/******************************************************************************
* @fn SSP_CCM_Auth_Encrypt
*
* @brief Generates CCM Authentication tag U.
*
* input parameters
* @param encrypt if set to 'true' then run encryption and set to 'flase' for
* authentication only.
* @param Mval - Length of authentication field in octets [0,2,4,6,8,10,12,14 or 16]
* @param N - Pointer to 13-byte Nonce
* @param M - Pointer to octet string 'm'
* @param len_m - Length of M[] in octets
* @param A - Pointer to octet string 'a'
* @param len_a - Length of A[] in octets
* @param AesKey - Pointer to AES Key or Pointer to Key Expansion buffer.
* @param Cstate - Pointer to output buffer
* @param ccmLVal - ccm L Value to be used.
*
* output parameters
*
* @param Cstate[] - The first Mval bytes contain Authentication Tag T
*
* @return ZStatus_t
*
*/
uint8 SSP_CCM_Auth_Encrypt (bool encrypt, uint8 Mval, uint8 *N, uint8 *M, uint16 len_m, uint8 *A,
uint16 len_a, uint8 *AesKey, uint8 *Cstate, uint8 ccmLVal)
{
unsigned char status;
if((status = CCMAuthEncryptStart(encrypt, Mval, N, M, len_m, A, len_a, 0,
Cstate, ccmLVal, false)) != AES_SUCCESS)
{
return status;
}
do
{
ASM_NOP;
}while(!(CCMAuthEncryptCheckResult()));
if((status = CCMAuthEncryptGetResult(Mval, len_m, Cstate)) != AES_SUCCESS)
{
return status;
}
return AES_SUCCESS;
}
//*****************************************************************************
//
// AES-CCM encrypt example
//
// param bEncrypt if set to true run encryption
// param pui8Key pointer to Key
// param ui8Mval length of authentication
// param pui8N Nonce
// param pui8M input message
// param ui16LenM length of message
// param pui8A Additional data
// param ui16LenA length of additional data
// param ui8KeyLocation location in Key RAM. Must be one of
// the following:
// KEY_AREA_0
// KEY_AREA_1
// KEY_AREA_2
// KEY_AREA_3
// KEY_AREA_4
// KEY_AREA_5
// KEY_AREA_6
// KEY_AREA_7
// param ui8CCMLVal Lval for ccm
// param ui8CCMIntEnable set to true to enable interrupts and false to disable
// param pui8ExpectedOutput pointer to expected output
// param pui8Cstate authentication tag
// param ui8CCMIntEnable set true/false to enable/disable interrupts
// param pui8ExpectedOutput pointer to Expected Output
//
// return AES_SUCCESS if successful
//
//*****************************************************************************
uint8_t CCMEncryptExample(bool bEncrypt,
uint8_t* pui8Key,
uint8_t ui8Mval,
uint8_t *pui8N,
uint8_t *pui8M,
uint16_t ui16LenM,
uint8_t *pui8A,
uint16_t ui16LenA,
uint8_t ui8KeyLocation,
uint8_t *pui8Cstate,
uint8_t ui8CCMLVal,
uint8_t ui8CCMIntEnable,
uint8_t *pui8ExpectedOutput)
{
uint8_t status;
if(ui8CCMIntEnable)
{
//
// Register AES interrupt
//
IntRegister(INT_AES, CCMIntHandler);
//
// example using interrupt service routine
//
if((status = AESLoadKey((uint8_t*)pui8Key, ui8KeyLocation)) !=
AES_SUCCESS)
{
return status;
}
if((status = CCMAuthEncryptStart (bEncrypt, ui8Mval, pui8N, pui8M,
ui16LenM, pui8A, ui16LenA,
ui8KeyLocation, pui8Cstate,
ui8CCMLVal, ui8CCMIntEnable))
!= AES_SUCCESS)
{
return status;
}
//
// wait for completion of the operation
//
do
{
ASM_NOP;
}while(ui8CCMIntHandler == 0 );
ui8CCMIntHandler = 0;
if((status = CCMAuthEncryptGetResult(ui8Mval, ui16LenM, pui8Cstate))
!= AES_SUCCESS)
{
return status;
}
}
else
{
//
// Unregister AES interrupt
//
IntUnregister(INT_AES);
//
// example using polling
//
if((status = AESLoadKey((uint8_t*)pui8Key, ui8KeyLocation))
!= AES_SUCCESS)
{
return status;
}
if((status = CCMAuthEncryptStart(bEncrypt, ui8Mval, pui8N, pui8M,
ui16LenM, pui8A, ui16LenA,
ui8KeyLocation, pui8Cstate,
ui8CCMLVal, ui8CCMIntEnable))
!= AES_SUCCESS)
{
return status;
}
//
// wait for completion of the operation
//
do
{
ASM_NOP;
}while(!(CCMAuthEncryptCheckResult()));
if((status = CCMAuthEncryptGetResult(ui8Mval, ui16LenM, pui8Cstate)) !=
AES_SUCCESS)
{
return status;
}
}
if (CCMMemCmp(pui8M, (uint8_t const *)pui8ExpectedOutput, ui16LenM) ==
false)
{
return AES_CCM_TEST_ERROR;
}
//
// Verify CCM output
//
if(bEncrypt)
{
if (CCMMemCmp(pui8Cstate, (uint8_t const *)pui8ExpectedOutput +
ui16LenM, ui8Mval) == false)
{
return AES_CCM_TEST_ERROR;
}
}
else
{
if (CCMMemCmp(pui8Cstate, (uint8_t const *)pui8ExpectedOutput,
ui8Mval) == false)
{
return AES_CCM_TEST_ERROR;
}
}
return AES_SUCCESS;
}
