From 6cb2d2461f869d5c9d986cccec5edf1021878df2 Mon Sep 17 00:00:00 2001 From: madmaxoft Date: Tue, 29 Apr 2014 17:37:15 +0200 Subject: Moved the rest of the Crypto objects into their own respective files. --- src/PolarSSL++/AesCfb128Decryptor.cpp | 67 +++++++++++++++++++++++++++++++++++ 1 file changed, 67 insertions(+) create mode 100644 src/PolarSSL++/AesCfb128Decryptor.cpp (limited to 'src/PolarSSL++/AesCfb128Decryptor.cpp') diff --git a/src/PolarSSL++/AesCfb128Decryptor.cpp b/src/PolarSSL++/AesCfb128Decryptor.cpp new file mode 100644 index 000000000..af0d5106e --- /dev/null +++ b/src/PolarSSL++/AesCfb128Decryptor.cpp @@ -0,0 +1,67 @@ + +// AesCfb128Decryptor.cpp + +// Implements the cAesCfb128Decryptor class decrypting data using AES CFB-128 + +#include "Globals.h" +#include "AesCfb128Decryptor.h" + + + + + +cAesCfb128Decryptor::cAesCfb128Decryptor(void) : + m_IVOffset(0), + m_IsValid(false) +{ +} + + + + + +cAesCfb128Decryptor::~cAesCfb128Decryptor() +{ + // Clear the leftover in-memory data, so that they can't be accessed by a backdoor + memset(&m_Aes, 0, sizeof(m_Aes)); +} + + + + + +void cAesCfb128Decryptor::Init(const Byte a_Key[16], const Byte a_IV[16]) +{ + ASSERT(!IsValid()); // Cannot Init twice + + memcpy(m_IV, a_IV, 16); + aes_setkey_enc(&m_Aes, a_Key, 128); + m_IsValid = true; +} + + + + + +void cAesCfb128Decryptor::ProcessData(Byte * a_DecryptedOut, const Byte * a_EncryptedIn, size_t a_Length) +{ + ASSERT(IsValid()); // Must Init() first + + // PolarSSL doesn't support AES-CFB8, need to implement it manually: + for (size_t i = 0; i < a_Length; i++) + { + Byte Buffer[sizeof(m_IV)]; + aes_crypt_ecb(&m_Aes, AES_ENCRYPT, m_IV, Buffer); + for (size_t idx = 0; idx < sizeof(m_IV) - 1; idx++) + { + m_IV[idx] = m_IV[idx + 1]; + } + m_IV[sizeof(m_IV) - 1] = a_EncryptedIn[i]; + a_DecryptedOut[i] = a_EncryptedIn[i] ^ Buffer[0]; + } +} + + + + + -- cgit v1.2.3