ctr-partial/src/main.c

/*---------------------------------------------------------------------------*
  Project:  TwlSDK - aes - demos - ctr-partial
  File:     main.c

  Copyright 2007-2008 Nintendo. All rights reserved.

  These coded instructions, statements, and computer programs contain
  proprietary information of Nintendo of America Inc. and/or Nintendo
  Company Ltd., and are protected by Federal copyright law. They may
  not be disclosed to third parties or copied or duplicated in any form,
  in whole or in part, without the prior written consent of Nintendo.

  $Date:: 2008-12-08#$
  $Rev: 9567 $
  $Author: hatamoto_minoru $
 *---------------------------------------------------------------------------*/
#include <twl.h>
#include <twl/aes.h>


/*---------------------------------------------------------------------------*
    Declare internal variables
 *---------------------------------------------------------------------------*/

// Message queue used for waiting for the end of AES processing
#define DEMO_MESSAGE_Q_SIZE     1
static OSMessageQueue   sMsgQ;
static OSMessage        sMsgQBuffer[DEMO_MESSAGE_Q_SIZE];

// Sample data to be encrypted
static const char DEMO_TEXT[] =
    "These coded instructions, statements, and computer programs contain "
    "proprietary information of Nintendo of America Inc. and/or Nintendo "
    "Company Ltd., and are protected by Federal copyright law.  They may "
    "not be disclosed to third parties or copied or duplicated in any form, "
    "in whole or in part, without the prior written consent of Nintendo.";

// Appropriate key to be used for encryption
static const AESKey DEMO_KEY =
    { 0xb3,0x2f,0x3a,0x91,0xe6,0x98,0xc2,0x76,
      0x70,0x6d,0xfd,0x71,0xbc,0xdd,0xb3,0x93, };


/*---------------------------------------------------------------------------*
    Internal function declarations
 *---------------------------------------------------------------------------*/

static void         DEMO_InitInteruptSystem(void);
static void         DEMO_InitAllocSystem(void);
static void         DEMO_AESCallback(AESResult result, void* arg);
static AESResult    DEMO_WaitAes(OSMessageQueue* pQ);
static void         DEMO_PrintBytes(const void* pvoid, u32 size);
static AESResult    DEMO_CtrDecryptPartial(
                        const AESCounter*   pCounter,
                        const void*         pEncrypted,
                        u32                 decryptOffset,
                        u32                 decryptSize,
                        void*               dst,
                        AESCallback         callback,
                        void*               arg );


/*---------------------------------------------------------------------------*
    Function definitions
 *---------------------------------------------------------------------------*/

/*---------------------------------------------------------------------------*
  Name:         SampleMain

  Description:  The main body of the sample.

  Arguments:    None.

  Returns:      Whether sample processing succeeded.
 *---------------------------------------------------------------------------*/
static BOOL SampleMain(void)
{
    BOOL bSuccess = FALSE;

    AESResult aesResult;
    AESCounter counter;
    const char* pPlainText = DEMO_TEXT;
    void* pEncrypted;
    void* pDecrypted;
    u32 srcSize;

    // Initialize the message queue for waiting on AES processing
    OS_InitMessageQueue(&sMsgQ, sMsgQBuffer, DEMO_MESSAGE_Q_SIZE);

    // Allocate the buffer to store encrypted/decrypted data.
    // Data size doesn't change with encryption/decryption.
    srcSize = (u32)STD_GetStringLength(pPlainText) + 1;
    pEncrypted = OS_Alloc(srcSize);
    pDecrypted = OS_Alloc(srcSize);

    if( ! SDK_IS_VALID_POINTER(pEncrypted)
     || ! SDK_IS_VALID_POINTER(pDecrypted) )
    {
        OS_TPrintf("fail to OS_Alloc\n");
        return FALSE;
    }

    // The first AES function to call must be AES_Init
    AES_Init();

    // The AES_Rand function is used to generate the initial counter value.
    // The initial counter value can be any number, but you must avoid ever reusing values if at all possible.
    //
    aesResult = AES_Rand(&counter, sizeof(counter));
    if( aesResult != AES_RESULT_SUCCESS )
    {
        OS_TPrintf("AES_Rand failed(%d)\n", aesResult);
        goto error_exit;
    }

    // Configure the encryption key
    aesResult = AES_SetKey(&DEMO_KEY);
    if( aesResult != AES_RESULT_SUCCESS )
    {
        OS_TPrintf("AES_SetKey failed(%d)\n", aesResult);
        goto error_exit;
    }


    // Display parameters
    OS_TPrintf("---- parameter -----------\n");
    OS_TPrintf("-- key\n");
    DEMO_PrintBytes(&DEMO_KEY, sizeof(DEMO_KEY));
    OS_TPrintf("-- counter initial value\n");
    DEMO_PrintBytes(&counter, sizeof(counter));


