aes.c

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//*****************************************************************************
//
// aes.c - Driver for the aes Module.
//
//*****************************************************************************
 
//*****************************************************************************
//
//
//*****************************************************************************
 
#include "inc/hw_memmap.h"
 
#ifdef __MSP430_HAS_AES__
#include "aes.h"
 
#include <assert.h>
 
uint8_t AES_setCipherKey (uint16_t baseAddress,
     const uint8_t * CipherKey
     )
{
    uint8_t i = 0;
    uint16_t tempVariable = 0;
 
    // Wait until AES accelerator is busy
    while(AESBUSY == (HWREG16(baseAddress + OFS_AESASTAT) & AESBUSY) );
 
    for (i = 0; i < 16; i = i + 2)
    {
        tempVariable = (uint16_t)(CipherKey[i]);
        tempVariable = tempVariable | ((uint16_t)(CipherKey[i + 1]) << 8);
        HWREG16(baseAddress + OFS_AESAKEY) = tempVariable;
    }
 
    // Wait until key is written
    while(0x00 == (HWREG16(baseAddress + OFS_AESASTAT) & AESKEYWR ));
 
    return STATUS_SUCCESS;
}
 
uint8_t AES_encryptData (uint16_t baseAddress,
    const uint8_t * Data,
    uint8_t * encryptedData)
{
    uint8_t i;
    uint16_t tempData = 0;
    uint16_t tempVariable = 0;
 
    // Set module to encrypt mode
    HWREG16(baseAddress + OFS_AESACTL0) &= ~AESOP_3;
 
    // Write data to encrypt to module
    for (i = 0; i < 16; i = i + 2)
    {
 
        tempVariable = (uint16_t)(Data[i]);
        tempVariable = tempVariable | ((uint16_t)(Data[i+1]) << 8);
        HWREG16(baseAddress + OFS_AESADIN) = tempVariable;
    }
 
    // Key that is already written shall be used
    // Encryption is initialized by setting AESKEYWR to 1
    HWREG16(baseAddress + OFS_AESASTAT) |= AESKEYWR;
 
    // Wait unit finished ~167 MCLK
    while(AESBUSY == (HWREG16(baseAddress + OFS_AESASTAT) & AESBUSY) );
 
    // Write encrypted data back to variable
    for (i = 0; i < 16; i = i + 2)
    {
        tempData = HWREG16(baseAddress + OFS_AESADOUT);
        *(encryptedData + i) = (uint8_t)tempData;
        *(encryptedData +i + 1) = (uint8_t)(tempData >> 8);
 
    }
 
    return STATUS_SUCCESS;
}
 
uint8_t AES_decryptData (uint16_t baseAddress,
    const uint8_t * Data,
    uint8_t * decryptedData)
{
    uint8_t i;
    uint16_t tempData = 0;
    uint16_t tempVariable = 0;
 
    // Set module to decrypt mode
    HWREG16(baseAddress + OFS_AESACTL0) |= (AESOP_3);
 
    // Write data to decrypt to module
    for (i = 0; i < 16; i = i + 2)
    {
        tempVariable = (uint16_t)(Data[i+1]  << 8);
        tempVariable = tempVariable | ((uint16_t)(Data[i]));
        HWREG16(baseAddress + OFS_AESADIN) = tempVariable;
    }
 
    // Key that is already written shall be used
    // Now decryption starts
    HWREG16(baseAddress + OFS_AESASTAT) |= AESKEYWR;
 
    // Wait unit finished ~167 MCLK
    while(AESBUSY == (HWREG16(baseAddress + OFS_AESASTAT) & AESBUSY ));
 
    // Write encrypted data back to variable
    for (i = 0; i < 16; i = i + 2)
    {
        tempData = HWREG16(baseAddress + OFS_AESADOUT);
        *(decryptedData + i ) = (uint8_t)tempData;
        *(decryptedData +i + 1) = (uint8_t)(tempData >> 8);
    }
 
    return STATUS_SUCCESS;
}
 
uint8_t AES_setDecipherKey (uint16_t baseAddress,
    const uint8_t * CipherKey)
{
    uint8_t i;
    uint16_t tempVariable = 0;
 
