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/* ----------------------------------------------------------------------------

 *         ATMEL Microcontroller Software Support

 * ----------------------------------------------------------------------------

 * Copyright (c) 2008, Atmel Corporation

 *

 * All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions are met:

 *

 * - Redistributions of source code must retain the above copyright notice,

 * this list of conditions and the disclaimer below.

 *

 * Atmel's name may not be used to endorse or promote products derived from

 * this software without specific prior written permission.

 *

 * DISCLAIMER: THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR

 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF

 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT ARE

 * DISCLAIMED. IN NO EVENT SHALL ATMEL 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.

 * ----------------------------------------------------------------------------

 */

//------------------------------------------------------------------------------

//         Headers

//------------------------------------------------------------------------------

#include "tdes.h"

#include <board.h>

#include <utility/assert.h>

#include <utility/trace.h>

//------------------------------------------------------------------------------

//         Global functions

//------------------------------------------------------------------------------

//------------------------------------------------------------------------------

/// Configures the triple-DES peripheral to cipher/decipher, use single-DES or

/// triple-DES, use two or three keys (when in triple-DES mode), start manually,

/// automatically or via the PDC and use the given operating mode (ECB, CBC,

/// CFB or OFB).

/// \param cipher  Encrypts if 1, decrypts if 0.

/// \param tdesmod  Single- or triple-DES mode.

/// \param keymod  Use two or three keys (must be 0 in single-DES mode).

/// \param smod  Start mode.

/// \param opmod  Encryption/decryption mode.

//------------------------------------------------------------------------------

void TDES_Configure(

    unsigned char cipher,

    unsigned int tdesmod,

    unsigned int keymod,

    unsigned int smod,

    unsigned int opmod)

{

    TRACE_DEBUG("TDES_Configure()\n\r");

    SANITY_CHECK((cipher & 0xFFFFFFFE) == 0);

    SANITY_CHECK((tdesmod & 0xFFFFFFFD) == 0);

    SANITY_CHECK((keymod & 0xFFFFFFEF) == 0);

    SANITY_CHECK((smod & 0xFFFFFCFF) == 0);

    SANITY_CHECK((opmod & 0xFFFFCFFF) == 0);

    // Reset peripheral

    AT91C_BASE_TDES->TDES_CR = AT91C_TDES_SWRST;

    // Configure mode register

    AT91C_BASE_TDES->TDES_MR = cipher | tdesmod | keymod | smod | opmod;

}

//------------------------------------------------------------------------------

/// Starts the encryption or decryption process if the TDES peripheral is

/// configured in manual or PDC mode.

//------------------------------------------------------------------------------

void TDES_Start(void)

{

    TRACE_DEBUG("TDES_Start()\n\r");

    SANITY_CHECK(((AT91C_BASE_TDES->TDES_MR & AT91C_TDES_SMOD) == AT91C_TDES_SMOD_MANUAL)

                 || ((AT91C_BASE_TDES->TDES_MR & AT91C_TDES_SMOD) == AT91C_TDES_SMOD_PDC));

    // Manual mode

    if ((AT91C_BASE_TDES->TDES_MR & AT91C_TDES_SMOD) == AT91C_TDES_SMOD_MANUAL) {

        AT91C_BASE_TDES->TDES_CR = AT91C_TDES_START;

    }

    // PDC mode

    else {

        AT91C_BASE_TDES->TDES_PTCR = AT91C_PDC_RXTEN | AT91C_PDC_TXTEN;

    }

}

//------------------------------------------------------------------------------

/// Returns the current status register value of the TDES peripheral.

//------------------------------------------------------------------------------

unsigned int TDES_GetStatus(void)

{

    TRACE_DEBUG("TDES_GetStatus()\n\r");

    return AT91C_BASE_TDES->TDES_ISR;

}

//------------------------------------------------------------------------------

/// Sets the 64-bits keys (one, two or three depending on the configuration)

/// that shall be used by the TDES algorithm.

/// \param pKey1  Pointer to key #1.

/// \param pKey2  Pointer to key #2 (shall be 0 in single-DES mode).

/// \param pKey3  Pointer to key #3 (shall be 0 when using two keys).

