+
+    EVP_MD_CTX_destroy(ctx);
+
+    return ret;
+}
+
+QByteArray CryptEngine::createRandomIv(int length)
+{
+    QByteArray ret(length, 0);
+
+    qint64 m_time = QDateTime::currentMSecsSinceEpoch();
+
+    RAND_seed(&m_time, sizeof m_time);
+
+    if(1 != RAND_bytes((unsigned char *) ret.data(), ret.length()))
+    {
+        handleOpenSslError();
+    }
+
+    return ret;
+}
+
+void CryptEngine::handleOpenSslError()
+{
+    throw std::runtime_error(ERR_reason_error_string(ERR_get_error()));
+}
+
 void CryptEngine::setKey(QString value)
 {
     m_cryptClass->setKey( value.toLatin1() );
diff --git a/src/crypt/cryptengine.h b/src/crypt/cryptengine.h
index 50f91a1..a0d990b 100644
--- a/src/crypt/cryptengine.h
+++ b/src/crypt/cryptengine.h
@@ -3,6 +3,12 @@
 
 #include <QObject>
 
+#include <openssl/evp.h>
+#include <openssl/err.h>
+#include <openssl/rand.h>
+
+#include <QDateTime>
+
 #include "../cipherssingleton.h"
 #include "cryptclassbase.h"
 #include "cryptclassnullcipher.h"
@@ -209,6 +215,9 @@ public: //Methods
 
 
 
+    static QByteArray createPasswordHash(const QString &password);
+
+    static QByteArray createRandomIv(int length);
 public slots:
     /**
     * \brief Slot called when an active algorithm gets selected.
@@ -257,6 +266,8 @@ private: //Attributes
     * \see CryptClassBase
     */
     CryptClassBase* m_cryptClass;
+
+    static void handleOpenSslError();
 };
 
 #endif // CRYPTENGINE_H