#include <memory.h>
#include "Types.h"

// "Derived from the RSA Data Security, Inc. MD5 Message Digest Algorithm"

/**
 * \brief          MD5 context structure
 */
typedef struct
{
    unsigned long total[2];     /*!< number of bytes processed  */
    unsigned long state[4];     /*!< intermediate digest state  */
    unsigned char buffer[64];   /*!< data block being processed */

    unsigned char ipad[64];     /*!< HMAC: inner padding        */
    unsigned char opad[64];     /*!< HMAC: outer padding        */
}
md5_context;

/**
 * \brief          MD5 context setup
 *
 * \param ctx      context to be initialized
 */
void md5_starts( md5_context *ctx );

/**
 * \brief          MD5 process buffer
 *
 * \param ctx      MD5 context
 * \param input    buffer holding the  data
 * \param ilen     length of the input data
 */
void md5_update( md5_context *ctx, unsigned char *input, int ilen );

/**
 * \brief          MD5 final digest
 *
 * \param ctx      MD5 context
 * \param output   MD5 checksum result
 */
void md5_finish( md5_context *ctx, unsigned char output[16] );

/**
 * \brief          Output = MD5( input buffer )
 *
 * \param input    buffer holding the  data
 * \param ilen     length of the input data
 * \param output   MD5 checksum result
 */
void md5( unsigned char *input, int ilen, unsigned char output[16] );

/**
 * \brief          Output = MD5( file contents )
 *
 * \param path     input file name
 * \param output   MD5 checksum result
 *
 * \return         0 if successful, 1 if fopen failed,
 *                 or 2 if fread failed
 */
int md5_file( char *path, unsigned char output[16] );

/**
 * \brief          MD5 HMAC context setup
 *
 * \param ctx      HMAC context to be initialized
 * \param key      HMAC secret key
 * \param keylen   length of the HMAC key
 */
void md5_hmac_starts( md5_context *ctx, unsigned char *key, int keylen );

/**
 * \brief          MD5 HMAC process buffer
 *
 * \param ctx      HMAC context
 * \param input    buffer holding the  data
 * \param ilen     length of the input data
 */
void md5_hmac_update( md5_context *ctx, unsigned char *input, int ilen );

/**
 * \brief          MD5 HMAC final digest
 *
 * \param ctx      HMAC context
 * \param output   MD5 HMAC checksum result
 */
void md5_hmac_finish( md5_context *ctx, unsigned char output[16] );

/**
 * \brief          Output = HMAC-MD5( hmac key, input buffer )
 *
 * \param key      HMAC secret key
 * \param keylen   length of the HMAC key
 * \param input    buffer holding the  data
 * \param ilen     length of the input data
 * \param output   HMAC-MD5 result
 */
void md5_hmac( unsigned char *key, int keylen,
               unsigned char *input, int ilen,
               unsigned char output[16] );

/**
 * \brief          Checkup routine
 *
 * \return         0 if successful, or 1 if the test failed
 */
int md5_self_test( int verbose );

/*
 * MD5 context setup
 */
void md5_starts( md5_context *ctx );

/*
 * MD5 process buffer
 */
void md5_update( md5_context *ctx, unsigned char *input, int ilen );

/*
 * MD5 final digest
 */
void md5_finish( md5_context *ctx, unsigned char output[16] );

unsigned int md5hash ( const void * input, int len, uint32_t seed );