    // Set module to decrypt mode
    HWREG16(baseAddress + OFS_AESACTL0) &= ~(AESOP0);
    HWREG16(baseAddress + OFS_AESACTL0) |= AESOP1;
 
    // Write cipher key to key register
    for (i = 0; i < 16; i = i + 2)
    {
        tempVariable = (uint16_t)(CipherKey[i]);
        tempVariable = tempVariable | ((uint16_t)(CipherKey[i + 1]) << 8);
        HWREG16(baseAddress + OFS_AESAKEY) = tempVariable;
    }
 
    // Wait until key is processed ~52 MCLK
    while((HWREG16(baseAddress + OFS_AESASTAT) & AESBUSY) == AESBUSY);
 
    return STATUS_SUCCESS;
}
 
void AES_clearInterrupt (uint16_t baseAddress )
{
    HWREG8(baseAddress + OFS_AESACTL0) &=  ~AESRDYIFG;
}
 
uint32_t AES_getInterruptStatus (uint16_t baseAddress)
{
    return ((HWREG8(baseAddress + OFS_AESACTL0) & AESRDYIFG) << 0x04);
}
 
void AES_enableInterrupt (uint16_t baseAddress)
{
    HWREG8(baseAddress + OFS_AESACTL0) |=  AESRDYIE;
}
 
void AES_disableInterrupt (uint16_t baseAddress)
{
    HWREG8(baseAddress + OFS_AESACTL0) &=  ~AESRDYIE;
}
 
void AES_reset (uint16_t baseAddress)
{
    HWREG8(baseAddress + OFS_AESACTL0) |=  AESSWRST;
}
 
uint8_t AES_startEncryptData (uint16_t baseAddress,
    const uint8_t * Data,
    uint8_t * encryptedData)
{
    uint8_t i;
    uint16_t tempVariable = 0;
 
    // Set module to encrypt mode
    HWREG16(baseAddress + OFS_AESACTL0) &= ~AESOP_3;
 
    // Write data to encrypt to module
    for (i = 0; i < 16; i = i + 2)
    {
        tempVariable = (uint16_t)(Data[i]);
        tempVariable = tempVariable | ((uint16_t)(Data[i+1]) << 8);
        HWREG16(baseAddress + OFS_AESADIN) = tempVariable;
    }
 
    // Key that is already written shall be used
    // Encryption is initialized by setting AESKEYWR to 1
    HWREG16(baseAddress + OFS_AESASTAT) |= AESKEYWR;
 
    return STATUS_SUCCESS;
}
 
uint8_t AES_startDecryptData (uint16_t baseAddress,
    const uint8_t * Data)
{
    uint8_t i;
    uint16_t tempVariable = 0;
 
    // Set module to decrypt mode
    HWREG16(baseAddress + OFS_AESACTL0) |= (AESOP_3);
 
    // Write data to decrypt to module
    for (i = 0; i < 16; i = i + 2)
    {
        tempVariable = (uint16_t)(Data[i+1]  << 8);
        tempVariable = tempVariable | ((uint16_t)(Data[i]));
        HWREG16(baseAddress + OFS_AESADIN) = tempVariable;
    }
 
    // Key that is already written shall be used
    // Now decryption starts
    HWREG16(baseAddress + OFS_AESASTAT) |= AESKEYWR;
 
    return STATUS_SUCCESS;
}
 
uint8_t AES_startSetDecipherKey (uint16_t baseAddress,
    const uint8_t * CipherKey)
{
    uint8_t i;
    uint16_t tempVariable = 0;
 
    HWREG16(baseAddress + OFS_AESACTL0) &= ~(AESOP0);
    HWREG16(baseAddress + OFS_AESACTL0) |= AESOP1;
 
