/* ---------------------------------------------------------------------------- | |
* SAM Software Package License | |
* ---------------------------------------------------------------------------- | |
* Copyright (c) 2013, Atmel Corporation | |
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* All rights reserved. | |
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* Redistribution and use in source and binary forms, with or without | |
* modification, are permitted provided that the following conditions are met: | |
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* - Redistributions of source code must retain the above copyright notice, | |
* this list of conditions and the disclaimer below. | |
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* Atmel's name may not be used to endorse or promote products derived from | |
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* DISCLAIMER: THIS SOFTWARE IS PROVIDED BY ATMEL "AS IS" AND ANY EXPRESS OR | |
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* ---------------------------------------------------------------------------- | |
*/ | |
/** \addtogroup sha_module Working with SHA | |
* \ingroup peripherals_module | |
* The SHA driver provides the interface to configure and use the SHA peripheral. | |
* \n | |
* | |
* The Secure Hash Algorithm (SHA) module requires a padded message according to FIPS180-2 | |
* specification. The first block of the message must be indicated to the module by a specific | |
* command. The SHA module produces a N-bit message digest each time a block is written and | |
* processing period ends. N is 160 for SHA1, 224 for SHA224, 256 for SHA256, 384 for SHA384, | |
* 512 for SHA512. | |
* | |
* To Enable a SHA encryption and decrypt,the user has to follow these few steps: | |
* <ul> | |
* <li> Configure SHA algorithm mode, key mode, start mode and operation mode by SHA_Configure(). </li> | |
* <li> Set SHA_FirstBlock() to indicates that the next block to process is the first one of a message.</li> | |
* <li> Input data for encryption by SHA_SetInput(). </li> | |
* <li> To start the encryption process with SHA_Start()</li> | |
* <li> To get the encryption reslut by SHA_GetOutput() </li> | |
* </ul> | |
* | |
* For more accurate information, please look at the SHA section of the | |
* Datasheet. | |
* | |
* Related files :\n | |
* \ref sha.c\n | |
* \ref sha.h\n | |
*/ | |
/*@{*/ | |
/*@}*/ | |
/** | |
* \file | |
* | |
* Implementation of Secure Hash Algorithm (SHA) | |
* | |
*/ | |
/*---------------------------------------------------------------------------- | |
* Headers | |
*----------------------------------------------------------------------------*/ | |
#include "chip.h" | |
/*---------------------------------------------------------------------------- | |
* Local functions | |
*----------------------------------------------------------------------------*/ | |
/*---------------------------------------------------------------------------- | |
* Exported functions | |
*----------------------------------------------------------------------------*/ | |
/** | |
* \brief Starts Manual hash algorithm process. | |
*/ | |
void SHA_Start(void) | |
{ | |
SHA->SHA_CR = SHA_CR_START; | |
} | |
/** | |
* \brief Resets the SHA. A software triggered hardware reset of the SHA interface is performed. | |
*/ | |
void SHA_SoftReset(void) | |
{ | |
SHA->SHA_CR = SHA_CR_SWRST; | |
} | |
/** | |
* \brief Indicates that the next block to process is the first one of a message. | |
*/ | |
void SHA_FirstBlock(void) | |
{ | |
SHA->SHA_CR = SHA_CR_FIRST; | |
} | |
/** | |
* \brief Configures an SHA peripheral with the specified parameters. | |
* \param mode Desired value for the SHA mode register (see the datasheet). | |
*/ | |
void SHA_Configure(uint32_t mode) | |
{ | |
SHA->SHA_MR = mode; | |
} | |
/** | |
* \brief Enables the selected interrupts sources on a SHA peripheral. | |
* \param sources Bitwise OR of selected interrupt sources. | |
*/ | |
void SHA_EnableIt(uint32_t sources) | |
{ | |
SHA->SHA_IER = sources; | |
} | |
/** | |
* \brief Disables the selected interrupts sources on a SHA peripheral. | |
* \param sources Bitwise OR of selected interrupt sources. | |
*/ | |
void SHA_DisableIt(uint32_t sources) | |
{ | |
SHA->SHA_IDR = sources; | |
} | |
/** | |
* \brief Get the current status register of the given SHA peripheral. | |
* \return SHA status register. | |
*/ | |
uint32_t SHA_GetStatus(void) | |
{ | |
return SHA->SHA_ISR; | |
} | |
/** | |
* \brief Set the 32-bit Input Data registers allow to load the data block used for hash processing. | |
* \param data Pointer data block. | |
* \param len 512/1024-bits block size | |
*/ | |
void SHA_SetInput(uint32_t *data, uint8_t len) | |
{ | |
uint8_t i; | |
uint8_t num; | |
num = len <= 16 ? len: 16; | |
for (i = 0; i < num ; i++) | |
SHA->SHA_IDATAR[i] = (data[i]); | |
num = len > 16 ? len - 16: 0; | |
for (i = 0; i < num; i++) | |
SHA->SHA_IODATAR[i] = (data[i+16]); | |
} | |
/** | |
* \brief Getread the resulting message digest and to write the second part of the message block when the | |
* SHA algorithm is SHA-384 or SHA-512. | |
* \param data pointer to the word that has been encrypted/decrypted.. | |
*/ | |
void SHA_GetOutput(uint32_t *data) | |
{ | |
uint8_t i; | |
for (i = 0; i < 16; i++) | |
data[i] = SHA->SHA_IODATAR[i]; | |
} |