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/*
* Copyright (c) 2017 SURFnet bv
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE
* GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
* IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
* IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
// TODO: Store context in securely allocated memory
/*****************************************************************************
OSSLEVPCMacAlgorithm.cpp
OpenSSL CMAC algorithm implementation
*****************************************************************************/
#include "config.h"
#include "OSSLEVPCMacAlgorithm.h"
#include "OSSLComp.h"
#include <openssl/err.h>
// Destructor
OSSLEVPCMacAlgorithm::~OSSLEVPCMacAlgorithm()
{
if (curCTX != NULL)
CMAC_CTX_free(curCTX);
}
// Signing functions
bool OSSLEVPCMacAlgorithm::signInit(const SymmetricKey* key)
{
// Call the superclass initialiser
if (!MacAlgorithm::signInit(key))
{
return false;
}
// Determine the cipher class
const EVP_CIPHER* cipher = getEVPCipher();
if (cipher == NULL)
{
ERROR_MSG("Invalid sign mac algorithm");
ByteString dummy;
MacAlgorithm::signFinal(dummy);
return false;
}
// Initialize the context
curCTX = CMAC_CTX_new();
if (curCTX == NULL)
{
ERROR_MSG("Failed to allocate space for CMAC_CTX");
return false;
}
// Initialize EVP signing
if (!CMAC_Init(curCTX, key->getKeyBits().const_byte_str(), key->getKeyBits().size(), cipher, NULL))
{
ERROR_MSG("CMAC_Init failed: %s", ERR_error_string(ERR_get_error(), NULL));
CMAC_CTX_free(curCTX);
curCTX = NULL;
ByteString dummy;
MacAlgorithm::signFinal(dummy);
return false;
}
return true;
}
bool OSSLEVPCMacAlgorithm::signUpdate(const ByteString& dataToSign)
{
if (!MacAlgorithm::signUpdate(dataToSign))
{
return false;
}
if (dataToSign.size() == 0) return true;
if (!CMAC_Update(curCTX, dataToSign.const_byte_str(), dataToSign.size()))
{
ERROR_MSG("CMAC_Update failed");
CMAC_CTX_free(curCTX);
curCTX = NULL;
ByteString dummy;
MacAlgorithm::signFinal(dummy);
return false;
}
return true;
}
bool OSSLEVPCMacAlgorithm::signFinal(ByteString& signature)
{
if (!MacAlgorithm::signFinal(signature))
{
return false;
}
size_t outLen = getMacSize();
signature.resize(outLen);
if (!CMAC_Final(curCTX, &signature[0], &outLen))
{
ERROR_MSG("CMAC_Final failed");
CMAC_CTX_free(curCTX);
curCTX = NULL;
return false;
}
signature.resize(outLen);
CMAC_CTX_free(curCTX);
curCTX = NULL;
return true;
}
// Verification functions
bool OSSLEVPCMacAlgorithm::verifyInit(const SymmetricKey* key)
{
// Call the superclass initialiser
if (!MacAlgorithm::verifyInit(key))
{
return false;
}
// Determine the cipher class
const EVP_CIPHER* cipher = getEVPCipher();
if (cipher == NULL)
{
ERROR_MSG("Invalid verify mac algorithm");
ByteString dummy;
MacAlgorithm::signFinal(dummy);
return false;
}
// Initialize the context
curCTX = CMAC_CTX_new();
if (curCTX == NULL)
{
ERROR_MSG("Failed to allocate space for CMAC_CTX");
return false;
}
// Initialize EVP signing
if (!CMAC_Init(curCTX, key->getKeyBits().const_byte_str(), key->getKeyBits().size(), cipher, NULL))
{
ERROR_MSG("CMAC_Init failed: %s", ERR_error_string(ERR_get_error(), NULL));
CMAC_CTX_free(curCTX);
curCTX = NULL;
ByteString dummy;
MacAlgorithm::verifyFinal(dummy);
return false;
}
return true;
}
bool OSSLEVPCMacAlgorithm::verifyUpdate(const ByteString& originalData)
{
if (!MacAlgorithm::verifyUpdate(originalData))
{
return false;
}
if (originalData.size() == 0) return true;
if (!CMAC_Update(curCTX, originalData.const_byte_str(), originalData.size()))
{
ERROR_MSG("CMAC_Update failed");
CMAC_CTX_free(curCTX);
curCTX = NULL;
ByteString dummy;
MacAlgorithm::verifyFinal(dummy);
return false;
}
return true;
}
bool OSSLEVPCMacAlgorithm::verifyFinal(ByteString& signature)
{
if (!MacAlgorithm::verifyFinal(signature))
{
return false;
}
ByteString macResult;
size_t outLen = getMacSize();
macResult.resize(outLen);
if (!CMAC_Final(curCTX, &macResult[0], &outLen))
{
ERROR_MSG("CMAC_Final failed");
CMAC_CTX_free(curCTX);
curCTX = NULL;
return false;
}
CMAC_CTX_free(curCTX);
curCTX = NULL;
return macResult == signature;
}
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