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Forum Post: RE: MSP432 AES Encryption using DMA

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Hi Thomas, I ran into the same problems but I did find a way to encrypt multiple AES blocks. Here's the example modified for two AES blocks. /* * ------------------------------------------- * MSP432 DriverLib - v3_21_00_05 * ------------------------------------------- * * --COPYRIGHT--,BSD,BSD * Copyright (c) 2016, Texas Instruments Incorporated * 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 following disclaimer. * * * Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * * Neither the name of Texas Instruments Incorporated nor the names of * its contributors may be used to endorse or promote products derived * from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR * CONTRIBUTORS 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. * --/COPYRIGHT--*/ /******************************************************************************* * MSP432 DMA - AES256 ECB Encryption/Decryption * * Description: In this code example, the DMA module is used to encrypt and * decrypt of block of data using the AES256 module. The ECB (electronic code * book) method of encryption/decryption is used in this example. A block of * 128-bits of data is fed into the AES256's DIN module by the use of the * MSP432's DMA module. While the data is being encrypted, the device is put * into LPM0 for power conservation. When the data encryption has finished, * the DMA and AES256 modules are reconfigured for decryption and the process * is repeated. At the end of the code, a no operation is inserted so that the * user can set a breakpoint and observe that the decrypted data is the same * as the original plaintext data. * * MSP432P401 * ------------------ * /|\| | * | | | * --|RST | * | | * | | * | | * | | * ******************************************************************************/ /* DriverLib Include */ #include "driverlib.h" /* Standard Includes */ #include #include /* Static Variables */ static bool isFinished; /* DMA Control Table */ #ifdef ewarm #pragma data_alignment=1024 #else #pragma DATA_ALIGN(controlTable, 1024) #endif uint8_t controlTable[256]; /* AES Data and Cipher Key */ static uint8_t Data[32] = { 0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88, 0x99, 0xAA, 0xBB, 0xCC, 0xDD, 0xEE, 0xFF, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F }; static uint8_t CipherKey[32] = { 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f }; static uint8_t DataAESencrypted[32]; // Encrypted data static uint8_t DataAESdecrypted[32]; // Decrypted data int main(void) { /* Halting WDT */ MAP_WDT_A_holdTimer(); MAP_Interrupt_disableMaster(); /* Initializing the variables */ isFinished = false; /* Restting the module, enabling AES DMA triggers, and setting to * encrypt mode (ECB) */ AES256->CTL0 = (AES256->CTL0 & ~(AESCM_3 | AESOP_3)) | AESCMEN; /* Load a cipher key to module */ MAP_AES256_setCipherKey(AES256_BASE, CipherKey, AES256_KEYLENGTH_256BIT); /* Configuring DMA module */ MAP_DMA_enableModule(); MAP_DMA_setControlBase(controlTable); /* * Primary DMA Channel, AES256 * Size = 16 bits * Source Increment = None * Destination Increment = 16bits * Arbitration = 1 , no other sources */ MAP_DMA_setChannelControl(UDMA_PRI_SELECT | DMA_CH0_AESTRIGGER0, UDMA_SIZE_16 | UDMA_SRC_INC_NONE | UDMA_DST_INC_16 | UDMA_ARB_1); MAP_DMA_setChannelTransfer(UDMA_PRI_SELECT | DMA_CH0_AESTRIGGER0, UDMA_MODE_AUTO, (void*) &AES256->DOUT, DataAESencrypted, 8); /* * Primary DMA Channel, AES256 * Size = 16 bits * Source Increment = 16 bits * Destination Increment = None * Arbitration = 1 , no other sources */ MAP_DMA_setChannelControl(UDMA_PRI_SELECT | DMA_CH1_AESTRIGGER1, UDMA_SIZE_16 | UDMA_SRC_INC_16 | UDMA_DST_INC_NONE | UDMA_ARB_1); MAP_DMA_setChannelTransfer(UDMA_PRI_SELECT | DMA_CH1_AESTRIGGER1, UDMA_MODE_AUTO, (void*) Data, (void*) &AES256->DIN, 8); /* Assigning/Enabling Interrupts */ MAP_DMA_assignInterrupt(DMA_INT1, 0); MAP_Interrupt_enableInterrupt(INT_DMA_INT1); MAP_DMA_assignChannel(DMA_CH0_AESTRIGGER0); MAP_DMA_assignChannel(DMA_CH1_AESTRIGGER1); MAP_DMA_clearInterruptFlag(0); MAP_DMA_clearInterruptFlag(1); MAP_Interrupt_enableMaster(); /* Enabling the DMA channels. Channel 1 is used for transfering the * plaintext data to the DIN register and Channel 0 is used to transfer the * encrypted data to an intermediary register. */ MAP_DMA_enableChannel(1); MAP_DMA_enableChannel(0); /* Setting the number of 128-bit blocks to encrypt. Setting the CTL1 * register will initiate the DMA transfer. Once all of the encryption * is completed, the DMA completion interrupt will be fired. */ AES256->CTL1 = 2; /* Waiting for the DMA finished flag */ while (!isFinished) { MAP_PCM_gotoLPM0InterruptSafe(); } while(1); } /* Completion interrupt for DMA */ void DMA_INT1_IRQHandler(void) { if (AES256->CTL1 == 0) { MAP_DMA_disableChannel(0); MAP_DMA_disableChannel(1); isFinished = true; } else { MAP_DMA_disableChannel(0); MAP_DMA_disableChannel(1); MAP_DMA_setChannelTransfer(UDMA_PRI_SELECT | DMA_CH0_AESTRIGGER0, UDMA_MODE_AUTO, (void*) &AES256->DOUT, (DataAESencrypted + 16), 8); MAP_DMA_setChannelTransfer(UDMA_PRI_SELECT | DMA_CH1_AESTRIGGER1, UDMA_MODE_AUTO, (void*) (Data + 16), (void*) &AES256->DIN, 8); MAP_DMA_enableChannel(1); MAP_DMA_enableChannel(0); } } Hopefully this helps. David

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