    // Encryption
    {
        // Performs encryption in AES CTR Mode
        aesResult = AES_CtrEncrypt( &counter,           // Initial counter value
                                    pPlainText,         // Data to be encrypted
                                    srcSize,            // Size of the data to encrypt
                                    pEncrypted,         // Buffer that stores encrypted data
                                    DEMO_AESCallback,   // Callback called at completion
                                    &sMsgQ );           // Callback parameters
        if( aesResult != AES_RESULT_SUCCESS )
        {
            OS_TPrintf("AES_CtrEncrypt failed(%d)\n", aesResult);
            goto error_exit;
        }

        // Wait for encryption to end
        aesResult = DEMO_WaitAes(&sMsgQ);
        if( aesResult != AES_RESULT_SUCCESS )
        {
            OS_TPrintf("AES_CtrEncrypt failed(%d)\n", aesResult);
            goto error_exit;
        }


        // Display results
        OS_TPrintf("---- encrypt -------------\n");
        OS_TPrintf("-- plain text (ascii)\n");
        OS_PutString(pPlainText);   // Use OS_PutString because OS_*Printf has a limit of 256 characters
        OS_TPrintf("\n");

        OS_TPrintf("-- plain text (hex)\n");
        DEMO_PrintBytes(pPlainText, srcSize);

        OS_TPrintf("-- encrypted (hex)\n");
        DEMO_PrintBytes(pEncrypted, srcSize);
    }

    // Decryption
    {
        // Performs decryption partially in AES CTR Mode
        const u32 decryptOffset = 80;       // Must be a multiple of AES_BLOCK_SIZE
        const u32 decryptSize   = 68;

        aesResult = DEMO_CtrDecryptPartial(
                        &counter,           // Initial counter value (must be the same as that used during encryption)
                        pEncrypted,         // Data to be decrypted
                        decryptOffset,      // Offset for the start of decryption (must be a multiple of AES_BLOCK_SIZE)
                        decryptSize,        // Size to decrypt
                        pDecrypted,         // Buffer that stores decrypted data
                        DEMO_AESCallback,   // Callback called at completion
                        &sMsgQ );           // Callback parameters
        if( aesResult != AES_RESULT_SUCCESS )
        {
            OS_TPrintf("AES_CtrDecrypt failed(%d)\n", aesResult);
            goto error_exit;
        }

        // Wait for decryption to end
        aesResult = DEMO_WaitAes(&sMsgQ);
        if( aesResult != AES_RESULT_SUCCESS )
        {
            OS_TPrintf("AES_CtrDecrypt failed(%d)\n", aesResult);
            goto error_exit;
        }

        // Add a null terminator because we want to display as text
        ((char*)pDecrypted)[decryptSize] = '\0';

        // Display results
        OS_TPrintf("---- decrypt -------------\n");
        OS_TPrintf("-- encrypted (hex)\n");
        DEMO_PrintBytes(pEncrypted, srcSize);

        OS_TPrintf("-- decrypted (hex)\n");
        DEMO_PrintBytes(pDecrypted, decryptSize);

        OS_TPrintf("-- decrypted (ascii)\n");
        OS_PutString(pDecrypted);   // Use OS_PutString because OS_*Printf has a limit of 256 characters
        OS_TPrintf("\n");

        // Confirm that data that was encrypted, then decrypted, matches original
        if( MI_CpuComp8(pDecrypted, pPlainText + decryptOffset, decryptSize) == 0 )
        {
            OS_TPrintf("** pDecrypted == pPlainText\n");
            bSuccess = TRUE;
        }
        else
        {
            OS_TPrintf("** pDecrypted != pPlainText\n");
        }
    }

error_exit:
    OS_Free(pDecrypted);
    OS_Free(pEncrypted);

    return bSuccess;
}


/*---------------------------------------------------------------------------*
  Name:         TwlMain

  Description:  The main function.

  Arguments:    None.

  Returns:      None.
 *---------------------------------------------------------------------------*/
void TwlMain(void)
{
    BOOL bSampleSucceeded = FALSE;

    // Initialization
    OS_Init();
    DEMO_InitInteruptSystem();
    DEMO_InitAllocSystem();
    OS_TPrintf("*** start aes demo\n");


    // Run demo
    if( OS_IsRunOnTwl() )
    {
        bSampleSucceeded = SampleMain();
    }
    else
    {
        OS_Warning("demo is not run on TWL");
    }


    // Display demo run results
    OS_TPrintf("*** End of demo\n");
    OS_TPrintf("demo %s\n", (bSampleSucceeded ? "succeeded": "failed"));
    GX_Init();
    *(GXRgb*)HW_BG_PLTT = (GXRgb)(bSampleSucceeded ? GX_RGB(0, 31, 0): GX_RGB(31, 0, 0));
    GX_DispOn();
    OS_Terminate();
}


/*---------------------------------------------------------------------------*
  Name:         DEMO_CtrDecryptPartial

  Description:  Partially decrypts the CTR Mode ciphertext.
                Decrypts 'decryptSize' bytes starting from the 'decryptOffset'-numbered byte of 'pEncrypted'.