//------------------------------------------------------------------------------

void TDES_SetKeys(

    const unsigned int *pKey1,

    const unsigned int *pKey2,

    const unsigned int *pKey3)

{

    TRACE_DEBUG("TDES_SetKeys()\n\r");

    SANITY_CHECK(pKey1);

    SANITY_CHECK((pKey2 && ((AT91C_BASE_TDES->TDES_MR & AT91C_TDES_TDESMOD) == AT91C_TDES_TDESMOD))

                 || (!pKey2 && ((AT91C_BASE_TDES->TDES_MR & AT91C_TDES_TDESMOD) == 0)));

    SANITY_CHECK((pKey3

                  && ((AT91C_BASE_TDES->TDES_MR & AT91C_TDES_TDESMOD) == AT91C_TDES_TDESMOD)

                  && ((AT91C_BASE_TDES->TDES_MR & AT91C_TDES_KEYMOD) == 0))

                 ||

                 (!pKey3

                  && ((AT91C_BASE_TDES->TDES_MR & AT91C_TDES_TDESMOD) == AT91C_TDES_TDESMOD)

                  && ((AT91C_BASE_TDES->TDES_MR & AT91C_TDES_KEYMOD) == AT91C_TDES_KEYMOD))

                 ||

                 (!pKey3

                  && ((AT91C_BASE_TDES->TDES_MR & AT91C_TDES_TDESMOD) == 0)

                  && ((AT91C_BASE_TDES->TDES_MR & AT91C_TDES_KEYMOD) == 0)));

    // Write key #1

    if (pKey1) {

        AT91C_BASE_TDES->TDES_KEY1WxR[0] = pKey1[0];

        AT91C_BASE_TDES->TDES_KEY1WxR[1] = pKey1[1];

    }

    // Write key #2

    if (pKey1) {

        AT91C_BASE_TDES->TDES_KEY2WxR[0] = pKey2[0];

        AT91C_BASE_TDES->TDES_KEY2WxR[1] = pKey2[1];

    }

    // Write key #2

    if (pKey1) {

        AT91C_BASE_TDES->TDES_KEY3WxR[0] = pKey3[0];

        AT91C_BASE_TDES->TDES_KEY3WxR[1] = pKey3[1];

    }

}

//------------------------------------------------------------------------------

/// Sets the input data to encrypt/decrypt using TDES.

/// \param pInput  Pointer to the 64-bits input data.

//------------------------------------------------------------------------------

void TDES_SetInputData(const unsigned int *pInput)

{

    TRACE_DEBUG("TDES_SetInputData()\n\r");

    SANITY_CHECK(pInput);

    AT91C_BASE_TDES->TDES_IDATAxR[0] = pInput[0];

    AT91C_BASE_TDES->TDES_IDATAxR[1] = pInput[1];

}

//------------------------------------------------------------------------------

/// Sets the input data buffer to encrypt/decrypt when in PDC mode.

/// \param pInput  Pointer to the input data.

/// \param size  Size of buffer in bytes.

//------------------------------------------------------------------------------

void TDES_SetInputBuffer(const unsigned int *pInput, unsigned int size)

{

    TRACE_DEBUG("TDES_SetInputBuffer()\n\r");

    SANITY_CHECK(pInput);

    SANITY_CHECK((size > 0) && ((size % 8) == 0));

    AT91C_BASE_TDES->TDES_TPR = (unsigned int) pInput;

    AT91C_BASE_TDES->TDES_TCR = size / 4;

}

//------------------------------------------------------------------------------

/// Stores the output data from the last TDES operation into the given 64-bits

/// buffers.

/// \param pOutput  Pointer to a 64-bits output buffer.

//------------------------------------------------------------------------------

void TDES_GetOutputData(unsigned int *pOutput)

{

    TRACE_DEBUG("TDES_GetOutputData()\n\r");

    SANITY_CHECK(pOutput);

    pOutput[0] = AT91C_BASE_TDES->TDES_ODATAxR[0];

    pOutput[1] = AT91C_BASE_TDES->TDES_ODATAxR[1];

}

//------------------------------------------------------------------------------

/// Sets the output buffer which will receive the encrypted/decrypted data when

/// using the PDC.

/// \param pOutput  Pointer to the output data.

/// \param size  Size of buffer in bytes.

//------------------------------------------------------------------------------

void TDES_SetOutputBuffer(unsigned int *pOutput, unsigned int size)

{

    TRACE_DEBUG("TDES_SetOutputBuffer()\n\r");

    SANITY_CHECK(pOutput);

    SANITY_CHECK((size > 0) && ((size % 8) == 0));

    AT91C_BASE_TDES->TDES_RPR = (unsigned int) pOutput;

    AT91C_BASE_TDES->TDES_RCR = size / 4;

}

//------------------------------------------------------------------------------

/// Sets the initialization vector to use when the TDES algorithm is configured

/// in a chained block mode (CBC, CFB or OFB).

/// \param pVector  Pointer to the 64-bits vector.

//------------------------------------------------------------------------------

void TDES_SetVector(const unsigned int *pVector)

{

    TRACE_DEBUG("TDES_SetVector()\n\r");

    SANITY_CHECK(pVector);

    AT91C_BASE_TDES->TDES_IVxR[0] = pVector[0];

    AT91C_BASE_TDES->TDES_IVxR[1] = pVector[1];

}