mcuxCsslMemory_Compare_example.c

Example constant-time memory compare (CSSL component mcuxCsslMemory).

Example constant-time memory compare (CSSL component mcuxCsslMemory)

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/* Copyright 2020-2021, 2025 NXP                                            */
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#include <mcuxClToolchain.h>
#include <stdbool.h>
#include <stdint.h>
#include <mcuxCsslMemory.h>
#include <mcuxCsslMemory_Examples.h>
#include <mcuxCsslFlowProtection.h>
#include <mcuxCsslFlowProtection_FunctionIdentifiers.h>
#include <mcuxCsslParamIntegrity.h>
 
#define EXIT_CODE_ERROR false   
#define EXIT_CODE_OK    true    
 
MCUXCSSL_MEMORY_EX_FUNCTION(mcuxCsslMemory_Compare_example)
{
    /* Define data arrays */
    ALIGNED uint8_t arr1[]             = {0xe4u, 0xf9u, 0x26u, 0x4cu, 0x65u, 0xe2u, 0x13u, 0xa3u,
                                          0x9au, 0x40u, 0xd7u, 0x87u, 0xccu, 0x0bu, 0x31u, 0x18u,
                                          0xacu, 0x55u, 0xb5u, 0x7du, 0x06u, 0x7fu, 0xceu, 0xe4u,
                                          0xb2u, 0x7eu, 0xd5u, 0xaau, 0x90u, 0x9au, 0x42u, 0x56u,
                                          0x76u};
    ALIGNED uint8_t arr2[sizeof(arr1)] = {0xe4u, 0xf9u, 0x26u, 0x4cu, 0x65u, 0xe2u, 0x13u, 0xa3u,
                                          0x9au, 0x40u, 0xd7u, 0x87u, 0xccu, 0x0bu, 0x31u, 0x18u,
                                          0xacu, 0x55u, 0xb5u, 0x7du, 0x06u, 0x7fu, 0xceu, 0xe4u,
                                          0xb2u, 0x7eu, 0xd5u, 0xaau, 0x90u, 0x9au, 0x42u, 0x56u,
                                          0x71u};
    ALIGNED uint8_t arr3[sizeof(arr1)] = {0xe4u, 0xf9u, 0x26u, 0x4cu, 0x65u, 0xe2u, 0x13u, 0xa3u,
                                          0x9au, 0x40u, 0xd7u, 0x87u, 0xccu, 0x0bu, 0x31u, 0x18u,
                                          0xacu, 0x55u, 0xb5u, 0x7du, 0x06u, 0x7fu, 0xceu, 0xe4u,
                                          0xb2u, 0x7eu, 0xd5u, 0xaau, 0x90u, 0x9au, 0x42u, 0x56u,
                                          0x76u};
 
    /* Pass length as zero => Should result in the zero length return code. */
    MCUX_CSSL_FP_FUNCTION_CALL_BEGIN(compareResultZeroLength, compareTokenZeroLength, mcuxCsslMemory_Compare(
    /* mcuxCsslParamIntegrity_Checksum_t chk,*/ MCUX_CSSL_PI_PROTECT(arr1, arr1, 0U),
    /* void const * lhs,                    */ arr1,
    /* void const * rhs,                    */ arr1,
    /* uint32_t length                      */ 0U));
 
    /* Check the return code of mcuxCsslMemory_Compare */
    if((MCUX_CSSL_FP_FUNCTION_CALLED(mcuxCsslMemory_Compare) != compareTokenZeroLength) || (MCUXCSSLMEMORY_STATUS_ZERO_LENGTH != compareResultZeroLength))
    {
        return EXIT_CODE_ERROR;
    }
 
    MCUX_CSSL_FP_FUNCTION_CALL_END();
 
    /* Compare arr1 with itself => Should be true */
    MCUX_CSSL_FP_FUNCTION_CALL_BEGIN(compareResult, compareToken, mcuxCsslMemory_Compare(
    /* mcuxCsslParamIntegrity_Checksum_t chk,*/ MCUX_CSSL_PI_PROTECT(arr1, arr1, sizeof(arr1)),
    /* void const * lhs,                    */ arr1,
    /* void const * rhs,                    */ arr1,
    /* uint32_t length                      */ sizeof(arr1)));
 
    /* Check the return code of mcuxCsslMemory_Compare */
    if((MCUX_CSSL_FP_FUNCTION_CALLED(mcuxCsslMemory_Compare) != compareToken) || (MCUXCSSLMEMORY_STATUS_EQUAL != compareResult))
    {
        return EXIT_CODE_ERROR;
    }
 
    MCUX_CSSL_FP_FUNCTION_CALL_END();
 
 
    /* Compare arr1 with arr2 => Should be false */
    MCUX_CSSL_FP_FUNCTION_CALL_BEGIN(compareResult1, compareToken1, mcuxCsslMemory_Compare(
    /* mcuxCsslParamIntegrity_Checksum_t chk,*/ MCUX_CSSL_PI_PROTECT(arr1, arr2, sizeof(arr1)),
    /* void const * lhs,                    */ arr1,
    /* void const * rhs,                    */ arr2,
    /* uint32_t length                      */ sizeof(arr1)));
 
    /* Check the return code of mcuxCsslMemory_Compare */
    if((MCUX_CSSL_FP_FUNCTION_CALLED(mcuxCsslMemory_Compare) != compareToken1) || (MCUXCSSLMEMORY_STATUS_NOT_EQUAL != compareResult1))
    {
        return EXIT_CODE_ERROR;
    }
 
    MCUX_CSSL_FP_FUNCTION_CALL_END();
 
 
    /* Compare arr1 with arr3 => Should be true */
    MCUX_CSSL_FP_FUNCTION_CALL_BEGIN(compareResult2, compareToken2, mcuxCsslMemory_Compare(
    /* mcuxCsslParamIntegrity_Checksum_t chk,*/ MCUX_CSSL_PI_PROTECT(arr1, arr3, sizeof(arr1)),
    /* void const * lhs,                    */ arr1,
    /* void const * rhs,                    */ arr3,
    /* uint32_t length                      */ sizeof(arr1)));
 
    /* Check the return code of mcuxCsslMemory_Compare */
    if((MCUX_CSSL_FP_FUNCTION_CALLED(mcuxCsslMemory_Compare) != compareToken2) || (MCUXCSSLMEMORY_STATUS_EQUAL != compareResult2))
    {
        return EXIT_CODE_ERROR;
    }
 
    MCUX_CSSL_FP_FUNCTION_CALL_END();
 
 
    /* No error occurred during execution, exit with EXIT_CODE_OK */
    return EXIT_CODE_OK;
}