    // Write cipher key to key register
    for (i = 0; i < 16; i = i + 2)
    {
        tempVariable = (uint16_t)(CipherKey[i]);
        tempVariable = tempVariable | ((uint16_t)(CipherKey[i+1]) << 8);
        HWREG16(baseAddress + OFS_AESAKEY) = tempVariable;
    }
 
    return STATUS_SUCCESS;
}
 
uint8_t  AES_getDataOut(uint16_t baseAddress,
                            uint8_t *OutputData
                            )
{
    uint8_t i;
    uint16_t tempData = 0;
 
    // If module is busy, exit and return failure
    if( AESBUSY == (HWREG16(baseAddress + OFS_AESASTAT) & AESBUSY))
        return STATUS_FAIL;
 
    // Write encrypted data back to variable
    for (i = 0; i < 16; i = i + 2)
    {
        tempData = HWREG16(baseAddress + OFS_AESADOUT);
        *(OutputData + i) = (uint8_t)tempData;
        *(OutputData +i + 1) = (uint8_t)(tempData >> 8);
    }
 
    return STATUS_SUCCESS;
}
 
uint8_t AES_isBusy (uint16_t baseAddress)
{
    return (HWREG16(baseAddress + OFS_AESASTAT) & AESBUSY);
}
 
void AES_clearErrorFlag (uint16_t baseAddress )
{
    HWREG8(baseAddress + OFS_AESACTL0) &=  ~AESERRFG;
}
 
uint32_t AES_getErrorFlagStatus (uint16_t baseAddress)
{
    return (HWREG8(baseAddress + OFS_AESACTL0) & AESERRFG);
}
 
uint8_t AES_startDecryptDataUsingEncryptionKey (
    uint16_t baseAddress,
    const uint8_t * Data)
{
    uint8_t i;
    uint16_t tempVariable = 0;
 
    // Set module to decrypt mode
    HWREG16(baseAddress + OFS_AESACTL0) &= ~(AESOP1);
    HWREG16(baseAddress + OFS_AESACTL0) |= AESOP0;
 
    // Write data to decrypt to module
    for (i = 0; i < 16; i = i + 2)
    {
        tempVariable = (uint16_t)(Data[i+1]  << 8);
        tempVariable = tempVariable | ((uint16_t)(Data[i]));
        HWREG16(baseAddress + OFS_AESADIN) = tempVariable;
    }
 
    // Key that is already written shall be used
    // Now decryption starts
    HWREG16(baseAddress + OFS_AESASTAT) |= AESKEYWR;
 
    return STATUS_SUCCESS;
}
 
uint8_t AES_decryptDataUsingEncryptionKey (uint16_t baseAddress,
    const uint8_t * Data,
    uint8_t * decryptedData)
{
    uint8_t i;
    uint16_t tempData = 0;
    uint16_t tempVariable = 0;
 
    // Set module to decrypt mode
    HWREG16(baseAddress + OFS_AESACTL0) &= ~(AESOP1);
    HWREG16(baseAddress + OFS_AESACTL0) |= AESOP0;
 
    // Write data to decrypt to module
    for (i = 0; i < 16; i = i + 2)
    {
        tempVariable = (uint16_t)(Data[i+1]  << 8);
        tempVariable = tempVariable | ((uint16_t)(Data[i]));
        HWREG16(baseAddress + OFS_AESADIN) = tempVariable;
    }
 
    // Key that is already written shall be used
    // Now decryption starts
    HWREG16(baseAddress + OFS_AESASTAT) |= AESKEYWR;
 
    // Wait unit finished ~214 MCLK
    while(AESBUSY == (HWREG16(baseAddress + OFS_AESASTAT) & AESBUSY) );
 
    // Write encrypted data back to variable
    for (i = 0; i < 16; i = i + 2)
    {
        tempData = HWREG16(baseAddress + OFS_AESADOUT);
        *(decryptedData + i ) = (uint8_t)tempData;
        *(decryptedData +i + 1) = (uint8_t)(tempData >> 8);
    }
 
    return STATUS_SUCCESS;
}
 
#endif
//*****************************************************************************
//
//
//*****************************************************************************