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*
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*/
//  SHA3_HMAC - HMAC using SHA3-256
#include "ucl_sha3.h"
#include <linux/string.h>
#define SHA3_256_HMAC
#include "sha384_software.h"

//---------------------------------------------------------------------------
/// Compute HMAC using SHA3-256.
///
/// @param[in] key
/// buffer for key
/// @param[in] ken_len
/// length of key
/// @param[in] message
/// buffer for message
/// @param[in] msg_len
/// length of message
/// @param[out] mac
/// 32 byte output mac
///
/// Restrictions:
///  Key length limited to 32 bytes.
///  Message Length is limited to 512 bytes.
///
/// @return
/// TRUE - command successful @n
/// FALSE - command failed
///
int sha3_256_hmac(unsigned char *key, int key_len, unsigned char *message, int msg_len, unsigned char *mac)
{
	int i;
	unsigned char thash[256];
	unsigned char tmac[256];
	unsigned char cat_input_thash[1024];
	unsigned char cat_input_final[1024];

	int blocksize = 136;
	int hashsize = 32;
	unsigned char opad[136];
	unsigned char ipad[136];

	memset(opad, 0x5C, blocksize);
	memset(ipad, 0x36, blocksize);

	//  Check to see if key is larger then blocksize
	if (key_len > blocksize)
		return 0;  // Not supported

	// check for blocks too big
	if (msg_len > 512)
		return 0;

	// Loop through bytes of ipad/opad and XOR with key
	for (i = 0; i < key_len; i++) {
		// XOR ipad with key
		ipad[i] ^= key[i];
		// XOR opad with key
		opad[i] ^= key[i];
	}

	// thash = hash(ipad || message)
	memcpy(cat_input_thash, ipad, blocksize);
	memcpy(&cat_input_thash[blocksize], message, msg_len);

	ucl_sha3_256(thash, cat_input_thash, blocksize + msg_len);

	// return hash(opad || thash)
	memcpy(cat_input_final, opad, blocksize);
	memcpy(&cat_input_final[blocksize], thash, hashsize);

	ucl_sha3_256(tmac, cat_input_final, blocksize + hashsize);

	memcpy(mac, tmac, hashsize);

	return 1;
}