  Arguments:    pCounter:       Initial counter value that was used at encryption
                pEncrypted:     Pointer to the ciphertext's starting address.
                                The pointer must be 4-byte aligned.
                decryptOffset:  Offset at which to start decryption.
                                Must be a multiple of AES_BLOCK_SIZE.
                decryptSize:    Size to decrypt
                dst:            Pointer to the buffer where the ciphertext is written out.
                                The pointer must be 4-byte aligned.
                callback:       Callback called when the process is complete.
                                NULL can be specified, in which case no callback is invoked.

                arg:            Parameter passed to the above callback.
                                NULL can be specified.

  Returns:      Returns the processing result.
 *---------------------------------------------------------------------------*/
static AESResult DEMO_CtrDecryptPartial(
    const AESCounter*   pCounter,
    const void*         pEncrypted,
    u32                 decryptOffset,
    u32                 decryptSize,
    void*               dst,
    AESCallback         callback,
    void*               arg )
{
    AESCounter counter;

    SDK_POINTER_ASSERT( pCounter );
    SDK_ASSERT( (decryptOffset % AES_BLOCK_SIZE) == 0 );

    // Partial decryption can be done by adding the amount of offset to the initial counter value, then decrypting.
    // The counter value is incremented once for each AES_BLOCK_SIZE.
    counter = *pCounter;
    AES_AddToCounter(&counter, decryptOffset / AES_BLOCK_SIZE);

    return AES_CtrDecrypt(
                &counter,
                (const u8*)pEncrypted + decryptOffset,
                decryptSize,
                dst,
                callback,
                arg );
}


/*---------------------------------------------------------------------------*
  Name:         DEMO_AESCallback

  Description:  This is the callback called at AES processing completion.
                It is of type AESCallback.

  Arguments:    result: AES processing result
                arg:    Last argument passed in AES_Ctr

  Returns:      None.
 *---------------------------------------------------------------------------*/
static void DEMO_AESCallback(AESResult result, void* arg)
{
    OSMessageQueue* pQ = (OSMessageQueue*)arg;
    (void)OS_SendMessage(pQ, (OSMessage)result, OS_MESSAGE_BLOCK);
}

/*---------------------------------------------------------------------------*
  Name:         DEMO_WaitAes

  Description:  Returns the result of awaiting AES processing completion.
                DEMO_AESCallback must have been specified in AES_Ctr.

  Arguments:    pQ: Message queue passed as the last AES_Ctr argument

  Returns:      AES processing result.
 *---------------------------------------------------------------------------*/
static AESResult DEMO_WaitAes(OSMessageQueue* pQ)
{
    OSMessage msg;
    (void)OS_ReceiveMessage(pQ, &msg, OS_MESSAGE_BLOCK);
    return (AESResult)msg;
}

/*---------------------------------------------------------------------------*
  Name:         DEMO_PrintBytes

  Description:  Outputs the specified binary array in hexadecimal to debug output.

  Arguments:    pvoid:  Pointer to the target binary array
                size:   Number of bytes in the target binary array

  Returns:      None.
 *---------------------------------------------------------------------------*/
static void DEMO_PrintBytes(const void* pvoid, u32 size)
{
    const u8* p = (const u8*)pvoid;
    u32 i;

    for( i = 0; i < size; ++i )
    {
        OS_TPrintf("%02X ", p[i]);
        if( i % 16 == 15 )
        {
            OS_TPrintf("\n");
        }
    }

    if( i % 16 != 0 )
    {
        OS_TPrintf("\n");
    }
}

/*---------------------------------------------------------------------------*
  Name:         DEMO_InitInteruptSystem

  Description:  Initializes interrupts.

  Arguments:    None.

  Returns:      None.
 *---------------------------------------------------------------------------*/
static void DEMO_InitInteruptSystem(void)
{
    // Enable master interrupt flag
    (void)OS_EnableIrq();
}

/*---------------------------------------------------------------------------*
  Name:         DEMO_InitAllocSystem

  Description:  Creates a heap and makes OS_Alloc usable.

  Arguments:    None.

  Returns:      None.
 *---------------------------------------------------------------------------*/
static void DEMO_InitAllocSystem(void)
{
    void* newArenaLo;
    OSHeapHandle hHeap;

    // Initialize the main arena's allocation system
    newArenaLo = OS_InitAlloc(OS_ARENA_MAIN, OS_GetMainArenaLo(), OS_GetMainArenaHi(), 1);
    OS_SetMainArenaLo(newArenaLo);

    // Create a heap in the main arena
    hHeap = OS_CreateHeap(OS_ARENA_MAIN, OS_GetMainArenaLo(), OS_GetMainArenaHi());
    (void)OS_SetCurrentHeap(OS_ARENA_MAIN, hHeap);
}