csu3_am335x/EVSE/GPL/plc-utils.LNX.2.1.20/source/key/HPAVKeyNMK.c

/*====================================================================*
*
*   Copyright (c) 2013 Qualcomm Atheros, Inc.
*
*   All rights reserved.
*
*====================================================================*/
/*====================================================================*
 *   
 *   void HPAVKeyNMK (uint8_t NMK [], const char * string);
 *
 *   HPAVKey.h
 *   
 *   compute the HomePlugAV compliant Network Membership Key (NMK) 
 *   for a NUL terminated string; return the key in buffer NMK []; 
 *   the key will be HPAVKEY_NMK_LEN bytes as defined in HPAVKey.h; 
 *
 *   seed the digest then salt the digest then rehash the digest 999 
 *   times per HomePlug AV Specification; 
 *   
 *
 *   Contributor(s);
 *	Charles Maier <cmaier@qca.qualcomm.com>
 *
 *--------------------------------------------------------------------*/

#ifndef HPAVKEYNMK_SOURCE
#define HPAVKEYNMK_SOURCE

#include <memory.h>

#include "../key/HPAVKey.h"
#include "../key/SHA256.h"

void HPAVKeyNMK (uint8_t NMK [], const char * string)

{
	struct sha256 sha256;
	uint8_t digest [SHA256_DIGEST_LENGTH];
	const uint8_t secret [] =
	{
		0x08,
		0x85,
		0x6D,
		0xAF,
		0x7C,
		0xF5,
		0x81,
		0x86
	};
	unsigned rehash = 999;
	SHA256Reset (& sha256);
	SHA256Write (& sha256, string, strlen (string));
	SHA256Write (& sha256, secret, sizeof (secret));
	SHA256Fetch (& sha256, digest);
	while (rehash--)
	{
		SHA256Reset (& sha256);
		SHA256Write (& sha256, digest, sizeof (digest));
		SHA256Fetch (& sha256, digest);
	}
	memcpy (NMK, digest, HPAVKEY_NMK_LEN);
	return;
}

#endif